Agilent Technologies E8257C PSG User`s guide

User’s Guide
Agilent Technologies
PSG Signal Generators
This guide applies to the following signal generator models:
E8267C PSG Vector Signal Generator
E8257C PSG Analog Signal Generator
E8247C PSG CW Signal Generator
Due to our continuing efforts to improve our products through firmware and hardware revisions, signal
generator design and operation may vary from descriptions in this guide. We recommend that you use the
latest revision of this guide to ensure you have up-to-date product information. Compare the print date of this
guide (see bottom of page) with the latest revision, which can be downloaded from the following website:
www.agilent.com/find/psg
Manufacturing Part Number: E8251-90253
Printed in USA
December 2003
© Copyright 2002, 2003 Agilent Technologies, Inc.
Notice
The material contained in this document is provided “as is”, and is subject to being changed, without notice,
in future editions.
Further, to the maximum extent permitted by applicable law, Agilent disclaims all warranties, either express
or implied with regard to this manual and to any of the Agilent products to which it pertains, including but
not limited to the implied warranties of merchantability and fitness for a particular purpose. Agilent shall not
be liable for errors or for incidental or consequential damages in connection with the furnishing, use, or
performance of this document or any of the Agilent products to which it pertains. Should Agilent have a
written contract with the User and should any of the contract terms conflict with these terms, the contract
terms shall control.
Questions or Comments about our Documentation?
We welcome any questions or comments you may have about our documentation. Please send us an E-mail
at sources_manuals@am.exch.agilent.com.
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Contents
1. Signal Generator Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Signal Generator Models and Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
E8247C PSG CW Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
E8257C PSG Analog Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
E8267C PSG Vector Signal Generator Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Firmware Upgrades. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
1. Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2. Softkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3. Knob . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
4. Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
5. Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
6. Save . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
7. Recall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
8. Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
9. MENUS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
10. Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
11. EXT 1 INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
12. EXT 2 INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
13. LF OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
14. Mod On/Off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
15. ALC INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
16. RF On/Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
17. Numeric Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
18. RF OUTPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
19. SYNC OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
20. VIDEO OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
21. Line Power LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
22. Power Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
23. Standby LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
24. Incr Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
25. GATE/PULSE/TRIGGER INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
26. Arrows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
27. Hold. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
28. Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
29. Display Contrast Decrease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
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30. Display Contrast Increase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
31. Local . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
32. Preset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
33. I/Q INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
34. DATA INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
35. DATA CLOCK INPUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
36. SYMBOL SYNC INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Front Panel Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1. Active Entry Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2. Frequency Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3. Annunciators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4. Digital Modulation Annunciators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5. Amplitude Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. Error Message Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7. Text Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8. Softkey Label Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Rear Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1. AC Power Receptacle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2. GPIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3. AUXILIARY INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4. LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5. STOP SWEEP IN/OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6. Z-AXIS BLANK/MKRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7. SWEEP OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8. TRIGGER OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9. TRIGGER IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
10. SOURCE SETTLED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11. EVENT 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
12. EVENT 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
13. PATTERN TRIG IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
14. BURST GATE IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
15. AUXILIARY I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
16. Digital Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
17. WIDEBAND I INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
18. WIDEBAND Q INPUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
19. COH (COHERENT CARRIER OUTPUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
20. I OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
21. I-bar OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
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22. Q OUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
23. Q-bar OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
24. BASEBAND GEN REF IN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
25. SMI (SOURCE MODULE INTERFACE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
26. 10 MHz OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
27. 10 MHz IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
28. 10 MHz EFC (Option UNR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
2. Basic Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Using Table Editors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Table Editor Softkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Modifying Table Items in the Data Fields. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Configuring the RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Configuring a Continuous Wave RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Configuring a Swept RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Extending the Frequency Range with a mm-Wave Source Module . . . . . . . . . . . . . . . . . . . . . . . .47
Modulating a Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Turning On a Modulation Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Applying a Modulation Format to the RF Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
Using Data Storage Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Using the Memory Catalog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
Using the Instrument State Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
Enabling Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Enabling a Software Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
3. Optimizing Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Selecting ALC Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
To Select an ALC Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
Using External Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
To Level with Detectors and Couplers/Splitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
To Level with a mm-Wave Source Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Creating and Applying User Flatness Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Creating a User Flatness Correction Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Creating a User Flatness Correction Array with a mm-Wave Source Module . . . . . . . . . . . . . . . .69
Adjusting Reference Oscillator Bandwidth (Option UNR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
To Select the Reference Oscillator Bandwidth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
To Restore Factory Default Settings: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
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4. Analog Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Analog Modulation Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Configuring AM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
To Set the Carrier Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
To Set the RF Output Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
To Set the AM Depth and Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
To Turn on Amplitude Modulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Configuring FM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
To Set the RF Output Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
To Set the RF Output Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
To Set the FM Deviation and Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
To Activate FM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Configuring ΦM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
To Set the RF Output Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
To Set the RF Output Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
To Set the FM Deviation and Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
To Activate FM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Configuring Pulse Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
To Set the RF Output Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
To Set the RF Output Amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
To Set the Pulse Period and Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
To Activate Pulse Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Configuring the LF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
To Configure the LF Output with an Internal Modulation Source . . . . . . . . . . . . . . . . . . . . . . . . . 84
To Configure the LF Output with a Function Generator Source . . . . . . . . . . . . . . . . . . . . . . . . . . 85
5. Dual Arbitrary Waveform Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Arbitrary (ARB) Waveform File Headers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Creating a File Header for a Modulation Format Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Modifying Header Information in a Modulation Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Storing Header Information for a Dual ARB Player Waveform Sequence . . . . . . . . . . . . . . . . . . 95
Modifying and Viewing Header Information in the Dual ARB Player . . . . . . . . . . . . . . . . . . . . . 95
Playing a Waveform File that Contains a Header. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Using the Dual ARB Waveform Player . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Accessing the Dual ARB Player . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Creating Waveform Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Building and Storing a Waveform Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Playing a Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
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Editing a Waveform Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
Storing and Loading Waveform Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Renaming a Waveform Segment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Using Waveform Markers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
To Place a Marker at the First Point within a Waveform Segment . . . . . . . . . . . . . . . . . . . . . . . .104
To Place a Marker Across a Range of Points within a Waveform Segment . . . . . . . . . . . . . . . . .104
To Place Repetitively Spaced Markers within a Waveform Segment. . . . . . . . . . . . . . . . . . . . . .105
To Use Marker 2 to Blank the RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
To Toggle Markers in an Existing Waveform Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
To Toggle Markers As You Create a Waveform Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
To Verify Marker Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
Waveform Marker Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Using Waveform Triggers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
To Use Segment Advance Triggering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Using Waveform Clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
To Configure Circular Clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
To Configure Rectangular Clipping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Waveform Clipping Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
6. Custom Arb Waveform Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120
Working with Predefined Setups (Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
Selecting a Custom ARB Setup or a Custom Digital Modulation State . . . . . . . . . . . . . . . . . . . .121
Working with User-Defined Setups (Modes)-Custom Arb Only . . . . . . . . . . . . . . . . . . . . . . . . . . .122
Modifying a Single-Carrier NADC Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
Customizing a Multicarrier Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123
Recalling a User-Defined Custom Digital Modulation State . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Working with Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
Using a Predefined FIR Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
Using a User-Defined FIR Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
Working with Symbol Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
To Set a Symbol Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
To Restore the Default Symbol Rate (Custom Real Time I/Q Only) . . . . . . . . . . . . . . . . . . . . . .133
Working with Modulation Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136
To Select a Predefined Modulation Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136
To Use a User-Defined Modulation Type (Real Time I/Q Only) . . . . . . . . . . . . . . . . . . . . . . . . .137
Configuring Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
To Set a Delayed, Positive Polarity, External Single Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
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To Set the ARB Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
7. Custom Real Time I/Q Baseband . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Working with Predefined Setups (Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Selecting a Predefined Real Time Modulation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Deselecting a Predefined Real Time Modulation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Working with Data Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Using a Predefined Data Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Using a User-Defined Data Pattern. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Using an Externally Supplied Data Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Working with Burst Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Configuring the Burst Rise and Fall Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
Using User-Defined Burst Shape Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Configuring Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
To Set the BBG Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
To Set the External DATA CLOCK to Receive Input as Either Normal or Symbol . . . . . . . . . . 159
To Set the BBG DATA CLOCK to External or Internal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
To Adjust the I/Q Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Working with Phase Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
To Set Phase Polarity to Normal or Inverted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Working with Differential Data Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Understanding Differential Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Using Differential Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
8. Multitone Waveform Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Creating, Viewing, and Optimizing Multitone Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
To Create a Custom Multitone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
To View a Multitone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
To Edit the Multitone Setup Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
To Minimize Carrier Feedthrough . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
To Determine Peak to Average Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
9. Two-Tone Waveform Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Creating, Viewing, and Modifying Two-Tone Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
To Create a Two-Tone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
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To View a Two-Tone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
To Minimize Carrier Feedthrough. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184
To Change the Alignment of a Two-Tone Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186
10. Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187
RF Output Power Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189
RF Output Power too Low . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189
The Power Supply has Shut Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .189
Signal Loss While Working with a Mixer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .190
Signal Loss While Working with a Spectrum Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192
No Modulation at the RF Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193
Sweep Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
Sweep Appears to be Stalled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
Cannot Turn Off Sweep Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
Incorrect List Sweep Dwell Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195
List Sweep Information is Missing from a Recalled Register . . . . . . . . . . . . . . . . . . . . . . . . . . .195
Data Storage Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196
Registers With Previously Stored Instrument States are Empty . . . . . . . . . . . . . . . . . . . . . . . . . .196
Saved Instrument State, but Register is Empty or Contains Wrong State. . . . . . . . . . . . . . . . . . .196
Cannot Turn Off Help Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197
Signal Generator Locks Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198
Fail-Safe Recovery Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198
Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200
Error Message File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .200
Error Message Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201
Error Message Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .202
Returning a Signal Generator to Agilent Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
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1
Signal Generator Overview
In the following sections, this chapter describes the models, options, and features available for Agilent PSG
signal generators. The modes of operation, front panel user interface, as well as front and rear panel
connectors are also described.
•
“Signal Generator Models and Features” on page 2
•
“Options” on page 4
•
“Firmware Upgrades” on page 4
•
“Modes of Operation” on page 5
•
“Front Panel” on page 6
•
“Front Panel Display” on page 13
•
“Rear Panel” on page 17
1
Signal Generator Overview
Signal Generator Models and Features
Signal Generator Models and Features
Table 1-1 lists the available PSG signal generator models along with their output signal types and frequency
range.
Table 1-1
PSG Signal Generator Models
Model
Type
Frequency Range
E8247C PSG CW signal generator
CW
250 kHz to 20 GHz, or
250 kHz to 40 GHz
E8257C PSG analog signal generator
Analog
250 kHz to 20 GHz, or
250 kHz to 40 GHz
E8267C PSG vector signal generator
Vector
250 kHz to 20 GHz
E8247C PSG CW Signal Generator Features
An E8247C PSG CW signal generator includes the following features:
•
CW output from 250 kHz to 20 GHz or 40 GHz
•
frequency resolution to 0.001 Hz
•
list and step sweep of frequency and amplitude, with multiple trigger sources
•
user flatness correction
•
external diode detector leveling
•
automatic leveling control (ALC) on and off modes; power calibration in ALC-off mode is available,
even without power search
•
10 MHz reference oscillator with external output
•
RS-232, GPIB, and 10Base-T LAN I/O interfaces
•
a millimeter head interface that is compatible with Agilent 83550 Series millimeter heads (for frequency
extension up to 110 GHz)
2
Chapter 1
Signal Generator Overview
Signal Generator Models and Features
E8257C PSG Analog Signal Generator Features
An E8257C PSG analog signal generator provides all the functionality of an E8247C PSG CW signal
generator and adds the following features:
•
open-loop or closed-loop AM
•
dc-synthesized FM to 10 MHz rates; maximum deviation depends on the carrier frequency
•
phase modulation (ΦM)
•
pulse modulation
•
external modulation inputs for AM, FM, ΦM, and pulse
•
simultaneous modulation configurations (except: FM with ΦM or Linear AM with Exponential AM)
•
an internal pulse generator that includes the following:
— selectable pulse modes: internal square, internal free-run, internal triggered, internal doublet, internal
gated, and external pulse; internal triggered, internal doublet, and internal gated require an
external trigger source
— adjustable pulse rate
— adjustable pulse period
— adjustable pulse width
— adjustable pulse delay
— selectable external pulse triggering: positive or negative
•
dual function generators that includes the following:
— 50Ω low frequency output, 0 to 3Vp, available through LF OUTPUT
— selectable waveforms: sine, dual-sine, swept-sine, triangle, positive ramp, negative ramp, square,
uniform noise, Gaussian noise, and dc
— adjustable frequency modulation rates
— selectable triggering in list and step sweep modes: free run (auto), trigger key (single), bus (remote),
and external
Chapter 1
3
Signal Generator Overview
Options
E8267C PSG Vector Signal Generator Features
An E8267C PSG vector signal generator provides all the functionality of an E8257C PSG analog signal
generator, and adds the following features:
•
internal I/Q modulator
•
external analog I/Q inputs
•
single-ended and differential analog I/Q outputs
Options
PSG signal generators have hardware, firmware, software, and documentation options. The data sheet
shipped with your signal generator provides an overview of available options. For details, refer to the
Agilent Technologies website.
1. Open: www.agilent.com/find/psg
2. Select the desired model.
3. Click View complete price list.
Firmware Upgrades
The firmware in your signal generator may be upgraded when new firmware is released. New firmware
releases may contain signal generator features and functionality not available in previous firmware releases.
To inquire about the availability of new signal generator firmware, contact Agilent at
http://www.agilent.com/find/upgradeassistant, or call the appropriate number listed in
Table 10-1 on page 203.
4
Chapter 1
Signal Generator Overview
Modes of Operation
Modes of Operation
All PSG signal generator models can be used in CW mode:
•
CW mode produces a single carrier signal.
— If you have an E8247C PSG CW signal generator, you can produce a CW single carrier signal
without modulation.
— If you have an E8257C PSG analog signal generator, you can produce a CW single carrier signal
without modulation, or you can add AM, FM, ΦM, or Pulse modulation to produce a single carrier
modulated signal; some of these modulations can be used together.
— If you have an E8267C PSG vector signal generator, you can produce a CW single carrier signal
without modulation, or you can add AM, FM, ΦM, Pulse, or I/Q modulation to produce a single
carrier modulated signal; some of these modulations can be used together.
In addition to CW and analog mode, all of the following modes are also available to the E8267C PSG vector
signal generator:
•
Custom Arb Waveform Generator mode can produce a single modulated carrier or multiple modulated
carriers. Each modulated carrier waveform must be calculated and generated before it can be output; this
signal generation occurs on the internal baseband generator (Option 002/602). Once a waveform has
been created, it can be stored and recalled which enables repeatable playback of test signals. To learn
more, refer to “Custom Arb Waveform Generator” on page 119.
•
Custom Real Time I/Q Baseband mode produces a single carrier, but it can be modulated with real time
data that allows real time control over all of the parameters that affect the signal. The single carrier signal
that is produced can be modified by applying various data patterns, filters, symbol rates, modulation
types, and burst shapes. To learn more, refer to “Custom Real Time I/Q Baseband” on page 145.
•
Two Tone mode produces two separate carrier signals without any kind of modulation; the frequency
spacing between the two carrier signals is adjustable as well as the amplitude of both carriers. To learn
more, refer to “Two-Tone Waveform Generator” on page 179.
•
Multitone mode produces any number of carrier signals without any kind of modulation; like Two Tone
mode, the frequency spacing between all carrier signals is adjustable as well as the amplitude of all
carriers. To learn more, refer to “Multitone Waveform Generator” on page 169.
•
Dual ARB mode is used to control the playback sequence of waveform segments that have been written
into the ARB memory located on the internal baseband generator (Option 002/602). These waveforms
can be generated using the internal baseband generator, in Custom Arb Waveform Generator mode, or
downloaded through a remote interface into the ARB memory. To learn more, refer to “Dual Arbitrary
Waveform Generator” on page 87.
Chapter 1
5
Signal Generator Overview
Front Panel
Front Panel
Figure 1-1 shows the E8267C PSG vector signal generator front panel with a list of items called out that
enable you to define, monitor, and manage input and output characteristics.
The description of each item also applies to both the E8257C PSG analog signal generator and the
E8247C PSG CW signal generator front panels. Not all items being described are available on every signal
generator; the list of items that your particular signal generator has is dependent on its model and options.
Figure 1-1
Front Panel Diagram (E8267C PSG Vector Signal Generator)
3. Knob
4. Amplitude
5. Frequency
6. Save
7. Recall
8. Trigger
9. MENUS
1. Display
2. Softkeys
10. Help
11. EXT 1 INPUT
E8267C Only
33. I/Q INPUTS
34. DATA INPUT
35. DATA CLOCK
36. SYMBOL SYNC
21. Line Power LED
22. Power Switch
23. Standby LED
6
12. EXT 2 INPUT
13. LF OUTPUT
14. Mod On/Off
15. ALC INPUT
16. RF On/Off
17. Numeric Keypad
18. RF OUTPUT
19. SYNC OUT
20. VIDEO OUT
24. Incr Set
25. GATE/PULSE/TRIGGER INPUT
26. Arrows
27. Hold
28. Return
29. Display Contrast Decrease
30. Display Contrast Increase
31. Local
32. Preset
Chapter 1
Signal Generator Overview
Front Panel
1. Display
The LCD screen provides information on the current function. Information can include status indicators,
frequency and amplitude settings, and error messages. Softkeys labels are located on the right-hand side of
the display. For more detail on the front panel display, see “Front Panel Display” on page 13.
2. Softkeys
Softkeys activate the displayed function to the left of each key.
3. Knob
Use the knob to increase or decrease a numeric value, changes a highlighted digit or character, or step
through lists or select items in a row.
4. Amplitude
Pressing this hardkey makes amplitude the active function. You can change the output amplitude or use the
menus to configure amplitude attributes such as power search, user flatness, and leveling mode.
5. Frequency
Pressing this hardkey makes frequency the active function. You can change the output frequency or use the
menus to configure frequency attributes such as frequency multiplier, offset, and reference.
6. Save
Pressing this hardkey accesses a menu of choices enabling you to save data in the instrument state register.
The instrument state register is a section of memory divided into 10 sequences (numbered 0 through 9) each
containing 100 registers (numbered 00 through 99). It is used to store and recall:
•
frequency and amplitude settings on an E8247C PSG CW signal generator
•
frequency, amplitude, and modulation settings on an E8257C PSG analog signal generator or E8267C
PSG vector signal generator
The Save hardkey provides a quick alternative to reconfiguring the signal generator through the front panel
or SCPI commands when switching between different signal configurations. Once an instrument state has
been saved, all of the frequency, amplitude, and modulation settings can be recalled with the Recall hardkey.
7. Recall
Restores an instrument state saved in a memory register. Refer to the Save hardkey for further information.
Chapter 1
7
Signal Generator Overview
Front Panel
8. Trigger
Initiates an immediate trigger event for a function such as a list, step, or ramp sweep (Option 007 only).
Before this hardkey can be used to initiate a trigger event, the trigger mode must be set to Trigger Key. For
example: press the Sweep/List hardkey, then one of the following sequences of softkeys:
•
•
More (1 of 2) > Sweep Trigger > Trigger Key
More (1 of 2) > Point Trigger > Trigger Key
9. MENUS
These keys open softkey menus for configuring various functions. For descriptions, see the Key Reference.
Table 1-2
E8247C PSG CW
Sweep/List
Utility
Hardkeys in Front Panel MENUS Group
E8257C PSG Analog
AM
Sweep/List
FM/ΦM
Utility
Pulse
LF Out
E8267C PSG Vector
Mode
Mux
AM
Sweep/List
Mode Setup
Aux Fctn
FM/Φ
M
Utility
I/Q
Pulse
LF Out
10. Help
Pressing this hardkey accesses a short description of any hardkey or softkey. There are two help modes
available on the signal generator: single and continuous. The single mode is the factory preset condition.
Toggle between single and continuous mode by pressing Utility > Instrument Info/Help Mode > Help Mode Single
Cont.
•
In single mode, help text is provided for the next key you press without activating the key’s function.
Any key pressed afterward exits the help mode and its function is activated.
•
In continuous mode, help text is provided for each subsequent key press until you press the Help hardkey
again or change to single mode. In addition, each key is active, meaning that the key function is executed
(except for the Preset key).
11. EXT 1 INPUT
This female BNC input connector (E8257C and E8267C only) accepts a ±1Vp signal for AM, FM, and ΦM.
For these modulations, ±1 Vp produces the indicated deviation or depth. When ac-coupled inputs are
selected for AM, FM, or ΦM and the peak input voltage differs from 1Vp by more than 3%, the HI/LO
display annunciators light. The input impedance is selectable as either 50 or 600Ω; the damage levels are
5 Vrms and 10 Vp. On signal generators with Option 1EM, this connector is relocated to the a rear panel.
8
Chapter 1
Signal Generator Overview
Front Panel
12. EXT 2 INPUT
This female BNC input connector (E8257C and E8267C only) accepts a ±1Vp signal for AM, FM, and ΦM.
With AM, FM, or ΦM, ±1 Vp produces the indicated deviation or depth. When ac-coupled inputs are
selected for AM, FM, or ΦM and the peak input voltage differs from 1Vp by more than 3%, the HI/LO
annunciators light on the display. The input impedance is selectable as either 50Ω or 600Ω and damage
levels are 5 Vrms and 10 Vp. On signal generators with Option 1EM, this input is relocated to the rear panel.
13. LF OUTPUT
This female BNC output connector (E8257C and E8267C only) outputs modulation signals generated by the
low frequency (LF) source function generator. This output is capable of driving 3Vp (nominal) into a 50Ω
load. On signal generators with Option 1EM, this output is relocated to the rear panel.
14. Mod On/Off
This hardkey (E8257C and E8267C only) enables or disables all active modulation formats (AM, FM, ΦM,
Pulse, or I/Q) applied to the output carrier signal available through the RF Output connector. This hardkey
does not set up or activate an AM, FM, ΦM, Pulse, or I/Q format; each modulation format must still be set
up and activated (for example, AM > AM On) or nothing is applied to the output carrier signal when the Mod
On/Off hardkey is enabled. The MOD ON/OFF annunciator, which is always present on the display, indicates
whether active modulation formats have been enabled or disabled with the Mod On/Off hardkey.
15. ALC INPUT
This female BNC input connector is used for negative external detector leveling. This connector accepts an
input of −0.2 mV to −0.5V. The nominal input impedance is 120 kΩ and the damage level is ±15V. On signal
generators with Option 1EM, this input is relocated to the rear panel.
16. RF On/Off
Pressing this hardkey toggles the operating state of the RF signal present at the RF OUTPUT connector.
Although you can set up and enable various frequency, power, and modulation states, the RF and microwave
output signal is not present at the RF OUTPUT until RF On/Off is set to On. An annunciator is always visible
in the display to indicate whether the RF is turned on or off.
17. Numeric Keypad
The numeric keypad consists of the 0 through 9 hardkeys, a decimal point hardkey, and a backspace hardkey
(
). The backspace hardkey enables you to backspace or alternate between a positive and a negative
value. When specifying a negative numeric value, the negative sign must be entered prior to entering the
numeric value.
Chapter 1
9
Signal Generator Overview
Front Panel
18. RF OUTPUT
This connector is the output for RF and microwave signals. The nominal output impedance is 50Ω. The
reverse-power damage levels are 0 Vdc, 0.5 watts nominal. On signal generators with Option 1EM, this
output is relocated to a rear panel female BNC connector.
19. SYNC OUT
This female BNC output connector (E8257C and E8267C only) outputs a synchronizing TTL-compatible
pulse signal that is nominally 50 ns wide during internal and triggered pulse modulation. The nominal
source impedance is 50Ω. On signal generators with Option 1EM, this output is relocated to the rear panel.
20. VIDEO OUT
This female BNC output connector (E8257C and E8267C only) outputs a TTL-level compatible pulse signal
that follows the output envelope in all pulse modes. The nominal source impedance is 50Ω. On signal
generators with Option 1EM, this output is relocated to the rear panel.
21. Line Power LED
This green LED indicates when the signal generator power switch is set to the on position.
22. Power Switch
In the on position, this switch activates full power to the signal generator; in standby, it deactivates all signal
generator functions. In standby, the signal generator remains connected to the line power and power is
supplied to some internal circuits.
23. Standby LED
This yellow LED indicates when the signal generator power switch is set to the standby condition.
24. Incr Set
This hardkey enables you to set the increment value of the current active function. This the increment value
of the current active function appears in the active entry area of the display. Use the numeric keypad, arrow
hardkeys, or the knob to adjust the increment value.
25. GATE/PULSE/TRIGGER INPUT
This female BNC input connector (E8257C and E8267C only) accepts an externally supplied pulse signal
for use as a pulse or trigger input. With pulse modulation, +1V is on and 0V is off (trigger threshold of 0.5V
with a hysteresis of 10%; so 0.6V would be on and 0.4V would be off). The damage levels are ±5Vrms and
10
Chapter 1
Signal Generator Overview
Front Panel
10Vp. The nominal input impedance is 50Ω. On signal generators with Option 1EM, this input is relocated to
the rear panel.
26. Arrows
These up and down arrow hardkeys are used to increase or decrease a numeric value, step through displayed
lists, or to select items in a row of a displayed list. Individual digits or characters may be highlighted using
the left and right arrow hardkeys. Once an individual digit or character is highlighted, its value can be
changed using the up and down arrow hardkeys.
27. Hold
Pressing this hardkey blanks the softkey label area and text areas on the display. Softkeys, arrow hardkeys,
the knob, the numeric keypad, and the Incr Set hardkey have no effect once this hardkey is pressed.
28. Return
Pressing this hardkey will return the signal generator one level back from its current softkey menu level to
the previous softkey menu level. It enables you to step back through the menus until you reach the first menu
you selected.
29. Display Contrast Decrease
Pressing this hardkey causes the display background to darken.
30. Display Contrast Increase
Pressing this hardkey causes the display background to lighten.
31. Local
Pressing this hardkey deactivates remote operation and returns the signal generator to front panel control.
32. Preset
Pressing this hardkey sets the signal generator to a known state (factory or user-defined).
Chapter 1
11
Signal Generator Overview
Front Panel
33. I/Q INPUTS
These female BNC input connectors (E8267C only) accept an externally supplied, analog, I/Q modulation;
the in-phase component is supplied through the I INPUT; the quadrature-phase component is supplied
through the Q INPUT. The signal level is
= 0.5 Vrms for a calibrated output level. The nominal input
impedance is 50Ω or 600Ω. The damage level is 1 Vrms and 10 Vpeak. To activate signals applied to these
connectors, press Mux > I/Q Source 1 or I/Q Source 2 and then select either Ext 50 Ohm or Ext 600 Ohm.On signal
generators with Option 1EM, these inputs are relocated to the rear panel.
34. DATA INPUT
This female BNC input connector (E8267C with Option 002/602 only) is CMOS compatible and accepts an
externally supplied serial data input for digital modulation applications. The expected input is a 3.3 V
CMOS signal (which is also TTL compatible) where a CMOS high = a data 1 and a CMOS low = a data 0.
The maximum input data rate is 50 Mb/s. The data must be valid on the falling edges of the data clock
(normal mode) or the on the falling edges of the symbol sync (symbol mode). The damage levels are
> +5.5 and < −0.5V. On signal generators with Option 1EM, this input is relocated to the rear panel.
35. DATA CLOCK INPUT
This female BNC input connector (E8267C only) is CMOS compatible and accepts an externally supplied
data-clock input signal to synchronize serial data for use with the internal baseband generator (Option
002/602). The expected input is a 3.3 V CMOS bit clock signal (which is also TTL compatible) where the
rising edge is aligned with the beginning data bit. The falling edge is used to clock the DATA and SYMBOL
SYNC signals. The maximum clock rate is 50 MHz. The damage levels are > +5.5 and < −0.5V. On signal
generators with Option 1EM, this input is relocated to the rear panel.
36. SYMBOL SYNC INPUT
This female BNC input connector (E8267C only) is CMOS compatible and accepts an externally supplied
symbol sync signal for use with the internal baseband generator (Option 002/602). The expected input is a
3.3 V CMOS bit clock signal (which is also TTL compatible). SYMBOL SYNC might occur once per
symbol or be a single one-bit-wide pulse that is used to synchronize the first bit of the first symbol. The
maximum clock rate is 50 MHz. The damage levels are > +5.5 and < −0.5V. SYMBOL SYNC can be used
in two modes:
•
When used as a symbol sync in conjunction with a data clock, the signal must be high during the first
data bit of the symbol. The signal must be valid during the falling edge of the data clock signal and may
be a single pulse or continuous.
•
When the SYMBOL SYNC itself is used as the (symbol) clock, the CMOS falling edge is used to clock
the DATA signal.
On signal generators with Option 1EM, this input is relocated to the rear panel.
12
Chapter 1
Signal Generator Overview
Front Panel Display
Front Panel Display
Figure 1-2 shows the front panel display. The LCD screen displays data fields, annotations, key press results,
softkey labels, error messages, and annunciators that represent various active signal generator functions.
Figure 1-2
1. Active Entry Area
Front Panel Display Diagram
2. Frequency Area
6. Error Message Area
3. Annunciators
7. Text Area
4. Digital Modulation
Annunciators
5. Amplitude Area
8. Softkey Label Area
1. Active Entry Area
The current active function is shown in this area. For example, if frequency is the active function, the current
frequency setting will be displayed here. If the current active function has an increment value associated
with it, that value is also displayed.
2. Frequency Area
The current frequency setting is shown in this portion of the display. Indicators are also displayed in this area
when the frequency offset or multiplier is used, the frequency reference mode is turned on, or a source
module is enabled.
Chapter 1
13
Signal Generator Overview
Front Panel Display
3. Annunciators
The display annunciators show the status of some of the signal generator functions and indicate any error
conditions. An annunciator position may be used by more than one function. This does not create a problem,
because only one function that shares an annunciator position can be active at a time.
ΦM
This annunciator (E8257C and E8267C only) appears when phase modulation is on. If
frequency modulation is on, the FM annunciator replaces ΦM.
ALC OFF
This annunciator appears when the ALC circuit is disabled. A second annunciator,
UNLEVEL, appears in the same position if the ALC is enabled and cannot maintain the
output level.
AM
This annunciator (E8257C and E8267C only) appears when amplitude modulation is on.
ARMED
This annunciator appears when a sweep has been initiated and the signal generator is
waiting for the sweep trigger event.
ATTEN HOLD
This annunciator (Option 1E1 or E8267C only) appears when the attenuator hold
function is on. When this function is on, the attenuator is held at its current setting.
DIG BUS
This annunciator appears when the Digital Bus is active, and the internal oven reference
oscillator is not cold (they appear in the same location).
ENVLP
This annunciator appears if a burst condition exists, such as when marker 2 is set to
enable RF blanking in the Dual ARB format.
ERR
This annunciator appears when an error message is in the error queue. This annunciator
does not turn off until you either view all the error messages or cleared the error queue.
To access error messages, press Utility > Error Info.
EXT
This annunciator appears when external leveling is on.
EXT1 LO/HI
This annunciator (E8257C and E8267C only) appears as either EXT1 LO or EXT1 HI,
when the ac-coupled signal to the EXT 1 INPUT is <0.97 Vp or >1.03 Vp.
EXT2 LO/HI
This annunciator (E8257C and E8267C only) is displayed as either EXT2 LO or
EXT2 HI. This annunciator appears when the ac-coupled signal to the EXT 2 INPUT is
<0.97 Vp or >1.03 Vp.
EXT REF
This annunciator appears when an external frequency reference is applied.
FM
This annunciator (E8257C and E8267C only) appears when frequency modulation is
turned on. If phase modulation is turned on, the ΦM annunciator will replace FM.
I/Q
This annunciator (E8267C with Option 002/602 only) appears when I/Q modulation is
turned on.
L
This annunciator appears when the signal generator is in listener mode and is receiving
information or commands over the RS-232, GPIB, or VXI-11 LAN interface.
14
Chapter 1
Signal Generator Overview
Front Panel Display
MOD ON/OFF
This annunciator (E8257C and E8267C only) which is always present on the display,
indicates whether active modulation formats have been enabled or disabled with the
Mod On/Off hardkey. Pressing the Mod On/Off hardkey enables or disables all active
modulation formats (AM, FM, ΦM, Pulse, or I/Q) that are applied to the output carrier
signal available through the RF Output connector. The Mod On/Off hardkey does not set
up or activate an AM, FM, ΦM, Pulse, or I/Q format; each individual modulation
format must still be set up and activated (for example, AM > AM On) or nothing will be
applied to the output carrier signal when the Mod On/Off hardkey is enabled.
OVEN COLD
This annunciator (Option UNR only) appears when the temperature of the internal oven
reference oscillator has dropped below an acceptable level. When this annunciator is on,
frequency accuracy is degraded. This condition should occur only if the signal generator
is disconnected from line power.
PULSE
This annunciator (E8257C and E8267C only) appears when pulse modulation is on.
R
This annunciator appears when the signal generator is remotely controlled over the
GPIB, RS-232, or VXI-11/Sockets LAN interface (TELNET operation does not activate
the R annunciator). When the R annunciator is on, the front panel keys are disabled,
except for the Local key and the line power switch. For information on remote
operation, refer to the Programming Guide.
RF ON/OFF
This annunciator indicates when the RF and microwave signal is present (RF ON) at the
RF OUTPUT, or if the RF and microwave signal is not present (RF OFF) at the RF
OUTPUT. Either condition of this annunciator is always visible in the display.
S
This annunciator appears when the signal generator has generated a service request
(SRQ) over the RS-232, GPIB, or VXI-11 LAN interface.
SWEEP
This annunciator appears when the signal generator is in list, step, or ramp sweep mode;
ramp sweep is available with Option 007 only. List mode is when the signal generator
can jump from point to point in a list (hop list); the list is traversed in ascending or
descending order. The list can be a frequency list, a power level list, or both. Step mode
is when a start, stop, and step value (frequency or power level) are defined and the
signal generator produces signals that start at the start value and increment by the step
value until it reaches the stop value. Ramp sweep mode (Option 007 only) is when a
start and stop value (frequency or power level) are defined and the signal generator
produces signals that start at the start value and produce a continuous output until it
reaches the stop value.
T
This annunciator appears when the signal generator is in talker mode and is transmitting
information over the GPIB, RS-232, or VXI-11 LAN interface.
UNLEVEL
This annunciator appears when the signal generator is unable to maintain the correct
output level. The UNLEVEL annunciator is not necessarily an indication of instrument
failure. Unleveled conditions can occur during normal operation. A second annunciator,
ALC OFF, will appear in the same position when the ALC circuit is disabled.
Chapter 1
15
Signal Generator Overview
Front Panel Display
This annunciator appears when any of the phase locked loops are unable to maintain
phase lock. You can determine which loop is unlocked by examining the error
messages.
UNLOCK
4. Digital Modulation Annunciators
All digital modulation annunciators (E8267C PSG with Option 002/602 only) appear in this location. These
annunciators appear only when the modulation is active, and only one digital modulation can be active at
any given time.
ARB
Dual Arbitrary Waveform Generator
M-TONE
Multitone Waveform Generator
CUSTOM
Custom Real Time I/Q Baseband
T-TONE
Two-Tone Waveform Generator
DIGMOD
Custom Arb Waveform Generator
5. Amplitude Area
The current output power level setting is shown in this portion of the display. Indicators are also displayed in
this area when amplitude offset is used, amplitude reference mode is turned on, external leveling mode is
enabled, a source module is enabled, and when user flatness is enabled.
6. Error Message Area
Abbreviated error messages are reported in this space. When multiple error messages occur, only the most
recent message remains displayed. Reported error messages with details can be viewed by pressing Utility >
Error Info.
7. Text Area
This text area of the display:
•
show signal generator status information, such as the modulation status, sweep lists, and file catalogs
•
displays the tables
•
enables you to perform functions such as managing information, entering information, and displaying or
deleting files
8. Softkey Label Area
The labels in this area define the function of the softkeys located immediately to the right of the label. The
softkey label may change depending upon the function selected.
16
Chapter 1
Signal Generator Overview
Rear Panel
Rear Panel
The signal generator rear panel (Figure 1-3) provides input, output, and remote interface connections.
Descriptions are provided for each rear panel connector. When Option 1EM is added, all front panel
connectors are moved to the real panel; for a description of these connectors, see “Front Panel” on page 6.
Figure 1-3
Rear Panel Diagram
16. Digital Bus
17. WIDEBAND I INPUT
15. AUXILIARY I/O
18. WIDEBAND Q INPUT
20. I OUT
21. I-bar OUT
19. COH
22. Q OUT
23. Q-bar OUT
24. BASEBAND GEN
25. SMI
26. 10 MHz OUT
27. 10 MHz IN
28. 10 MHz EFC
(Option UNR)
1. AC Power Receptacle
2. GPIB
3. AUXILIARY INTERFACE
4. LAN
14. BURST GATE IN
13. PATTERN TRIG
12. EVENT 2
11. EVENT 1
5. STOP SWEEP IN/OUT
6. Z-AXIS BLANK/MKRS
7. SWEEP OUT
8. TRIGGER OUT
9. TRIGGER IN
10. SOURCE SETTLED
Chapter 1
17
Signal Generator Overview
Rear Panel
1. AC Power Receptacle
The ac line voltage is connected here. The power cord receptacle accepts a three-pronged power cable that is
shipped with the signal generator.
2. GPIB
This GPIB interface allows listen and talk capability with compatible IEEE 488.2 devices.
3. AUXILIARY INTERFACE
This 9-pin D-subminiature female connector is an RS-232 serial port that can be used for serial
communication and Master/Slave source synchronization.
Table 1-3
Auxiliary Interface Connector
Pin Number
Signal Description
Signal Name
1
No Connection
2
Receive Data
RECV
3
Transmit Data
XMIT
4
+5V
5
Ground, 0V
6
No Connection
7
Request to Send
RTS
8
Clear to Send
CTS
9
No Connection
Figure 1-4
View looking into
rear panel connector
4. LAN
This LAN interface allows ethernet local area network communication through a 10Base-T LAN cable. The
yellow LED on the interface illuminates when data transmission (transfer/receive) is present. The green
LED illuminates when there is a delay in data transmission or no data transmission is present.
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Signal Generator Overview
Rear Panel
5. STOP SWEEP IN/OUT
This female BNC connector (Option 007 only) provides an open-collector, TTL-compatible input/output
signal that is used during ramp sweep operation. It provides low level (nominally 0V) output during sweep
retrace and band-cross intervals. It provides high level (nominally +5V) output during the forward portion of
sweep. Sweep stops when this input/output connector is grounded externally.
6. Z-AXIS BLANK/MKRS
This female BNC connector (Option 007 only) supplies a +5V (nominal) level during retrace and
band-switch intervals of a step, list, or ramp sweep. During ramp sweep, this female BNC connector
supplies a –5V (nominal) level when the RF frequency is at a marker frequency and intensity marker mode
is on. This connection is most commonly used to interface with an Agilent 8757D scalar network analyzer.
7. SWEEP OUT
This female BNC connector outputs a voltage proportional to the RF power or frequency sweep ranging
from 0 V at the start of sweep and goes to +10 V (nominal) at the end of sweep, regardless of sweep width.
The output impedance is less than 1Ω and can drive a 2 kΩ load.
When connected to an Agilent Technologies 8757D network analyzer, it generates a selectable number of
equally spaced 1 ms 10 V pulses (nominal) across a ramp (analog) sweep. The number of pulses can be set
from 101 to 1601 by remote control through the 8757D.
8. TRIGGER OUT
This female BNC connector, in step/list sweep mode, outputs a TTL signal that is high at the start of a dwell
sequence or when waiting for a point trigger in manual sweep mode. The signal is low when the dwell is
over or when a point trigger is received. In ramp sweep mode, the output provides 1601 equally-spaced 1 µs
pulses (nominal) across a ramp sweep. When using LF Out, the output provides a 2 µs pulse at the start of
LF sweep.
9. TRIGGER IN
This female BNC connector accepts a 3.3V CMOS signal that is used for point-to-point triggering in manual
sweep mode or a low-frequency (LF) sweep in external sweep mode. Triggering can occur on either the
positive or negative edge of the signal start. The damage level is ≤ −4 V or ≥ +10 V.
10. SOURCE SETTLED
This female BNC connector provides an indication when the signal generator has settled to a new frequency
or power level. A low indicates that the source has settled.
Chapter 1
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Signal Generator Overview
Rear Panel
11. EVENT 1
This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602);
on signal generators without Option 002/602, this female BNC connector is non-functional.
In real-time mode, the EVENT 1 connector outputs a pattern or frame synchronization pulse for triggering
or gating external equipment. It may be set to start at the beginning of a pattern, frame, or timeslot and is
adjustable to within ± one timeslot with one bit resolution.
In arbitrary waveform mode, the EVENT 1 connector outputs a timing signal generated by Marker 1.
A marker (3.3V CMOS high when positive polarity is selected; 3.3V CMOS low when negative polarity is
selected) is output on the EVENT 1 connector whenever a Marker 1 is turned on in the waveform. The
damage levels for this connector are > +8V and < −4V.
12. EVENT 2
This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602);
on signal generators without Option 002/602, this female BNC connector is non-functional. In real-time
mode, the EVENT 2 connector outputs a data enable signal for gating external equipment. This is applicable
when external data is clocked into internally generated timeslots.
Data is enabled when the signal is low. In arbitrary waveform mode, the EVENT 2 connector outputs a
timing signal generated by Marker 2. A marker (3.3V CMOS high when positive polarity is selected; 3.3V
CMOS low when negative polarity is selected) is output on the EVENT 2 connector whenever a Marker 2 is
turned on in the waveform. The damage levels for this connector are > +8V and < −4V.
13. PATTERN TRIG IN
This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602);
on signal generators without Option 002/602, this female BNC connector is non-functional. This connector
accepts a signal that triggers an internal pattern or frame generator to start single pattern output. Minimum
pulse width is 100 ns. Damage levels are > +5.5 and < −0.5V.
14. BURST GATE IN
This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602);
on signal generators without Option 002/602, this female BNC connector is non-functional. This connector
accepts a signal for gating burst power. Burst gating is used when you are externally supplying data and
clock information.
The input signal must be synchronized with the external data input that will be output during the burst. The
burst power envelope and modulated data are internally delayed and re-synchronized. The input signal must
be CMOS high for normal burst RF power or CW RF output power and CMOS low for RF off. Damage
levels are > +5.5 and < −0.5V.
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Chapter 1
Signal Generator Overview
Rear Panel
15. AUXILIARY I/O
This female 37-pin connector (E8267C only) is active only on instruments with an internal baseband
generator (Option 002/602); on signal generators without Option 002/602, this connector is non-functional.
This connector provides access to the inputs and outputs described in the following figure.
Figure 1-5
View looking into
rear panel connector
Auxiliary I/O Connector (Female 37-Pin)
Used with an internal baseband generator. In arbitrary waveform mode, this pin output
a timing signal generated by Marker 3. A marker (3.3V CMOS high when positive
polarity is selected; 3.3V CMOS low when negative polarity is selected) is output on
this pin when a Marker 3 is turned on in the waveform.
Reverse damage levels: > +8V and < −4V.
Used with an internal baseband generator. In arbitrary waveform mode, this pin
outputs a timing signal generated by Marker 4. A marker (3.3V CMOS high
when positive polarity is selected; 3.3V CMOS low when negative polarity is
selected) is output on this pin when a Marker 4 is turned on in the waveform.
Reverse damage levels: > +8V and < −4V.
Accepts a signal that triggers an internal pattern or frame generator to
start single pattern output. Minimum pulse width: 100 ns.
Damage levels: > +5.5 and < −0.5V
Used with an internal baseband generator. This pin accepts a CMOS signal
for synchronization of external data and alternate power signal timing.
Damage levels are > +8V and < −4V.
Used with an internal baseband generator. This pin outputs data (CMOS)
from the internal data generator or the externally supplied signal at data input
Used with an internal baseband generator. This pin relays a
CMOS bit clock signal for synchronizing serial data.
Used with an internal baseband generator. This pin outputs the CMOS
symbol clock for symbol synchronization, one data clock period wide.
Chapter 1
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Signal Generator Overview
Rear Panel
16. Digital Bus
This is a proprietary bus used for Agilent Baseband Studio products, which require an E8267C with Option
602. This connector is not operational for general purpose customer use. Signals are present only when a
Baseband Studio option is installed (for details, refer to www.agilent.com/find/basebandstudio). The
Dig Bus annunciator appears on the display when the Digital Bus is active (and the internal oven reference
oscillator is not cold—they appear in the same location).
17. WIDEBAND I INPUT
This female BNC connector (E8267C only) is used with wideband external I/Q inputs (Option 015). It
accepts wide-band AM and allows direct high-bandwidth analog inputs to the I/Q modulator in the
3.2−20 GHz range. This input is not calibrated and accepts a 0 dBm maximum power. On signal generators
without Option 015, this connector is non-functional.
18. WIDEBAND Q INPUT
This female BNC connector (E8267C only) is used with wideband external I/Q inputs (Option 015); on
signal generators without Option 015, this female BNC connector is non-functional. This female BNC
connector allows direct high-bandwidth analog inputs to the I/Q modulator in the 3.2 to 20 GHz frequency
range. This input is not calibrated and accepts a 0 dBm maximum power.
19. COH (COHERENT CARRIER OUTPUT)
This female SMA connector (E8267C only) outputs an RF signal that is phase coherent with the signal
generator carrier. The coherent carrier connector outputs RF that is not modulated with AM, pulse, or I/Q
modulation, but is modulated with FM or ΦM (when FM or ΦM are on).
The output power is nominally 0 dBm. The output frequency range is from 249.99900001 MHz to 3.2 GHz;
this output is not useful for output frequencies > 3.2 GHz. If the RF output frequency is below
249.99900001 MHz, the coherent carrier output signal will have the following frequency:
•
•
Frequency of coherent carrier = (1E9 − Frequency of RF output) in Hz.
Damage levels are 20 Vdc and 13 dBm reverse RF power.
20. I OUT
This female BNC connector (E8267C only) can be used with an internal baseband generator (Option
002/602) to output the analog, in-phase component of I/Q modulation; on signal generators without Option
002/602, this female BNC connector can be used to output the in-phase component of an external I/Q
modulation that has been fed into the I input connector. The nominal output impedance of the I OUT
connector is 50Ω, dc-coupled.
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Signal Generator Overview
Rear Panel
21. I-bar OUT
This female BNC connector (E8267C only) can be used with an internal baseband generator (Option
002/602) to output the complement of the analog, in-phase component of I/Q modulation; on signal
generators without Option 002/602, this female BNC connector can be used to output the complement of the
in-phase component of an external I/Q modulation that has been fed into the I input connector.
I-bar OUT is used in conjunction with I OUT to provide a balanced baseband stimulus. Balanced signals are
signals present in two separate conductors that are symmetrical relative to ground and are opposite in
polarity (180 degrees out of phase). The nominal output impedance of the I-bar OUT connector is 50Ω,
dc-coupled.
22. Q OUT
This female BNC connector (E8267C only) can be used with an internal baseband generator (Option
002/602) to output the analog, quadrature-phase component of I/Q modulation; on signal generators without
Option 002/602, this female BNC connector can be used to output the quadrature-phase component of an
external I/Q modulation that has been fed into the Q input connector. The nominal output impedance of the
Q OUT connector is 50Ω, dc-coupled.
23. Q-bar OUT
This female BNC connector (E8267C only) can be used with an internal baseband generator (Option
002/602) to output the complement of the analog, quadrature-phase component of I/Q modulation; on signal
generators without Option 002/602, this female BNC connector can be used to output the complement of the
quadrature-phase component of an external I/Q modulation that has been fed into the Q input connector.
Q-bar OUT is used in conjunction with Q OUT to provide a balanced baseband stimulus. Balanced signals
are signals present in two separate conductors that are symmetrical relative to ground and are opposite in
polarity (180 degrees out of phase). The nominal output impedance of the Q-bar OUT connector is 50Ω,
dc-coupled.
24. BASEBAND GEN REF IN
This female BNC connector (E8267C only) is used with an internal baseband generator (Option 002/602);
on signal generators without Option 002/602, this female BNC connector is non-functional. This connector
accepts a 0 to +20 dBm sine wave or TTL square wave signal from an external timebase reference. This
external timebase reference clock is used by the internal baseband generator for both component and
receiver test applications (only the internal baseband generator can be locked to this external reference; the
RF frequency remains locked to the 10 MHz reference).
This connector accepts rates from 250 kHz through 100 MHz; the nominal input impedance is 50Ω. at
13 MHz, ac-coupled. The internal clock for the arbitrary waveform generator is locked to this signal when
external reference is selected in the ARB setup. The minimum pulse width must be > 10 ns. The damage
levels are > +8V and < −8V.
Chapter 1
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Signal Generator Overview
Rear Panel
25. SMI (SOURCE MODULE INTERFACE)
This interface is used to connect to compatible Agilent Technologies 83550 Series mm-wave source
modules.
26. 10 MHz OUT
This female BNC connector outputs a nominal signal level of > +4 dBm and has an output impedance of
50Ω. The accuracy is determined by the timebase used.
27. 10 MHz IN
This female BNC connector accepts an external timebase reference input signal level of >−3 dBm. The
reference must be 1, 2, 2.5, 5, or 10 MHz, within ±1 ppm. The signal generator detects when a valid
reference signal is present at this connector and automatically switches from internal to external reference
operation. The nominal input impedance is 50Ω. For Option UNR, this BNC connector accepts a signal with
a nominal input level of 5 ±5 dBm. The external frequency reference must be 10 MHz, within ±1 ppm. The
nominal input impedance is 50Ω with a damage level of ≥ 10 dBm.
28. 10 MHz EFC (Option UNR)
This female BNC input connector accepts an external dc voltage, ranging from −5 to +5V, for electronic
frequency control (EFC) of the internal 10 MHz reference oscillator. This voltage inversely tunes the
oscillator about its center frequency approximately −0.0025 ppm/V. The input resistance is greater than
1 MΩ. When not in use, this connector should be shorted using the supplied shorting cap to assure a stable
operating frequency.
24
Chapter 1
2
Basic Operation
In the following sections, this chapter describes operations common to all Agilent PSG signal generators:
•
“Using Table Editors” on page 26
•
“Configuring a Continuous Wave RF Output” on page 28
•
“Configuring a Swept RF Output” on page 31
•
“Using Ramp Sweep (Option 007)” on page 37
•
“Extending the Frequency Range with a mm-Wave Source Module” on page 47
•
“Turning On a Modulation Format” on page 50
•
“Applying a Modulation Format to the RF Output” on page 51
•
“Using Data Storage Functions” on page 52
•
“Enabling Options” on page 57
25
Basic Operation
Using Table Editors
Using Table Editors
Table editors simplify configuration tasks, such as creating a list sweep. This section provides information to
familiarize you with basic table editor functionality using the List Mode Values table editor as an example.
Press Preset > Sweep/List > Configure List Sweep.
The signal generator displays the List Mode Values table editor, as shown below.
Figure 2-1
Active Function Area
Table Name
Cursor
Table Items
Table Softkeys
Active Function Area
displays the active table item while its value is edited
Cursor
an inverse video identifier used to highlight specific table items for
selection and editing
Table Softkeys
select table items, preset table values, and modify table structures
Table Items
values arranged in numbered rows and titled columns (The columns
are also known as data fields. For example, the column below the
Frequency title is known as the Frequency data field).
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Chapter 2
Basic Operation
Using Table Editors
Table Editor Softkeys
The following table editor softkeys are used to load, navigate, modify, and store table item values.
Edit Item
displays the selected item in the active function area of the display where the item’s
value can be modified
Insert Row
inserts an identical row of table items above the currently selected row
Delete Row
deletes the currently selected row
Goto Row
opens a menu of softkeys (Enter, Goto Top Row, Goto Middle Row, Goto Bottom Row, Page Up,
and Page Down) used to quickly navigate through the table items
Insert Item
inserts an identical item in a new row below the currently selected item
Delete Item
deletes the item from the bottom row of the currently selected column
Page Up and
Page Down
displays table items that occupy rows outside the limits of the ten-row table display area
More (1 of 2)
accesses Load/Store and its associated softkeys
Load/Store
opens a menu of softkeys (Load From Selected File, Store To File, Delete File, Goto Row, Page
Up, and Page Down) used to load table items from a file in the memory catalog, or to
store the current table items as a file in the memory catalog
Modifying Table Items in the Data Fields
1. If not already displayed, open the List Mode Values table editor (shown in Figure 2-1 on page 26):
Press Preset > Sweep/List > Configure List Sweep
2. Use the arrow keys or the knob to move the table cursor over the desired item.
In Figure 2-1, the first item in the Frequency data field is selected.
3. Press Edit Item.
The selected item is displayed in the active function area of the display.
4. Use the knob, arrow keys, or the numeric keypad to modify the value.
5. Press Enter.
The modified item is now displayed in the table.
Chapter 2
27
Basic Operation
Configuring the RF Output
Configuring the RF Output
This section provides information on how to create continuous wave and swept RF (on page 31) outputs. It
also has information on using a mm-Wave source module to extend the signal generator’s frequency range
(see page 47).
Configuring a Continuous Wave RF Output
These procedures demonstrate how to set the following parameters:
•
•
•
•
RF output frequency
frequency reference and frequency offset (on page 29)
RF output amplitude (on page 30)
amplitude reference and amplitude offset (page 30)
Setting the RF Output Frequency
Set the RF output frequency to 700 MHz, and increment or decrement the output frequency in 1 MHz steps.
1. Return the signal generator to the factory-defined state: Press Preset.
NOTE
You can change the preset condition of the signal generator to a user-defined state. For these
examples, however, use the factory-defined preset state (set the Preset Normal User softkey
in the Utility menu to Normal).
2. Observe the FREQUENCY area of the display (in the upper left-hand corner).
The value displayed is the maximum specified frequency of the signal generator.
3. Press RF On/Off.
The RF On/Off hardkey must be pressed before the RF signal is available at the
RF OUTPUT connector. The display annunciator changes from RF OFF to RF ON. The maximum
specified frequency should be output at the RF OUTPUT connector (at the signal generator’s minimum
power level).
4. Press Frequency > 700 > MHz.
The 700 MHz RF frequency should be displayed in the FREQUENCY area of the display and also in the
active entry area.
5. Press Frequency > Incr Set > 1 > MHz.
This changes the frequency increment value to 1 MHz.
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Chapter 2
Basic Operation
Configuring the RF Output
6. Press the up arrow key.
Each press of the up arrow key increases the frequency by the increment value last set with the Incr Set
hardkey. The increment value is displayed in the active entry area.
7. The down arrow decreases the frequency by the increment value set in the previous step. Practice
stepping the frequency up and down in 1 MHz increments.
You can also adjust the RF output frequency using the knob. As long as frequency is the active function
(the frequency is displayed in the active entry area), the knob will increase and decrease the RF output
frequency.
8. Use the knob to adjust the frequency back to 700 MHz.
Setting the Frequency Reference and Frequency Offset
The following procedure sets the RF output frequency as a reference frequency to which all other frequency
parameters are relative. The frequency initially shown on the display is 0.00 Hz (the frequency output by
the hardware minus the reference frequency). Although the display changes, the frequency output does not
change. Any subsequent frequency changes are shown as incremental or decremental to 0 Hz.
1. Preset the signal generator: Press: Preset
2. Set the frequency reference to 700 MHz:
Press: Frequency > 700 > MHz > More (1 of 3) > Freq Ref Set.
This activates the frequency reference mode and sets the current output frequency (700 MHz) as the
reference value. The FREQUENCY area displays 0.000 Hz, which is the frequency output by the
hardware (700 MHz) minus the reference value (700 MHz). The REF indicator activates and the
Freq Ref Off On softkey toggles to On.
3. Turn on the RF output: Press RF On/Off.
The display annunciator changes from RF OFF to RF ON. The RF frequency at the RF OUTPUT
connector is 700 MHz.
4. Set the frequency increment value to 1 MHz: Press Frequency > Incr Set > 1 > MHz.
5. Increment the output frequency by 1 MHz: Press the up arrow key.
The FREQUENCY area display changes to show 1.000 000 000 MHz, which is the frequency output by
the hardware (700 MHz + 1 MHz) minus the reference frequency (700 MHz). The frequency at the RF
OUTPUT changes to 701 MHz.
6. Enter a 1 MHz offset: Press More (1 of 3) > Freq Offset > 1 > MHz.
The FREQUENCY area displays 2.000 000 00 MHz, which is the frequency output by the hardware
(701 MHz) minus the reference frequency (700 MHz) plus the offset (1 MHz). The OFFS indicator
activates. The frequency at the RF OUTPUT connector is still 701 MHz.
Chapter 2
29
Basic Operation
Configuring the RF Output
Setting the RF Output Amplitude
1. Preset the signal generator: Press Preset.
The AMPLITUDE area of the display shows the minimum power level of the signal generator. This is the
normal preset RF output amplitude.
2. Turn on the RF output: Press RF On/Off.
The display annunciator changes to RF ON. At the RF OUTPUT connector, the RF signal is output at the
minimum power level.
3. Change the amplitude to −20 dBm: Press Amplitude > −20 > dBm.
The new output power displays in the AMPLITUDE area of the display and in the active entry area. Until
you press a different front panel function key, amplitude remains the active function. You can also
change the amplitude using the up and down arrow keys or the knob.
Setting the Amplitude Reference and Amplitude Offset
The following procedure sets the RF output power as an amplitude reference to which all other amplitude
parameters are relative. The amplitude initially shown on the display is 0 dB (the power output by the
hardware minus the reference power). Although the display changes, the output power does not change. Any
subsequent power changes are shown as incremental or decremental to 0 dB.
1. Press Preset.
2. Set the amplitude to −20 dBm: Press Amplitude > -20 > dBm.
3. Activate the amplitude reference mode and set the current output power (−20 dBm) as the reference
value: Press More (1 of 2) > Ampl Ref Set.
The AMPLITUDE area displays 0.00 dB, which is the power output by the hardware (−20 dBm) minus
the reference value (−20 dBm). The REF indicator activates and the Ampl Ref Off On softkey toggles On.
4. Turn the RF output on: Press RF On/Off.
The display annunciator changes to RF ON. The power at the RF OUTPUT connector is −20 dBm.
5. Change the amplitude increment value to 10 dB: Press Incr Set > 10 > dB.
6. Use the up arrow key to increase the output power by 10 dB.
The AMPLITUDE area displays 10.00 dB, which is the power output by the hardware
(-20 dBm plus 10 dBm) minus the reference power (−20 dBm). The power at the RF OUTPUT
connector changes to −10 dBm.
7. Enter a 10 dB offset: Press Ampl Offset > 10 > dB.
The AMPLITUDE area displays 20.00 dB, which is the power output by the hardware (−10 dBm) minus
the reference power (−20 dBm) plus the offset (10 dB). The OFFS indicator activates. The power at the
RF OUTPUT connector is still −10 dBm.
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Chapter 2
Basic Operation
Configuring the RF Output
Configuring a Swept RF Output
A PSG signal generator has up to three sweep types: step sweep, list sweep, and ramp sweep (Option 007).
NOTE
List sweep data cannot be saved within an instrument state, but can be saved to the memory
catalog. For instructions on saving list sweep data, see “Storing Files to the Memory
Catalog” on page 53.
During swept RF output, the FREQUENCY and AMPLITUDE areas of the signal generator’s
display are deactivated, depending on what is being swept.
Step sweep (see page 32) and ramp sweep (see page 34) provide a linear progression through the
start-to-stop frequency and/or amplitude values, while list sweep enables you to create a list of arbitrary
frequency, amplitude, and dwell time values and sweep the RF output based on that list.
The list sweep example uses the points created in the step sweep example as the basis for a new list sweep.
Ramp sweep (see page 37) is faster than step or list sweep, and is designed to work with an 8757D scalar
network analyzer.
Chapter 2
31
Basic Operation
Configuring the RF Output
Using Step Sweep
Step sweep provides a linear progression through the start-to-stop frequency and/or amplitude values. You
can toggle the direction of the sweep, up or down. When the Sweep Direction Down Up softkey is set to Up,
values are swept from the start amplitude/frequency to the stop amplitude/frequency. When set to Down,
values are swept from the stop amplitude/frequency to the start amplitude/frequency.
When a step sweep is activated, the signal generator sweeps the RF output based on the values entered for
RF output start and stop frequencies and amplitudes, a number of equally spaced points (steps) to dwell
upon, and the amount of dwell time at each point; dwell time is the minimum period of time after the settling
time that the signal generator will remain at its current state. The frequency, amplitude, or frequency and
amplitude of the RF output will sweep from the start amplitude/frequency to the stop amplitude/frequency,
dwelling at equally spaced intervals defined by the # Points softkey value.
To Configure a Single Step Sweep
In this procedure, you create a step sweep with nine, equally-spaced points, and the following parameters:
•
•
•
frequency range from 500 MHz to 600 MHz
amplitude from −20 dBm to 0 dBm
dwell time 500 ms at each point
1. Press Preset.
2. Press Sweep/List.
This opens a menu of sweep softkeys.
3. Press Sweep Repeat Single Cont.
This toggles the sweep repeat from continuous to single.
4. Press Configure Step Sweep.
5. Press Freq Start > 500 > MHz.
This changes the start frequency of the step sweep to 500 MHz.
6. Press Freq Stop > 600 > MHz.
This changes the stop frequency of the step sweep to 600 MHz.
7. Press Ampl Start > -20 > dBm.
This changes the amplitude level for the start of the step sweep.
8. Press Ampl Stop > 0 > dBm.
This changes the amplitude level for the end of the step sweep.
9. Press # Points > 9 > Enter.
This sets the number of sweep points to nine.
10. Press Step Dwell > 500 > msec.
This sets the dwell time at each point to 500 milliseconds.
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Chapter 2
Basic Operation
Configuring the RF Output
11. Press Return > Sweep > Freq & Ampl.
This sets the step sweep to sweep both frequency and amplitude data. Selecting this softkey returns you
to the previous menu and turns on the sweep function.
12. Press RF On/Off.
The display annunciator changes from RF OFF to RF ON.
13. Press Single Sweep.
A single sweep of the frequencies and amplitudes configured in the step sweep is executed and available
at the RF OUTPUT connector. On the display, the SWEEP annunciator appears for the duration of the
sweep and a progress bar shows the progression of the sweep. The Single Sweep softkey can also be used
to abort a sweep in progress. To see the frequencies sweep again, press Single Sweep to trigger the
sweep.
To Configure a Continuous Step Sweep
Press Sweep Repeat Single Cont.
This toggles the sweep from single to continuous. A continuous repetition of the frequencies and amplitudes
configured in the step sweep are now available at the RF OUTPUT connector. The SWEEP annunciator
appears on the display, indicating that the signal generator is sweeping and progression of the sweep is
shown by a progress bar.
Chapter 2
33
Basic Operation
Configuring the RF Output
Using List Sweep
List sweep enables you to create a list of arbitrary frequency, amplitude, and dwell time values and sweep
the RF output based on the entries in the List Mode Values table.
Unlike a step sweep that contains linear ascending/descending frequency and amplitude values, spaced at
equal intervals throughout the sweep, list sweep frequencies and amplitudes can be entered at unequal
intervals, nonlinear ascending/descending, or random order.
For convenience, the List Mode Values table can be copied from a previously configured step sweep. Each
step sweep point’s associated frequency, amplitude and dwell time values are entered into a row in the List
Mode Values table, as the following example illustrates.
To Configure a Single List Sweep Using Step Sweep Data
In this procedure, you will leverage the step sweep points and change the sweep information by editing
several points in the List Mode Values table. For information on using tables, see “Using Table Editors” on
page 26.
1. Press Sweep Repeat Single Cont.
This toggles the sweep repeat from continuous to single. The SWEEP annunciator is turned off. The
sweep will not occur until it is triggered.
2. Press Sweep Type List Step.
This toggles the sweep type from step to list.
3. Press Configure List Sweep.
This opens another menu displaying softkeys that you will use to create the sweep points. The display
shows the current list data. (When no list has been previously created, the default list contains one point
set to the signal generator’s maximum frequency, minimum amplitude, and a dwell time of 2 ms.)
4. Press More (1 of 2) > Load List From Step Sweep > Confirm Load From Step Data.
The points you defined in the step sweep are automatically loaded into the list.
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Chapter 2
Basic Operation
Configuring the RF Output
To Edit List Sweep Points
1. Press Return > Sweep > Off.
Turning the sweep off allows you to edit the list sweep points without generating errors. If sweep
remains on during editing, errors occur whenever one or two point parameters (frequency, power, and
dwell) are undefined.
2. Press Configure List Sweep.
This returns you to the sweep list table.
3. Use the arrow keys to highlight the dwell time in row 1.
4. Press Edit Item.
The dwell time for point 1 becomes the active function.
5. Press 100 > msec.
This enters 100 ms as the new dwell time value for row 1. Note that the next item in the table (in this
case, the frequency value for point 2) becomes highlighted after you press the terminator softkey.
6. Using the arrow keys, highlight the frequency value in row 4.
7. Press Edit Item > 545 > MHz.
This changes the frequency value in row 4 to 545 MHz.
8. Highlight any column in the point 7 row and press Insert Row.
This adds a new point between points 7 and 8. A copy of the point 7 row is placed between points 7 and
8, creating a new point 8, and renumbering the successive points.
9. Highlight the frequency item for point 8, then press Insert Item.
Pressing Insert Item shifts frequency values down one row, beginning at point 8. Note that the original
frequency values for both points 8 and 9 shift down one row, creating an entry for point 10 that contains
only a frequency value (the power and dwell time items do not shift down).
The frequency for point 8 is still active.
10. Press 590 > MHz.
11. Press Insert Item > -2.5 > dBm.
This inserts a new power value at point 8 and shifts down the original power values for points 8 and 9 by
one row.
12. Highlight the dwell time for point 9, then press Insert Item.
A duplicate of the highlighted dwell time is inserted for point 9, shifting the existing value down to
complete the entry for point 10.
Chapter 2
35
Basic Operation
Configuring the RF Output
To Configure a Single List Sweep
1. Press Return > Sweep > Freq & Ampl
This turns the sweep on again. No errors should occur if all parameters for every point have been defined
in the previous editing process.
2. Press Single Sweep.
The signal generator will single sweep the points in your list. The SWEEP annunciator activates during
the sweep.
3. Press More (1 of 2) > Sweep Trigger > Trigger Key.
This sets the sweep trigger to occur when you press the Trigger hardkey.
4. Press More (2 of 2) > Single Sweep.
This arms the sweep. The ARMED annunciator is activated.
5. Press the Trigger hardkey.
The signal generator will single sweep the points in your list and the SWEEP annunciator will be
activated during the sweep.
To Configure a Continuous List Sweep
Press Sweep Repeat Single Cont.
This toggles the sweep from single to continuous. A continuous repetition of the frequencies and amplitudes
configured in the list sweep are now available at the RF OUTPUT connector. The SWEEP annunciator
appears on the display, indicating that the signal generator is sweeping and progression of the sweep is
shown by a progress bar.
36
Chapter 2
Basic Operation
Configuring the RF Output
Using Ramp Sweep (Option 007)
Ramp sweep provides a linear progression through the start-to-stop frequency and/or amplitude values.
Ramp sweep is much faster than step or list sweep, and is designed to work with an 8757D scalar network
analyzer. This section describes the ramp sweep capabilities available in PSG signal generators with Option
007. You will learn how to use basic ramp sweep, and how to configure a ramp sweep for a master/slave
setup (see page 45).
Refer to the Programming Guide for an example program that uses pass-thru commands in a ramp sweep
system (pass-thru commands enable you to temporarily interrupt ramp sweep system interaction so that you
can send operating instructions to the PSG).
Using Basic Ramp Sweep Functions
This procedure demonstrates the following tasks (each task builds on the previous task):
•
“Configuring a Frequency Sweep” on page 38
•
“Using Markers” on page 40
•
“Adjusting Sweep Time” on page 42
•
“Using Alternate Sweep” on page 43
•
“Configuring an Amplitude Sweep” on page 44
Chapter 2
37
Basic Operation
Configuring the RF Output
Configuring a Frequency Sweep
1. Set up the equipment as shown in Figure 2-2.
NOTE
Figure 2-2
The PSG signal generator is not compatible with the GPIB system interface of an 8757A,
8757C, or 8757E. For these older scalar network analyzers, do not connect the GPIB
cable in Figure 2-2. This method provides only a subset of 8757D functionality. See the
PSG Data Sheet for details. Use the 8757A/C/E documentation instead of this
procedure.
Equipment Setup
2. Turn on both the 8757D and the PSG.
3. On the 8757D, press SYSTEM > MORE > SWEEP MODE and verify that the SYSINTF softkey is set to ON.
This ensures that the system interface mode is activated on the 8757D. The system interface mode
enables the instruments to work as a system.
4. Press Utility > GPIB/RS-232 LAN to view the PSG’s GPIB address under the GPIB Address softkey. If you
want to change it, press GPIB Address and change the value.
5. On the 8757D, press LOCAL > SWEEPER and check the GPIB address. If it does not match that of the PSG,
change the value.
38
Chapter 2
Basic Operation
Configuring the RF Output
6. Preset either instrument.
Presetting one of the instruments should automatically preset the other as well. If both instruments do
not preset, check the GPIB connection, GPIB addresses, and ensure the 8757D is set to system interface
mode (SYSINTF set to ON).
The PSG automatically activates a 2 GHz to maximum frequency ramp sweep with a constant amplitude
of 0 dBm. Notice that the RF ON, SWEEP, and PULSE annunciators appear on the PSG display. The
PULSE annunciator appears because the 8757D is operating in AC mode.
The PSG also switches its remote language setting to 8757D System, allowing the PSG to talk to the
8757D during ramp sweep operations. You can confirm this by pressing Utility > GPIB/RS-232 LAN and
observing the selection under the Remote Language softkey.
NOTE
During swept RF output, the FREQUENCY and/or AMPLITUDE areas of the signal
generator’s display are deactivated, depending on what is being swept. In this case,
since frequency is being swept, nothing appears in the FREQUENCY area of the display.
7. Press Frequency > Freq CW.
The current continuous wave frequency setting now controls the RF output and ramp sweep is turned off.
8. Press Freq Start.
The ramp sweep settings once again control the RF output and the CW mode is turned off. Pressing any
one of the softkeys Freq Start, Freq Stop, Freq Center, or Freq Span activates a ramp sweep with the current
settings.
NOTE
In a frequency ramp sweep, the start frequency must be lower than the stop frequency.
9. Adjust the settings for Freq Center and Freq Span so that the frequency response of the device under test
(DUT) is clearly seen on the 8757D display.
Notice how adjusting these settings also changes the settings for the Freq Start and Freq Stop softkeys. You
may need to rescale the response on the 8757D for a more accurate evaluation of the amplitude. Figure
2-3 on page 40 shows an example of a bandpass filter response.
Chapter 2
39
Basic Operation
Configuring the RF Output
Figure 2-3
Bandpass Filter Response on 8757D
Using Markers
1. Press Markers.
This opens a table editor and associated marker control softkeys. You can use up to 10 different markers,
labeled 0 through 9.
2. Press Marker Freq and select a frequency value within the range of your sweep.
In the table editor, notice how the state for marker 0 automatically turns on. The marker also appears on
the 8757D display.
3. Use the arrow keys to move the cursor in the table editor to marker 1 and select a frequency value within
the range of your sweep, but different from marker 0.
Notice that marker 1 is activated and is the currently selected marker, indicated by the marker arrow
pointing down. As you switch between markers, using the arrow keys, you will notice that the selected
marker’s arrow points down, while all others point up.
Notice also that the frequency and amplitude data for the currently selected marker is displayed on the
8757D.
40
Chapter 2
Basic Operation
Configuring the RF Output
4. Move the cursor back to marker 0 and press Delta Ref Set > Marker Delta Off On to On.
In the table editor, notice that the frequency values for each marker are now relative to marker 0. Ref
appears in the far right column (also labeled Ref) to indicate which marker is the reference. Refer to
Figure 2-4.
Figure 2-4
Marker Table Editor
5. Move the cursor back to marker 1 and press Marker Freq. Turn the front panel knob while observing
marker 1 on the 8757D.
On the 8757D, notice that the displayed amplitude and frequency values for marker 1 are relative to
marker 0 as the marker moves along the trace. Refer to Figure 2-5.
Chapter 2
41
Basic Operation
Configuring the RF Output
Figure 2-5
Delta Markers on 8757D
6. Press Turn Off Markers.
All active markers turn off. Refer to the Key Reference for information on other marker softkey
functions.
Adjusting Sweep Time
1. Press Sweep/List.
This opens a menu of sweep control softkeys and displays a status screen summarizing all the current
sweep settings.
2. Press Configure Ramp/Step Sweep.
Since ramp is the current sweep type, softkeys in this menu specifically control ramp sweep settings.
When step is the selected sweep type, the softkeys control step sweep settings. Notice that the Freq Start
and Freq Stop softkeys appear in this menu in addition to the Frequency hardkey menu.
42
Chapter 2
Basic Operation
Configuring the RF Output
3. Press Sweep Time to Manual > 5 > sec.
In auto mode, the sweep time automatically sets to the fastest allowable value. In manual mode, you can
select any sweep time slower than the fastest allowable. The fastest allowable sweep time is dependent
on the number of trace points and channels being used on the 8757D and the frequency span.
4. Press Sweep Time to Auto.
The sweep time returns to its fastest allowable setting.
Using Alternate Sweep
1. Press the Save hardkey.
This opens the table editor and softkey menu for saving instrument states. Notice that the Select Reg
softkey is active. (For more information on saving instrument states refer to “Using the Instrument State
Register” on page 54.)
2. Turn the front panel knob until you find an available register and press SAVE. Remember this saved
register number. If no registers are available, you can write over an in-use register, by pressing Re-SAVE.
NOTE
When you are using the PSG in a system with an 8757 network analyzer, you are limited to
using registers 1 through 9 in sequence 0 for saving and recalling states.
3. Press Sweep/List > Configure Ramp/Step Sweep and enter new start and stop frequency values for the ramp
sweep.
4. Press Alternate Sweep Register and turn the front panel knob to select the register number of the
previously saved sweep state.
5. Press Alternate Sweep Off On to On.
The signal generator alternates between the original saved sweep and the current sweep. You may need
to adjust 8757D settings to effectively view both sweeps, such as setting channel 2 to measure sensor A.
Refer to Figure 2-6.
Chapter 2
43
Basic Operation
Configuring the RF Output
Figure 2-6
Alternating Sweeps on 8757D
Configuring an Amplitude Sweep
1. Press Return > Sweep > Off.
This turns off both the current sweep and the alternate sweep from the previous task. The current CW
settings now control the RF output.
2. Press Configure Ramp/Step Sweep.
3. Using the Ampl Start and Ampl Stop softkeys, set an amplitude range to be swept.
4. Press Return > Sweep > Ampl.
The new amplitude ramp sweep settings control the RF output and the CW mode is turned off.
44
Chapter 2
Basic Operation
Configuring the RF Output
Configuring a Ramp Sweep for a Master/Slave Setup
This procedure shows you how to configure two PSGs and an 8757D to work in a master/slave setup.
1. Set up the equipment as shown in Figure 2-7. Use a 9-pin, D-subminiature, male RS-232 cable with the
pin configuration shown in Figure 2-8 on page 46 to connect the auxiliary interfaces of the two PSGs.
You can also order the cable (part number 8120-8806) from Agilent Technologies.
By connecting the master PSG’s 10 MHz reference standard to the slave PSG’s 10 MHz reference input,
the master’s timebase supplies the frequency reference for both PSGs.
Figure 2-7
Chapter 2
Master/Slave Equipment Setup
45
Basic Operation
Configuring the RF Output
Figure 2-8
RS-232 Pin Configuration
2. Set up the slave PSG’s frequency and power settings.
By setting up the slave first, you avoid synchronization problems.
3. Set up the master PSG’s frequency, power, and sweep time settings.
The two PSGs can have different frequency and power settings for ramp sweep.
4. Set the slave PSG’s sweep time to match that of the master.
Sweep times must be the same for both PSGs.
5. Set the slave PSG to continuous triggering.
The slave must be set to continuous triggering, but the master can be set to any triggering mode.
6. On the slave PSG, press Sweep/List > Sweep Type > Sweep Control > Slave.
This sets the PSG to operate in slave mode.
7. On the master PSG, press Sweep/List > Sweep Type > Sweep Control > Master.
This sets the PSG to operate in master mode.
46
Chapter 2
Basic Operation
Configuring the RF Output
Extending the Frequency Range with a mm-Wave Source Module
The RF output frequency of the signal generator can be multiplied using an Agilent 83550 Series
millimeter-wave source module. The signal generator/mm-wave source module’s output is automatically
leveled when the instruments are connected. The output frequency range depends on the specific mm-wave
source module.
NOTE
To ensure adequate RF amplitude at the mm-wave source module RF input, when using an
E8267C PSG, E8247C PSG with Option 1EA, or E8257C PSG with Option 1EA, maximum
amplitude loss through the adapters and cables connected between the signal generator’s RF
output and the mm-wave source module’s RF input should be less than 1.5 dB.
Required Equipment
•
Agilent 83550 Series millimeter-wave source module
•
Agilent 8349B microwave amplifier
Signal generators without Option 1EA (E8247C PSG and E8257C PSG) require an Agilent 8349B
microwave amplifier. Signal generators with Option 1EA can drive the output of millimeter-wave source
modules to maximum specified power without a microwave amplifier.
•
cables and adapters as required
Connect the Equipment
CAUTION
To prevent damage to the signal generator, turn off the line power to the signal generator
before connecting the source module interface cable to the rear panel SOURCE MODULE
interface connector.
1. Turn off the signal generator’s line power.
2. Connect the equipment as shown.
•
E8247C PSG and E8257C PSG without Option 1EA, use the setup in Figure 2-9.
•
E8267C PSG or E8247C PSG and E8257C PSG with Option 1EA, use the setup in Figure 2-10.
Chapter 2
47
Basic Operation
Configuring the RF Output
Figure 2-9
Setup for E8247C PSG and E8257C PSG without Option 1EA
Setting the Signal Generator
1. Turn on the signal generator’s line power.
Upon power-up, the signal generator automatically:
48
•
senses the mm-wave source module,
•
switches the signal generator’s leveling mode to external/source module (power is leveled at the
mm-wave source module output),
•
sets the mm-wave source module frequency and amplitude to the source module’s preset values, and
•
in the FREQUENCY and AMPLITUDE areas of the signal generator, displays the RF output frequency
and amplitude values available at the mm-wave source module output.
Chapter 2
Basic Operation
Configuring the RF Output
Figure 2-10
Setup for E8267C PSG or E8247C PSG and E8257C PSG with Option 1EA
The MMMOD indicator in the FREQUENCY area and the MM indicator in the AMPLITUDE area of the signal
generator’s display indicate that the mm-wave source module is active.
NOTE
Refer to the mm-wave source module specifications for the specific frequency and
amplitude ranges.
2. If the RF OFF annunciator is displayed, press RF On/Off.
Leveled power should be available at the output of the millimeter-wave source module.
To obtain flatness-corrected power, refer to “Creating and Applying User Flatness Correction” on page 64.
Chapter 2
49
Basic Operation
Modulating a Signal
Modulating a Signal
This section describes how to turn on a modulation format, and how to apply it to the RF output.
Turning On a Modulation Format
A modulation format can be turned on prior to or after setting the signal parameters.
1. Access the first menu within the modulation format.
This menu displays a softkey that associates the format’s name with off and on. For example, AM >
AM Off On. For some formats, the off/on key may appear in additional menus other than the first one.
2. Press the modulation format off/on key until On highlights.
Figure 2-11 shows the portion of the AM modulation format’s first menu that displays the state of the
modulation format, as well as the active modulation format annunciator.
The modulation format generates, but the carrier signal is not modulated until you apply it to the RF
output (see page 51).
Depending on the modulation format, the signal generator may require a few seconds to build the signal.
Within the digital formats (E8267C PSG with Option 002/602 only), you may see a BaseBand
Reconfiguring status bar appear on the display. Once the signal is generated, an annunciator showing the
name of the format appears on the display, indicating that the modulation format is active. For digital
formats (E8267C PSG with Option 002/602 only), the I/Q annunciator appears in addition to the name of
the modulation format.
Figure 2-11
Example of AM Modulation Format Off and On
First AM Menu
Modulation format is off
Active Modulation Format Annunciator
Modulation format is on
50
Chapter 2
Basic Operation
Modulating a Signal
Applying a Modulation Format to the RF Output
The carrier signal is modulated when the Mod On/Off key is set to On, and an individual modulation format is
active.
When the Mod On/Off key is set to Off, the MOD OFF annunciator appears on the display.When the key is set
to On, the MOD ON annunciator shows in the display, whether or not there is an active modulation format.
The annunciators simply indicate whether the carrier signal will be modulated when a modulation format is
turned on.
To Turn RF Output Modulation On
Press the Mod On/Off key until the MOD ON annunciator appears in the display.
The carrier signal should be modulated with all active modulation formats. This is the factory default.
To Turn RF Output Modulation Off
Press the Mod On/Off key until the MOD OFF annunciator appears in the display.
The carrier signal is no longer modulated or capable of being modulated when a modulation format is active.
Figure 2-12
Carrier Signal Modulation Status
Mod Set to On—Carrier is Modulated
AM Modulation Format is Active
Mod Set to Off—Carrier is
not Modulated
AM Modulation Format is Active
Mod Set to On—Carrier is
not Modulated
No Active Modulation Format
Chapter 2
51
Basic Operation
Using Data Storage Functions
Using Data Storage Functions
This section explains how to use the two forms of signal generator data storage: the memory catalog and the
instrument state register.
Using the Memory Catalog
The Memory Catalog is the signal generator’s interface for viewing, storing, and saving files; it can be
accessed through the signal generator’s front panel or a remote controller. (For information on performing
these tasks remotely, see the Programming Guide.)
Table 2-1
Memory Catalog File Types and Associated Data
Binary
binary data
State
instrument state data (controlling instrument operating
parameters, such as frequency, amplitude, and mode)
LIST
sweep data from the List Mode Values table including
frequency, amplitude, and dwell time
User Flatness
user flatness calibration correction pair data (user-defined
frequency and corresponding amplitude correction values)
FIR
Finite Impulse Response (FIR) filter coefficients
ARB Catalog Types
(E8267C PSG with Option 002/602 only) user created files Waveform Catalog Types: WFM1 (waveform file),
NVARB Catalog Types:
NVWFM (non-volatile, ARB waveform file),
NVMKR (non-volatile, ARB waveform marker file),
Seq (ARB sequence file),
MTONE (ARB multitone file),
DMOD (ARB digital modulation file),
MDMOD (ARB multicarrier digital modulation file)
Modulation Catalog Types
(E8267C PSG with Option 002/602 only) associated data for I/Q
and FSK (frequency shift keying) modulation files
Shape
burst shape of a pulse
Bit
Bit
52
Chapter 2
Basic Operation
Using Data Storage Functions
Storing Files to the Memory Catalog
To store a file to the memory catalog, first create a file. For this example, use the default list sweep table.
1. Press Preset.
2. Press Sweep/List > Configure List Sweep > More (1 of 2) > Load/Store.
This opens the “Catalog of List Files”.
3. Press Store to File.
This displays a menu of alphabetical softkeys for naming the file. Store to: is displayed in the active
function area.
4. Enter the file name LIST1 using the alphabetical softkeys and the numeric keypad (for the numbers 0 to
9).
5. Press Enter.
The file should be displayed in the “Catalog of List Files”, showing the file name, file type, file size, and
the date and time the file was modified.
Viewing Stored Files in the Memory Catalog
1. Press Utility > Memory Catalog > Catalog Type.
All files in the memory catalog are listed in alphabetical order, regardless of which catalog type you
select. File information appears on the display and includes the file name, file type, file size, and the date
and time the file was modified.
2. Press List.
The “Catalog of List Files” is displayed.
3. Press Catalog Type > State.
The “Catalog of State Files” is displayed.
4. Press Catalog Type > All.
The “Catalog of All Files” is displayed. For a complete list of file types, refer to Table 2-1 on page 52.
Chapter 2
53
Basic Operation
Using Data Storage Functions
Using the Instrument State Register
The instrument state register is a section of memory divided into 10 sequences (numbered 0 through 9) each
containing 100 registers (numbered 00 through 99). It is used to store and recall instrument settings. It
provides a quick way to reconfigure the signal generator when switching between different signal
configurations. Once an instrument state has been saved, you can recall the instrument settings for that state
with minimum effort.
NOTE
List sweep data is not saved within an instrument state. For instructions on saving list sweep
data, see “Storing Files to the Memory Catalog” on page 53.
Saving an Instrument State
1. Preset the signal generator, then enables amplitude modulation (the AM annunciator will turn on):
a. Press Frequency > 800 > MHz.
b. Press Amplitude > 0 > dBm.
c. Press AM > AM Off On.
2. Press Save > Select Seq.
The sequence number becomes the active function. The signal generator displays the last sequence used.
Using the arrow keys, set the sequence to 1.
3. Press Select Reg.
The register number in sequence 1 becomes the active function. The signal generator displays either the
last register used accompanied by the text: (in use), or (if no registers are in use) register 00
accompanied by the text: (available). Use the arrow keys to select register 01.
4. Press Save Seq[1] Reg[01].
This saves this instrument state in sequence 1, register 01 of the instrument state register.
5. Press Add Comment to Seq[1] Reg[01].
This enables you to add a descriptive comment to sequence 1 register 01.
6. Using the alphanumeric softkeys or the knob, enter a comment and press Enter.
7. Press Edit Comment In Seq[1] Reg[01].
If you wish, you can now change the descriptive comment for sequence 1 register 01.
After making changes to an instrument state, you can save it back to a specific register by highlighting that
register and pressing Re-SAVE Seq[n] Reg[nn].
54
Chapter 2
Basic Operation
Using Data Storage Functions
Recalling an Instrument State
Using this procedure, you will learn how to recall instrument settings saved to an instrument state register.
1. Press Preset.
2. Press the Recall hardkey.
Notice that the Select Seq softkey shows sequence 1. (This is the last sequence that you used.)
3. Press RECALL Reg.
The register to be recalled in sequence 1 becomes the active function. Press the up arrow key once to
select register 1. Your stored instrument state settings should have been recalled.
Deleting Registers and Sequences
These procedures describe how to delete registers and sequences saved to an instrument state register.
Deleting a Specific Register within a Sequence
1. Press Preset.
2. Press the Recall or Save hardkey.
Notice that the Select Seq softkey shows the last sequence that you used.
3. Press Select Seq and enter the sequence number containing the register you want to delete.
4. Press Select Reg and enter the register number you want to delete.
Notice that the Delete Seq[n] Reg[nn] should be loaded with the sequence and register you want to delete.
5. Press Delete Seq[n] Reg[nn].
This deletes the chosen register.
Chapter 2
55
Basic Operation
Using Data Storage Functions
Deleting All Registers within a Sequence
1. Press Preset.
2. Press the Recall or Save hardkey.
Notice that the Select Seq softkey shows the last sequence that you used.
3. Press Select Seq and enter the sequence number containing the registers you want to delete.
4. Press Delete all Regs in Seq[n].
This deletes all registers in the selected sequence.
Deleting All Sequences
CAUTION
Be sure you want to delete the contents of all registers and all sequences in the instrument
state register.
1. Press Preset.
2. Press the Recall or Save hardkey.
Notice that the Select Seq softkey shows the last sequence that you used.
3. Press Delete All Sequences.
This deletes all of the sequences saved in the instrument state register.
56
Chapter 2
Basic Operation
Enabling Options
Enabling Options
You can retrofit your signal generator after purchase to add new capabilities. Some new optional features are
implemented in hardware that you must install. Some options are implemented in software, but require the
presence of optional hardware in the instrument. This example shows you how to enable software options.
Enabling a Software Option
A license key (provided on the license key certificate) is required to enable each software option.
1. Access the Software Options menu:
Utility > Instrument Adjustments > Instrument Options > Software Options.
The following is an example of the signal generator display, which lists any enabled software options,
and any software options that can be enabled:
2. Verify that the host ID shown on the display matches the host ID on the license key certificate. The host
ID is a unique number for every instrument. If the host ID on the license key certificate does not match
your instrument, the license key cannot enable the software option.
3. Verify that any required hardware is installed. Because some software options are linked to specific
hardware options, before the software option can be enabled, the appropriate hardware option must be
installed. For example, Option 420 (radar simulation modulation format) requires that Option 002/602
(internal baseband generator) be installed. If the software option that you intend to install is listed in a
grey font, the required hardware may not be installed (look for an X in the “Selected” column of the
appropriate hardware option in the Hardware Options menu).
Chapter 2
57
Basic Operation
Enabling Options
4. Enable the software option:
a. Highlight the desired option.
b. Press Modify License Key, and enter the 12-character license key (from the license key certificate).
c. Verify that you want to reconfigure the signal generator with the new option:
Proceed With Reconfiguration > Confirm Change
The instrument enables the option and reboots.
58
Chapter 2
3
Optimizing Performance
In the following sections, this chapter describes procedures that improve the performance of the Agilent PSG
signal generator.
•
Selecting ALC Bandwidth (below)
•
“Using External Leveling” on page 60
•
“Creating and Applying User Flatness Correction” on page 64
•
“Adjusting Reference Oscillator Bandwidth (Option UNR)” on page 76
Selecting ALC Bandwidth
For internal leveling, the signal generator uses automatic leveling control (ALC) circuitry prior to the RF
output. ALC bandwidth has five selections: automatic, 100 Hz, 1 kHz, 10 kHz, and 100 kHz. In automatic
mode (the preset selection), the signal generator automatically adjusts the ALC bandwidth among three of
the four possible settings, depending on the active functions (see Figure 3-1).
Figure 3-1
Decision Tree for Automatic ALC Bandwidth Selection
RF OUTPUT No
< 2 MHz
No
AM OFF
PULSE OFF
Yes
Yes
ALC BW
100 Hz
ALC BW
1 kHz
AM OFF No
PULSE ON
Yes
ALC BW
10 kHz
AM ON
PULSE ON
No
Yes
AM ON
PULSE OFF
Yes
ALC BW
100 kHz
To Select an ALC Bandwidth
Press Amplitude > ALC BW > 100 Hz, 1 kHz, 10 kHz, or 100 kHz.
This overrides the automatic ALC bandwidth selection with your specific selection.
59
Optimizing Performance
Using External Leveling
Using External Leveling
The PSG signal generator can be externally leveled by connecting an external sensor at the point where
leveled RF output power is desired. This sensor detects changes in RF output power and returns a
compensating voltage to the signal generator’s ALC input. The ALC circuitry raises or lowers (levels) the
RF output power based on the voltage received from the external sensor, ensuring constant power at the
point of detection.
There are two types of external leveling available on the PSG. You can use external leveling with a detector
and coupler/power splitter setup, or a millimeter-wave source module.
To Level with Detectors and Couplers/Splitters
Figure 3-2 illustrates a typical external leveling setup. The power level feedback to the ALC circuitry is
taken from the external negative detector, rather than the internal signal generator detector. This feedback
voltage controls the ALC system, leveling the RF output power at the point of detection.
To use detectors and couplers/splitters for external leveling at an RF output frequency of
10 GHz and an amplitude of 0 dBm, follow the instructions in this section.
Required Equipment
•
Agilent 8474E negative detector
•
Agilent 87301D directional coupler
•
cables and adapters, as required
Connect the Equipment
Set up the equipment as shown in Figure 3-2.
Figure 3-2
60
External Detector Leveling with a Directional Coupler
Chapter 3
Optimizing Performance
Using External Leveling
Configure the Signal Generator
1. Press Preset.
2. Press Frequency > 10 > GHz.
3. Press Amplitude > 0 > dBm.
4. Press RF On/Off.
5. Press Leveling Mode > Ext Detector.
This deactivates the internal ALC detector and switches the ALC input path to the front panel ALC
INPUT connector. The EXT indicator is activated in the AMPLITUDE area of the display.
NOTE
For signal generators with Option 1E1, notice that the ATTN HOLD (attenuator hold)
annunciator is displayed. During external leveling, the signal generator automatically
uncouples the attenuator from the ALC system for all external leveling points. While in this
mode, the RF output amplitude adjustment is limited to −20 to +25 dBm, the adjustment
range of the ALC circuitry. For more information, see “External Leveling with Option 1E1
Signal Generators” on page 63.
6. Observe the coupling factor printed on the directional coupler at the detector port. Typically, this value is
−10 to −20 dB.
Enter the positive dB value of this coupling factor into the signal generator.
7. Press More (1 of 2) > Ext Detector Coupling Factor > 16 (or the positive representation of the value listed at
the detector port of the directional coupler) > dB.
Leveled output power is now available at the output of the directional coupler.
NOTE
Chapter 3
While operating in external leveling mode, the signal generator’s displayed RF output
amplitude is affected by the coupling factor value, resulting in a calculated approximation of
the actual RF output amplitude. To determine the actual RF output amplitude at the point of
detection, measure the voltage at the external detector output and refer to Figure 3-3 or
measure the power directly with a power meter.
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Optimizing Performance
Using External Leveling
Determining the Leveled Output Power
Figure 3-3 shows the input power versus output voltage characteristics for typical Agilent Technologies
diode detectors. Using this chart, you can determine the leveled power at the diode detector input by
measuring the external detector output voltage. You must then add the coupling factor to determine the
leveled output power. The range of power adjustment is approximately -20 to +25 dBm.
Figure 3-3
62
Typical Diode Detector Response at 25° C
Chapter 3
Optimizing Performance
Using External Leveling
External Leveling with Option 1E1 Signal Generators
Signal generators with Option 1E1 contain a step attenuator prior to the RF output connector. During
external leveling, the signal generator automatically holds the present attenuator setting (to avoid power
transients that may occur during attenuator switching) as the RF amplitude is changed. A balance must be
maintained between the amount of attenuation and the optimum ALC level to achieve the required RF
output amplitude. For optimum accuracy and minimum noise, the ALC level should be greater than −10
dBm.
For example, leveling the CW output of a 30 dB gain amplifier to a level of −10 dBm requires the output of
the signal generator to be approximately −40 dBm when leveled. This is beyond the amplitude limits of the
ALC modulator alone, resulting in an unleveled RF output. Inserting 45 dB of attenuation results in an ALC
level of +5 dBm, well within the range of the ALC modulator.
NOTE
In the example above, 55 dB is the preferred attenuation choice, resulting in an ALC level
of +15 dBm. This provides adequate dynamic range for AM or other functions that vary the
RF output amplitude.
To achieve the optimum ALC level at the signal generator RF output of −40 dBm for an unmodulated
carrier, follow these steps:
1. Press Amplitude > Set Atten > 45 > dB.
2. Press Set ALC Level > 5 > dBm.
This sets the attenuator to 45 dB and the ALC level to +5 dBm, resulting in an RF output amplitude of -40
dBm, as shown in the AMPLITUDE area of the display.
To obtain flatness-corrected power, refer to “Creating and Applying User Flatness Correction” on page 64.
To Level with a mm-Wave Source Module
Millimeter-wave source module leveling is similar to external detector leveling. The power level feedback
signal to the ALC circuitry is taken from the millimeter-wave source module, rather than the internal signal
generator detector. This feedback signal levels the RF output power at the mm-wave source module output
through the signal generator’s rear panel SOURCE MODULE interface connector.
For instructions and setups, see “Extending the Frequency Range with a mm-Wave Source Module” on
page 47.
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Creating and Applying User Flatness Correction
Creating and Applying User Flatness Correction
User flatness correction allows the digital adjustment of RF output amplitude for up to 1601 frequency
points in any frequency or sweep mode. Using an Agilent E4416A/17A or E4418B/19B power meter
(controlled by the signal generator through GPIB) to calibrate the measurement system, a table of power
level corrections is created for frequencies where power level variations or losses occur. These frequencies
may be defined in sequential linear steps or arbitrarily spaced.
To allow different correction arrays for different test setups or different frequency ranges, you may save
individual user flatness correction tables to the signal generator’s memory catalog and recall them on
demand.
Use the steps in the next sections to create and apply user flatness correction to the signal generator’s RF
output.
Afterward, use the steps in “Recalling and Applying a User Flatness Correction Array” on page 68 to recall
a user flatness file from the memory catalog and apply it to the signal generator’s RF output.
Creating a User Flatness Correction Array
In this example, you create a user flatness correction array. The flatness correction array contains ten
frequency correction pairs (amplitude correction values for specified frequencies), from 1 to 10 GHz in
1 GHz intervals.
An Agilent E4416A/17A/18B/19B power meter (controlled by the signal generator via GPIB) and E4413A
power sensor are used to measure the RF output amplitude at the specified correction frequencies and
transfer the results to the signal generator. The signal generator reads the power level data from the power
meter, calculates the correction values, and stores the correction pairs in the user flatness correction array.
If you do not have the required Agilent power meter, or if your power meter does not have a GPIB interface,
you can enter correction values manually.
Required Equipment
•
•
•
•
Agilent E4416A/17A/18B/19B power meter
Agilent E4413A E Series CW power sensor
GPIB interface cable
adapters and cables, as required
NOTE
64
If the setup has an external leveling configuration, the equipment setup in Figure 3-4
assumes that the steps necessary to correctly level the RF output have been followed. If you
have questions about external leveling, refer to “Using External Leveling” on page 60.
Chapter 3
Optimizing Performance
Creating and Applying User Flatness Correction
Configure the Power Meter
1.
2.
3.
4.
Select SCPI as the remote language for the power meter.
Zero and calibrate the power sensor to the power meter.
Enter the appropriate power sensor calibration factors into the power meter as appropriate.
Enable the power meter’s cal factor array.
NOTE
For operating information on a particular power meter/sensor, refer to its operating guide.
Connect the Equipment
Connect the equipment as shown in Figure 3-4.
NOTE
Figure 3-4
Chapter 3
During the process of creating the user flatness correction array, the power meter is slaved
to the signal generator via GPIB. No other controllers are allowed on the GPIB interface.
User Flatness Correction Equipment Setup
65
Optimizing Performance
Creating and Applying User Flatness Correction
Configure the Signal Generator
1. Press Preset.
2. Configure the signal generator to interface with the power meter.
a. Press Amplitude > More (1 of 2) > User Flatness > More (1 of 2) > Power Meter > E4416A, E4417A, E4418B,
or E4419B.
b. Press Meter Address > enter the power meter’s GPIB address > Enter.
c. For E4417A and E4419B models, press Meter Channel A B to select the power meter’s active channel.
d. Press Meter Timeout to adjust the length of time before the instrument generates a timeout error if
unsuccessfully attempting to communicate with the power meter.
3. Press More (2 of 2) > Configure Cal Array > More (1 of 2) > Preset List > Confirm Preset.
This opens the User Flatness table editor and presets the cal array frequency/correction list.
4. Press Configure Step Array.
This opens a menu for entering the user flatness step array data.
5. Press Freq Start > 1 > GHz.
6. Press Freq Stop > 10 > GHz.
7. Press # of Points > 10 > Enter.
Steps 4, 5, and 6 enter the desired flatness-corrected frequencies into the step array.
8. Press Return > Load Cal Array From Step Array > Confirm Load From Step Data.
This populates the user flatness correction array with the frequency settings defined in the step array.
9. Press Amplitude > 0 > dBm.
10. Press RF On/Off.
This activates the RF output and the RF ON annunciator is displayed on the signal generator.
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Creating and Applying User Flatness Correction
Perform the User Flatness Correction
NOTE
If you are not using an Agilent E4416A/17A/18B/19B power meter, or if your power meter
does not have a GPIB interface, you can perform the user flatness correction manually. For
instructions, see “Performing the User Flatness Correction Manually” on page 67.
1. Press More (1 of 2) > User Flatness > Do Cal.
This creates the user flatness amplitude correction value table entries. The signal generator enters the
user flatness correction routine and a progress bar is shown on the display.
2. Press Done.
This loads the amplitude correction values into the user flatness correction array.
If desired, press Configure Cal Array.
This opens the user flatness correction array, where you can view the stored amplitude correction values.
The user flatness correction array title displays User Flatness: (UNSTORED) indicating that the
current user flatness correction array data has not been saved to the memory catalog.
Performing the User Flatness Correction Manually
If you are not using an Agilent E4416A/17A/18B/19B power meter, or if your power meter does not have a
GPIB interface, complete the steps in this section and then continue with the user flatness correction tutorial.
1. Press More (1 of 2) > User Flatness > Configure Cal Array.
This opens the User Flatness table editor and places the cursor over the frequency value
(1 GHz) for row 1. The RF output changes to the frequency value of the table row containing the cursor
and 1.000 000 000 00 is displayed in the AMPLITUDE area of the display.
2. Observe and record the measured value from the power meter.
3. Subtract the measured value from 0 dBm.
4. Move the table cursor over the correction value in row 1.
5. Press Edit Item > enter the difference value from step 3 > dB.
The signal generator adjusts the RF output amplitude based on the correction value entered.
6. Repeat steps 2 through 5 until the power meter reads 0 dBm.
7. Use the down arrow key to place the cursor over the frequency value
for the next row. The RF output changes to the frequency value of the table row containing the cursor, as
shown in the AMPLITUDE area of the display.
8. Repeat steps 2 through 7 for every entry in the User Flatness table.
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Creating and Applying User Flatness Correction
Save the User Flatness Correction Data to the Memory Catalog
This process allows you to save the user flatness correction data as in the signal generator’s memory catalog.
With several user flatness correction files saved to the memory catalog, any file can be recalled, loaded into
the correction array, and applied to the RF output to satisfy specific RF output flatness requirements.
1. Press Load/Store.
2. Press Store to File.
3. Enter the file name FLATCAL1 using the alphanumeric softkeys, numeric keypad, or the knob.
4. Press Enter.
The user flatness correction array file FLATCAL1 is now stored in the memory catalog as a UFLT file.
Applying a User Flatness Correction Array
Press Return > Return > Flatness Off On.
This applies the user flatness correction array to the RF output. The UF indicator is activated in the
AMPLITUDE section of the signal generator’s display and the frequency correction data contained in the
correction array is applied to the RF output amplitude.
Recalling and Applying a User Flatness Correction Array
Before performing the steps in this section, complete “Creating a User Flatness Correction Array” on
page 64.
1. Press Preset.
2. Press Amplitude > More (1 of 2) > User Flatness > Configure Cal Array > More (1 of 2) >
Preset List > Confirm Preset.
3. Press More (2 of 2) > Load/Store.
4. Ensure that the file FLATCAL1 is highlighted.
5. Press Load From Selected File > Confirm Load From File.
This populates the user flatness correction array with the data contained in the file FLATCAL1. The user
flatness correction array title displays User Flatness: FLATCAL1.
6. Press Return > Flatness Off On.
This applies the user flatness correction data contained in FLATCAL1.
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Creating and Applying User Flatness Correction
Returning the Signal Generator to GPIB Listener Mode
During the user flatness correction process, the power meter is slaved to the signal generator via GPIB, and
no other controllers are allowed on the GPIB interface. The signal generator operates in GPIB talker mode,
as a device controller for the power meter. In this operating mode, it cannot receive SCPI commands via
GPIB.
If the signal generator is to be interfaced to a remote controller after performing the user flatness correction,
its GPIB controller mode must be changed from GPIB talker to GPIB listener.
If an RF carrier has been previously configured, you must save the present instrument state before returning
the signal generator to GPIB listener mode.
1. Save your instrument state to the instrument state register.
For instructions, see “Saving an Instrument State” on page 54.
2. Press GPIB Listener Mode.
This presets the signal generator and returns it to GPIB listener mode. The signal generator can now
receive remote commands executed by a remote controller connected to the GPIB interface.
3. Recall your instrument state from the instrument state register.
For instructions, see “Saving an Instrument State” on page 54.
Creating a User Flatness Correction Array with a mm-Wave Source Module
In this example, a user flatness correction array is created to provide flatness-corrected power at the output
of an Agilent 83554A millimeter-wave source module driven by an E8247C signal generator.
The flatness correction array contains 28 frequency correction pairs (amplitude correction values for
specified frequencies), from 26.5 to 40 GHz in 500 MHz intervals. This will result in 28 evenly spaced
flatness corrected frequencies between 26.5 GHz and 40 GHz at the output of the 83554A millimeter-wave
source module.
An Agilent E4416A/17A/18B/19B power meter (controlled by the signal generator via GPIB) and R8486A
power sensor are used to measure the RF output amplitude of the millimeter-wave source module at the
specified correction frequencies and transfer the results to the signal generator. The signal generator reads
the power level data from the power meter, calculates the correction values, and stores the correction pairs in
the user flatness correction array.
If you do not have the required Agilent power meter, or if your power meter does not have a GPIB interface,
you can enter correction values manually.
Chapter 3
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Optimizing Performance
Creating and Applying User Flatness Correction
Required Equipment
•
Agilent 83554A millimeter-wave source module
•
Agilent E4416A/17A/18B/19B power meter
•
Agilent R8486A power sensor
•
Agilent 8349B microwave amplifier (required for signal generators without Option 1EA)
•
GPIB interface cable
•
adapters and cables as required
NOTE
The equipment setups in Figure 3-5 and Figure 3-6 assume that the steps necessary to
correctly level the RF output have been followed. If you have questions about leveling with
a millimeter-wave source module, refer to “To Level with a mm-Wave Source Module” on
page 63.
Configure the Power Meter
1. Select SCPI as the remote language for the power meter.
2. Zero and calibrate the power sensor to the power meter.
3. Enter the appropriate power sensor calibration factors into the power meter as appropriate.
4. Enable the power meter’s cal factor array.
NOTE
70
For operating information on your particular power meter/sensor, refer to their operating
guides.
Chapter 3
Optimizing Performance
Creating and Applying User Flatness Correction
Connect the Equipment
CAUTION
To prevent damage to the signal generator, turn off the line power to the signal generator
before connecting the source module interface cable to the rear panel SOURCE MODULE
interface connector.
1. Turn off the line power to the signal generator.
2. Connect the equipment. For standard signal generators, use the setup in Figure 3-5. For Option 1EA
signal generators, use the setup in Figure 3-6.
NOTE
During the process of creating the user flatness correction array, the power meter is slaved to
the signal generator via GPIB. No other controllers are allowed on the GPIB interface.
Figure 3-5
User Flatness with mm-Wave Source Module for a Signal Generator without Option 1EA
Chapter 3
71
Optimizing Performance
Creating and Applying User Flatness Correction
Figure 3-6
NOTE
User Flatness with mm-Wave Source Module and Option 1EA Signal Generator
To ensure adequate RF amplitude at the mm-wave source module RF input when using
Option 1EA signal generators, maximum amplitude loss through the adapters and cables
connected between the signal generator’s RF output and the mm-wave source module’s RF
input should be less than 1.5 dB.
Configure the Signal Generator
1. Turn on the signal generator’s line power. At power-up, the signal generator automatically does the
following:
•
•
•
•
senses the mm-wave source module
switches the signal generator’s leveling mode to external/source module
sets the mm-wave source module frequency and amplitude to the source module’s preset values
displays the RF output frequency and amplitude available at the mm-wave source module output
The MMMOD indicator in the FREQUENCY area and the MM indicator in the AMPLITUDE area of the signal
generator’s display indicate that the mm-wave source module is active
NOTE
72
For specific frequency/amplitude ranges, see the mm-wave source module specifications.
Chapter 3
Optimizing Performance
Creating and Applying User Flatness Correction
2. Configure the signal generator to interface with the power meter.
a. Press Amplitude > More (1 of 2) > User Flatness > More (1 of 2) > Power Meter > E4416A, E4417A, E4418B,
or E4419B.
b. Press Meter Address > enter the power meter’s GPIB address > Enter.
c. For E4417A and E4419B models, press Meter Channel A B to select the power meter’s active channel.
d. Press Meter Timeout to adjust the length of time before the instrument generates a timeout error if
unsuccessfully attempting to communicate with the power meter.
3. Press More (2 of 2) > Configure Cal Array > More (1 of 2) > Preset List > Confirm Preset.
This opens the User Flatness table editor and resets the cal array frequency/correction list.
4. Press Configure Step Array.
This opens a menu for entering the user flatness step array data.
5. Press Freq Start > 26.5 > GHz.
6. Press Freq Stop > 40 > GHz.
7. Press # of Points > 28 > Enter.
This enters the desired flatness-corrected frequencies (26.5 GHz to 40 GHz in 500 MHz intervals) into
the step array.
8. Press Return > Load Cal Array From Step Array > Confirm Load From Step Data.
This populates the user flatness correction array with the frequency settings defined in the step array.
9. Press Amplitude > 0 > dBm.
10. Press RF On/Off.
This activates the RF output and the RF ON annunciator is displayed on the signal generator.
Perform the User Flatness Correction
NOTE
If you are not using an Agilent E4416A/17A/18B/19B power meter, or if your power meter
does not have a GPIB interface, you can perform the user flatness correction manually. For
instructions, see Performing the User Flatness Correction Manually below.
1. Press More (1 of 2) > User Flatness > Do Cal.
This creates the user flatness amplitude correction value table entries. The signal generator begins the
user flatness correction routine and a progress bar is shown on the display.
Chapter 3
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Optimizing Performance
Creating and Applying User Flatness Correction
2. When prompted, press Done.
This loads the amplitude correction values into the user flatness correction array.
If desired, press Configure Cal Array.
This opens the user flatness correction array, where you can view the list of defined frequencies and their
calculated amplitude correction values. The user flatness correction array title displays User
Flatness: (UNSTORED) indicating that the current user flatness correction array data has not been
saved to the memory catalog.
Performing the User Flatness Correction Manually
If you are not using an Agilent E4416A/17A/18B/19B power meter, or if your power meter does not have a
GPIB interface, complete the steps in this section and then continue with the user flatness correction tutorial.
1. Press More (1 of 2) > User Flatness > Configure Cal Array.
This opens the User Flatness table editor and places the cursor over the frequency value (26.5 GHz) for
row 1. The RF output changes to the frequency value of the table row containing the cursor and 26.500
000 000 00 is displayed in the AMPLITUDE area of the display.
2. Observe and record the measured value from the power meter.
3. Subtract the measured value from 0 dBm.
4. Move the table cursor over the correction value in row 1.
5. Press Edit Item > enter the difference value from step 3 > dB.
The signal generator adjusts the RF output amplitude based on the correction value entered.
6. Repeat steps 2 through 5 until the power meter reads 0 dBm.
7. Use the down arrow key to place the cursor over the frequency value for the next row. The RF output
changes to the frequency value highlighted by the cursor, as shown in the AMPLITUDE area of the
display.
8. Repeat steps 2 through 7 for each entry in the User Flatness table.
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Chapter 3
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Creating and Applying User Flatness Correction
Save the User Flatness Correction Data to the Memory Catalog
This process allows you to save the user flatness correction data as a file in the signal generator’s memory
catalog. With several user flatness correction files saved to the memory catalog, specific files can be
recalled, loaded into the correction array, and applied to the RF output to satisfy various RF output flatness
requirements.
1. Press Load/Store.
2. Press Store to File.
3. Enter the file name FLATCAL2 using the alphanumeric softkeys and the numeric keypad.
4. Press Enter.
The user flatness correction array file FLATCAL2 is now stored in the memory catalog as a UFLT file.
Applying the User Flatness Correction Array
1. Press Return > Return > Flatness Off On.
This applies the user flatness correction array to the RF output. The UF indicator is activated in the
AMPLITUDE section of the signal generator’s display and the frequency correction data contained in the
correction array is applied to the RF output amplitude of the mm-wave source module.
Recalling and Applying a User Flatness Correction Array
Before performing the steps in this section, complete the section “Creating a User Flatness Correction Array
with a mm-Wave Source Module” on page 69.
1. Press Preset.
2. Press Amplitude > More (1 of 2) > User Flatness > Configure Cal Array > More (1 of 2) >
Preset List > Confirm Preset.
3. Press More (2 of 2) > Load/Store.
4. Ensure that the file FLATCAL2 is highlighted.
5. Press Load From Selected File > Confirm Load From File.
This populates the user flatness correction array with the data contained in the file FLATCAL2. The user
flatness correction array title displays User Flatness: FLATCAL2.
6. Press Return > Flatness Off On.
This activates flatness correction using the data contained in the file FLATCAL2.
Chapter 3
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Optimizing Performance
Adjusting Reference Oscillator Bandwidth (Option UNR)
Adjusting Reference Oscillator Bandwidth (Option UNR)
The reference oscillator bandwidth (sometimes referred to as loop bandwidth) in signal generators with
Option UNR (improved close-in phase noise) is adjustable in fixed steps for either an internal or external
10 MHz frequency reference. The reference bandwidth can be set to 25, 55, 125, 300, or 650 Hz; models
without option UNR have a fixed reference oscillator bandwidth of about 15 Hz.
The reference oscillator bandwidth is the frequency below which the PSG derives its reference directly from
the internal or external frequency reference. Above this frequency, stability and phase noise are governed by
the synthesizer hardware within the PSG.
To optimize the overall phase noise performance of the signal generator for your particular application,
make this adjustment depending on your confidence in the stability and phase noise of the external or
internal reference versus the synthesizer hardware for various frequency offsets from the carrier.
To Select the Reference Oscillator Bandwidth
When using the internal timebase reference:
1. Press Utility > Instrument Adjustments > Reference Oscillator Adjustment > Internal Ref Bandwidth.
2. Select the desired bandwidth.
When using an external timebase reference:
1. Press Utility > Instrument Adjustments > Reference Oscillator Adjustment > External Ref Bandwidth.
2. Select the desired bandwidth.
To Restore Factory Default Settings:
Internal Timebase: 125 Hz
External Timebase: 25 Hz
Press Utility > Instrument Adjustments > Reference Oscillator Adjustment > Restore Factory Defaults.
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Chapter 3
4
Analog Modulation
In the following sections, this chapter describes the analog modulation capability in Agilent E8257C PSG
Analog and E8267C PSG Vector Signal Generators.
•
“Analog Modulation Waveforms” on page 78
•
“Configuring AM” on page 79
•
“Configuring FM” on page 80
•
“Configuring ΦM” on page 81
•
“Configuring Pulse Modulation” on page 82
•
“Configuring the LF Output” on page 83
77
Analog Modulation
Analog Modulation Waveforms
Analog Modulation Waveforms
The signal generator can modulate the RF carrier with four types of analog modulation:
•
•
•
•
amplitude,
frequency,
phase, and
pulse.
Available internal waveforms include:
Sine
sine wave with adjustable amplitude and frequency
Dual-Sine
dual-sine waves with individually adjustable frequencies and a percent-ofpeak-amplitude setting for the second tone (available from function generator only)
Swept-Sine
swept-sine wave with adjustable start and stop frequencies, sweep rate, and sweep
trigger settings (available from function generator only)
Triangle
triangle wave with adjustable amplitude and frequency
Ramp
ramp with adjustable amplitude and frequency
Square
square wave with adjustable amplitude and frequency
Noise
noise with adjustable amplitude generated as a peak-to-peak value (RMS value is
approximately 80% of the displayed value)
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Chapter 4
Analog Modulation
Configuring AM
Configuring AM
In this example, you will learn how to generate an amplitude-modulated RF carrier.
To Set the Carrier Frequency
1. Press Preset.
2. Press Frequency > 1340 > kHz.
To Set the RF Output Amplitude
Press Amplitude > 0 > dBm.
To Set the AM Depth and Rate
1. Press the AM hardkey.
2. Press AM Depth > 90 > %.
3. Press AM Rate > 10 > kHz.
The signal generator is now configured to output a 0 dBm, amplitude-modulated carrier at 1340 kHz with
the AM depth set to 90% and the AM rate set to 10 kHz. The shape of the waveform is a sine wave. Notice
that sine is the default selection for the AM Waveform softkey, which can be viewed by pressing (More 1 of 2).
To Turn on Amplitude Modulation
Follow these remaining steps to output the amplitude-modulated signal.
1. Press the AM Off On softkey to On.
2. Press the front panel RF On Off key.
The AM and RF ON annunciators are now displayed. This indicates that you have enabled amplitude
modulation and the signal is now being transmitted from the RF OUTPUT connector.
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79
Analog Modulation
Configuring FM
Configuring FM
In this example, you will learn how to create a frequency-modulated RF carrier.
To Set the RF Output Frequency
1. Press Preset.
2. Press Frequency > 1 > GHz.
To Set the RF Output Amplitude
Press Amplitude > 0 > dBm.
To Set the FM Deviation and Rate
1. Press the FM/ΦM hardkey.
2. Press FM Dev > 75 > kHz.
3. Press FM Rate > 10 > kHz.
The signal generator is now configured to output a 0 dBm, frequency-modulated carrier at 1 GHz with a
75 kHz deviation and a 10 kHz rate. The shape of the waveform is a sine wave. (Notice that sine is the
default for the FM Waveform softkey. Press More (1 of 2) to see the softkey.)
To Activate FM
1. Press FM Off On to On.
2. Press RF On/Off.
The FM and RF ON annunciators are now displayed. This indicates that you have enabled frequency
modulation and the signal is now being transmitted from the RF OUTPUT connector.
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Analog Modulation
Configuring ΦM
Configuring ΦM
In this example, you will learn how to create a phase-modulated RF carrier.
To Set the RF Output Frequency
1. Press Preset.
2. Press Frequency > 3 > GHz.
To Set the RF Output Amplitude
Press Amplitude > 0 > dBm.
To Set the FM Deviation and Rate
1. Press the FM/ΦM hardkey.
2. Press the FM ΦM softkey.
3. Press FM Dev > .25 > pi rad.
4. Press FM Rate > 10 > kHz.
The signal generator is now configured to output a 0 dBm, phase-modulated carrier at 3 GHz with a 0.25 p
radian deviation and 10 kHz rate. The shape of the waveform is a sine wave. (Notice that sine is the default
for the FM Waveform softkey. Press More (1 of 2) to see the softkey.)
To Activate FM
1. Press FM Off On.
2. Press RF On/Off.
The FM and RF ON annunciators are now displayed. This indicates that you have enabled phase modulation
and the signal is now being transmitted from the RF OUTPUT connector.
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Analog Modulation
Configuring Pulse Modulation
Configuring Pulse Modulation
In this example, you will learn how to create a pulse-modulated RF carrier.
To Set the RF Output Frequency
1. Press Preset.
2. Press Frequency > 2 > GHz.
To Set the RF Output Amplitude
Press Amplitude > 0 > dBm.
To Set the Pulse Period and Width
1. Press Pulse > Pulse Period > 100 > usec.
2. Press Pulse > Pulse Width > 24 > usec.
The signal generator is now configured to output a 0 dBm, pulse-modulated carrier at 2 GHz with a
100-microsecond pulse period and 24-microsecond pulse width. The pulse source is set to Internal Free Run.
(Notice that Internal Free Run is the default for the Pulse Source softkey.)
To Activate Pulse Modulation
Follow these remaining steps to output the pulse-modulated signal.
1. Press Pulse Off On to On.
2. Press RF On/Off.
The Pulse and RF ON annunciators are now displayed. This indicates that you have enabled pulse
modulation and the signal is now being transmitted from the RF OUTPUT connector.
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Configuring the LF Output
Configuring the LF Output
The signal generator has a low frequency (LF) output (described on page 9). The LF output’s source can be
switched between Internal 1 Monitor, Internal 2 Monitor, Function Generator 1, or Function Generator 2.
Using Internal 1 Monitor or Internal 2 Monitor as the LF output source, the LF output provides a replica of the
signal from the internal source that is being used to modulate the RF output. The specific modulation
parameters for this signal are configured through the AM, FM, or FM menus.
Using Function Generator 1 or Function Generator 2 as the LF output source, the function generator section of
the internal modulation source drives the LF output directly. Frequency and waveform are configured from
the LF output menu, not through the AM, FM, or FM menus. You can select the waveform shape from the
following choices:
Sine
sine wave with adjustable amplitude and frequency
Dual-Sine
dual-sine waves with individually adjustable frequencies and a percent-ofpeak-amplitude setting for the second tone (available from function generator 1 only)
Swept-Sine
a swept-sine wave with adjustable start and stop frequencies, sweep rate, and sweep
trigger settings (available from function generator 1 only)
Triangle
triangle wave with adjustable amplitude and frequency
Ramp
ramp with adjustable amplitude and frequency
Square
square wave with adjustable amplitude and frequency
Noise
noise with adjustable amplitude generated as a peak-to-peak value (RMS value is
approximately 80% of the displayed value)
DC
direct current with adjustable amplitude
NOTE
The LF Out Off On softkey controls the operating state of the LF output. However when the
LF output source selection is Internal Monitor, you have three ways of controlling the output.
You can use the modulation source (AM, FM, or FM) on/off key, the LF output on/off key,
or the Mod On/Off softkey.
The RF On/Off hardkey does not apply to the LF OUTPUT connector.
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Analog Modulation
Configuring the LF Output
To Configure the LF Output with an Internal Modulation Source
In this example, the internal FM modulation is the LF output source.
NOTE
Internal modulation (Internal Monitor) is the default LF output source.
Configuring the Internal Modulation as the LF Output Source
1. Press Preset.
2. Press the FM/ΦM hardkey.
3. Press FM Dev > 75 > kHz.
4. Press FM Rate > 10 > kHz.
5. Press FM Off On.
You have set up the FM signal with a rate of 10 kHz and 75 kHz of deviation. The FM annunciator is
activated indicating that you have enabled frequency modulation.
Configuring the Low Frequency Output
1. Press the LF Out hardkey.
2. Press LF Out Amplitude > 3 > Vp.
3. Press LF Out Off On.
You have configured the LF output signal for a 3 volt sine wave (default wave form) output which is
frequency modulated using the Internal 1 Monitor source selection (default source).
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Configuring the LF Output
To Configure the LF Output with a Function Generator Source
In this example, the function generator is the LF output source.
Configuring the Function Generator as the LF Output Source
1. Press Preset.
2. Press the LF Out hardkey.
3. Press LF Out Source > Function Generator 1.
Configuring the Waveform
1. Press LF Out Waveform > Swept-Sine.
2. Press LF Out Start Freq > 100 > Hz.
3. Press LF Out Stop Freq > 1 > kHz.
4. Press Return > Return.
This returns you to the top LF Output menu.
Configuring the Low Frequency Output
1. Press LF Out Amplitude > 3 > Vp.
This sets the LF output amplitude to 3 Vp.
2. Press LF Out Off On.
The LF output is now transmitting a signal using Function Generator 1 that is providing a
3 Vp swept-sine waveform. The waveform is sweeping from 100 Hz to 1 kHz.
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5
Dual Arbitrary Waveform Generator
In the following sections, this chapter describes the Dual Arb mode, which is available only in E8267C PSG
vector signal generators with Option 002/602:
•
“Arbitrary (ARB) Waveform File Headers” on page 88
•
“Using the Dual ARB Waveform Player” on page 99
•
“Using Waveform Clipping” on page 112
•
“Waveform Clipping Concepts” on page 113
•
“Using Waveform Markers” on page 104
•
“Waveform Marker Concepts” on page 108
•
“Using Waveform Triggers” on page 111
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Arbitrary (ARB) Waveform File Headers
An ARB waveform file header enables you to save instrument setup information (key format settings) along
with a waveform. When you retrieve a stored waveform, the header information is applied so that when the
waveform starts playing, the dual ARB player is set up the same way each time.
Headers can also store a user-specified 32-character description of the waveform or sequence file.
A default header is automatically created whenever a waveform is generated, a waveform sequence is
created, or a waveform file is downloaded to the PSG (for details on downloading files, see the PSG
Programming Guide).
The following signal generator settings are saved in a file header:
•
ARB sample clock rate
•
Runtime scaling (only in the dual ARB player)
•
Marker polarity (markers 1 through 4)
•
Marker routing functions (markers 1 through 4)
— ALC hold
— Alternate amplitude
— RF blanking
•
High crest mode (only in the dual ARB player)
•
Modulator attenuation
•
Modulator filter
•
I/Q output filter (used when routing signals to the rear panel I/Q outputs)
•
Other instrument optimization settings (for files generated by the PSG) that cannot be set by the user.
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Creating a File Header for a Modulation Format Waveform
When you turn on a modulation format, the PSG generates a temporary waveform file
(AUTOGEN_WAVEFORM), with a default file header. The default header has no signal generator settings
saved to it.
This procedure, which is the same for all ARB formats, demonstrates how to create a file header for a
Custom digital modulation format.
1. Preset the signal generator.
2. Turn on the Custom modulation format:
Press Mode > Custom > ARB Waveform Generator > Digital Modulation Off On to On
A default file header is created, and the temporary waveform file (AUTOGEN_WAVEFORM) plays.
Figure 5-1 shows the PSG’s display.
Figure 5-1
Custom Digital Modulation First-Level Softkey Menu
First-Level Softkey Menu
(Some ARB formats
have a second page)
At this point, a default file header has been created, with default (unspecified) settings that do not reflect
the current signal generator settings for the active modulation. To save the settings for the active
modulation, you must modify the default settings before you save the header information with the
waveform file (see “Modifying Header Information in a Modulation Format” on page 90).
NOTE
Chapter 5
Each time an ARB modulation format is turned on, a new temporary waveform file
(AUTOGEN_WAVEFORM) and file header are generated, overwriting the previous
temporary file and file header. Because all ARB formats use the same file name, this happens
even if the previous AUTOGEN_WAVEFORM file was created by a different
ARB modulation format.
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Modifying Header Information in a Modulation Format
This procedure builds on the previous procedure, explaining the different areas of a file header, and showing
how to access, modify, and save changes to the information.
In a modulation format, you can access a file header only while the modulation format is active (on). In this
procedure, we work within the Custom digital modulation format. All ARB modulation formats and the dual
ARB player access the file header using the same key presses, except that for some modulation formats, you
may have to go to page two of the first-level softkey menu.
1. From the first-level softkey menu (shown in Figure 5-1 on page 89), open the Header Utilities menu:
Press ARB Setup > Header Utilities
The default header for the Custom digital modulation waveform is displayed (see Figure 5-2). In the
Saved Header Settings column, the signal generator settings for the active format are shown as
Unspecified, which means that no settings have been saved to the file header. If a setting is
unspecified in the file header, the current value for that setting does not change when the waveform is
selected for later use.
The Current Inst. Settings column shows the current signal generator settings for the active
modulation. These settings become the saved header settings when they are saved to the file header (as
demonstrated in step two).
Figure 5-2
Custom Digital Modulation Default Header Display
Lets you enter/edit the
Description field
Clears the Saved Header
Settings column to the
default settings
Saves the Current Inst.
Settings column to the
Saved Header Settings
column
Current signal generator
settings
Note:
Page 1
Parameters that are inactive (such as
Runtime Scaling) can be set only in
the dual ARB player.
Page 2
Default Header Settings
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2. Save the information in the Current Inst. Settings column to the file header:
Press Save Setup To Header.
The same settings are now displayed in both the Saved Header Settings column and the Current
Inst. Settings column. The settings in the Saved Header Settings column are the ones that
have been saved in the file header.
The following signal generator settings are saved to the file header:
32-Character Description:
A description entered for the header, such as a the waveform’s function (saved/edited
with the Edit Description key, see Figure 5-2 on page 90).
Sample Rate:
The ARB sample clock rate.
Runtime Scaling:
The Runtime scaling value. Runtime scaling is applied in real-time while the
waveform is playing. This setting can be changed only for files in the dual ARB player.
Marker 1...4 Polarity:
The marker polarity, positive or negative.
ALC Hold Routing:
Which marker, if any, implements the PSG’s ALC hold function.
The ALC hold function holds the ALC modulator at its current level when the marker
signal is low. When the marker signal goes high, the ALC hold function is
discontinued. If the RF Blank Routing function is selected, it automatically activates
the ALC hold for the same marker.
Alt Ampl. Routing:
Which marker, if any, triggers the PSG’s alternate amplitude feature when the marker
signal is low. When the marker signal goes high, the trigger is terminated disengaging
alternate amplitude. You must configure the alternate amplitude parameters, accessed
in the Amplitude hardkey menu.
RF Blank Routing:
Which marker, if any, implements the PSG’s RF blanking function when the marker
signal is low. Selecting RF blanking also implements ALC hold. When the marker
signal goes high, RF blanking is discontinued.
NOTE
All waveforms generated in the PSG have a marker on the first sample point. To see the desired
results from the three routing selections, you may need to select a range of sample (marker)
points. To set the marker points, use the Set Marker on Range of Points softkey in the Marker Utilities
menu. Refer to “To Place a Marker Across a Range of Points within a Waveform Segment” on
page 104 for more information.
I/Q Mod Filter:
The I/Q modulator filter setting. The modulator filter affects the I/Q signal modulated
onto the RF carrier.
I/Q Output Filter:
The I/Q output filter setting. The I/Q output filter is used for I/Q signals routed to the
rear panel I and Q outputs.
Mod Attenuation:
The I/Q modulator attenuation setting.
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3. Return to the ARB Setup menu: Press Return.
This menu lets you change the current instrument settings. Figure 5-3 shows the ARB Setup softkey
menu and the softkey paths used in steps four through nine.
4. Set the ARB sample clock to 5 MHz: Press ARB Sample Clock > 5 > MHz.
5. Set the modulator attenuation to 15 dB:
Press More (1 of 2) > Modulator Atten n.nn dB Manual Auto to Manual > 15 > dB.
6. Set the I/Q modulation filter to a through:
Press I/Q Mod Filter Manual Auto to Manual > Through.
7. Set marker one to blank the RF output at the set marker point(s):
Press More (2 of 2) > Marker Utilities > Marker Routing > Pulse/RF Blank > Marker 1.
For information on setting markers, see “Using Waveform Markers” on page 104.
8. Set the polarity of Marker 1 negative: Press Return > Marker Polarity > Marker 1 Polarity Neg Pos to Neg.
9. Return to the Header Utilities menu: Press Return > Return > Header Utilities.
Notice that the Current Inst. Settings column now reflects the changes made to the current
signal generator setup in steps 4 through 8, but that the saved header values have not changed (as shown
in Figure 5-4 on page 94).
10. Save the current settings to the file header: Press Save Setup To Header softkey.
The settings from the Current Inst. Settings column now appear in the Saved Header
Settings column. The file header has been modified and the current instrument settings saved. This is
shown in Figure 5-5 on page 94.
While a modulation format is active, the waveform file (AUTOGEN_WAVEFORM) is playing and you can
modify the header information within the active modulation format. Once you turn the modulation format
off, the header information is available only in the dual ARB player. If you turn the modulation format off
and then on, you overwrite the previous AUTOGEN_WAVEFORM file and its file header. To avoid this,
rename the file before you turn the modulation format back on (see page 103).
When you store the waveform file (see page 103), the header information is stored with the waveform.
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Figure 5-3
ARB Setup Softkey Menu and Marker Utilities
Dual ARB Player softkey
(it does not appear in the ARB formats)
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Figure 5-4
Differing Values between Header and Current Setting Columns
Values differ between
the two columns
Page 1
Values differ between
the two columns
Page 2
Figure 5-5
Saved File Header Changes
Page 1
Page 2
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Storing Header Information for a Dual ARB Player Waveform Sequence
When you create a waveform sequence (described on page 101), the PSG automatically creates a default file
header, which takes priority over the headers for the waveform segments that compose the waveform
sequence. During a waveform sequence playback, the waveform segment headers are ignored (except to
verify that all required options are installed). When you store the waveform sequence, its file header is
stored with it.
Modifying and Viewing Header Information in the Dual ARB Player
Once a modulation format is turned off, the waveform file is available only to the dual ARB player. This is
also true for downloaded waveform files. Because of this, future edits to a waveform’s header information
must be performed using the dual ARB player.
To modify header information in the dual ARB player, the waveform file must be playing in the dual ARB
player (although you can view the header information in the dual ARB player without playing the file)
You can reapply saved header settings by reselecting the waveform file for playback. When you do this, the
values from the Saved Header Settings column are applied to the PSG.
Modifying Header Information
All of the same header characteristics shown in “Modifying Header Information in a Modulation Format” on
page 90 are valid in the dual ARB player. This task guides you through selecting a waveform file and
accessing the header for the selected file, then refers you back to the aforementioned procedure to perform
the modifications.
1. Select a waveform:
a. Press Mode > Dual ARB > Select Waveform.
b. Using the arrow keys, highlight the desired waveform file.
c. Press the Select Waveform softkey.
2. Play the waveform: Press ARB Off On to On.
3. Access the header: Press ARB Setup > Header Utilities.
4. Refer to “Modifying Header Information in a Modulation Format” to edit the header information:
•
For a default header, read the information in step one on page 90, then perform the remaining steps in
the procedure.
•
To modify an existing file header, start with step three on page 92.
The rest of this section focuses on the additional file header operations found in the dual ARB player.
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Viewing Header Information with the Dual ARB Player Off
One of the differences between a modulation format and the dual ARB player is that even when the dual
ARB player is off, you can view a file header. You cannot, however, modify the displayed file header unless
the dual ARB player is on, and the displayed header is selected for playback. With the dual ARB player off,
perform the following steps.
1. Select a waveform:
a. Press Mode > Dual ARB > Select Waveform.
b. Highlight the desired waveform file.
c. Press the Select Waveform softkey.
2. Access the file header: Press ARB Setup > Header Utilities.
The header information is now visible in the PSG display. As shown in Figure 5-6, the header editing
softkeys are grayed-out, meaning they are inactive.
Figure 5-6
Viewing Header Information
Header editing softkeys
grayed-out
File header information and
current signal generator
settings
Note: When the dual ARB
player is off, the current
instrument settings column
does not update; the values
displayed may not be valid.
Page 1
Page 2
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Viewing Header Information for a Different Waveform File
While a waveform is playing in the dual ARB player, you can view the header information of a different
waveform file, but you can modify the header information only for the waveform that is currently playing.
When you select another waveform file, the header editing softkeys are grayed-out (see Figure 5-6). This
task guides you through the available viewing choices.
1. View the waveform file list: Press Mode > Dual ARB > ARB Setup > Header Utilities > View Different Header.
As shown in Figure 5-7, there is an alphabetical list of waveform files in the table.
Figure 5-7
Waveform File List for Viewing a Different Header
Current waveform file type
Waveform File Types
Table
2. View all waveform segments in non-volatile memory:
a. Press the Catalog Type softkey. As shown in Figure 5-7, you have a choice of three waveform file
types that can be displayed in the table accessed in step one.
NVWFM
displays all waveform segments stored in non-volatile memory
Seq
displays all waveform sequence files
WFM1
displays all waveform segments stored in volatile memory
b. Press the NVWFM softkey. The table displays the waveform files in non-volatile memory.
3. View a waveform file’s header information: Highlight a file and press the View Header softkey.
The header information for the selected waveform file appears in the PSG display. If there is a waveform
playing, its header information is replaced by this information, but the waveform settings used by the
signal generator do not change. To return to the header information for the playing waveform, either
press View Different Header, select the current playing waveform file, and press View Header, or
press Return > Header Utilities.
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Playing a Waveform File that Contains a Header
After a waveform file (AUTOGEN_WAVEFORM) is generated in a modulation format and the format is
turned off, the file becomes accessible to and can be played back in only the dual ARB player. This is also
true for downloaded waveform files (downloading files is described in the Programming Guide). When the
waveform is selected for playback, the saved header information is used by the signal generator. Some of
these settings appear as part of the labels of the softkeys used to set the parameters, and also appear on the
dual ARB summary display (see Figure 5-8).
NOTE
The signal generator used to play back a stored waveform file must have the same options
as are required to generate the file.
For details on applying file header settings and playing back a waveform, see “Playing a Waveform” on
page 102.
To properly set up the instrument:
1. Select the waveform.
2. Modify the signal generator settings as desired.
3. Turn on the dual ARB.
Figure 5-8
File Header Settings
Can change when a
waveform is selected
The waveform is not selected;
preset settings are applied.
Summary Display
Header setting same as
preset setting
Header setting applied
The waveform is selected;
saved header settings are
applied.
Summary Display
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Using the Dual ARB Waveform Player
Using the Dual ARB Waveform Player
The dual arbitrary (ARB) waveform player is used to edit and play waveform files. There are two types of
waveform files: segments (WFM1) and sequences (SEQ). A segments is an individual waveform that is
defined using an installed ARB format, such as Two Tone, and created using the internal arbitrary waveform
generator. A sequences is several individual segments strung together in one file. Waveform files can also be
created remotely and downloaded to the PSG for playback as a segment. For information on downloading
waveforms, refer to the Programming Guide.
A waveform is generated when an ARB modulation format is turned on, and is named
AUTOGEN_WAVEFORM. Because this default file name is shared among all ARB formats, if the file is
not renamed in the dual ARB player after turning the modulation format off, it is overwritten when the same
or another ARB format is turned on.
Waveform player features include waveform clipping, markers, and triggering. Clipping allows you to
reduce high power peaks, which can cause adjacent channel noise. Markers and triggering are useful for
synchronizing the output of the signal generator with other devices.
Before you can work with a waveform file, it must reside in volatile memory. A newly generated segment
file (AUTOGEN_WAVEFORM) initially resides in volatile memory until you store it to non-volatile
memory. Whenever you cycle the power on the PSG or download new firmware, you must reload your
waveform file from non-volatile memory.
Accessing the Dual ARB Player
Press Mode > Dual ARB.
You are now at the first-level softkey menu as shown in the following figure. Most procedures after the
procedure “Creating the First Waveform Segment” on page 100 start from this first-level softkey menu.
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Creating Waveform Segments
There are two ways to provide waveform segments for use by the waveform sequencer. You can either
download a waveform via remote interface or generate a waveform using one of the ARB modulation
formats. For information on downloading waveforms via remote interface, see the Programming Guide.
The following procedure describes how to create waveform segments using internally generated two tone
and multitone waveforms. In this example, you generate two waveform segments, then name and store them
in ARB memory. After the two waveform segments are named and stored in ARB memory, they are used to
build a waveform sequence in the procedure, “Building and Storing a Waveform Sequence” on page 101.
Generating the First Waveform
1. Press Preset.
2. Press Mode > Two Tone.
3. Press Alignment Left Cent Right to Right.
4. Press Two Tone Off On to On.
5. Press Two Tone Off On to Off.
This generates a two tone waveform with the tone on the right placed at the carrier frequency. During
waveform generation, the T-TONE and I/Q annunciators activate. The waveform is stored in volatile
memory with the default file name AUTOGEN_WAVEFORM, as you will see in the next section. The Two
Tone mode was turned off after generation because a waveform cannot be renamed as a segment while it
is in use.
NOTE
Because there can be only one AUTOGEN_WAVEFORM waveform in memory at any given
time, you must rename this file to clear the way for a second waveform.
Creating the First Waveform Segment
1. Press Mode > Dual ARB.
2. Press Waveform Segments.
3. Press Load Store to Store.
4. Highlight the default segment AUTOGEN_WAVEFORM.
5. Press More (1 of 2) > Rename Segment > Editing Keys > Clear Text.
6. Enter a file name (for example, TTONE) using the alpha keys and the numeric keypad, and press Enter.
The waveform segment is renamed and remains in volatile memory as a WFM1 file.
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Generating the Second Waveform
Use the following steps to generate a new multitone waveform with nine tones. During waveform
generation, the M-TONE and I/Q annunciators activate. The waveform is stored in volatile memory with the
default file name AUTOGEN_WAVEFORM.
1. Press Mode > Multitone > Initialize Table > Number Of Tones > 9 > Enter > Done.
2. Generate the waveform: press Multitone Off On to On.
3. Because a waveform cannot be renamed as a segment while it is in use, turn off Multitone mode now
that the waveform has been generated: press Multitone Off On to Off.
Creating the Second Waveform Segment
In the following steps, the second waveform segment is renamed and remains in volatile memory as a
WFM1 file.
1.
2.
3.
4.
5.
Press Mode > Dual ARB > Waveform Segments > Load Store to Store.
Highlight the default segment AUTOGEN_WAVEFORM.
Press More (1 of 2) > Rename Segment > Editing Keys > Clear Text.
Enter a file name (for example, MTONE) using the alpha keys and the numeric keypad.
Press Enter.
Building and Storing a Waveform Sequence
This example shows how to build and edit a waveform sequence using two waveform segments. If you have
not created the waveform segments, complete the steps in “Creating Waveform Segments” on page 100. If
you need to save or load waveform segments, see “Storing and Loading Waveform Segments” on page 103.
Selecting the Waveform Segments
Use the following steps to define a sequence as one repetition of the two-tone waveform segment followed
by one repetition of the nine-tone multitone waveform segment.
1.
2.
3.
4.
Press Mode > Dual ARB > Waveform Sequences > Build New Waveform Sequence > Insert Waveform.
Highlight the first waveform segment (for example, TTONE) and press Insert Selected Waveform.
Highlight the second waveform segment (for example, MTONE) and press Insert Selected Waveform.
Press Done Inserting.
Storing the Waveform Sequence
Store the sequence under a new name to the Catalog of Seq Files in the memory catalog.
1. Press Name and Store.
2. Enter a file name (for example, TTONE+MTONE) using the alpha keys and the numeric keypad.
3. Press Enter.
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Playing a Waveform
You can play a waveform sequence or a waveform segment using this procedure. Both waveform types
follow the same process.
This example plays a waveform sequence. If you have not created waveform segments and used them to
build and store a waveform sequence, complete the steps in the previous procedures, “Creating Waveform
Segments” on page 100, “Building and Storing a Waveform Sequence” on page 101.
Selecting a Waveform Sequence
1. Press Select Waveform.
2. Highlight a waveform (for example, TTONE+MTONE) from the Sequence column of the Select
Waveform catalog, and press Select Waveform.
The display shows the currently selected waveform (for example, Selected Waveform:
SEQ:TTONE+MTONE).
Generating the Waveform
Press ARB Off On until On is highlighted.
This plays the waveform sequence created in the previous sections. During the waveform sequence
generation, the ARB and I/Q annunciators activate.
Editing a Waveform Sequence
This procedure demonstrates how to edit waveform segments within a waveform sequence, and then save
the edited sequence under a new name. Within the editing display, you can change the number of times each
segment plays (the repetitions), delete segments, add segments, toggle markers on or off (for more on
markers, see “To Toggle Markers As You Create a Waveform Sequence” on page 107), and save changes.
NOTE
1.
2.
3.
4.
If you do not store changes to the waveform sequence prior to exiting the waveform
sequence editing display, the changes are removed.
Press Waveform Sequences > Edit Selected Waveform Sequence, and highlight the first entry.
Press Edit Repetitions > 100 > Enter. The second segment is automatically selected.
Press Edit Repetitions > 200 > Enter.
Save the edited file as a new waveform sequence:
a. Press Name And Store.
b. Press Editing Keys > Clear Text, then enter a new file name (for example, TTONE100+MTONE200).
c. Press Enter.
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You have now changed the number of repetitions for each waveform segment entry from 1 to 100 and 200,
respectively. The sequence has been stored under a new name to the Catalog of Seq Files in the
signal generator’s memory catalog.
To play the waveform sequence, refer to “Playing a Waveform” on page 102.
Storing and Loading Waveform Segments
Waveform segments can reside in volatile memory as WFM1 files, or they can be stored to non-volatile
memory as NVWFM files, or both. To play or edit a waveform file, it must reside in volatile memory.
Because files stored in volatile memory do not survive a power cycle, it is a good practice to store important
files to non-volatile memory and load them to volatile memory whenever you want to use them.
Storing Waveform Segments to Non-volatile Memory
1. Press Mode > Dual ARB > Waveform Segments.
2. If necessary, press Load Store to Store.
3. Press Store All To NVWFM Memory.
Copies of all WFM1 waveform segment files have been stored in non-volatile memory as NVWFM files.
You can also store files individually by highlighting the file and pressing
Store Segment To NVWFM Memory.
Loading Waveform Segments from Non-volatile Memory
1.
2.
3.
4.
Clear out the volatile memory and delete all WFM1 files: Power cycle the instrument.
Press Mode > Dual ARB > Waveform Segments.
If necessary, press Load Store to Load.
Press Load All From NVWFM Memory.
Copies of all NVWFM waveform segment files have been loaded into volatile memory as WFM1 files. You
can also load files individually by highlighting the file and pressing
Load Segment From NVWFM Memory.
Renaming a Waveform Segment
1. Press Mode > Dual ARB > Waveform Segments.
2. Highlight the desired file and press Rename Segment > Editing Keys > Clear Text.
3. Enter the desired file name, then press Enter.
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Using Waveform Markers
Using Waveform Markers
Waveform markers provide auxiliary output signals that are synchronized with a waveform segment. You
can place up to four markers on a waveform segment. However, only Marker 1 and Marker 2 can be placed
using the waveform player’s user interface (for more information, refer to “Waveform Marker Concepts” on
page 108).
Using markers, you can construct an output signal as a trigger to synchronize another instrument to a given
portion of a waveform. You can also place markers into a waveform sequence, either as the sequence is
being built or within an existing waveform sequence.
For instructions on verifying marker operation, see “To Verify Marker Operation” on page 107.
To Place a Marker at the First Point within a Waveform Segment
If you have not created a waveform segment, complete the steps in the previous sections, “Generating the
First Waveform” on page 100 and “Creating the First Waveform Segment” on page 100.
1.
2.
3.
4.
Press Mode > Dual ARB > Waveform Segments.
Press Load Store.
Highlight a waveform segment (for example, TTONE).
Press Waveform Utilities > Set Markers > Set Marker On First Point.
This sets Marker 1 (selected by default) on the first point in the selected waveform segment.
To Place a Marker Across a Range of Points within a Waveform Segment
If you have not created a waveform segment, complete the steps in the previous sections, “Generating the
First Waveform” on page 100 and “Creating the First Waveform Segment” on page 100.
1.
2.
3.
4.
5.
6.
7.
Press Mode > Dual ARB > Waveform Segments.
Press Load Store.
Highlight a waveform segment (for example, TTONE).
Press Waveform Utilities > Set Markers > Set Marker On Range Of Points.
Press First Mkr Point > 10 > Enter.
Press Last Mkr Point > 163830 > Enter.
Press Apply To Waveform.
NOTE
The last marker point must be greater than or equal to the first marker point.
This activates Marker 1 (selected by default) from point 10 to point 163830 in the selected waveform
segment.
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Using Waveform Markers
To Place Repetitively Spaced Markers within a Waveform Segment
If you have not created a waveform segment, complete the steps in the previous sections, “Generating the
First Waveform” on page 100 and “Creating the First Waveform Segment” on page 100.
1.
2.
3.
4.
5.
6.
7.
8.
Press Mode > Dual ARB > Waveform Segments.
Press Load Store.
Highlight a waveform segment (for example, TTONE).
Press Waveform Utilities > Set Markers > Set Marker On Range Of Points.
Press First Mkr Point > 10 > Enter.
Press Last Mkr Point > 163830 > Enter.
Press # Skipped Points > 2 > Enter.
Press Apply To Waveform.
NOTE
The last marker point must be greater than or equal to the first marker point.
This activates Marker 1 (selected by default) every three points from point 10 to point 163830 in the selected
waveform segment.
To Use Marker 2 to Blank the RF Output
If you have not created a waveform segment, complete the steps in the previous sections, “Generating the
First Waveform” on page 100 and “Creating the First Waveform Segment” on page 100.
NOTE
RF blanking applies to Marker 2 only. Marker 1 does not blank the RF output. For more
information, see “Waveform Marker Concepts” on page 108.
Press Preset.
Press Mode > Dual ARB > Select Waveform.
Highlight a waveform segment (for example, TTONE).
Press Select Waveform.
Press Mode > Dual ARB > ARB Setup > Mkr 2 To RF Blank Off On.
Press Return > Arb On Off to On.
Press Waveform Segments > Load Store > Waveform Utilities > Set Markers > Marker 1 2 >
Set Marker On Range of Points.
8. Press First Mkr Point > 10 > Enter.
9. Press Last Mkr Point > 163830 > Enter.
10. Press Apply To Waveform.
1.
2.
3.
4.
5.
6.
7.
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Using Waveform Markers
To Toggle Markers in an Existing Waveform Sequence
In a waveform sequence, you can independently toggle the operating state of the markers on each waveform
segment. When you build a waveform sequence, the markers on each segment are toggled to the last marker
operating state that was used.
In this example, you learn how to toggle markers within an existing waveform sequence. If you have not
created waveform segments, used them to build and store a waveform sequence, and configured markers for
the waveform sequence, complete the steps in the previous sections, “Creating Waveform Segments” on
page 100, “Building and Storing a Waveform Sequence” on page 101, and “To Place a Marker at the First
Point within a Waveform Segment” on page 104.
1. Press Mode > Dual ARB > Waveform Sequences.
2. Highlight the desired waveform sequence (for example, TTONE+MTONE).
3. Press Edit Selected Waveform Sequence.
4. Highlight the desired waveform segment (for example, WFM1:TTONE).
5. Press Toggle Markers > Toggle Marker 1 or Toggle Marker 2.
6. Highlight the next desired waveform segment.
7. Press Toggle Marker 1 or Toggle Marker 2.
8. Repeat steps 6 and 7 until you have finished modifying the desired waveform segments.
9. Press Return.
10. Press Name And Store.
11. Press Enter.
The markers are toggled per your selections, and the changes have been saved to the selected sequence file.
An entry (1,2, or 12) in the Mk column indicates that a marker is active. No entry in that column means
that both markers are off, as shown in Figure 5-9.
Figure 5-9
Marker
Column
This entry
shows both
markers on.
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Using Waveform Markers
To Toggle Markers As You Create a Waveform Sequence
You can combine waveform segments to create a waveform sequence while independently toggling the
markers of each waveform segment.
In this example, you learn how to toggle markers while building a waveform sequence. If you have not
created waveform segments, complete the steps in the previous section, “Creating Waveform Segments” on
page 100.
Press Mode > Dual ARB > Waveform Sequences > Build New Waveform Sequence.
Press Insert Waveform.
Highlight the desired waveform segment (for example, TTONE).
Press Insert Selected Waveform > Insert Selected Waveform > Done Inserting.
Highlight the first waveform segment.
An entry (1, 2 or 12) in the Mk column indicates that a marker is active. No entry in that column means
that both markers are off.
6. Press Toggle Markers.
7. Press Toggle Marker 1 and Toggle Marker 2 until only 2 is showing in the Mk column.
8. Highlight the next waveform segment.
9. Press Toggle Marker 1 and Toggle Marker 2 until both 1 and 2 are showing in the Mk column.
10. Press Return.
1.
2.
3.
4.
5.
You now have a waveform sequence that contains two TTONE waveform segments. Marker 2 is on for the
first waveform segment and markers 1 and 2 are on for the second waveform segment.
To Verify Marker Operation
In this example, you learn how to verify marker operation. If you have not created waveform segments and
applied makers, complete the steps in the previous sections, “Creating Waveform Segments” on page 100
and “To Place a Marker at the First Point within a Waveform Segment” on page 104.
Once you set a marker on a waveform segment, you can detect the marker pulse at the EVENT 1 or EVENT
2 connectors (EVENT 1 for this example). For more information, see “Waveform Marker Concepts” on
page 108
1.
2.
3.
4.
Press Mode > Dual ARB > Select Waveform.
Highlight the desired waveform segment or sequence.
Press ARB Off On to On.
Connect an oscilloscope input to the EVENT 1 connector, and trigger on the Event 1 signal.
When a marker is present, a marker pulse is displayed on the oscilloscope.
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Using Waveform Markers
Waveform Marker Concepts
The Dual Arb mode of the signal generator has four markers that you can place on a waveform segment.
Marker 1 and Marker 2 provide auxiliary output signals to the rear-panel EVENT 1 and EVENT 2
connectors, respectively. Markers 3 and 4 are available only for custom-programmed waveforms, and they
provide auxiliary output signals to pins 19 and 18 of the rear-panel AUXILIARY I/O connector,
respectively. You can construct these output signals as a trigger signal to synchronize another instrument to a
given portion of a waveform. The following timing diagrams describe the effects of Markers 1 and 2 on the
state of the signal at the EVENT 1 and EVENT 2 rear panel connectors.
NOTE
If marker polarity selection is not be available in your version of the firmware, marker
polarity is always positive.
Table 5-1
Marker File
Bit 1
Signal At EVENT
1 Connector
Marker 1 and EVENT 1
Waveform
point n
point n+1
point n+2
point n+3
...
For Marker Polarity = Positive
For Marker Polarity = Negative
Figure 5-10
Positive
Marker File
Bit 1
±
Marker
Polarity
108
EVENT 1
Negative
Chapter 5
Dual Arbitrary Waveform Generator
Using Waveform Markers
Table 5-2
Marker 2 and EVENT 2
Marker File
Bit 2
Signal At
EVENT 2 Connector
Waveform point
n
point n+1
point n+2
point n+3
...
For Marker Polarity = Positive
For Marker Polarity = Negative
RF Output
RF Unblanked (low)
Mkr 2 to RF Blank = Off
RF Unblanked
RF Output
RF Blanked
RF Blanked
Mkr 2 to RF Blank = On
Marker Polarity = Positive
RF Output
RF Unblanked
Mkr 2 to RF blank = On
Marker Polarity = Negative
Chapter 5
RF Unblanked
RF Blanked
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Using Waveform Markers
Positive
EVENT 2
±
Marker File
Bit 2
Marker
Polarity
Marker 2
Blanks RF
when Marker
is Low
Negative
Marker 2 to
RF Blank
Off On
A waveform sequence comprises waveform segments. When you combine segments to form a
sequence, you can enable or disable Marker 1 and/or Marker 2 on a segment-by-segment basis.
When you select a sequence to output, the markers embedded in any one segment of that sequence are
output only if the sequence marker for that segment is enabled (toggled on). This makes it possible to output
markers for some segments in a sequence, but not for others.
±
Marker File
Bit 1
Sequence
Marker 1
EVENT 1
Marker
Polarity
EVENT 2
±
Marker File
Bit 2
Sequence
Marker 2
RF Blanking
Marker 2
to RF
Blank
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Using Waveform Triggers
Using Waveform Triggers
The dual arbitrary waveform generator includes several different triggering options: single, gated, segment
advance, and continuous. The trigger source can be the Trigger hardkey, a command sent through the remote
interface, or an external signal applied to the TRIGGER IN rear panel connector.
To Use Segment Advance Triggering
Using this procedure, you learn how to control sequence playback of two waveform segments using segment
advance triggering.
If you have not created and stored a waveform sequence, complete the steps in the previous sections,
“Creating Waveform Segments” on page 100, and “Building and Storing a Waveform Sequence” on
page 101.
Configuring the Waveform Sequence Trigger
1.
2.
3.
4.
5.
6.
7.
Press Preset.
Press Mode > Dual ARB > Select Waveform.
Highlight a waveform sequence file (for example, TTONE100+MTONE200).
Press Select Waveform.
Press Trigger > Segment Advance.
Press Trigger > Trigger Setup > Trigger Source > Trigger Key.
Press Return > Return > ARB Off On to On.
The first waveform segment in the sequence (TTONE) plays and modulates the RF carrier. The waveform
player has been programmed to stop the playback of the current waveform segment and start the playback of
the next waveform segment in the sequence when a trigger is received from the front panel Trigger hardkey.
You can now enable the RF output and use the signal.
Triggering the Second Waveform
1. Press the Trigger hardkey.
2. Observe the second waveform segment in the sequence (MTONE) is now playing.
Pressing the Trigger hardkey stops the playback of the first waveform segment and starts the playback of the
second waveform segment. Pressing the Trigger hardkey again will return the waveform player to the first
waveform segment.
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Using Waveform Clipping
Using Waveform Clipping
Clipping limits power peaks in waveform segments by clipping the I and Q data to a selected percentage of
its highest peak. Circular clipping is defined as clipping the composite I/Q data (I and Q data are equally
clipped). Rectangular clipping is defined as independently clipping the I and Q data. For more information,
see “Waveform Clipping Concepts” on page 113.
In this section, you learn how to clip waveform segments. If you have not created waveform
segments, complete the steps in the previous section, “Creating Waveform Segments” on page 100.
To Configure Circular Clipping
1. Press Mode > Dual ARB > Waveform Segments.
2. Press Load Store to Store.
3. Highlight the first waveform segment (for example, TTONE).
4. Press Waveform Utilities > Clipping.
5. Press Clip |I+jQ| To > 80 > % > Apply to Waveform.
The I and Q data are both clipped by 80%. You will see 80.0% displayed below the Clip |I+jQ| To softkey.
To Configure Rectangular Clipping
1. Press Mode > Dual ARB > Waveform Segments.
2. Press Load Store to Store.
3. Highlight the second waveform segment (for example, MTONE).
4. Press Waveform Utilities > Clipping.
5. Press Clipping Type |I+jQ| |I|,|Q|.
This activates the Clip |I| To and Clip |Q| To softkeys that allow you to configure rectangular
(independent) I and Q data clipping.
6. Press Clip |I| To > 80 > %.
7. Press Clip |Q| To > 40 > % > Apply to Waveform.
The I and Q data are individually clipped by 80% and 40%, respectively. You will see 80.0% displayed
below the Clip |I| To softkey and 40.0% below the Clip |Q| To softkey.
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Using Waveform Clipping
Waveform Clipping Concepts
Waveforms with high power peaks can cause intermodulation distortion, which generates spectral regrowth
(a condition that interferes with signals in adjacent frequency bands). The clipping function allows you to
reduce high power peaks.
The clipping feature is available only with the Dual Arb mode.
How Power Peaks Develop
To understand how clipping reduces high power peaks, it is important to know how the peaks develop as the
signal is constructed. I/Q waveforms can be the summation of multiple channels (see Figure 5-11).
Whenever most or all of the individual channel waveforms simultaneously contain a bit in the same state
(high or low), an unusually high power peak (negative or positive) occurs in the summed waveform. This
does not happen frequently because the high and low states of the bits on these channel waveforms are
random, which causes a cancelling effect.
Figure 5-11
Multiple Channel Summing
The I and Q waveforms combine in the I/Q modulator to create an RF waveform. The magnitude of the RF
envelope is determined by the equation
, where the squaring of I and Q always results in a positive
value.
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Using Waveform Clipping
As shown in Figure 5-12., simultaneous positive and negative peaks in the I and Q waveforms do not cancel
each other, but combine to create an even greater peak.
Figure 5-12
114
Combining the I and Q Waveforms
Chapter 5
Dual Arbitrary Waveform Generator
Using Waveform Clipping
How Peaks Cause Spectral Regrowth
Because of the relative infrequency of high power peaks, a waveform will have a high peak-to-average
power ratio (see Figure 5-13). Because a transmitter’s power amplifier gain is set to provide a specific
average power, high peaks can cause the power amplifier to move toward saturation. This causes
intermodulation distortion, which generates spectral regrowth.
Figure 5-13
Peak-to-Average Power
Spectral regrowth is a range of frequencies that develops on each side of the carrier (similar to sidebands)
and extends into the adjacent frequency bands (see Figure 5-14). Consequently, spectral regrowth interferes
with communication in the adjacent bands. Clipping can provide a solution to this problem.
Figure 5-14
Chapter 5
Spectral Regrowth Interfering with Adjacent Band
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Dual Arbitrary Waveform Generator
Using Waveform Clipping
How Clipping Reduces Peak-to-Average Power
You can reduce peak-to-average power, and consequently spectral regrowth, by clipping the waveform to a
selected percentage of its peak power. The PSG vector signal generator provides two different methods of
clipping: circular and rectangular.
During circular clipping, clipping is applied to the combined I and Q waveform (|I + jQ|). Notice in Figure
5-15 that the clipping level is constant for all phases of the vector representation and appears as a circle.
During rectangular clipping, clipping is applied to the I and Q waveforms separately (|I|, |Q|). Notice in
Figure 5-16 on page 117 that the clipping level is different for I and Q; therefore, it appears as a rectangle in
the vector representation. With either method, the objective is to clip the waveform to a level that effectively
reduces spectral regrowth, but does not compromise the integrity of the signal. Figure 5-17 on page 118 uses
two complementary cumulative distribution plots to show the reduction in peak-to-average power that
occurs after applying circular clipping to a waveform.
The lower you set the clipping value, the lower the peak power that is passed (or the more the signal is
clipped). Often, the peaks can be clipped successfully without substantially interfering with the rest of the
waveform. Data that might be lost in the clipping process is salvaged because of the error correction inherent
in the coded systems. If you clip too much of the waveform, however, lost data is irrecoverable. You may
have to try several clipping settings to find a percentage that works well.
Figure 5-15
116
Circular Clipping
Chapter 5
Dual Arbitrary Waveform Generator
Using Waveform Clipping
Figure 5-16
Chapter 5
Rectangular Clipping
117
Dual Arbitrary Waveform Generator
Using Waveform Clipping
Figure 5-17
118
Reduction of Peak-to-Average Power
Chapter 5
6
Custom Arb Waveform Generator
This chapter describes the Custom Arb Waveform Generator mode which is available only in E8267C PSG
vector signal generators.
This chapter includes the following major sections:
•
“Overview” on page 120
•
“Working with Predefined Setups (Modes)” on page 121
•
“Working with Filters” on page 125
•
“Working with Symbol Rates” on page 133
•
“Working with Modulation Types” on page 136
•
“Configuring Hardware” on page 143
See also:
•
“Using Waveform Markers” on page 104
•
“Arbitrary (ARB) Waveform File Headers” on page 88
119
Custom Arb Waveform Generator
Overview
Overview
Custom Arb Waveform Generator mode can produce a single modulated carrier or multiple modulated
carriers. Each modulated carrier waveform must be calculated and generated before it can be output; this
signal generation occurs on the internal baseband generator (Option 002/602). Once a waveform has been
created, it can be stored and recalled which enables repeatable playback of test signals.
To begin using the Custom Arb Waveform Generator mode, select whether to create a single modulated
carrier or a multiple modulated carrier waveform:
•
If you want to create a single modulated carrier waveform, start by selecting a Digital Modulation Setup
from a set of predefined modes (setups). Once a predefined mode is selected, you can modify the
Modulation Type, the Filter being used, the Symbol Rate, and the type of Triggering; the Data Pattern is
random by default. This modified setup can then be stored and reused.
•
If you want to create a multiple modulated carrier waveform, start by selecting a Multicarrier Setup from
a set of predefined modes (setups). Once a predefined mode is selected, you can modify the number of
carriers to be created, the frequency spacing between each carrier, whether the phase offset between each
carrier is to be fixed or random, and the type of Triggering; the Data Pattern is random by default, the
Filter is set to 40 MHz by default, and the Symbol Rate is automatically specified by the selected
Modulation Type being used.
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Working with Predefined Setups (Modes)
Working with Predefined Setups (Modes)
When you select a predefined mode, default values for components of the setup (including the filter, symbol
rate, and modulation type) are automatically specified.
Selecting a Custom ARB Setup or a Custom Digital Modulation State
1. Preset the signal generator: press Preset.
2. Press Mode > Custom > Arb Waveform Generator > Setup Select.
3. Select either:
•
one of the predefined modulation setups: NADC, PDC, PHS, GSM, DECT, EDGE, APCO 25 w/C4FM, APCO
25 w/CQPSK, CDPD, PWT, or TETRA
This selects a predefined setup where filtering, symbol rate, and modulation type are defined by the
predefined modulation setup (mode) that you selected and returns you to the top-level custom
modulation menu; it does not include bursting or channel coding.
or
•
Custom Digital Mod State
This selects a custom setup stored in the Catalog of DMOD Files (see page 122 for information
on creating a custom digital modulation setup).
Chapter 6
121
Custom Arb Waveform Generator
Working with User-Defined Setups (Modes)-Custom Arb Only
Working with User-Defined Setups (Modes)−Custom Arb Only
Modifying a Single-Carrier NADC Setup
In this procedure, you learn how to start with a single-carrier NADC digital modulation and modify it to a
custom waveform with customized modulation type, symbol rate, and filtering.
1. Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Setup Select > NADC.
3. Press Digital Mod Define > Modulation Type > PSK > QPSK and OQPSK > QPSK.
4. Press Symbol Rate > 56 > ksps.
5. Press Filter > Select > Nyquist.
6. Press Return > Return > Digital Modulation Off On.
This generates a waveform with the custom single-carrier NADC digital modulation state. The display
changes to Dig Mod Setup: NADC (Modified). During waveform generation, the DIGMOD and
I/Q annunciators appear and the custom single-carrier digital modulation state is stored in volatile
memory.
7. Set the RF output frequency to 835 MHz.
8. Set the output amplitude to 0 dBm.
9. Press RF On/Off.
The user-defined NADC signal is now available at the RF OUTPUT connector.
10. Press Return > Return.
This returns to the top-level Digital Modulation menu, where Digital Modulation Off On is the first softkey.
11. Press Digital Mod Define > Store Custom Dig Mod State > Store To File.
If there is already a file name from the Catalog of DMOD Files occupying the active entry
area, press: Edit Keys > Clear Text
12. Enter a file name (for example, NADCQPSK) using the alpha keys and the numeric keypad.
13. Press Enter.
The user-defined single-carrier digital modulation state should now be stored in non-volatile memory.
The RF output amplitude, frequency, and operating state settings are not stored as part of a user-defined
digital modulation state file.
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Working with User-Defined Setups (Modes)-Custom Arb Only
Customizing a Multicarrier Setup
In this procedure, you learn how to customize a predefined multicarrier digital modulation setup by creating
a custom 3-carrier EDGE digital modulation state.
1. Press Preset.
2. Press Mode > Custom > Arb Waveform Generator > Multicarrier Off On.
3. Press Multicarrier Define > Initialize Table > Carrier Setup > EDGE > Done.
4. Highlight the Freq Offset value (500.000 kHz) for the carrier in row 2, and
press Edit Item > −625 > kHz.
5. Highlight the Power value (0.00 dB) for the carrier in row 2, and press Edit Item > −10 > dB.
You have a custom 2-carrier EDGE waveform with a carrier at a frequency offset of −625 kHz and a
power level of −10.00 dBm.
6. Press Return > Digital Modulation Off On.
This generates a waveform with the custom multicarrier EDGE state. The display changes to Dig Mod
Setup: Multicarrier (Modified). During waveform generation, the DIGMOD and I/Q
annunciators appear and the new custom multicarrier EDGE state is stored in volatile memory.
7.
Set the RF output frequency to 890.01 MHz.
8. Set the output amplitude to −10 dBm.
9. Press RF On/Off.
The custom multicarrier EDGE waveform is available at the RF OUTPUT connector; it does not include
bursting or channel coding.
10. Press Mode > Custom > Arb Waveform Generator, where Digital Modulation Off On is the first softkey.
11. Press Multicarrier Off On > Multicarrier Define > More (1 of 2) > Load/ Store > Store To File.
If there is already a file name from the Catalog of MDMOD Files occupying the active entry area,
press Edit Keys > Clear Text.
12. Enter a file name (for example, EDGEM1) using the alpha keys and the numeric keypad, and press Enter.
The user-defined multicarrier digital modulation state is now stored in non-volatile memory.
NOTE
Chapter 6
The RF output amplitude, frequency, and operating state settings (such as RF On/Off) are
not stored as part of a user-defined digital modulation state file. For more information,
refer to “Using Data Storage Functions” on page 52.
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Working with User-Defined Setups (Modes)-Custom Arb Only
Recalling a User-Defined Custom Digital Modulation State
In this procedure, you learn how to select (recall) a previously stored custom digital modulation state from
the Memory Catalog (the Catalog of DMOD Files).
1. Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Setup Select.
3. Press More (1 of 2) > Custom Digital Mod State.
4. Press Select File to select a custom modulation state from the Catalog of DMOD Files.
The user-defined custom digital modulation state should now be recalled from non-volatile memory.
Because the RF output amplitude, frequency, and operating state settings are not stored as part of a
user-defined digital modulation state file, they must still be set or recalled separately. For more
information, refer to “Using Data Storage Functions” on page 52.
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Working with Filters
Working with Filters
This section provides information on using predefined (page 126) and user-defined (page 127) FIR filters.
NOTE
The procedures in this section apply only to filters created in either the Custom Arb
Waveform Generator or Custom Real Time I/Q Baseband mode; they do not work with
downloaded files, such as those created in Matlab.
The Filter menu selections enable you to apply a filter to the generated signal, define a finite impulse
response (FIR) filter, change a Root Nyquist or Nyquist filter alpha, change a Gaussian filter BbT, or restore
all filter parameters to their default state. In Custom Real Time I/Q mode, you can also optimize a FIR filter
for Error Vector Magnitude (EVM) or Adjacent Channel Power (ACP)
Predefined Filters (Filter > Select)
•
Root Nyquist is a root-raised cosine pre-modulation FIR filter. Use a Root Nyquist filter when you want to
place half of the filtering in the transmitter and the other half in the receiver. The ideal root-raised cosine
filter frequency response has unity gain at low frequencies, the square root of raised cosine function in
the middle, and total attenuation at high frequencies. The width of the middle frequencies is defined by
the roll off factor or Filter Alpha (0 < Filter Alpha < 1).
•
Nyquist is a raised cosine pre-modulation FIR filter. You can use a Nyquist filter to reduce the bandwidth
required by a signal without losing information. The ideal raised cosine filter frequency response
comprises unity gain at low frequencies, a raised cosine function in the middle, and total attenuation at
high frequencies. The width of the middle frequencies is defined by the roll off factor or Filter Alpha (0
< Filter Alpha < 1).
•
Gaussian is a Gaussian pre-modulation FIR filter.
•
User FIR enables you to select from a Catalog of FIR filters; use this selection if the other predefined FIR
filters do not meet your needs. For more information, see Define User FIR, below.
•
Rectangle is a rectangular pre-modulation FIR filter.
•
APCO 25 C4FM is an APCO 25-specified C4FM filter; this is a Nyquist filter with an alpha of 0.200 that is
combined with a shaping filter.
Filter Parameters
•
Define User FIR is available for when the predefined FIR filters do not meet your needs. You can define
FIR coefficients and set the oversample ratio (number of filter coefficients per symbol) to be applied to a
custom FIR filter.
Chapter 6
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Custom Arb Waveform Generator
Working with Filters
•
Filter Alpha enables you to adjust the filter alpha for a Nyquist or root Nyquist filter. If a Gaussian filter is
used, you will see Filter BbT; this softkey is grayed out when any other filter is selected.
•
(Custom Realtime I/Q Baseband Only) Optimize FIR for EVM ACP enables you to optimize a Nyquist
or root Nyquist filter for minimized error vector magnitude (EVM) or for minimized adjacent channel
power (ACP); the softkey is grayed out when any other filter is selected.
•
Restore Default Filters replaces the current FIR filter with the default FIR filter for the selected format.
Using a Predefined FIR Filter
Selecting a Predefined FIR Filter
1. Preset the instrument: Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Select
or
Mode > Custom > Real Time I/Q Baseband > Filter > Select >
3. Select the desired filter. If the filter you want is not in the first list, press More (1 of 2).
Adjusting the Filter Alpha of a Predefined Root Nyquist or Nyquist Filter
1. Preset the instrument: Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Filter Alpha
or
Mode > Custom > Real Time I/Q Baseband > Filter > Filter Alpha
3. Enter a new Filter Alpha value and press Enter.
Adjusting the Bandwidth-Bit-Time (BbT) Product of a Predefined Gaussian Filter
1. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Select > Gaussian
or
Mode > Custom > Real Time I/Q Baseband > Filter > Select > Gaussian
2. Press Filter BbT.
3. Enter a new Bandwidth-Bit-Time (BbT) product filter parameter and press Enter.
Optimizing a Nyquist or Root Nyquist FIR Filter for EVM or ACP (Custom Realtime I/Q Baseband only)
1. Preset the instrument: Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Filter > Optimize FIR For EVM or ACP.
The FIR filter is now optimized for minimum error vector magnitude (EVM) or for minimum adjacent
channel power (ACP). This feature applies only to Nyquist and root Nyquist filters; the softkey is grayed
out when any other filter is selected.
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Working with Filters
Restoring Default FIR Filter Parameters
1. Preset the instrument: Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Filter > Restore Default Filter.
This replaces the current FIR filter with the default filter for the selected modulation format.
Using a User-Defined FIR Filter
FIR filters can be created and modified by defining the FIR coefficients or by defining the oversample ratio
(number of filter coefficients per symbol) to be applied to your own custom FIR filter.
To Modify Predefined FIR Coefficients for a Gaussian Filter Using the FIR Values Editor
You can define from 1 to 32 FIR coefficients, where the maximum combination of symbols and oversample
ratio is 1024 coefficients. While the FIR Values editor allows a maximum filter length of 1024 coefficients,
the PSG hardware is limited to 64 symbols for real-time and 512 symbols for arbitrary waveform generation
(the number of symbols equals the number of coefficients divided by the oversample ratio).
If you enter more than 64 symbols for real-time or 512 symbols for arbitrary waveform generation, the PSG
cannot use the filter; it will decimate the filter (throw away coefficients) until the required condition is met
and then use the filter, but fine resolution may be lost from the impulse response.
FIR filters stored in signal generator memory can easily be modified using the FIR Values editor. In this
example, you will load the FIR Values editor with coefficient values from a default FIR filter (or, if one has
been defined, a user-defined FIR file that has been stored in the Memory Catalog), modify the coefficient
values, and store the new file to the Memory Catalog.
1. Press Preset.
2. Press Mode > Custom > Arb Waveform Generator > Digital Mod Define > Filter
or
Mode > Custom > Real Time I/Q Baseband > Filter
3. Press Define User FIR > More (1 of 2) > Load Default FIR > Gaussian.
4. Press Filter BbT > 0.300 > Enter.
5. Press Filter Symbols > 8 > Enter.
6. Press Generate.
NOTE
Chapter 6
The actual oversample ratio during modulation is automatically selected by the instrument.
A value between 4 and 16 is chosen dependent on the symbol rate, the number of bits
per symbol of the modulation type, and the number of symbols.
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Custom Arb Waveform Generator
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7. Press Display Impulse Response. A graph displays the impulse response of the current FIR coefficients.
8. Press Return.
9. Highlight coefficient 15.
10. Press 0 > Enter.
11. Press Display Impulse Response.
The graphic display can provide a useful troubleshooting tool (in this case, it indicates that a coefficient
value is set incorrectly, resulting in an improper Gaussian response).
12. Press Return.
13. Highlight coefficient 15.
14. Press 1 > Enter.
15. Press Load/Store > Store To File.
16. Name the file NEWFIR2, and press Enter.
The contents of the current FIR Values editor are stored to a file in the Memory Catalog and the Catalog
of FIR Files is updated to show the new file.
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Working with Filters
To Create a User-Defined FIR Filter with the FIR Values Editor
In this procedure, you use the FIR Values editor to create and store an 8-symbol, windowed, sinc function
filter with an oversample ratio of 4. The Oversample Ratio (OSR) is the number of filter coefficients per
symbol.
You can define from 1 to 32 FIR coefficients, where the maximum combination of symbols and oversample
ratio is 1024 coefficients.
The FIR Values editor allows a maximum filter length of 1024 coefficients, but the PSG hardware is limited
to 512 symbols for arbitrary waveform generation, and 64 symbols for real-time waveform generation. The
number of symbols equals the number of coefficients divided by the oversample ratio. If you enter more than
the maximum number of symbols, the PSG cannot use the filter; it decimates the filter (throws away
coefficients) until the required condition is met and then uses the filter, but fine resolution may be lost from
the impulse response.
1. Press Preset.
2. Press Mode > Custom > Arb Waveform Generator > Digital Mod Define > Filter
or
Mode > Custom > Real Time I/Q Baseband > Filter
3. Press Define User FIR > More (1 of 2).
4. Press Delete All Rows > Confirm Delete Of All Rows > More (2 of 2).
This brings up the FIR Values editor and clears the table of existing values.
5. Press Edit Item.The Value field for coefficient 0 should be highlighted.
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6. Use the numeric keypad to type the first value (−0.000076) from the following table and press Enter. As
you press the numeric keys, the numbers are displayed in the active entry area. (If you make a mistake,
you can correct it using the backspace key.) Continue entering the coefficient values from the table until
all 16 values have been entered.
Coefficient
Value
Coefficient
Value
Coefficient
Value
0
−0.000076
6
0.043940
12
0.123414
1
−0.001747
7
0.025852
13
0.442748
2
−0.005144
8
−0.035667
14
0.767329
3
−0.004424
9
−0.116753
15
0.972149
4
0.007745
10
−0.157348
5
0.029610
11
−0.088484
7. Press Mirror Table.
In a windowed sinc function filter, the second half of the coefficients are identical to the first half, but in
reverse order. The signal generator provides a mirror table function that automatically duplicates the
existing coefficient values in the reverse order; coefficients 16 through 31 are automatically generated
and the first of these coefficients (number 16) highlights, as shown in the following figure.
8. For this example, the desired OSR is 4, which is the default, so no action is necessary.
The Oversample Ratio (OSR) is the number of filter coefficients per symbol. Acceptable values range
from 1 through 32; the maximum combination of symbols and oversampling ratio allowed by the FIR
Values editor is 1024. Remember, however, that the instrument hardware is limited to 64 symbols for
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Working with Filters
real-time waveform generation, and 512 symbols for arbitrary waveform generation. The number of
symbols equals the number of coefficients divided by the oversample ratio.
9. Press More (1 of 2) > Display FFT (fast Fourier transform).
A graph displays the fast Fourier transform of the current set of FIR coefficients. The signal generator
has the capability of graphically displaying the filter in both time and frequency dimensions.
10. Press Return > Display Impulse Response.
A graph shows the impulse response of the current set of FIR coefficients.
11. Press Return > Load/Store > Store To File.
The Catalog of FIR Files appears along with the amount of memory available.
12. If there is already a file name occupying the active entry area, press: Edit Keys > Clear Text
13. Using the alphabetic menu and the numeric keypad, enter NEWFIR1 as the file name.
14. Press Enter.
The NEWFIR1 file is the first file name listed. (If you have previously stored other FIR files, additional
file names are listed below NEWFIR1.) The file type is FIR and the size of the file is 260 bytes. The
amount of memory used is also displayed. The number of files that can be saved depends on the size of
the files and the amount of memory used.
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132
Chapter 6
Custom Arb Waveform Generator
Working with Symbol Rates
Working with Symbol Rates
The Symbol Rate menu enables you to set the rate at which I/Q symbols are fed to the I/Q modulator. The
default transmission symbol rate can also be restored in this menu.
•
Symbol Rate (displayed as Sym Rate) is the number of symbols per second that are transmitted using
the modulation (displayed as Mod Type) along with the filter and filter alpha (displayed as Filter).
Symbol rate directly influences the occupied signal bandwidth.
Symbol Rate is the Bit Rate divided by the number of bits that can be transmitted with each symbol; this
is also known as the Baud Rate.
•
Bit Rate is the frequency of the system bit stream. The internal baseband generator (Option 002/602)
automatically streams the selected Data Pattern at the appropriate rate to accommodate the symbol rate
setting (Bit Rate = Symbols/s x Number of Bits/Symbol).
•
Occupied Signal Bandwidth = Symbol Rate x (1 + Filter Alpha); therefore, the occupied signal
bandwidth is dependent on the filter alpha of the Nyquist or Root Nyquist filter being used. (To change
the filter alpha, refer to the procedure, “Adjusting the Filter Alpha of a Predefined Root Nyquist or
Nyquist Filter” on page 126.)
To Set a Symbol Rate
1. Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Symbol Rate
or
Mode > Custom > Real Time I/Q Baseband > Symbol Rate
3. Enter a new symbol rate and press Msps, ksps, or sps.
To Restore the Default Symbol Rate (Custom Real Time I/Q Only)
•
Press Mode > Custom > Real Time I/Q Baseband > Symbol Rate > Restore Default Symbol Rate.
This replaces the current symbol rate with the default symbol rate for the selected modulation format.
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133
Bits
Per
Symbol
Bit Rate =
Symbols/s x Number of Bits/Symbol
Internal Symbol Rate
(Minimum Maximum)
Custom Real Time Only
External Symbol Rate
(Minimum Maximum)
QPSK and OQPSK
(quadrature phase shift keying and
offset quadrature phase shift keying)
Includes: QPSK, IS95 QPSK,
Gray Coded QPSK, OQPSK,
IS95 OQPSK
2
90 bps − 100 Mbps
45 sps − 50 Msps
45 sps − 25 Msps
BPSK
(binary phase shift keying)
1
45 bps − 50 Mbps
45 sps − 50 Msps
45 sps − 50 Msps
π/4 DQPSK
2
90 bps − 100 Mbps
45 sps − 50 Msps
45 sps − 25 Msps
8PSK
(eight phase state shift keying)
3
135 bps − 150 Mbps
45 sps − 50 Msps
45 sps − 16.67 Msps
16PSK
(sixteen phase state shift keying)
4
180 sps − 200 Mbps
45 sps − 50 Msps
45 sps − 12.5 Msps
D8PSK
(eight phase state shift keying)
3
135 bps − 150 Mbps
45 sps − 50 Msps
45 sps − 16.67 Msps
MSK
MSK
1
45 bps − 50 Mbps
45 sps − 50 Msps
45 sps − 50 Msps
Minimum
Shift
Keying
(GSM - Global System for
Mobile Communications)
FSK
2-Lvl FSK
1
45 bps − 50 Mbps
45 sps − 50 Msps
45 sps − 50 Msps
Frequency
Shift
Keying
4-Lvl FSK
2
90 bps − 100 Mbps
45 sps − 50 Msps
45 sps − 25 Msps
8-Lvl FSK
3
135 bps − 150 Mbps
45 sps − 50 Msps
45 sps − 16.67 Msps
16-Lvl FSK
4
180 bps − 200 Mbps
45 sps − 50 Msps
45 sps − 12.5 Msps
C4FM
2
90 bps − 100 Mbps
45 sps − 50 Msps
45 sps − 25 Msps
PSK
Phase
Shift
Keying
Custom Arb Waveform Generator
Working with Symbol Rates
134
Modulation Type
Chapter 6
Chapter 6
Modulation Type
Bits
Per
Symbol
Bit Rate =
Symbols/s x Number of Bits/Symbol
Internal Symbol Rate
(Minimum Maximum)
Custom Real Time Only
External Symbol Rate
(Minimum Maximum)
QAM
4QAM
2
90 bps − 100 Mbps
45 sps − 50 Msps
45 sps − 25 Msps
Quadrature
Amplitude
Modulation
16QAM
4
180 bps − 200 Mbps
45 sps − 50 Msps
45 sps − 12.5 Msps
32QAM
5
225 bps − 250 Mbps
45 sps − 50 Msps
45 sps − 10 Msps
64QAM
6
270 bps − 300 Mbps
45 sps − 50 Msps
45 sps − 8.33 Msps
128QAM
There is no preset value for this
modulation, it must be user defined.
7
315 bps − 350 Mbps
45 sps − 50 Msps
45 sps − 7.14 Msps
256QAM
8
360 bps − 400 Mbps
45 sps − 50 Msps
45 sps − 6.25 Msps
Custom Arb Waveform Generator
Working with Symbol Rates
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Custom Arb Waveform Generator
Working with Modulation Types
Working with Modulation Types
The Modulation Type menu enables you to specify the type of modulation applied to the carrier signal when
the Mod On Off hardkey is on.
When the Custom Off On softkey is on:
•
For Custom Arb, the BBG creates a sampled version of the I/Q waveform based on a random data
pattern and the modulation type that has been selected.
•
For Custom Real Time I/Q, the real-time custom I/Q symbol builder creates I/Q symbols based on the
data pattern and modulation type that has been selected (see “Working with Data Patterns” on page 147
for information on selecting a data pattern).
In Custom Real Time I/Q, you can also:
•
Create user-defined modulation type (see page 137) that can be used immediately or saved to the
Memory Catalog.
•
Restore all modulation parameters to their default state.
To Select a Predefined Modulation Type
1. Press Preset.
2. Press Mode > Custom > ARB Waveform Generator > Digital Mod Define > Modulation Type > Select
or
Mode > Custom > Real Time I/Q Baseband > Modulation Type > Select
3. Select one of the available modulation types.
NOTE
136
If you select QPSK and OQPSK, you must make a specific selection from the menu that displays.
Chapter 6
Custom Arb Waveform Generator
Working with Modulation Types
To Use a User-Defined Modulation Type (Real Time I/Q Only)
Creating a 128QAM I/Q Modulation Type User File with the I/Q Values Editor
In I/Q modulation schemes, symbols appear in default positions in the I/Q plane. Using the I/Q Values
editor, you can define your own symbol map by changing the position of one or more symbols. Use the
following procedure to create and store a 128-symbol QAM modulation.
NOTE
Although this procedure provides a quick way to implement a 128QAM modulation format,
it does not take full advantage of the I/Q modulator’s dynamic range. This is because you
begin with a 256QAM constellation, and delete unwanted points. The remaining points that
make up the 128QAM constellation are closer together than if you had mapped each point
specifically. Additionally, this approach does not enable you to define the bit pattern
associated with each symbol point, as you could if the 128QAM constellation had been
defined one point at a time.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q >
More (1 of 2) > Load Default I/Q Map > QAM > 256QAM.
This loads a default 256QAM I/Q modulation into the I/Q Values editor.
3. Press More (2 of 2) > Display I/Q Map.
In the next steps, you will delete specific portions of this I/Q constellation and change it into a 128QAM
with 128 I/Q states.
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4. Press Return > Goto Row > 0011 0000 > Enter; this is row 48.
5. Press the Delete Row softkey 16 times.
Repeat this pattern of steps using the following table:
Goto Row...
Press the Delete Row softkey...
0110 0000 (96)
16 times
1001 0000 (144)
16 times
1100 0000 (192)
16 times
0001 0000 (16)
4 times
0001 0100 (20)
4 times
0001 1000 (24)
8 times
0011 0000 (48)
4 times
0011 0100 (52)
4 times
0011 1000 (56)
4 times
0101 1000 (88)
8 times
0111 0000 (112)
4 times
0111 0100 (116)
4 times
0111 1000 (120)
8 times
6. Press Display I/Q Map to view the new constellation that has been
created. The I/Q State Map in this example has 128 symbols.
7. Press Return. When the contents of an I/Q Values table have not
been stored, I/Q Values (UNSTORED) appears on the display.
8. Press More (1 of 2) > Load/Store > Store To File.
If there is already a file name from the Catalog of IQ Files
occupying the active entry area, press the following keys:
Editing Keys > Clear Text
9. Enter a file name (for example, 128QAM) using the alpha keys and
the numeric keypad.
10. Press Enter.
The user-defined I/Q State Map should now be stored in the Catalog of IQ Files.
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Working with Modulation Types
Creating a QPSK I/Q Modulation Type User File with the I/Q Values Editor
In I/Q modulation schemes, symbols appear in default positions in the I/Q plane. Using the I/Q Values
editor, you can define your own symbol map by changing the position of one or more symbols. Use the
following procedure to create and store a 4-symbol unbalanced QPSK modulation.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) >
Delete All Rows > Confirm Delete All Rows.
This loads a default 4QAM I/Q modulation and clears the I/Q Values editor.
3. Enter the I and Q values listed in the following table:
Symbol
Data
I Value
Q Value
0
0000
0.500000
1.000000
1
0001
−0.500000
1.000000
2
0010
0.500000
−1.000000
3
0011
−0.500000
−1.000000
a. Press 0.5 > Enter.
b. Press 1 > Enter.
c. Enter the remaining I and Q values.
As the I value updates, the highlight moves to the first Q entry (and provides a default value of 0) and an
empty row of data appears below the first row. As the Q value updates, the highlight moves to the next I
value. As you press the numeric keys, the numbers display in the active entry area. If you make a
mistake, use the backspace key and retype.
Also note that 0.000000 appears as the first entry in the list of Distinct Values, and that
0.500000 and 1.000000 are listed as the distinct values.
4. Press More (2 of 2) > Display I/Q Map.
An I/Q State Map is displayed from the current values in the I/Q Values table.
The I/Q State Map in this example has four symbols. The I/Q State Map uses the following four unique
values: 0.5, 1.0, −0.5, and −1.0 to create the four symbols. It is not the number of values that defines how
many symbols a map has, but how those values are combined.
5. Press Return.
When the contents of an I/Q Values table have not been stored, I/Q Values (UNSTORED) appears
on the display.
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6. Press More (1 of 2) > Load/Store > Store To File.
If there is already a file name from the Catalog of IQ Files occupying the active entry area, press
the following keys: Editing Keys > Clear Text
7. Enter a file name (for example, NEW4QAM) using the alpha keys and the numeric keypad.
8. Press Enter. The user-defined I/Q State Map should now be stored in the Catalog of IQ Files and
can be recalled even after the E8267C PSG signal generator has been turned off.
Modifying a Predefined I/Q Modulation Type (I/Q Symbols) & Simulating Magnitude Errors & Phase Errors
Use the following procedure to manipulate symbol locations which simulate magnitude and phase errors. In
this example, you edit a 4QAM constellation to move one symbol closer to the origin.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) >
Load Default I/Q Map > QAM > 4QAM.
This loads a default 4QAM I/Q modulation into the I/Q Values editor.
3. Press More (2 of 2).
4. In the I/Q Values editor, navigate to Data 00000000 and press Edit Item.
5. Press .235702 > Enter, then .235702 > Enter.
When you press Enter the first time, the I value updates and the highlight moves to the first Q entry. The
second time, the Q value updates and the highlight moves to the following I entry.
6. Press Display I/Q Map. Note that one symbol has moved, as shown.
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Creating an FSK Modulation Type User File with the Frequency Values Editor
Use this procedure to set the frequency deviation for data 00, 01, 10, and 11 to configure a user-defined
FSK modulation.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User FSK > More (1 of 2) >
Delete All Rows > Confirm Delete All Rows.
This accesses the Frequency Values editor and clears the previous values.
3. Press 600 > Hz.
4. Press 1.8 > kHz.
5. Press -600 > Hz.
6. Press -1.8 > kHz.
Each time you enter a value, the Data column increments to the next binary number, up to a total of 16
data values (from 0000 to 1111). An unstored file of frequency deviation values is created for the
custom 4-level FSK file.
7. Press Load/Store > Store To File.
If there is already a file name from the Catalog of FSK Files occupying the active entry area, press
the following keys:
Edit Keys > Clear Text
8. Enter a file name (for example, NEWFSK) using the alpha keys and the numeric keypad.
9. Press Enter.
The user-defined FSK modulation should now be stored in the Catalog of FSK Files.
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Working with Modulation Types
Modifying a Predefined FSK Modulation Type User File with the Frequency Values Editor
Using the Frequency Values editor, you can define, modify, and store user-defined frequency shift
keying modulation. The Frequency Values editor is available for custom Real-Time I/Q Baseband
mode, but is not available for waveforms generated in custom Arb Waveform Generator mode. Use this
example to learn how to add errors to a default FSK modulation.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User FSK > More (1 of 2) >
Load Default FSK.
3. Press Freq Dev > 1.8 > kHz.
4. Press 4-Lvl FSK.
This sets the frequency deviation and opens the Frequency Values editor with the 4-level FSK
default values displayed. The frequency value for data 0000 is highlighted.
5. Press -1.81 > kHz.
6. Press -590 > Hz.
7. Press 1.805 > kHz.
8. Press 610 > Hz.
As you modify the frequency deviation values, the cursor moves to the next data row. An unstored file of
frequency deviation values is created for your custom 4-level FSK file.
9. Press Load/Store > Store To File.
If there is already a file name from the Catalog of FSK Files occupying the active entry area, press
the following keys:
Edit Keys > Clear Text
10. Enter a file name (for example, NEWFSK) using the alpha keys and the numeric keypad.
11. Press Enter.
The user-defined FSK modulation should now be stored in the Catalog of FSK Files.
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Configuring Hardware
Configuring Hardware
•
“To Set the ARB Reference” see page 144
To Set a Delayed, Positive Polarity, External Single Trigger
Using this procedure, you learn how to utilize an external function generator to apply a delayed
single-trigger to a custom multicarrier waveform.
1. Connect an Agilent 33120A function generator or equivalent to the signal generator PATT TRIGGER IN
port, as shown in Figure 6-1.
Figure 6-1
2. On the signal generator, press Preset.
3. Press Mode > Custom > Arb Waveform Generator.
4. Press Multicarrier Off On until On is highlighted.
5. Press Trigger > Single.
6. Press Trigger > Trigger Setup >Trigger Source > Ext.
7. Press Ext Polarity Neg Pos until Pos is highlighted.
8. Press Ext Delay Off On until On is highlighted.
9. Press Ext Delay Time > 100 > msec.
The Custom Arb Waveform Generator has been configured to play a single multicarrier waveform
100 milliseconds after it detects a change in TTL state from low to high at the PATT TRIG IN rear panel
connector.
10. Set the function generator waveform to a 0.1 Hz square wave at an output level of 0 to 5V.
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Configuring Hardware
11. On the signal generator, press Mode > Custom > Arb Waveform Generator > Digital Modulation Off On until
On is highlighted.
This generates a waveform with the custom multicarrier state and the display changes to Dig Mod
Setup: Multicarrier.
During waveform generation, the DIGMOD and I/Q annunciators activate and the new custom
multicarrier state is stored in volatile ARB memory. The waveform should be modulating the RF carrier.
12. Press RF On/Off.
The externally single-triggered custom multicarrier waveform should be available at the signal
generator’s RF OUTPUT connector 100 ms after receiving a change in TTL state from low to high at the
PATT TRIG IN.
To Set the ARB Reference
Setting for an External or Internal Reference
1. Press Custom > Arb Waveform Generator > More (1 of 2).
2. Press ARB Reference Ext Int to select either external or internal as the waveform sample clock reference.
•
If you select Ext, you must enter the reference frequency (250 kHz to 100 MHz) and apply the
reference signal to the rear-panel BASEBAND GEN REF IN.
•
If you select Int, the internal clock is used for the arbitrary waveform (ARB) frequency reference.
Setting the External Frequency
The external Arb reference frequency is only used when the ARB Reference Ext Int softkey has been set to Ext
(external).
1. Press Custom > Arb Waveform Generator > More (1 of 2).
2. Press Reference Freq, enter a desired frequency (250 kHz to 100 MHz), and press MHz, kHz, or Hz.
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7
Custom Real Time I/Q Baseband
This chapter describes the Custom Real Time I/Q Baseband mode which is available only in E8267C PSG
vector signal generators.
This chapter includes the following major sections:
•
“Overview” on page 146
•
“Working with Predefined Setups (Modes)” on page 146
•
“Working with Data Patterns” on page 147
•
“Working with Burst Shapes” on page 153
•
“Configuring Hardware” on page 158
•
“Working with Phase Polarity” on page 160
•
“Working with Differential Data Encoding” on page 160
See also:
•
“Working with Filters” on page 125
•
“Working with Symbol Rates” on page 133
•
“Working with Modulation Types” on page 136
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Custom Real Time I/Q Baseband
Overview
Overview
Custom Real Time I/Q Baseband mode can produce a single carrier, but it can be modulated with real time
data that allows real time control over all of the parameters that affect the signal. The single carrier signal
that is produced can be modified by applying various data patterns, filters, symbol rates, modulation types,
and burst shapes.
To begin using the Custom Real Time I/Q Baseband mode, start by selecting from a set of predefined modes
(setups) or specify a setup by selecting a Data Pattern, Filter, Symbol Rate, Modulation Type, Burst Shape,
Configure Hardware, Phase Polarity, and whether Diff Data Encode is off or on.
Working with Predefined Setups (Modes)
When you select a predefined mode, default values for components of the setup (including the filter, symbol
rate, and modulation type) are automatically specified.
Selecting a Predefined Real Time Modulation Setup
The following steps select a predefined mode where filtering, symbol rate, and modulation type are defined
by the APCO 25 w/C4FM digital modulation standard, and return to the top-level custom modulation menu.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband.
3. Press More (1 of 3) > More (2 of 3) > Predefined Mode > APCO 25 w/C4FM.
4. Press More (3 of 3).
Deselecting a Predefined Real Time Modulation Setup
To deselect any predefined mode that has been previously selected, and return to the top-level custom
modulation menu:
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband.
3. Press More (1 of 3) > More (2 of 3) > Predefined Mode > None.
4. Press More (3 of 3).
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Working with Data Patterns
Working with Data Patterns
This section provides information on the following:
•
“Using a Predefined Data Pattern” on page 148
•
“Using a User-Defined Data Pattern” on page 149
•
“Using an Externally Supplied Data Pattern” on page 152
The Data menu enables you to select from predefined and user defined data patterns. Data Patterns are used
for transmitting continuous streams of unframed data. When the Custom Off On softkey is on, the real-time
custom I/Q symbol builder creates I/Q symbols based on the data pattern and modulation type that has been
selected. Refer to “Working with Modulation Types” on page 136 for information on selecting a modulation
type.
The following data patterns are available:
•
PN sequence allows you to access a menu (PN9, PN11, PN15, PN20, PN23) for internal data generation
of pseudorandom sequences (pseudorandom noise sequences); a pseudorandom noise sequence is a
periodic binary sequence approximating, in some sense, a Bernoulli “coin tossing” process with
equiprobable outcomes.
•
FIX4 0000 allows you to define a 4-bit repeating sequence data pattern and make it the active function.
The selected 4-bit pattern will be repeated as necessary to provide a continuous stream of data.
•
Other Patterns allows you to access a menu of choices (4 1’s & 4 0’s, 8 1’s & 8 0’s, 16 1’s & 16 0’s, 32
1’s & 32 0’s, or 64 1’s & 64 0’s) from which you can select a data pattern. Each pattern contains an equal
number of ones and zeroes. The selected pattern will be repeated as necessary to provide a continuous
stream of data.
•
User File allows you to access a menu of choices from which you can create a file and store it to the
Catalog of Bit Files, select from a Catalog of Bit Files and use it, or select from a Catalog of Bit Files,
edit the file, and resave the file.
•
Ext allows data patterns to be fed into the I/Q symbol builder, through the DATA port, in real-time.
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Using a Predefined Data Pattern
Selecting a Predefined PN Sequence Data Pattern
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Data > PN Sequence.
3. Press one of the following: PN9, PN11, PN15, PN20, PN23.
Selecting a Predefined Fixed 4-bit Data Pattern
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Data > FIX4.
3. Press 1010 > Enter > Return.
Selecting a Predefined Data Pattern Containing an Equal Number of 1s & 0s
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Data > Other Patterns.
3. Press one of the following:
4 1’s & 4 0’s, 8 1’s & 8 0’s, 16 1’s & 16 0’s, 32 1’s & 32 0’s, or 64 1’s & 64 0’s.
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Using a User-Defined Data Pattern
User Files (user-defined data pattern files) can be created and modified using the signal generator’s Bit
File Editor or they can be created on a remote computer and moved to the signal generator for direct
use; these remotely created data pattern files can also be modified with the Bit File Editor. For information
on creating user-defined data files on a remote computer, see the programming guide.
These procedures demonstrate how to use the Bit File Editor to create, edit, and store user-defined
data pattern files for use within the custom real-time I/Q baseband generator modulation. For this example, a
user file is defined within a custom digital communication.
Creating a Data Pattern User File with the Bit File Editor
This procedure uses the Bit File Editor to create a Data Pattern User File and stores the resulting file in the
Memory Catalog (described on page 52).
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Data > User File > Create File.
This opens the Bit File Editor, which contains three columns, as shown in the following figure.
Offset
(in Hex)
NOTE
Chapter 7
Bit Data
Cursor Position
indicator (in Hex)
Hexadecimal Data
File Name indicator
When you create a new file, the default name is UNTITLED, or UNTITLED1, and so forth.
This prevents overwriting previous files.
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3. Enter the 32 bit values shown using the numeric keypad.
Bit data is entered into the Bit File Editor in 1-bit format. The current hexadecimal value of the binary
data is shown in the Hex Data column and the cursor position (in hexadecimal) is shown in the
Position indicator.
Enter These Bit Values
Hexadecimal Data
Cursor Position
4. Press More (1 of 2) > Rename > Editing Keys > Clear Text.
5. Enter a file name (for example, USER1) using the alpha keys and the numeric keypad.
6. Press Enter.
The user file should be renamed and stored to the Memory Catalog with the name USER1.
Selecting a Data Pattern User File from the Catalog of Bit Files
In this procedure, you learn how to select a data pattern user file from the Catalog of Bit Files. If you have
not created and stored a user-defined data file, complete the steps in the previous section, “Creating a Data
Pattern User File with the Bit File Editor” on page 149.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Data > User File.
3. Highlight the file to be selected (for example, USER1).
4. Press Edit File.
The Bit File Editor should open the selected file (for example, USER1).
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Modifying an Existing Data Pattern User File
In this example, you learn how to modify an existing data pattern user file by navigating to a particular bit
position and changing its value. Next, you will learn how to invert the bit values of an existing data pattern
user file.
If you have not already created, stored, and recalled a data pattern user file, complete the steps in the
previous sections, “Creating a Data Pattern User File with the Bit File Editor” on page 149 and “Selecting a
Data Pattern User File from the Catalog of Bit Files” on page 150.
Navigating the Bit Values of an Existing Data Pattern User File
1. Press Goto > 4 > C > Enter.
This moves the cursor to bit position 4C, of the table, as shown in the following figure.
Cursor moves to new position
Chapter 7
Position indicator changes
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Inverting the Bit Values of an Existing Data Pattern User File
1. Press 1011.
This inverts the bit values that are positioned 4C through 4F. Notice that hex data in this row has now
changed to 76DB6DB6, as shown in the following figure.
Bits 4C through 4F inverted
Hex Data changed
To Apply Bit Errors to an Existing Data Pattern User File
This example demonstrates how to apply bit errors to an existing data pattern user file. If you have not
created and stored a data pattern user file, first complete the steps in the previous section, “Creating a Data
Pattern User File with the Bit File Editor” on page 149.
1. Press Apply Bit Errors.
2. Press Bit Errors > 5 > Enter.
3. Press Apply Bit Errors.
Notice both Bit Errors softkeys change value as they are linked.
Using an Externally Supplied Data Pattern
In this procedure, an external real time data pattern is supplied through DATA, DATA CLOCK, and
SYMBOL SYNC connectors.
1.
2.
3.
4.
5.
152
Press Preset.
Press Mode > Custom > Real Time I/Q Baseband > Data > Ext.
Connect the real-time data to the DATA input.
Connect the data clock trigger signal to DATA CLOCK input.
Connect the symbol sync trigger to the SYMBOL SYNC input.
Chapter 7
Custom Real Time I/Q Baseband
Working with Burst Shapes
Working with Burst Shapes
•
“Configuring the Burst Rise and Fall Parameters” on page 154
•
“Using User-Defined Burst Shape Curves” on page 155
The Burst Shape menu enables you to modify the rise and fall time, rise and fall delay, and the burst shape
(either sine or user file defined). In addition, you can define the shape of the burst and preview the burst
shape through a Rise Shape Editor, or restore all of the burst shape parameters back to their original default
state.
Rise time
the period of time, specified in bits, where the burst increases from a minimum of
−70 dB (0) to full power (1).
Fall time
the period of time, specified in bits, where the burst decreases from full power (1) to a
minimum of −70 dB (0).
Rise delay
the period of time, specified in bits, that the start of the burst rise is delayed. Rise delay
can be either negative or positive. Entering a delay other than zero shifts the full power
point earlier or later than the beginning of the first useful symbol.
Fall delay
the period of time, specified in bits, that the start of the burst fall is delayed. Fall delay
can be either negative or positive. Entering a delay other than zero shifts the full power
point earlier or later than the end of the last useful symbol.
User-defined
burst shape
up to 256 user-entered values, which define the shape of the curve in the specified rise
or fall time. The values can vary between 0 (no power) and 1 (full power) and are scaled
linearly. Once specified, the values are resampled as necessary to create the cubic spline
that passes through all of the sample points.
The default burst shape of each format is implemented according to the standards of the format selected. You
can, however, modify the following aspects of the burst shape:
User-Defined
Values
User-Defined
Values
Power
1
0
Rise
Delay
Rise
Time
Fall
Delay
Fall
Time
Time
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Burst shape maximum rise and fall time values are affected by the following factors:
•
•
the symbol rate
the modulation type
When the rise and fall delays equal 0, the burst shape attempts to synchronize the maximum burst shape
power to the beginning of the first valid symbol and the ending of the last valid symbol.
If you find that the error vector magnitude (EVM) or adjacent channel power (ACP) increases when you turn
bursting on, you can adjust the burst shape to assist with troubleshooting.
Configuring the Burst Rise and Fall Parameters
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Burst Shape.
3. Press Rise Time > 5 > bits.
4. Press Rise Delay > 1 > bits.
5. Press Fall Time > 5 > bits.
6. Press Fall Delay > 1 > bits.
This configures the burst shape for the custom real-time I/Q baseband digital modulation format. For
instructions on creating and applying user-defined burst shape curves, see “To Create and Store
User-Defined Burst Shape Curves” on page 155.
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Using User-Defined Burst Shape Curves
You can adjust the shape of the rise time curve and the fall time curve using the Rise Shape and Fall
Shape editors. Each editor enables you to enter up to 256 values, equidistant in time, to define the shape of
the curve. The values are then resampled to create the cubic spline that passes through all of the sample
points.
The Rise Shape and Fall Shape editors are available for custom real-time I/Q baseband generator
waveforms. They are not available for waveforms generated by the dual arbitrary waveform generator.
You can also design burst shape files externally and download the data to the signal generator. For more
information, see the programming guide.
To Create and Store User-Defined Burst Shape Curves
Using this procedure, you learn how to enter rise shape sample values and mirror them as fall shape values
to create a symmetrical burst curve.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Burst Shape.
3. Press Define User Burst Shape > More (1 of 2) > Delete All Rows > Confirm Delete Of All Rows.
4. Enter values similar to the sample values in the following table:
Rise Shape Editor
Sample
Value
Sample
Value
0
0.000000
5
0.900000
1
0.400000
6
0.950000
2
0.600000
7
0.980000
3
0.750000
8
0.990000
4
0.830000
9
1.000000
a. Highlight the value (1.000000) for sample 1.
b. Press .4 > Enter.
c. Press .6 > Enter.
d. Enter the remaining values for samples 3 through 9 from the table above.
e. Press More (2 of 2) > Edit Fall Shape > Load Mirror Image of Rise Shape >
Confirm Load Mirror Image of Rise Shape.
This changes the fall shape values to a mirror image of the rise shape values.
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Figure 7-1
5. Press More (1 of 2) > Display Burst Shape.
This displays a graphical representation of the waveform’s rise and fall characteristics.
Figure 7-2
NOTE
To return the burst shape to the default conditions, press Return > Return >
Confirm Exit From Table Without Saving > Restore Default Burst Shape.
6. Press Return > Load/Store > Store To File.
If there is already a file name from the Catalog of SHAPE Files occupying the active entry
area, press the following keys: Editing Keys > Clear Text
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7. Enter a file name (for example, NEWBURST) using the alpha keys and the numeric keypad.
8. Press Enter.
The contents of the current Rise Shape and Fall Shape editors are stored to the Catalog of
SHAPE Files. This burst shape can now be used to customize a modulation or as a basis for a new
burst shape design.
To Select and Recall a User-Defined Burst Shape Curve from the Memory Catalog
Once a user-defined burst shape file is stored in the Memory Catalog, it can be recalled for use with
real-time I/Q baseband generated digital modulation.
This example requires a user-defined burst shape file stored in memory. If you have not created and stored a
user-defined burst shape file, complete the steps in the previous sections.
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Burst Shape > Burst Shape Type > User File.
3. Highlight the desired burst shape file (for example, NEWBURST).
4. Press Select File.
The selected burst shape file is now applied to the current real-time I/Q baseband digital modulation
state.
5. Press Return > Custom Off On.
This generates the custom modulation with user-defined burst shape created in the previous steps.
During waveform generation, the CUSTOM and I/Q annunciators activate. The waveform is now
modulating the RF carrier.
6. Press RF On/Off.
The current real-time I/Q baseband digital modulation format with user-defined burst shape should be
available at the signal generator’s RF OUTPUT connector.
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Configuring Hardware
Configuring Hardware
•
“To Set the BBG Reference” on page 158
•
“To Set the External DATA CLOCK to Receive Input as Either Normal or Symbol” on page 159
•
“To Set the BBG DATA CLOCK to External or Internal” on page 159
•
“To Adjust the I/Q Scaling” on page 159
To Set the BBG Reference
Setting for an External or Internal Reference
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Configure Hardware displays a menu where you can set the BBG Reference to External or Internal.
2. Press BBG Ref Ext Int to select either external or internal as the bit-clock reference for the data generator.
If external is selected, apply the reference frequency to the rear-panel BASEBAND GEN REF IN
connector.
Setting the External Frequency
The BBG reference external frequency is used only when the BBG Ref Ext Int softkey has been set to Ext
(external).
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Configure Hardware displays a menu where you can set the external BBG reference frequency.
2. Press Ext BBG Ref Freq.
3. Use the numeric keypad to a desired frequency, then press MHz, kHz, or Hz.
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Configuring Hardware
To Set the External DATA CLOCK to Receive Input as Either Normal or Symbol
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Configure Hardware allows you to access a menu from which you can set the external DATA CLOCK to
receive input as either Normal or Symbol.
2. Press Ext Data Clock to select either Normal or Symbol; this setting has no effect in internal clock mode.
•
When set to Normal, the DATA CLOCK input connector requires a bit clock.
•
When set to Symbol, a one-shot or continuous symbol sync signal must be provided to the SYMBOL
SYNC input connector.
To Set the BBG DATA CLOCK to External or Internal
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Configure Hardware allows you to access a menu from which you can set the BBG DATA CLOCK to
receive input from External or Internal.
2. Press BBG Data Clock Ext Int to select either external or internal.
•
When set to Ext (external), the DATA CLOCK connector is used to supply the BBG Data Clock.
•
When set to Int (internal), the internal data clock is used.
To Adjust the I/Q Scaling
Adjusting the I/Q Scaling (amplitude of the I/Q outputs) multiplies the I and Q data by the I/Q scaling factor
that is selected and can be used to improve the Adjacent Channel Power (ACP). Lower scaling values equate
to better ACP. This setting has no effect with MSK or FSK modulation.
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Configure Hardware.
Configure Hardware allows you to access a menu from which you can adjust the I/Q Scaling.
2. Press I/Q Scaling, enter a desired I/Q scaling level, and press %.
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Working with Phase Polarity
Working with Phase Polarity
To Set Phase Polarity to Normal or Inverted
1. Press Mode > Custom > Real Time I/Q Baseband > More (1 of 3) > Phase Polarity Normal Invert.
Phase Polarity Normal Invert enables you to either leave the selection as Normal (so that the phase
relationship between the I and Q signals is not altered by the phase polarity function), or set to Invert and
invert the internal Q signal, reversing the rotation direction of the phase modulation vector.
When you choose Invert, the in-phase component lags the quadrature-phase component by 90° in the
resulting modulation. Inverted phase polarity is required by some radio standards and it is useful for
lower sideband mixing applications. The inverted selection also applies to the I, I-bar, Q, and Q-bar
output signals.
Working with Differential Data Encoding
The Diff Data Encode Off On menu enables you to toggle the operational state of the signal generator’s
differential data encoding.
•
When set to Off, data bits are not encoded prior to modulation.
•
When set to On, data bits are encoded prior to modulation. Differential encoding uses an exclusive-OR
function to generate a modulated bit. Modulated bits will have a value of 1 if a data bit is different from
the previous bit or they will have a value of 0 if a data bit is the same as the previous bit.
This section provides information about the following:
•
“Understanding Differential Encoding”
•
“Using Differential Encoding” on page 165
Understanding Differential Encoding
Differential encoding is a digital-encoding technique whereby a binary value is denoted by a signal change
rather than a particular signal state. Using differential encoding, binary data in any user-defined I/Q or FSK
modulation can be encoded during the modulation process via symbol table offsets defined in the
Differential State Map.
For example, consider the signal generator’s default 4QAM I/Q modulation. With a user-defined modulation
based on the default 4QAM template, the I/Q Values editor contains data that represent four symbols (00,
01, 10, and 11) mapped into the I/Q plane using two distinct values, 1.000000 and -1.000000. These four
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symbols can be differentially encoded during the modulation process by assigning symbol table offset values
associated with each data value. Figure 7-3 shows the 4QAM modulation in the I/Q Values editor.
Figure 7-3
NOTE
The number of bits per symbol can be expressed using the following formula. Because the
equation is a ceiling function, if the value of x contains a fraction, x is rounded up to the
next whole number.
Where x = bits per symbol, and y = the number of differential states.
The following illustration shows a 4QAM modulation I/Q State Map.
2nd Symbol
Data = 00000001
Distinct values: -1, +1
3rd Symbol
Data = 00000010
Distinct values: -1, -1
Chapter 7
2
3
1
1st Symbol
Data = 00000000
Distinct values: +1, +1
4
4th Symbol
Data = 00000011
Distinct values: +1, -1
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Differential Data Encoding
In real-time I/Q baseband digital modulation waveforms, data (1’s and 0’s) are encoded, modulated onto a
carrier frequency and subsequently transmitted to a receiver. In contrast to differential encoding, differential
data encoding modifies the data stream prior to I/Q mapping. Where differential encoding encodes the raw
data by using symbol table offset values to manipulate I/Q mapping at the point of modulation, differential
data encoding uses the transition from one bit value to another to encode the raw data.
Differential data encoding modifies the raw digitized data by creating a secondary, encoded data stream that
is defined by changes in the digital state, from 1 to 0 or from 0 to 1, of the raw data stream. This
differentially encoded data stream is then modulated and transmitted.
In differential data encoding, a change in a raw data bit’s digital state, from 1 to 0 or from 0 to 1, produces a
1 in the encoded data stream. No change in digital state from one bit to the next, in other words a bit with a
value of 1 followed by another bit with a value of 1 or a bit with a value of 0 followed by the same, produces
a 0 in the encoded data. For instance, differentially encoding the data stream containing 01010011001010
renders 1111010101111.
Differential data encoding can be described by the following equation:
transmittedbit ( i ) = databit ( i – 1 ) ⊕ databit ( i )
For a bit-by-bit illustration of the encoding process, see the following illustration:
0 1 0 1 0 0 1 1 0 0 1 0 1
raw (unencoded) data
change =
no change =
1 1 1 1 0 1 0 1 0 1 1 1 1
differentially encoded data
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How Differential Encoding Works
Differential encoding employs offsets in the symbol table to encode user-defined modulation schemes. The
Differential State Map editor is used to introduce symbol table offset values, which in turn cause
transitions through the I/Q State Map based on their associated data value. Whenever a data value is
modulated, the offset value stored in the Differential State Map is used to encode the data by transitioning
through the I/Q State Map in a direction and distance defined by the symbol table offset value.
Entering a value of +1 causes a 1-state forward transition through the I/Q State Map. As an example,
consider the following data/symbol table offset values. These symbol table offsets result in one of the
transitions shown.
NOTE
The following I/Q State Map illustrations show all possible state transitions using a
particular symbol table offset value. The actual state-to-state transition depends on the state
in which the modulation starts.
xx
Example
Data
Offset
Value
1
00000000
+1
2
00000001
−1
3
00000010
+2
4
00000011
0
Example 3
transition 2 states forward
Chapter 7
Example 1
transition 1 state forward
Example 2
transition 1 state backward
Example 4
no transition
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Working with Differential Data Encoding
1st
1st Symbol
3rd Symbol
5th
{
{
Data = 0011100001
2nd Symbol
3rd
{
{
{
2nd
5th Symbol
4th Symbol
4th
Data Value
00
01
10
11
Symbol Table Offset
+1
-1
+2
+0
When applied to the user-defined default 4QAM I/Q map, starting from the 1st symbol (data 00), the
differential encoding transitions for the data stream (in 2-bit symbols) 0011100001 appear in the previous
illustration.
As you can see, the 1st and 4th symbols, having the same data value (00), produce the same state transition
(forward 1 state). In differential encoding, symbol values do not define location; they define the direction
and distance of a transition through the I/Q State Map.
For instructions on configuring differential encoding, see “Understanding Differential Encoding” on
page 160.
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Using Differential Encoding
Differential encoding is a digital-encoding technique that denotes a binary value by a signal change rather
than a particular signal state. It is available for Custom Real Time I/Q Baseband mode. It is not available for
waveforms generated by Arb Waveform Generator mode.
The signal generator’s Differential State Map editor enables you to modify the differential state map
associated with user-defined I/Q and user-defined FSK modulations. In this procedure, you create a
user-defined I/Q modulation and then configure, activate, and apply differential encoding to the user-defined
modulation. For more information, see “Understanding Differential Encoding” on page 160.
This section includes information on following:
•
“Configuring User-Defined I/Q Modulation”
•
“Accessing the Differential State Map Editor” on page 166
•
“Editing the Differential State Map” on page 166
Configuring User-Defined I/Q Modulation
1. Press Preset.
2. Press Mode > Custom > Real Time I/Q Baseband > Modulation Type > Define User I/Q > More (1 of 2) >
Load Default I/Q Map > QAM > 4QAM.
This loads a default 4QAM I/Q modulation and displays it in the I/Q Values editor. The default 4QAM I/Q
modulation contains data that represent 4 symbols (00, 01, 10, and 11) mapped into the I/Q plane using 2
distinct values (1.000000 and −1.000000). These 4 symbols will be traversed during the modulation process
by the symbol table offset values associated with each symbol of data.
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Accessing the Differential State Map Editor
•
Press Configure Differential Encoding.
This opens the Differential State Map editor. At this point, you see the data for the 1st symbol
(00000000) and the cursor prepared to accept an offset value.You are now prepared to create a custom
differential encoding for the user-defined default 4QAM I/Q modulation.
Data
Symbol Table Offset Values Entry Area
Editing the Differential State Map
1. Press 1 > Enter.
This encodes the first symbol by adding a symbol table offset of 1. The symbol rotates forward through
the state map by 1 value when a data value of 0 is modulated.
2. Press +/- > 1 > Enter.
This encodes the second symbol by adding a symbol table offset of -1. The symbol rotates backward
through the state map by 1 value when a data value of 1 is modulated.
NOTE
At this point, the modulation has one bit per symbol. For the first two data values
(00000000 and 00000001) only the last bits (the 0 and the 1, respectively) are
significant.
3. Press 2 > Enter.
This encodes the third symbol by adding a symbol table offset of 2. The symbol rotates forward through
the state map by 2 values when a data value of 10 is modulated.
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4. Press 0 > Enter.
This encodes the fourth symbol by adding a symbol table offset of 0. The symbol does not rotate through
the state map when a data value of 11 is modulated.
NOTE
At this point, the modulation has two bits per symbol. For the data values 00000000,
00000001, 00000010, 00000011, the symbol values are 00, 01, 10, and 11 respectively.
5. Press Return > Differential Encoding Off On.
This applies the custom differential encoding to a user-defined modulation.
NOTE
Notice that (UNSTORED) appears next to Differential State Map on the signal
generator’s display. Differential state maps are associated with the user-defined
modulation for which they were created.
To save a custom differential state map, you must store the user-defined modulation for
which it was designed. Otherwise the symbol table offset data is purged when you press
the Confirm Exit From Table Without Saving softkey when exiting from the I/Q or FSK
editor.
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8
Multitone Waveform Generator
This chapter describes the Multitone mode, which is available only in E8267C PSG vector signal generators.
This chapter includes the following major sections:
•
“Overview” on page 170
•
“Creating, Viewing, and Optimizing Multitone Waveforms” on page 171
169
Multitone Waveform Generator
Overview
Overview
The multitone mode builds a waveform that has up to 64 CW signals, or tones. Using the Multitone
Setup table editor, you can define, modify, and store waveforms for playback. Multitone waveforms are
generated by the internal I/Q baseband generator.
The multitone waveform generator is typically used for testing the intermodulation distortion characteristics
of multi-channel devices, such as mixers or amplifiers. Intermodulation distortion (IMD) occurs when
non-linear devices with multiple input frequencies cause unwanted outputs at other frequencies or interfere
with adjacent channels. The multitone waveform generator supplies a waveform with a user-specified
number of tones whose IMD products can be measured using a spectrum analyzer and used as a reference
when measuring the IMD generated by a device-under-test.
Multitone waveforms are created using the internal I/Q baseband generator and stored in ARB memory for
playback. Although the multitone mode generates a high-quality waveform, a small amount of IMD, carrier
feedthrough, and feedthrough-related IMD occurs. Carrier feedthrough may be observed when an even
number of tones are generated, since there are no tones at the center carrier frequency to mask the
feedthrough. To minimize carrier feedthrough for an even-numbered multitone signal, it is necessary to
manually adjust the I and Q offsets while observing the center carrier frequency with a spectrum analyzer.
For measurements that require more than 64 tones or the absence of IMD and carrier feedthrough, you can
create up to 1024 distortion-free multitone signals using Agilent Technologies Signal Studio software
Option 408.
NOTE
170
For more information about multitone waveform characteristics and the PSG vector signal
generator multitone format, download Application Note 1410 from our website by going to
www.agilent.com and searching for “AN 1410” in Test & Measurement.
Chapter 8
Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
Creating, Viewing, and Optimizing Multitone Waveforms
This section describes how to set up, generate, and optimize a multitone waveform while viewing it with a
spectrum analyzer. Although you can view a generated multitone signal using any spectrum analyzer that
has sufficient frequency range, an Agilent Technologies PSA high-performance spectrum analyzer was used
for this demonstration. Before generating your signal, connect the spectrum analyzer to the signal generator
as shown in Figure 8-1.
Figure 8-1
Spectrum Analyzer Setup
To Create a Custom Multitone Waveform
Using the Multitone Setup table editor, you can define, modify and store user-defined multitone
waveforms. Multitone waveforms are generated by the dual arbitrary waveform generator.
1. Preset the signal generator.
2. Set the signal generator RF output frequency to 20 GHz.
3. Set the signal generator RF output amplitude to 0 dBm.
4. Press Mode > Multitone > Initialize Table > Number of Tones > 9 > Enter.
5. Press Freq Spacing > 1 > MHz.
6. Press Initialize Phase Fixed Random to Random.
7. Press Done.
8. Press Multitone Off On to On.
9. Turn on the RF output.
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Creating, Viewing, and Optimizing Multitone Waveforms
The multitone signal should be available at the signal generator RF OUTPUT connector.
Figure 8-2 on page 172 shows what the signal generator display should look like after all steps have been
completed. Notice that the M-TONE, I/Q, RF ON, and MOD ON annunciators are displayed and the
parameter settings for the signal are shown in the status area of the signal generator display. The multitone
waveform is stored in volatile ARB memory.
The waveform has nine tones spaced 1 MHz apart with random initial phase values. The center tone is
placed at the carrier frequency, while the other eight tones are spaced in 1 MHz increments from the center
tone. If you create an even number of tones, the carrier frequency will be centered between the two middle
tones.
Figure 8-2
To View a Multitone Waveform
This procedure describes how to configure the spectrum analyzer to view a multitone waveform and its IMD
products. Actual key presses will vary, depending on the model of spectrum analyzer you are using.
1. Preset the spectrum analyzer.
2. Set the carrier frequency to 20 GHz.
3. Set the frequency span to 20 MHz.
4. Set the amplitude for a 10 dB scale with a 4 dBm reference.
5. Adjust the resolution bandwidth to sufficiently reduce the noise floor to expose the IMD products. A 9.1
kHz setting was used in our example.
6. Turn on the peak detector.
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Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
7. Set the attenuation to 14 dB, so you’re not overdriving the input mixer on the spectrum analyzer.
You should now see a waveform with nine tones and a 20 GHz center carrier frequency that is similar to the
one shown in Figure 8-3 on page 173. You will also see IMD products at 1 MHz intervals above and below
the highest and lowest tones.
Figure 8-3
Multitone
Channels
Intermodulation
Distortion
To Edit the Multitone Setup Table
This procedure builds upon the previous procedure.
1. Press Initialize Table > Number of Tones > 10 > Enter.
2. Press Done.
3. Highlight the value (On) in the State column for the tone in row 2.
4. Press Toggle State.
5. Highlight the value (0 dB) in the Power column for the tone in row 4.
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Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
6. Press Edit Item > -10 > dB.
7. Highlight the value (0) in the Phase column for the tone in row 4.
8. Press Edit Item > 123 > deg.
9. Press Apply Multitone.
NOTE
Whenever a change is made to a setting while the multitone generator is operating (Multitone
Off On set to On), you must apply the change by pressing the Apply Multitone softkey before
the updated waveform will be generated. When you apply a change, the baseband generator
creates a multitone waveform using the new settings and replaces the existing waveform in
ARB memory.
You have now changed the number of tones to 10, disabled tone 2, and changed the power and phase of tone
4. Figure 8-4 on page 174 shows what the multitone setup table display on the signal generator should look
like after all steps have been completed. The spectrum analyzer should display a waveform similar to the
one shown in Figure 8-5 on page 175. Notice that even-numbered multitone waveforms have a small amount
of carrier feedthrough at the center carrier frequency.
Figure 8-4
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Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
Figure 8-5
Tone 1
Tone 10
Carrier
Feedthrough
Intermodulation
Distortion
Carrier
Feedthrough
Distortion
To Minimize Carrier Feedthrough
This procedure describes how to minimize carrier feedthrough and measure the difference in power between
the tones and their intermodulation distortion products. Carrier feedthrough can only be observed with
even-numbered multitone waveforms.
This procedure builds upon the previous procedure.
1. On the spectrum analyzer, set the resolution bandwidth for a sweep rate of about
100-200 ms. This will allow you to dynamically view the carrier feedthrough spike as you make
adjustments.
2. On the signal generator, press I/Q > I/Q Adjustments > I/Q Adjustments Off On to On.
3. Press I Offset and turn the rotary knob while observing the carrier feedthrough with the spectrum
analyzer. Changing the I offset in the proper direction will reduce the feedthrough level. Adjust the level
as low as possible.
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Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
4. Press Q Offset and turn the rotary knob to further reduce the carrier feedthrough level.
5. Repeat steps 3 and 4 until you have reached the lowest possible carrier feedthrough level.
6. On the spectrum analyzer, return the resolution bandwidth to its previous setting.
7. Turn on waveform averaging.
8. Create a marker and place it on the peak of one of the end tones.
9. Create a delta marker and place it on the peak of the adjacent intermodulation product, which should be
spaced 10 MHz from the marked tone.
10. Measure the power difference between the tone and its distortion product.
You should now see a display that is similar to the one shown in Figure 8-6 on page 176. Your optimized
multitone signal can now be used to measure the IMD products generated by a device-under-test.
Note that carrier feedthrough changes with time and temperature. Therefore, you will need to periodically
readjust your I and Q offsets to keep the signal optimized.
Figure 8-6
Tone 1
Tone 10
Minimized
Carrier
Feedthrough
Intermodulation
Distortion
176
Carrier
Feedthrough
Distortion
Chapter 8
Multitone Waveform Generator
Creating, Viewing, and Optimizing Multitone Waveforms
To Determine Peak to Average Characteristics
This procedure describes how to set the phases of the tones in a multitone waveform and determine the peak
to average characteristics by plotting the complementary cumulative distribution function (CCDF).
1. Press Mode > Multitone > Initialize Table > Number of Tones > 64 > Enter.
2. Press Freq Spacing > 20 > kHz.
3. Press Initialize Phase Fixed Random to Fixed.
4. Press Done.
5. Press Apply Multitone.
6. Press More (1 of 2) > Waveform Statistics > Plot CCDF.
You should now see a display that is similar to the one shown in Figure 8-7. The CCDF plot displays the
peak to average characteristics of the waveform with all phases set to zero.
Figure 8-7
CCDF Plot with Fixed Phase Set
Peak
Power
7. Press Mode Setup > Initialize Table.
8. Press Initialize Phase Fixed Random to Random.
9. Press Random Seed Fixed Random to Random.
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Creating, Viewing, and Optimizing Multitone Waveforms
10. Press Done.
11. Press Apply Multitone.
12. Press More (1 of 2) > Waveform Statistics > Plot CCDF.
You should now see a display that is similar to the one shown in Figure 8-8. The CCDF plot displays the
peak to average characteristics of the waveform with randomly generated phases and a random seed.
The random phase setup simulates the typically random nature of multitone waveforms. Notice that
randomly distributed phases result in a much lower peak to average ratio than fixed phases. An increase
in the number of tones with random phases will decrease the probability of a maximum peak power
occurrence.
Figure 8-8
CCDF Plot with Random Phase Set
Peak
Power
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Chapter 8
9
Two-Tone Waveform Generator
In the following sections, this chapter describes the Two Tone mode, which is available only in E8267C PSG
vector signal generators.
•
“Overview” on page 180
•
“Creating, Viewing, and Modifying Two-Tone Waveforms” on page 181
179
Two-Tone Waveform Generator
Overview
Overview
The two-tone mode builds a waveform that has two equal-powered CW signals, or tones. The default
waveform has two tones that are symmetrically spaced from the center carrier frequency, and have
user-defined amplitude, carrier frequency, and frequency separation settings. The user can also align the
tones left or right, relative to the carrier frequency.
The two-tone waveform generator is designed for testing the intermodulation distortion characteristics of
non-linear devices, such as mixers or amplifiers. Intermodulation distortion (IMD) occurs when non-linear
devices with multiple input frequencies interfere with adjacent channels or cause unwanted outputs at other
frequencies. The two-tone waveform generator supplies a signal whose IMD products can be measured
using a spectrum analyzer and used as a reference when measuring the IMD generated by a
device-under-test.
Two-tone waveforms are created using the internal I/Q baseband generator and stored in ARB memory for
playback. Although the two-tone mode generates a high-quality waveform, a small amount of IMD occurs.
In addition to IMD, a small amount of carrier feedthrough and feedthrough-related IMD may be present
when the spacing between the tones is centered on the carrier frequency. To minimize carrier feedthrough for
a two-tone signal, you must manually adjust the I and Q offsets while observing the center carrier frequency
with a spectrum analyzer. For measurements that require the absence of IMD and carrier feedthrough, you
can create distortion-free multitone signals using Agilent Technologies’ Signal Studio software Option 408.
NOTE
180
For more information about two-tone waveform characteristics and the PSG vector signal
generator two-tone format, download Application Note 1410 from our website by going to
www.agilent.com and searching for “AN 1410” in Test & Measurement.
Chapter 9
Two-Tone Waveform Generator
Creating, Viewing, and Modifying Two-Tone Waveforms
Creating, Viewing, and Modifying Two-Tone Waveforms
This section describes how to set up, generate, and modify a two-tone waveform while viewing it with a
spectrum analyzer. Although you can view a generated two-tone signal using any spectrum analyzer that has
sufficient frequency range, an Agilent Technologies PSA Series High-Performance Spectrum Analyzer was
used for this demonstration. Before generating your signal, connect the spectrum analyzer to the signal
generator as shown in Figure 9-1.
Figure 9-1
Spectrum Analyzer Setup
To Create a Two-Tone Waveform
This procedure describes how to create and a basic, center-aligned, two-tone waveform.
1. Preset the signal generator.
2. Set the signal generator RF output frequency to 20 GHz.
3. Set the signal generator RF output amplitude to 0 dBm.
4. Press Mode > Two Tone > Freq Separation > 10 > MHz.
5. Press Two Tone Off On to On.
6. Turn on the RF output.
The two-tone signal is now available at the signal generator RF OUTPUT connector. Figure 9-2 shows what
the signal generator display should look like after all steps have been completed. Notice that the T-TONE,
I/Q, RF ON, and MOD ON annunciators are displayed and the parameter settings for the signal are shown
in the status area of the signal generator display.
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Two-Tone Waveform Generator
Creating, Viewing, and Modifying Two-Tone Waveforms
Figure 9-2
To View a Two-Tone Waveform
This procedure describes how to configure the spectrum analyzer to view a two-tone waveform and its IMD
products. Actual key presses will vary, depending on the model of spectrum analyzer you are using.
1. Preset the spectrum analyzer.
2. Set the carrier frequency to 20 GHz.
3. Set the frequency span to 60 MHz.
4. Set the amplitude for a 10 dB scale with a 4 dBm reference.
5. Adjust the resolution bandwidth to sufficiently reduce the noise floor to expose the IMD products. A 9.1
kHz setting was used in our example.
6. Turn on the peak detector.
7. Set the attenuation to 14 dB, so you’re not overdriving the input mixer on the spectrum analyzer.
You should now see a two-tone waveform with a 20 GHz center carrier frequency that is similar to the one
shown in Figure 9-3 on page 183. You will also see IMD products at 10 MHz intervals above and below the
generated tones, and a carrier feedthrough spike at the center frequency with carrier feedthrough distortion
products at 10 MHz intervals above and below the center carrier frequency.
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Creating, Viewing, and Modifying Two-Tone Waveforms
Figure 9-3
Two-Tone
Channels
Carrier
Feedthrough
Intermodulation
Distortion
Carrier Feedthrough
Distortion
Chapter 9
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Two-Tone Waveform Generator
Creating, Viewing, and Modifying Two-Tone Waveforms
To Minimize Carrier Feedthrough
This procedure describes how to minimize carrier feedthrough and measure the difference in power between
the tones and their intermodulation distortion products. Carrier feedthrough only occurs with center-aligned
two-tone waveforms.
This procedure builds upon the previous procedure.
1. On the spectrum analyzer, set the resolution bandwidth for a sweep rate of about
100-200 ms. This will allow you to dynamically view the carrier feedthrough spike as you make
adjustments.
2. On the signal generator, press I/Q > I/Q Adjustments > I/Q Adjustments Off On to On.
3. Press I Offset and turn the rotary knob while observing the carrier feedthrough with the spectrum
analyzer. Changing the I offset in the proper direction will reduce the feedthrough level. Adjust the level
as low as possible.
4. Press Q Offset and turn the rotary knob to further reduce the carrier feedthrough level.
5. Repeat steps 3 and 4 until you have reached the lowest possible carrier feedthrough level.
6. On the spectrum analyzer, return the resolution bandwidth to its previous setting.
7. Turn on waveform averaging.
8. Create a marker and place it on the peak of one of the two tones.
9. Create a delta marker and place it on the peak of the adjacent intermodulation product, which should be
spaced 10 MHz from the marked tone.
10. Measure the power difference between the tone and its distortion product.
You should now see a display that is similar to the one shown in Figure 9-4 on page 185. Your optimized
two-tone signal can now be used to measure the IMD products generated by a device-under-test.
Note that carrier feedthrough changes with time and temperature. Therefore, you will need to periodically
readjust your I and Q offsets to keep your signal optimized.
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Two-Tone Waveform Generator
Creating, Viewing, and Modifying Two-Tone Waveforms
Figure 9-4
Main Marker
Minimized
Carrier
Feedthrough
Delta Marker
Chapter 9
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Two-Tone Waveform Generator
Creating, Viewing, and Modifying Two-Tone Waveforms
To Change the Alignment of a Two-Tone Waveform
This procedure describes how to align a two-tone waveform left or right, relative to the center carrier
frequency. Because the frequency of one of the tones is the same as the carrier frequency, this alignment
eliminates carrier feedthrough. However, image frequency interference caused by left or right alignment
may cause minor distortion of the two-tone signal. This procedure builds upon the previous procedure.
1. On the signal generator, press Mode Setup > Alignment Left Cent Right to Left.
2. Press Apply Settings to regenerate the waveform.
NOTE
Whenever a change is made to a setting while the two-tone generator is operating (Two Tone
Off On set to On), you must apply the change by pressing the Apply Settings softkey before
the updated waveform will be generated. When you apply a change, the baseband generator
creates a two-tone waveform using the new settings and replaces the existing waveform in
ARB memory.
3. On the spectrum analyzer, temporarily turn off waveform averaging to refresh your view more quickly.
You should now see a left-aligned two-tone waveform that is similar to the one shown in Figure 9-5.
Figure 9-5
Upper Tone
Aligned with
Carrier
Frequency
Two-Tone
Channels
Intermodulation
Distortion
Carrier
Frequency
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Chapter 9
10 Troubleshooting
This chapter provides basic troubleshooting information for Agilent PSG signal generators. If you do not
find a solution here, refer to the Service Guide.
NOTE
If the signal generator displays an error, always read the error message text by pressing
Utility > Error Info.
•
“RF Output Power Problems” on page 189
•
“No Modulation at the RF Output” on page 193
•
“Sweep Problems” on page 194
•
“Data Storage Problems” on page 196
•
“Cannot Turn Off Help Mode” on page 197
•
“Signal Generator Locks Up” on page 198
•
“Error Messages” on page 200
•
“Returning a Signal Generator to Agilent Technologies” on page 203
187
Troubleshooting
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Chapter 10
Troubleshooting
RF Output Power Problems
RF Output Power Problems
Check the RF ON/OFF annunciator on the display. If it reads RF OFF, press RF On/Off to toggle the RF
output on.
RF Output Power too Low
1. Look for an OFFS or REF indicator in the AMPLITUDE area of the display.
OFFS tells you that an amplitude offset has been set. An amplitude offset changes the value shown in the
AMPLITUDE area of the display but does not affect the output power. The amplitude displayed is equal to
the current power output by the signal generator hardware plus the value for the offset.
To eliminate the offset, press the following keys:
Amplitude > More (1 of 2) > Ampl Offset > 0 > dB.
REF tells you that the amplitude reference mode is activated. When this mode is on, the displayed
amplitude value is not the output power level. It is the current power output by the signal generator
hardware minus the reference value set by the Ampl Ref Set softkey.
To exit the reference mode, follow these steps:
a. Press Amplitude > More (1 of 2).
b. Press Ampl Ref Off On until Off is highlighted.
You can then reset the output power to the desired level.
2. If you are using the signal generator with an external mixer, see “Signal Loss While Working with a
Mixer” on page 190.
3. If you are using the signal generator with a spectrum analyzer, see “Signal Loss While Working with a
Spectrum Analyzer” on page 192.
The Power Supply has Shut Down
If the power supply is not working, it requires repair or replacement. There is no user-replaceable power
supply fuse. Refer to the Service Guide for instructions.
Chapter 10
189
Troubleshooting
RF Output Power Problems
Signal Loss While Working with a Mixer
If you experience signal loss at the signal generator’s RF output during low-amplitude coupled operation
with a mixer, you can solve the problem by adding attenuation and increasing the RF output amplitude of the
signal generator.
Figure 10-1 on page 190 shows a hypothetical configuration in which the signal generator provides a low
amplitude signal to a mixer.
Figure 10-1
Effects of Reverse Power on ALC
SIGNAL GENERATOR
OUTPUT CONTROL
ALC LEVEL
= - 8 dBm
RF OUTPUT
= - 8 dBm
MIXER
RF LEVEL
CONTROL
DETECTOR
MEASURES
- 8 dBm
ALC LEVEL
LO
DETECTOR
MEASURES
- 5 dBm
REVERSE
POWER
LO FEEDTHRU
= - 5 dBm
LO LEVEL
= +10 dBm
IF
The internally leveled signal generator RF output (and ALC level) is -8 dBm. The mixer is driven with an
LO of +10 dBm and has an LO-to-RF isolation of 15 dB. The resulting LO feedthrough of -5 dBm enters the
signal generator’s RF output connector and arrives at the internal detector.
Depending on frequency, it is possible for most of this LO feedthrough energy to enter the detector. Since
the detector responds to its total input power regardless of frequency, this excess energy causes the ALC to
reduce the RF output of the signal generator. In this example, the reverse power across the detector is
actually greater than the ALC level, which may result in loss of signal at the RF output.
Figure 10-2 on page 191 shows a similar configuration with the addition of a 10 dB attenuator connected
between the RF output of the signal generator and the input of the mixer. The signal generator’s ALC level is
increased to +2 dBm and transmitted through a 10 dB attenuator to achieve the required -8 dBm amplitude at
the mixer input.
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RF Output Power Problems
Figure 10-2
Reverse Power Solution
SIGNAL GENERATOR
OUTPUT CONTROL
ALC LEVEL/
RF OUTPUT
= +2 dBm
RF INPUT
= - 8 dBm
10 dB
ATTEN
RF LEVEL
CONTROL
DETECTOR
MEASURES
+2 dBm
ALC LEVEL
MIXER
DETECTOR
MEASURES
- 15 dBm
REVERSE
POWER
LO
LO LEVEL
= +10 dBm
LO FEEDTHRU
= - 5 dBm
IF
Compared to the original configuration, the ALC level is 10 dB higher while the attenuator reduces the LO
feedthrough (and the RF output of the signal generator) by 10 dB. Using the attenuated configuration, the
detector is exposed to a +2 dBm desired signal versus the
-15 dBm undesired LO feedthrough. This 17 dB difference between desired and undesired energy results in
a maximum 0.1 dB shift in the signal generator’s RF output level.
Chapter 10
191
Troubleshooting
RF Output Power Problems
Signal Loss While Working with a Spectrum Analyzer
The effects of reverse power can cause problems with the signal generator’s RF output when the signal
generator is used with a spectrum analyzer that does not have preselection capability.
Some spectrum analyzers have as much as +5 dBm LO feedthrough at their RF input port at some
frequencies. If the frequency difference between the LO feedthrough and the RF carrier is less than the ALC
bandwidth, the LO’s reverse power can cause amplitude modulation of the signal generator’s RF output. The
rate of the undesired AM equals the difference in frequency between the spectrum analyzer’s LO
feedthrough and the RF carrier of the signal generator.
Reverse power problems can be solved by using one of two unleveled operating modes: ALC off or power
search.
Setting ALC Off Mode
ALC off mode deactivates the automatic leveling circuitry prior to the signal generator’s RF output. In this
mode, a power meter is required to measure the output of the signal generator and assist in achieving the
required output power at the point of detection.
Use the following steps to set the signal generator to the ALC off mode:
1.
2.
3.
4.
5.
6.
7.
Preset the signal generator: press Preset.
Set the desired frequency: press Frequency and enter the desired frequency.
Set the desired amplitude: press Amplitude and enter the desired amplitude.
Turn the RF off: set RF On/Off to Off
Turn the signal generator’s automatic leveling control (ALC) off: press Amplitude > ALC Off On to Off.
Monitor the RF output amplitude as measured by the power meter.
Press Amplitude and adjust the signal generator’s RF output amplitude until the desired power is
measured by the power meter.
Setting Power Search Mode
Power search mode executes a power search routine that temporarily activates the ALC, calibrates the power
of the current RF output, and then disconnects the ALC circuitry.
Use the following steps to set the signal generator to manual fixed power search mode:
1.
2.
3.
4.
5.
6.
192
Preset the signal generator: press Preset.
Set the desired frequency: press Frequency and enter the desired frequency.
Set the desired amplitude: press Amplitude and enter the desired amplitude.
Turn the signal generator’s automatic leveling control (ALC) off: press Amplitude > ALC Off On to Off.
Turn the RF on: set RF On/Off to On.
Press Do Power Search.
This executes the manual fixed power search routine, which is the default mode.
Chapter 10
Troubleshooting
No Modulation at the RF Output
There are three power search modes: manual, automatic, and span.
When Power Search is set to Manual, pressing Do Power Search executes the power search calibration routine
for the current RF frequency and amplitude. In this mode, if there is a change in RF frequency or amplitude,
you will need to press Do Power Search again.
When Power Search is set to Auto, the calibration routine is executed whenever the frequency or amplitude of
the RF output is changed.
When Power Search is set to Span, pressing Do Power Search executes the power search calibration routine
over a selected range of frequencies at one time. The power search corrections are then stored and used
whenever the signal generator is tuned within the selected range of frequencies.
No Modulation at the RF Output
Check the MOD ON/OFF annunciator on the display. If it reads MOD OFF, press Mod On/Off to toggle the
modulation on.
Although you can set up and enable various modulations, the RF carrier is modulated only when you have
also set Mod On/Off to On.
For digital modulation, make sure that I/Q Off On is set to On.
Chapter 10
193
Troubleshooting
Sweep Problems
Sweep Problems
Sweep Appears to be Stalled
The current status of the sweep is indicated as a shaded rectangle in the progress bar. You can observe the
progress bar to determine if the sweep is progressing. If the sweep appears to have stalled, check the
following:
❏ Have you turned on the sweep by pressing any of the following key sequences?
Sweep/List > Sweep > Freq
Sweep/List > Sweep > Ampl
Sweep/List > Sweep > Freq & Ampl
❏ Is the sweep in continuous mode? If the sweep is in single mode, be sure that you have pressed the Single
Sweep softkey at least once since completion of the prior sweep. Try setting the mode to continuous to
determine if the missing single sweep is blocking the sweep.
❏ Is the signal generator receiving the appropriate sweep trigger? Try setting the
Sweep Trigger softkey to Free Run to determine if a missing sweep trigger is blocking the sweep.
❏ Is the signal generator receiving the appropriate point trigger? Try setting the Point Trigger softey to Free
Run to determine if a missing point trigger is blocking the sweep.
❏ Is the dwell time appropriate? Try setting the dwell time to one second to determine if the dwell time was
set to a value which was too slow or too fast for you to see.
❏ Do you have at least two points in your step sweep or list sweep?
Cannot Turn Off Sweep Mode
Press Sweep/List > Sweep > Off.
In the sweep mode menu you can choose to set the sweep to various sweep types or to turn sweep off.
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Troubleshooting
Sweep Problems
Incorrect List Sweep Dwell Time
If the signal generator does not dwell for the correct period of time at each sweep list point, follow these
steps:
1. Press Sweep/List > Configure List Sweep.
This displays the sweep list values.
2. Check the sweep list dwell values for accuracy.
3. Edit the dwell values if they are incorrect.
NOTE
The effective dwell time at the RF OUTPUT connector is the sum of the value set for the
dwell plus processing time, switching time, and settling time. This additional time added to
the dwell is generally a few milliseconds. The TTL/CMOS output available at the
TRIG OUT connector, however, is asserted high only during the actual dwell time.
If the list dwell values are correct, continue to the next step.
4. Observe if the Dwell Type List Step softkey is set to Step.
When Step is selected, the signal generator will sweep the list points using the dwell time set for step
sweep rather than the sweep list dwell values.
To view the step sweep dwell time, follow these steps:
a. Press Configure Step Sweep.
b. Observe the value set for the Step Dwell softkey.
List Sweep Information is Missing from a Recalled Register
List sweep information is not stored as part of the instrument state in an instrument state register. Only the
current list sweep is available to the signal generator. List sweep data can be stored in the instrument catalog.
For instructions, see “Storing Files to the Memory Catalog” on page 53.
Chapter 10
195
Troubleshooting
Data Storage Problems
Data Storage Problems
Registers With Previously Stored Instrument States are Empty
The save/recall registers are backed-up by a battery when line power to the signal generator is not
connected. The battery may need to be replaced.
To verify that the battery has failed:
1. Turn off line power to the signal generator.
2. Unplug the signal generator from line power.
3. Plug in the signal generator.
4. Turn on the signal generator.
5. Observe the display for error messages.
If either error message −311 or −700 is stored in the error message queue, the signal generator’s battery
has failed.
6. Refer to the Service Guide for battery replacement instructions.
Saved Instrument State, but Register is Empty or Contains Wrong State
If you select a register number greater than 99, the signal generator automatically selects register 99 to save
the instrument state.
If the register number you intended to use is empty or contains the wrong instrument state, recall register 99:
Press Recall > 99 > Enter.
The lost instrument state may be saved there.
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Troubleshooting
Cannot Turn Off Help Mode
Cannot Turn Off Help Mode
1. Press Utility > Instrument Info/Help Mode
2. Press Help Mode Single Cont until Single is highlighted.
The signal generator has two help modes; single and continuous.
When you press Help in single mode (the factory preset condition), help text is provided for the next key you
press. Pressing another key will exit the help mode and activate the key’s function.
When you press Help in continuous mode, help text is provided for the next key you press and that key’s
function is also activated (except for Preset). You will stay in help mode until you press Help again or change
to single mode.
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Troubleshooting
Signal Generator Locks Up
Signal Generator Locks Up
If the signal generator is locked up, check the following:
•
Make sure that the signal generator is not in remote mode (in remote mode, the R annunciator appears on
the display). To exit remote mode and unlock the front panel keypad, press Local.
•
Make sure that the signal generator is not in local lockout condition. Local lockout prevents front panel
operation. For more information on local lockout, refer to the Programming Guide.
•
Check for a progress bar on the signal generator display, which indicates that an operation is in progress.
•
Press Preset.
•
Cycle power on the signal generator.
Fail-Safe Recovery Sequence
Use the fail-safe recovery sequence only if the previous suggestions do not resolve the problem.
CAUTION
This process does reset the signal generator, but it also destroys the following types of data:
•
•
•
NOTE
all user files (instrument state and data files)
DCFM/DCΦM calibration data
persistent states
Do not attempt to perform any other front panel or remote operations during the fail-safe
sequence.
To run the fail-safe sequence, follow these steps:
1. Hold down the Preset key while cycling power.
2. Continue to hold down the Preset key until the following message is displayed:
WARNING
You are entering the diagnostics menu which can cause unpredictable instrument
behavior. Are you sure you want to continue?
CAUTION
Carefully read the entire message! It may list additional risks with this procedure.
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Signal Generator Locks Up
3. Release the Preset key.
4. To continue with the sequence, press Continue (to abort with no lost files, press Abort).
5. When the sequence concludes:
a. Cycle power.
Cycling power restores all previously installed options. Because calibration files are restored from
EEPROM, you should see several error messages.
b. Perform the DCFM/DCΦM calibration.
Refer to the DCFM/DCΦM Cal softkey description in the Key Reference.
c. Agilent Technologies is interested in the circumstances that made it necessary for you to initiate this
procedure. Please contact us at the appropriate telephone number listed in Table 10-1 on page 203.
We would like to help you eliminate any repeat occurrences.
Chapter 10
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Troubleshooting
Error Messages
Error Messages
If an error condition occurs in the signal generator, it is reported to both the front panel display error queue
and the SCPI (remote interface) error queue. These two queues are viewed and managed separately; for
information on the SCPI error queue, refer to the Programming Guide.
NOTE
When there is an unviewed message in the front panel error queue, the ERR annunciator
appears on the signal generator’s display.
Characteristic
Front Panel Display Error Queue
Capacity (#errors)
30
Overflow Handling
Circular (rotating).
Drops oldest error as new error comes in.
Viewing Entries
Press: Utility > Error Info > View Next (or Previous) Error Message
Clearing the Queue
Press: Utility > Error Info > Clear Error Queue(s)
Unresolved Errorsa
Re-reported after queue is cleared.
No Errors
When the queue is empty (every error in the queue has been read, or the queue is cleared), the
following message appears in the queue:
0
No Error Message(s) in Queue
a. Errors that must be resolved. For example, unlock.
Error Message File
A complete list of error messages is provided in the file errormesages.pdf, on the CDROM supplied with
your instrument.
In the error message list, an explanation is generally included with each error to further clarify its meaning.
The error messages are listed numerically. In cases where there are multiple listings for the same error
number, the messages are in alphabetical order.
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Chapter 10
Troubleshooting
Error Messages
Error Message Format
When accessing error messages through the front panel display error queue, the error numbers, messages
and descriptions are displayed on an enumerated (“1 of N”) basis.
Error messages appear in the lower-left corner of the display as they occur.
Explanation provided in the Error Message List
(This is not displayed on the instrument)
Chapter 10
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Troubleshooting
Error Messages
Error Message Types
Events do not generate more than one type of error. For example, an event that generates a query error will
not generate a device-specific, execution, or command error.
Query Errors (–499 to –400) indicate that the instrument’s output queue control has detected a problem
with the message exchange protocol described in IEEE 488.2, Chapter 6. Errors in this class set the query
error bit (bit 2) in the event status register (IEEE 488.2, section 11.5.1). These errors correspond to message
exchange protocol errors described in IEEE 488.2, 6.5. In this case:
•
Either an attempt is being made to read data from the output queue when no output is either present or
pending, or
•
data in the output queue has been lost.
Device Specific Errors (–399 to –300, 201 to 703, and 800 to 810) indicate that a device operation did not
properly complete, possibly due to an abnormal hardware or firmware condition. These codes are also used
for self-test response errors. Errors in this class set the device-specific error bit (bit 3) in the event status
register (IEEE 488.2, section 11.5.1).
The <error_message> string for a positive error is not defined by SCPI. A positive error indicates that the
instrument detected an error within the GPIB system, within the instrument’s firmware or hardware, during
the transfer of block data, or during calibration.
Execution Errors (–299 to –200) indicate that an error has been detected by the instrument’s execution
control block. Errors in this class set the execution error bit (bit 4) in the event status register (IEEE 488.2,
section 11.5.1). In this case:
•
Either a <PROGRAM DATA> element following a header was evaluated by the device as outside of its
legal input range or is otherwise inconsistent with the device’s capabilities, or
•
a valid program message could not be properly executed due to some device condition.
Execution errors are reported after rounding and expression evaluation operations are completed. Rounding
a numeric data element, for example, is not reported as an execution error.
Command Errors (–199 to –100) indicate that the instrument’s parser detected an IEEE 488.2 syntax error.
Errors in this class set the command error bit (bit 5) in the event status register (IEEE 488.2, section 11.5.1).
In this case:
•
Either an IEEE 488.2 syntax error has been detected by the parser (a control-to-device message was
received that is in violation of the IEEE 488.2 standard. Possible violations include a data element that
violates device listening formats or whose type is unacceptable to the device.), or
•
an unrecognized header was received. These include incorrect device-specific headers and incorrect or
unimplemented IEEE 488.2 common commands.
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Returning a Signal Generator to Agilent Technologies
Returning a Signal Generator to Agilent Technologies
To return your signal generator to Agilent Technologies, follow these steps:
1. Be prepared to give your service representative as much information as possible regarding the signal
generator’s problem.
2. Call the phone number listed in Table 10-1 appropriate to the signal generator’s location. After sharing
information regarding the signal generator and its condition, you will receive information regarding
where to ship your instrument for repair.
3. Ship the signal generator in the original factory packaging materials, if they are available. If not, use
similar packaging to properly protect the instrument.
Table 10-1
Contacting Agilent
Online assistance: www.agilent.com/find/assist
United States
(tel) 1 800 452 4844
Latin America
(tel) (305) 269 7500
(fax) (305) 269 7599
Canada
(tel) 1 877 894 4414
(fax) (905) 282-6495
New Zealand
(tel) 0 800 738 378
(fax) (+64) 4 495 8950
Japan
(tel) (+81) 426 56 7832
(fax) (+81) 426 56 7840
Australia
(tel) 1 800 629 485
(fax) (+61) 3 9210 5947
Europe
(tel) (+31) 20 547 2323
(fax) (+31) 20 547 2390
Asia Call Center Numbers
Country
Phone Number
Singapore
1-800-375-8100
(65) 836-0252
Malaysia
1-800-828-848
1-800-801664
Philippines
(632) 8426802
1-800-16510170 (PLDT Subscriber
Only)
(632) 8426809
1-800-16510288 (PLDT
Subscriber Only)
Thailand
(088) 226-008 (outside Bangkok)
(662) 661-3999 (within Bangkok)
(66) 1-661-3714
Hong Kong
800-930-871
(852) 2506 9233
Taiwan
0800-047-866
(886) 2 25456723
People’s Republic of
China
800-810-0189 (preferred)
10800-650-0021
10800-650-0121
India
1-600-11-2929
000-800-650-1101
Chapter 10
Fax Number
203
Troubleshooting
Returning a Signal Generator to Agilent Technologies
204
Chapter 10
Index
Symbols
ΦM, 81
Numerics
10 MHz connectors, 24
128QAM I/Q modulation, creating, 137
1410, application note, 170, 180
A
AC power receptacle, 18
ACP, 126, 154
active entry area (display), 13
adjustments, display, 11
Agilent Technologies, 203
ALC
annunciator, 14
bandwidth selection, 59
input connector, 9
limitations, amplitude, 61
off mode, setting, 192
with attenuator option, 63
Alpha adjustment (filter), 126
alternate ramp sweep, 43
AM, 14, 79
amplifier, microwave, 47
amplitude
display area, 16
hardkey, 7
LF output, 84
modulation. See AM
ramp sweep, 44
reference & offset, 30
analog modulation, 77–85
analog PSG features, 3
annunciators, 14
application note 1410, 170, 180
ARB
file catalogs, 52
reference, setting, 144
waveform header files, 88–98
See also Custom Arb waveform generator
See also Dual Arbitrary waveform generator
Index
ARMED annunciator, 14
arrow hardkeys, 11
ATTEN HOLD annunciator, 14
attenuator, external leveling, 63
automatic leveling control. See ALC
AUXILIARY I/O connector, 21
AUXILIARY INTERFACE connector, 18
B
bandwidth
ALC, selecting, 59
reference oscillator, adjusting, 76
baseband generator
custom Arb mode, 119
custom real time I/Q mode, 145
Dual Arb mode, 87
Multitone mode, 169
REF IN connector, 23
settings, 158, 159
Two-Tone mode, 179
BbT, adjusting, 126
binary files, 52
bit files, 52
bits per symbol, equation, 161
BURST GATE IN connector, 20
burst shapes, 153–157
C
carrier feedthrough, minimizing, 175, 184
carrier signal, modulating, 51
CCDF, 177
ceiling function, bits per symbol, 161
certificate, license key, 57
clipping, 112–118
COH connector, 22
comments, adding & editing (instrument state), 54
concepts
differential data encoding, 160
FIR filters, 125
waveform clipping, 113
waveform markers, 108
Configuring the Burst Rise and Fall Parameters, 154
connectors, 6, 17
205
Index
continuous
list sweep, 36
step sweep, 33
wave RF output, 28
contrast adjustments (display), 11
correction array (user flatness)
configuration, 66
load from step array, 66
viewing, 67
See also user flatness correction
couplers/splitters, using, 60
Custom Arb waveform generator, 119–144
Custom Real Time I/Q baseband, 145–167
CW PSG features, 2
D
data, 196
clock, 12, 159
fields, editing, 27
files, 52
input, 12
patterns, 147
See also instrument state register
See also memory catalog
default FIR filter, restoring, 127
Delete Item softkey, 27
Delete Row softkey, 27
description, adding & editing (instrument state), 54
detector, diode response, 62
detector, using, 60
differential data encoding, 160–167
DIG BUS annunciator, 14
Digital Bus connector, 22
digital modulation
annunciators, 16
custom, 119–144, 145–167
dual arb, 87–118
multitone, 169–178
two-tone, 179–186
diode detector response, 62
display, 11, 13
DMOD files, 52
dual ARB player, 99
Dual Arbitrary waveform generator, 87–118
dwell time, 32
206
E
Edit Item softkey, 27
ERR annunciator, 14, 200
error messages, 16, 200
EVENT connectors, 20
EVM, 126, 154
EXT
annunciators, 14
INPUT connectors, 8, 9
external
data clock, setting, 159
detector, diode response, 62
trigger, setting, 143
F
fail-safe recovery sequence, 198
failures. See troubleshooting
fall delay, burst shape, 154
fall time, burst shape, 154
features, signal generator, 2
feedthrough, carrier, minimizing, 184
files
catalogs, 52
using, 53–56
waveform segment, 103
waveform sequence, 101, 102
See also instrument state register
See also memory catalog
filters, 125–132
FIR, 52, 125
firmware, upgrades, 4
flatness correction. See user flatness correction
FM, 14, 80
ΦM, 14, 81
FM/Φ hardkey, 8
FM/ΦM hardkey, 8
frequency
display area, 13
hardkey, 7
modulation. See FM
offset, 29
ramp sweep, 38
reference, 29
RF output, setting, 28
Index
Index
front panel description, 6–16
FSK
files, 52
modulation, 136, 141, 142
G
GATE/PULSE/TRIGGER INPUT connector, 10
Gaussian filter, selecting, 126
Goto Row softkey, 27
GPIB, 18, 69
H
hardkeys, 6–11
hardware, configuring, 143, 158
header files (ARB waveform), 88–98
Help hardkey, 8
help mode troubleshooting, 197
Hold hardkey, 11
I
I OUT connector, 22
I/O connector, auxiliary, 21
I/Q
4QAM state map, 161
annunciator, 14
files, 52
input connectors, 12
modulation, 140, 165
scaling, adjusting, 159
I-bar OUT connector, 23
IMD. See intermodulation distortion
Incr Set hardkey, 10
Insert Item softkey, 27
Insert Row softkey, 27
instrument state register
comments, adding and editing, 54
troubleshooting, 196
using, 54
See also memory catalog
interface connectors
AUXILIARY INTERFACE, 18
GPIB, 18
LAN, 18
RS-232, 18
interface, remote, 69
Index
intermodulation distortion
from power peaks, 115
testing non-linear devices, 170, 180
K
key, license, 57
keypad, numeric, 9
keys, 6–11
knob, front panel, 7
L
L (listener mode) annunciator, 14
LAN connector, 18
LEDs, 10
leveling
ALC, 9, 192
external, 60–63
internal, 59
mm-wave source module, using, 47
LF output, 9, 83–85
license key, 57
line power LED, 10
list
error messages, 200
files, 52
mode values table editor, 26
sweep, 34, 195
listener mode annunciator, 14
Load/Store softkey, 27
Local hardkey, 11
low frequency output. See LF output
M
magnitude error simulation, 140
markers
blanking in sequence, 110
output, 19
ramp sweep, 40
toggling in waveform sequence, 106, 107
waveform, 104
master/slave setup, 45
MDMOD files, 52
memory catalog, 52, 196
See also instrument state register
MENUS hardkeys, 8
207
Index
microwave amplifier, 47
mixer, signal loss while using, 190
mm-wave source module
extending frequency range with, 47
leveling with, 63
user flatness correction array, creating, 69–75
mod on/off, 9, 15
models, signal generator, 2
modes of operation, 5
modulation
amplitude. See AM
analog, 78
annunciators, 14–16
applying, 50
file catalogs, 52
frequency. See FM
on/off hardkey, 9
phase. See ΦM
predefined setups, 121, 146
pulse, 82
types, 136
user-defined, 122, 165
See also digital modulation
MSK modulation, 136
MTONE files, 52
multitone waveform generator, 169–178
N
non-linear devices, testing, 170, 180
numeric keypad, 9
NVMKR files, 52
NVWFM files, 52
Nyquist filters, 126
O
offset, 29, 30
on/off switch, 10
options, 4, 57
oscillator, reference, adjusting BW, 76
output. See LF output and RF output
OVEN COLD annunciator, 15
208
P
Page Down softkey, 27
Page Up softkey, 27
PATTERN TRIG IN connector, 20
peak to average characteristics, 177
peak-to-average power, reducing, 116
performance, optimizing, 59–76
phase
error simulation, 140
modulation. See ΦM
polarity, 160
player, dual ARB, 99
power
meter, 64, 192
peaks, 113–115
receptacle, AC, 18
search mode, 192
supply troubleshooting, 189
switch, 10
predefined filters, 125
predefined modulation setups, 121, 146
Preset hardkey, 11
problems. See troubleshooting
PSK modulation, 136
pulse
annunciator, 15
input, 10
modulation, 82
Q
Q OUT connector, 23
QAM modulation, 136, 161
Q-bar OUT connector, 23
QPSK I/Q modulation, creating, 139
queue, error, 200
R
R (remote) annunciator, 15
ramp sweep, 37–46
Real Time I/Q, 145–167
rear panel description, 17
Recall hardkey, 7
recovery sequence, fail-safe, 198
Index
Index
rectangular clipping, 112
reference
amplitude, setting, 30
frequency, setting, 29
oscillator bandwidth, adjusting, 76
registers, 54, 55
remote control, 69
remote operation annunciator, 15
repair, return instructions, 203
Return hardkey, 11
RF output
annunciator, 15
configuring, 28–49
connector, 10
leveling, external, 60–63
mm-wave source module, using, 47
On/Off hardkey, 9
sweeping, 31
troubleshooting, 189
user flatness correction, 64–75
rise delay, burst shape, 154
rise time, burst shape, 154
root Nyquist filters, 126
RS-232 connector, 18
S
S (service request) annunciator, 15
Save hardkey, 7
Seq files, 52
sequences
deleting, 55
instrument state register, 54
renaming, 102
toggling markers in, 106, 107
service request annunciator, 15
service. See troubleshooting
shape files, 52
signal loss, troubleshooting, 189
Signal Studio software, 170, 180
single step sweep, 32
SMI connector, 24
softkeys, 7, 16, 27
SOURCE SETTLED OUTPUT connector, 19
spectral regrowth, 115
spectrum analyzer, troubleshooting signal loss, 192
Index
standby LED, 10
state files, 52
step array (user flatness), 64
See also user flatness correction
step attenuator, external leveling, 63
step sweep, 32–33
STOP SWEEP connector, 19
storage, troubleshooting, 196
sweep
annunciator, 15
list, 34
output, 19
ramp, 37–46
RF output, 31
step, 32
trigger, 36
troubleshooting, 194
Sweep/List hardkey, 8
switch, power, 10
symbol rates, 133
SYMBOL SYNC INPUT connector, 12
SYNC OUT connector, 10
T
T (talker mode) annunciator, 15
table editor, using, 26–27
talker mode annunciator, 15
text display area, 16
trigger
hardkey, 8
inputs
GATE/PULSE/TRIGGER, 10
PATTERN TRIG IN, 20
TRIGGER IN, 19
output, 19
setting, 36, 143
waveform, 111
troubleshooting, 187–203
two-tone, 179–186
U
UNLEVEL annunciator, 15
UNLOCK annunciator, 16
user flatness, 52, 64–75
209
Index
user-defined
burst shape curves, 155
data patterns, 149
files, 52
filters, 127, 129
modulation type
custom arb, 122
real time I/Q, 137, 165
V
vector PSG features, 4
VIDEO OUT connector, 10
W
waveforms
analog modulation, 78
ARB header files, 88–98
clipping, 112–118
custom, 119–144
Custom Real Time I/Q baseband, 145–167
dual arb, 87–118
file catalogs, 52
file, renaming, 103
markers, 104
multitone, 169–178
player, dual ARB, 99
segments, 100–103
sequence
blanking markers, 110
building and storing, 101–103
renaming, 102
toggling markers, 106, 107
triggers, 111
two-tone, 179–186
WFM1 files, 52
WIDEBAND I INPUT connector, 22
WIDEBAND Q INPUT connector, 22
Z
Z-AXIS BLANK/MKRS connector, 19
210
Index