The HP 8569B Spectrum Analyzer provides a visual display of RF and microwave signals in the frequency domain. Input signal amplitude is plotted on the CRT as a function of frequency and has absolute amplitude and frequency calibration from 10 MHz to 22 GHz. It is designed for simplicity of operation, most measurements can be made using only three controls.
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rhO-
OPERATION AND SERViCE MANUAL
This
SERIAL NUMBERS manual applies directly to HP Model 8569B
Spectrum Analyzers having serial prefix number
2244A.
For additional important information about serial numbers see INSTRUMENTS COVERED BY
MANUAL in Section I.
volume 1 GENERAL INFORMATION
INSTALLATION AND OPERATION VERIFICATION
CopyrIght © 1982,HEWLETT·PACKARD COMPANY
1424 FOUNTAIN GROVE PARKWAY, SANTA ROSA, CALIFORNIA, 85404, U.S.A.
MANUAL PARTNO. 08588-10032
Prtnted: December 1182
Scans by
ARTEK MEDIA
=>
Model 8569B
Contents
Section
GENERALINFORMATION
1-1.
Introduction
1-3.
Description
1-9.
Manual0rganization
1-11.
Specifications
1-13.
Safety Considerations
1·1
1-2
1-18.
Instruments Covered By Manual. . . . . . . 1-3
1-27.
Options....................... 1-3
1-1
1-1
1-1
1·1
140.
Accessories Supplied 14
142.
Equipment Available 14
149.
Recommended Test Equipment. . . . . . . 14
CONTENTS
Page
Section
Page
2-3.
2-5.
2-25.
2-31.
2-33.
2-34.
2-35.
2·36.
Initial Inspection
Preparation for Use
Storage and Shipment
Operation Verification
Operational Check
Tuning Accuracy
Frequency Span Width and
Resolution Bandwidth
Accuracy 2-10
Amplitude Accuracy . . . . . . . . . . . . . 2-12
2-1
2·1
2-7
2-7
2·8
2-8
II INSTALLATION AND OPERATION
VERIFICATION
2-1.
Introduction
2·1
2-1
III OPERATION
3-1.
Introduction
34.
Routine Maintenance
3-1
3-1
3-1
LIST OF ILLUSTRATIONS
Figure
Page
1-1. HP Model 8569B Spectrum Analyzer with
Accessories Supplied . . . . . . . . . . . . . . . . . . 1-0
1-2. Typical Serial Number Plate . . . . . . . . . . . . . . 1-3
1-3. Service Accessories Package. . . . . . . . . . . . .. 1-12
2-1.
Line Voltage Selection with Power
Module PC Board 24
Figure Page
2-2. Attaching Rack Mounting Hardware and Handles. . . . . . . . . . . . . . . . . . . . . . . . 2-5
2-3. Packaging for Shipment Using Factory
Packaging Materials
24. Operation Verification Test Setup
2-5.
Span Width Accuracy Measurement
2-6
2-9
2-11
LIST OF TABLES
Table Page
1-1. HP Model 8569B Specifications
1-2. HP Model 8569B Supplemental
1-5
Characteristics . . . . . . . . . . . . . . . . . . . . . . 1-8
1-3. Recommended Test Equipment. . . . . . . . . .. 1-14
Table
2-1.
AC Power Cables Available
2-2.
Rack-Mounting Kits for HP 8569B
2-3.
Operational Check
24.
Operation Verification Test Record
Page
2-2
2-3
2-14
2-17
General Information
HP 8569B
Model 8569B
LINE POWER CABLE
(SEE TABLE 2-1 FOR
HP PART NUMBER)
1-0
Figure 1-1. HP Model 8569B Spectrum Analyzer with Accessories Supplied
ModeI8569B
General Information
1-1.
INTRODUCTION
1-2.
This Operation and Service manual contains information required to install, operate, test, adjust, and service the Hewlett-Packard Model 8569B Spectrum Analyzer. Figure 1-1 shows the instrument and accessories supplied. This section covers instrument identification, description, options, accessories, specifications, and other basic information.
1-3.
DESCRIPTION
1-4.
The HP Model 8569B Spectrum Analyzer provides a visual display of RF and microwave signals in the frequency domain. Input signal amplitude is plotted on the CRT as a function of frequency.
1-5.
The HP Model 8569B is designed for simplicity of operation. Most measurements can be made using only three controls, once the normal settings
(marked in green) have been preset. The HP Model
8569B has absolute amplitude and frequency calibration from 10 MHz to 22 GHz. The frequency span, bandwidth, and video filter are all coupled with automatic sweep time to maintain a calibrated display and to simplify operation of the analyzer.
1-6.
Internal preselection eliminates most spurious images and multiple responses to simplify signal identification. The preselector also extends dynamic range of the analyzer and provides some protection for the input mixer.
1-7.
The frequency range of the HP Model 8569B is 10 MHz to 22 GHz in direct coaxial input and 12.4
to 115GHz when used with external mixers.
1-8.
The HP Model 8569B has a digital display with the spectral information contained in either of two independent traces. Major control settings are annotated on the CRT above the graticule area. Signal processing controls for the digital display include trace normalization, a maximum hold function, digital averaging, and trace storage. A hard-copy record of the display may be obtained through direct instrument control of listen-only plotters. The HP Model
8569B has an HP-IB capability that allows controller interrogation of display information or controller entry of messages and trace data.
1-9.
MANUAL ORGANIZATION
1-10. This manual is divided into eight sections as follows:
SECTION I, GENERAL INFORMATION, contains the instrument description and specifications, explains accessories and options, and lists recommended test equipment.
SECTION II, INSTALLATION AND OPERA-
TION VERIFICATION, contains information concerning initial mechanical inspection, preparation for use, operating environment, packaging and shipping, and operation verification.
SECTION III, OPERATION, contains detailed operating instructions for operation of the instrument.
SECTION IV, PERFORMANCE TESTS, contains the necessary tests to verify that the electrical operation of the instrument is in accordance with published specifications.
SECTION V, ADJUSTMENTS, contains the necessary adjustment procedures to properly adjust the instrument after repair.
SECTION VI, REPLACEABLE PARTS, contains the information necessary to order parts and/or assemblies for the instrument.
SECTION VII, MANUAL BACKDATING
CHANGES, contains backdating information to make this manual compatible with earlier equipment configurations.
SECTION VIII, SERVICE, contains schematic diagrams, block diagrams, component location illustrations, circuit descriptions, and troubleshooting information to aid in repair of the instrument.
1-11.
SPECIFICATIONS
1-12. Instrument specifications are listed in Table
1-1. These specifications are the performance standards or limits against which the instrument is tested.
1-1
Model 8569B
General Information
Table 1-2 lists supplemental characteristics. Supplemental characteristics are not specifications but are typical characteristics included as additional information for the user.
NOTE
To ensure that the HP Model 8569B meets the specifications listed in
Table 1·1, performance tests (Section
IV) should be performed every six months.
1·13.
SAFETYCONSIDERATIONS
1-14:.
~efore operating this instrument, you should
~arrulianze yourself with the safety markings on the
Instrument and safety instructions in this manual
This instrument has been manufactured and tested according to international safety standards. However, to ensure safe operation of the instrument and personal safety of the user and service personnel, the cautions and warnings in this manual must be followed. Refer to individual sections of this manual for
?etailed safety notation concerning the use of the
Instrument as described in those individual sections.
1·15.
Safety Symbols
Instruction manual symbol: the apparatus will be marked with this symbol when It is neeessary for the user to refer to the instruction manual in order to protect the apparatus against damage.
Indicates dangerous voltages.
Earth terminal
I
WARNING
I
The WARNING sign denotes a haz· ard. It calls attention to a proeedure, practice, or the like, which, If not correctly performed or adhered to, could result In Injury or loss of life. Do not proceed beyond a
WARNING sign until the Indicated conditions are fully understood and met.
The CAUTION sign denotes a haz· ard. It calls attention to an operat· ing procedure, practice, or the like, which, If not correctly peformed or adhered to, could result in damage to or destruction of part or all of the equipment. Do not proceed beyond a CAUTION sign until the
Indicated conditions are fully understood and met.
1-2
1·16.
Service
1-17.
Although this instrument has been manufactured in accordance with international safety standards, this manual contains information, cautions and warnings which must be followed to insure safe operation and to keep the instrument safe. Service should be performed only by qualified service personnel, and the following warnings should be observed:
I
WARNINGS'
Any maintenance or repair of the opened instrument under voltage should be avoided as much as posslble, and when inevitable, should be carried out only by a skilled person who is aware of the hazard involved.
Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its source of supply.
Make sure that only fuses with the required rated current and of the specified type (normal blow, time delay, etc.) are used for replacement.
The use of repaired fuses and the short·circuiting of fuseholders must be avoided.
When it is likely that the protection has been impaired, the instrument must be made inoperative and be secured against any unintended operation.
If this instrument is to be energized via an auto-transformer (for voltage reduction) make sure the common terminal is connected to the earthed pole of the power source.
BEFORE SWITCHING ON THE
INSTRUMENT, the protective earth terminals of the instrument must be connected to the protective conductor of the mains power cord. The mains plug shall only be inserted in a socket outlet provided with a protective earth contact. The protective action must not be negated by the use of an extension cord (power cord)
Model 8569B
1-20. Attached to the rear of each section of your instrument is a serial number plate (Figure 1-2). The serial number is in two parts. The first four digits and letter are the serial number prefix; the last five digits are the suffix. The prefix is the same for all identical instruments; it changes only when a change is made to the instrument. The suffix, however, is assigned sequentially and is different for each instrument. The contents of this manual apply to instruments with the serial number prefix(es) listed under
SERIAL NUMBERS on the title page.
General Information
1-22.
An instrument manufactured after the printing of this manual may have a serial number prefix that is not listed on the title page. This unlisted serial number prefix indicates the instrument is different from those described in this manual. The manual for this newer instrument is accompanied by a yellow
Manual Changes supplement. This supplement contains "change information" that explains how to adapt the manual to the newer instrument.
1-23. In addition to change information, the supplement may contain information for correcting errors in the manual. To keep this manual as current and accurate as possible, Hewlett-Packard recommends that you periodically request the latest Manual Changes supplement. The supplement carries a manual identification block that includes the model number, print date of the manual, and manual part number. Complimentary copies of the supplement are available from Hewlett-Packard. Addresses of
Hewlett-Packard offices are located at the back of this manual.
1-25. Instruments manufactured before the printing of this manual have been assigned serial number prefixes other than those for which this manual was written directly. Manual backdating information is provided in Section VII to adapt this manual to any such earlier assigned serial number prefix.
1-26.
This information should not be confused with information contained in the yellow Manual
Changes supplement, which is intended to adapt this manual to instruments manufactured after the printing of this manual.
SERIAL NUMBER
-
, sER,2J03A01726
OPT l f7h,i .
HE WLE r t, f->ACKARD
'\./1"
J
".~
".
l ' It..
,A
Figure
1-2. Typical Serial Number Plate
1-29. Option 001 provides an internally connected, l00-MHz comb generator that is switched in by a front-panel push button.
1-31. Option 002 deletes the two most narrow RES-
OLUTION BW settings, .3 kHz and .1 kHz, provided on the standard instrument.
1-3
General Information
1-33.
Option 400 permits operation on 50, 60, and
400 Hz mains. All specifications are identical to those of the standard HP Model 8569B except for operating temperature range and power requirements (see Table 1-1).
1-35.
Option 908, HP Part Number 5061-0078, includes flanges and hardware required to mount the
HP Model 8569Bin an equipment rack with horizontal spacing of 482.6 mm (19 in.), See Figure 2-2 for installation procedure.
1-37.
One additional Operation and Service Manual is provided for each Option 910 ordered.
To obtain Option 910 after shipment of the instrument, specify the manual part number printed on the title page of the manual.
1-39.
Option 913, HP Part Number 5061-<>084, combines a Front Handle Kit with Option 908, Rack
Flange
See Figure 2-2 for installation procedure.
1-41.
Figure 1-1 shows the HP Model 8569B Spectrum Analyzer and line power cord. One 5Q-ohm termination (HP 1810-01180, connected to the frontpanelIST LO OUTPUT port, is also supplied.
Mode18569B
1-44. A Service Accessories Package is available for convenience in aligning and troubleshooting the spectrum analyzer. The Service Accessories Package is shown in Figure 1-3. The package may be obtained from Hewlett-Packard by ordering HP Part Number
08569-60035.
This mixer extends the frequency range of the HP Model
8569B to 40 GHz. Transition sections (HP Models
11518, 11519A, and 11520A) are available to adapt the HP Model 11517A External Mixer to standard waveguide sizes.
This camera can be used with the
Model 8569B to make a permanent record of measurements.
A polyethylene transit case,
HP Part Number 1540-0654, is available for protection of the HP 8569BSpectrum Analyzer.
1-50.
Equipment required for operation verification, performance tests, adjustments, and troubleshooting of the HP Model 8569B is listed in Table 1-
3. Other equipment may be substituted if it meets or exceeds the critical specifications listed in the table.
1-4
Model 8569B
General Information
Table
1-1.
HP Model 8569B Specifications
(1
of 3)
FREQUENCY RANGE
Internal mixing 0.01 to 22 GHz
Covered in six ranges selectable by Frequency Band push buttons (in GHz): .01 to 1.8; 1.7 to 4.1; 3.8 to 8.5;
5.8 to 12.9;8.5 to 18; 10.5to 22.
External mixing 12.4to 115 GHz
Covered in four ranges selectable by Frequency Band push buttons (in GHz): 12.4-26.5 (6+ harmonic mode);
21-44 (10+ harmonic mode); 33-71 (16+ harmonic mode); and 53-115 (26+ harmonic mode).
Center Frequency
The center frequency represented by the CRT is indicated by the digital frequency displays on the front panel and the CRT.
Zero Span
Analyzer becomes a manually tuned receiver (for the time domain display of signal modulation) set to the frequency indicated by the digital frequency displays.
SPECTRAL RESOLUTION AND STABILITY
FREQUENCY ACCURACY
Tuning Accuracy
The overall tuning accuracy of the digital frequency readout in any span mode:
.01 to 115 GHz
± (5 MHz or 0.2% of center frequency, whichever is greater, + 20% of frequency span per division)
CRT digital readout resolution (included in tuning accuracy)
Internal mixing, 100 kHz; external mixing, 1 MHz
FREQUENCY SPANS
(on a 10 division CRT horizontal axis)
1.7t022GHz
Multiband span of spectrum from 1.7 to 22 GHz in one sweep. The frequency (position) corresponding to the tuning marker is set by the Tuning control and indicated by the digital frequency displays on the front panel and the CRT.
Full Band
Displays spectrum of entire Frequency Band selected. Tuning marker displayed in Full Band mode
(becomes center frequency when Per Divison mode is selected). Marker frequency is given on the digital displays.
Per Division
Eighteen calibrated spans from 1 kHzl Div to 500
MHz/Div in a 1, 2, 5,10 sequence. In "F" position the entire Frequency Band selected is spanned.
Span width accuracy
The frequency error for any two points on the display for spans from 500 MHz to 20 kHz/Div (unstabllized) is less than ±5% of the indicated separation; for stabilized spans 100 kHz/Div and less, the error is less than ± 15%.
Resolution Bandwidths
Resolution (3 dB) bandwidths from.1 kHz to 3 MHz in
1,3 sequence. Bandwidth may be varied independently or coupled to Frequency SpanlDiv control. Optimum coupling (convenient ratio of Frequency
SpanlDiv to Resolution Bandwidth) is indicated by alignment of markers
(~~) on both controls.
Uncoupled, the controls for Frequency SpanlDiv and
Resolution Bandwidth may be independently set so any resolution bandwidth (3 MHz to .1 kHz) may be used with any span width (F and 500 MHz to 1 kHz/Div). Analyzer is calibrated if UNCAL is not displayed.
Resolution Bandwidth accuracy
Individual resolution bandwidth 3 dB points:
<
±15%.
Selectivity: (60 dB/3 dB bandwidth ratio) widths 3 kHz to 3 MHz;
<
15:1 for band-
<
11:1 for bandwidths.1 kHz to 1 kHz.
Stability
Total residual FM
Stabilized:
<
100 Hz POp in 0.1 sec, .01- 4.1 GHz
Unstabilized:
<
10 kHz pop in 0.1 sec, .01- 4.1 GHz
(Fundamental mixing)
Stabilization range: First LO automatically stabilized
(unless auto stabilizer is OFF) for frequency spans
100 kHz/Div or less.
Noise sidebands: At least 75 dB down, greater than
30 kHz from center of CW signal when set to a 1 kHz Resolution Bandwidth and a 10 Hz (.01) Video
Filter (fundamental mixing).
AMPLITUDE RANGE -
Internal mixer
Measurement range:
Damage levels:
Total RF power: + 30 dBm (1 watt) de or ac «
<
500 source impedance):
OV with 0 dB input attenuation (1 amp); ± 7V with
<!:
10 dB input attenuation (0.14 amp)
1-5
General Information
Mode18569B
Table
1-1 HP Model 8569B Specifications (2 of 3)
Peak pulse power:
+
50 dBm «10!"sec. pulse width, 0.01
% duty cycle),
;?:
20 dB attentuation
Gain compression:
<
1 dB for - 7 dBm input level with 0 dB attenuation.
Average Noise Level:
Sensitivity (minimum discernible signal) is given by the signal level which is equal to the average noise level, causing approximately a 3-dB peak above the noise. Maximum average noise level with 1 kHz Resolution Bandwidth (0 dB attenuation and 0.003 (3 Hz) video filter) is given in the table below. Sensitivity in the external mixing bands (harmonic modes 6 +,10 +,16 + and 26 +) assumes an external mixer conversion loss of
30 dB.
Frequency First IF
Harmonic Avg. Noise Level
Band (GHz) In MHz
Mode
(dBm)
.01·1.8
1.7-4.1
3.8-8.5
5.8·12.9
2050
321.4
321.4
321.4
1-
1-
2-
3-
-113
-110
-107
-100
8.5-18
10.5-22
12.4-26.5
21-44
33-71
53-115
321.4
321.4
321.4
321.4
321.4
321.4
4+
5+
6+
10+
16+
26+
-95
-90
-104
-104
-104
-104
Reference Level
Reference Level range: +60 dBm' to -112 dBm in 10 dB steps and continuous 0 to -12 dB calibrated vernier.
Reference Level accuracy:
With Sweep TimelDivision control in Auto setting, the optimum sweep rate is selected automatically for any combination of Frequency Span/Div, Resolution
Bandwidth and Video Filter settings. Thus, the Auto
Sweep setting insures a calibrated amplitude display within the following limits:
Calibrator output
-10dBm ±0.3dB
100 MHz
:to
10 kHz
Reference Level variation (Input Attenuator at 0 dB)
10 dB steps, + 20°C to + 30°C:
-10to -70dBm:
<
±0.5dB·
-10to -100dBm:
< ±1.0dB
-10to -70dBm:
< ±1.0dB,0°Cto +55°C
1-6
Ilnput level not to exceed +30 dBm damage level.
Vernier (0 to -12 dB) continuous: Maximum error
< ±0.5 dB, when read from Reference Level Fine control.
Input Attenuator (at preselector input, 70 dB range in 10 dB steps)
Step size variation: o to 60 dB, 0.01-18 GHz:
< ± 1.0 dB o to 40 dB, 0.01·22 GHz: < ± 1.5 dB
Maximum cumulative error: o to 60 dB, 0.01-18 GHz:
< ±2.4 dB o to 40 dB, 0.01-22 GHz: < ± 2.5 dB
Frequency Response (with 0 or 10 dB of Input
Attenuation)
Frequency response includes input attenuator, preselector and mixer frequency response plus mixing mode gain variation (band to band) and assumes preselector peaking.
Frequency Band (GHz)
.01-1.8
1.7-4.1
3.8-8.5
5.8-12.9
8.5·18
10.5-22
Frequency Response
(± dB MAX.)
1.2
1.5
2.5
2.5
3.0
4.5
Switching between bandwidths: 3 MHz to 300 kHz,
<
± 0.5 dB; 3 MHz to 0.1 kHz, < ± 1.0 dB.
Calibrated display range
Log expanded from reference level down:
70 dB with 10 dBlDiv scale factor
40 dB with 5 dB/Div scale factor
16 dB with 2 dBlDiv scale factor
8 dB with 1 dB/Div scale factor
Linear: Full scale from 0.56 !"V (-112 dBm across 50 ohms to 224 volts (+60 dBm)' in 10 dB steps and continuous 0 to -12 dB vernier. Full scale signals in linear translate to approximately full scale signals in the log modes.
Display accuracy
Log:
<
± 0.1 dB/dB but not more than ± 1.5 dB over
70 dB display range.
Linear:
<
± 3% of reference level.
Residual responses (no signal present at input):
With 0 dB input attenuation and fundamental mixing
(0.01 to 4.1 GHz): < - 90 dBm.
Signal Identifier:
Provided over entire frequency range and in all Frequency Span / Div. settings. Correct response is a 2
MHz shift to left and approximately a 6 dB lower amplitude. (Reads incorrectly for 100 MHz CAL OUT-
PUT Signal.)
Model 8569B
General Information
WEIGHT:
Net: 29.1 kg (64 Ibs.)
Shipping: 40.9 kg (90 Ibs.)
Tab/e 1-1. HP Mode/8569B Specifications (] of])
SWEEP TIME
Auto: Sweep time is automatically controlled by Frequency SpanlDiv, Resolution Bandwidth and Video Filter controls to maintain an absolute amplitude calibrated display.
Calibrated Sweep times: 21 internal sweep times from
21'secIDiv to 10 seclDiv in 1,2,5 sequence. Sweep time accuracy
±
10% except for 2, 5, and 10 sec/Div, which are ±20%. Swept frequency modes use sweep times 2 mseclDiv through 10 seclDiv. When operated as a fixed tuned receiver (Zero Span) the full range of sweep·times
(2 I'sec to 10 seclDiv) may be used to display modulation waveforms. Sweep times that are too fast or too slow for the Resolution Bandwidth, Frequency Span/ Div, and
Video Filter settings (producing an uncalibrated display) are indicated by an UNCAL warning on the CRT. Sweep times
:5
2 mseclDiv
(:5
5 mseclDiv when in Max Hold, Digital Averaging, or INP-B....A Normalization) produce a mixed mode display with analog traces and CRT control readouts on the CRT.
LO OUTPUT (2.00
to 4.46 GHz):
+7 dBm minimum, 0 to 35°C;
+
5 dBm minimum, 35 to 55°C.
TEMPERATURE RANGE:
Operating O°C to 55°C
Storage - 40° C to + 75°C.
HUMIDITY RANGE (Operating):
< 95% R.H. O°C to +40°C.
EMI:
Conducted and radiated interference is in compliance with MID-STD 461A Methods CE03 and RE02, CISPR publication 11 (1975) and Messempfaenger- Postverfuegung 526/527/79 (Kennzeichnung Mit FNummer/Funkschutzzeichen).
POWER REQUIREMENTS
48-Q6 Hz; 100,120,220 or 240 volts (-10% to + 5%); 220 VA maximum. Fan cooled.
DIMENSIONS
458 mm wide: 188 mm high, 565 mm deep (18 in. x
73/8 in. x 22 1/4 in.)
~.JI!1..D...n.
..
- r t
JJ U "
TOP
_ l.---468mm (18 in.I-----1-r!----565 mm
~
122.25in.,~
It
OPTION 001
Intemal100 MHz Comb Generator
Frequency Range: 0.01 to 22 GHz
Frequency Accuracy:
:5
± 0.007%
OPTION 002
Deletes .3 kHz and .1 kHz resolution BW settings.
All specifications Identical to standard HP 8569B except:
Spectral Resolution and Stability
Resolution Bandwidths: Resolution (3 dB) bandwidths from 1 kHz to 3 MHz in a 1, 3 sequence.
Selectivity: (60 dB/3 dB bandwidth ratio) < 15:1 for bandwidths 1 kHz to 3 MHz.
Stability
Total Residual FM
Stabilized: <200 Hz pop in 0,1 sec..01-4.1 GHz.
OPTION 400
Permits operation on 48-440 Hz mains.
All specifications Identical to standard HP 8569B except:
Power requirements: 48 to 440 Hz; 100, 120, 220 or 240 volts (-10% to + 5%); 220 VA maximum. Fan cooled.
'Input level not to exceed + 137 dBI'V damage level.
1-7
General Information
Model 8569B
Table 1-2. HP Model 8569B Supplemental Characteristics (1 of 4)
FREQUENCY SPANS
1.7t022 GHz
When this mode is selected the analyzer displays the entire spectrum from 1.7 to 22 GHz. A 3 MHz Resolu· tion Bandwidth, 9 kHz Video Filter, and 100 msec/div
Sweep Time are automatically selected.
Full Band
When selected by panel pushbutton, analyzer displays spectrum of Frequency Band chosen. This automatically selects a 3 MHz Resolution bandwidth and a 9 kHz Video Filter. Sweep Time/Div varies from approximately 10 msec to 100 msec/div depending on which Frequency Band is chosen. Tuning marker frequency (position) indicates where analyzer tuning will be centered If a Per Division span mode is chosen.
Per Division
In "F" position (full band), the entire range of the Frequency Band selected is spanned, thus allowing the use of Resolution Bandwidth and Video Filter settings other than those chosen when the Full Band pushbutton is depressed. Center frequency of the analyzer's display is set by the tuning control and indicated by the LED readouts. The Frequency CAL control to the right of the display window on the front panel is used to set the LED readout to agree with the actual center frequency of the CRT display (normally set using the 100 MHz CAL OUTPUT as a 0.100 GHz frequency reference).
Out-of-range blanking
The out-of-range portion of the CRT trace is automatically blanked whenever the analyzer is swept beyond a band edge.
RESOLUTION
Bandwidth Ranges
See Figure 1 for curves of typical analyzer resolution using different IF bandwidths.
IF Bandwidth shape:
Approximately gaussian (synchronously tuned, 4pole filter)
Frequency drift (fundamental mixing, .01-4.1 GHz) long term
At fixed center frequency after 1 hour warm·up:
Stabilized < ±3.0 kHz/10 minutes
Unstabilized < ±25 kHz/10 minutes
With Temperature Changes:
Stabilized < 10 kHz/·C
Unstabilized <200 kHZ/·C
Auto stabilizer may be disabled in narrow spans
«
100 kHz/Div) by depressing front panel pushbutton switch to "OFF" position.
VIDEO FILTER
Video Filter bandwidths typically ± 20% of nominal value.
Post detection low-pass filter used to average displayed noise for a smooth trace. Nominal settings are given as decimal fractions of the Resolution
Bandwidth: OFF, .3, .1, .03, .01, and .003. A 1 Hz
NOISE AVG (noise averaging) setting is provided for noise level measurement.
60
70
50
40
'0
~
,:~
1\
\ \
1\
\
\
\
\
~
\
~
\
\
\
1\
~
~ ~
~~
%
~
~
~
~
'I
1\,
80
100 Hz
1 kHz
'1\
~
1\
,~
10kHz 100 kHz
SIGNAL SEPARATION
1 MHz
'\
10MHl
Figure
1.
Typical Spectrum Analyzer Resolution
INTERNALPRESELECTOR
Freauency Ranae
0.01 to 1.8 GHz
DeacrlDtlon
Low-pass filter
1.7to22GHz
Tracking YIG tuned filter
ReJection
>50 dB above
2.05GHz
> 70 dB greater than 642.8 MHz from center of pass band 1.7
to 18GHz.
>60 dB from 18 to 22 GHz
TRACKING PRESELECTOR
Preselector skirt roll-off: Characteristics of a three-pole filter (nominally 18 dB/octave), 3 dB bandwidth typically varies from 25 MHz (at 1.7 GHz)to 70 MHz (at 22 GHz).
Model 8569B
General Information
Table
1-2 HP Model 8569B Supplemental Characteristics (2 of 4)
tn-
DYNAMIC RANGE
Maximum power ratio of two signals simultaneously present at the input that may be measured within the limits of specified accuracy, sensitivity and distortion
(i.e., spurious responses): 0.01 to 22 GHz
>
70 dB.
Spurious responses: (Input attenuator set to 0 dB)
Second harmonic distortion
Frequency Range Input Power
0.01 ·1.8 GHz
1.7-22GHz
-40dBm
+30dBm
"May be below average noise level
Relative Distortion
< -70dB
< -130dB"
~ t
60
20
30 -
40 -
50
I
I
09
if./
~:"/..,~o
1"/
I",
-
I " l . : _ _
"
I
~
::'
J;
-1:"1
:"'-----~__l--+-~
/,,~'"
<Q' '" :-.,....
-+---;--+---1
~I:" 1~1·i
-: i!:i'~I:>'--L----i_-+----i_-f
~(I€../+.
-+---;--+---;--+---1
!
;
~
70 t---+-+--.........
j,-10.5-22.0 GHz
80
~
90
...
f·.....
_ '_
I
8+::...,..;~':":~+·~.-=:':":~~::..j.z--!---1
,~~
6Hz
1.7~.1 GHz
0.01-1.8 GHz i::
Sensl:~v~~HZBW)
-
~~i'~-
2nd Order Products - - -
120 3rd Order produ~
•• _ _•
130
~O
_..I_..
I
22 GHz (2nd end 3rd order)
ISignel Separetion;ol00 MHz
-70 -60
I - ; - - : -
-so
~ -30 -20 -10 O' +10 +20 +30
Effective Input Level in dBm (Signel Level-Input Attenuetion)
Third order Intermodulation
Frequency
Range
For Two Input Signals With
Total Power Signal 5ep.
0.01·22GHz
1.7·12.9GHz
1.7·22GHz
-30dBm ~SOkHz
-10dBm
~70MHz
-10 dBm
~
100 MHz
"May be below average noise level
Relative
Distortion
< -70dB
< -130dB"
< -130dB"
For typical harmonic and third order intermodulation distortion, see Figure 2.
Image and MUltiple Responses:
Frequency
0.01-1.8 GHz
1.7-18GHz
18-22GHz
Imlge
(oul of bind)
< -SOdB
<-70dB
< -60dB
Multiple
(In-bind) non-existent
< -70dB
< -60dB
Figure
2. Optimum Dynamic Range Chart
AMPLITUDE ACCURACY
The overall amplitude accuracy of a measurement depends on an analyzer's performance and the measurement technique used.
Applying IF substitution eliminates errors caused by the display, bandwidth gain variation, scale factor and input attenuator step size.
Only IF gain variation (reference level change with input attenuation constant: <
±
0.5 dB), calibrator amplitude
« ±
0.3 dB), and frequency response remain. In brief, IF substitution minimizes error by minimizing control changes from the reference measurement (e.g., calibration).
For measurements in the Frequency Bands covering 1.7
to 22 GHz that don't require the best possible accuracy, the front panel preselector peak may be left centered in
1-9
1-10
General Information
Model 8569B
Table
1-2. HP Model 8569B Supplemental Characteristics (3 of 4)
its "green" setting. Best amplitude accuracy is obtained by peaking the preselector at the frequency of interest.
Reference Level Variation (For any change of scale taetor):
<
±
1 dB.
FREQUENCY RESPONSE AND AVERAGE
NOISE LEVEL
For typical frequency response and average noise level versus input frequency, see Figure 3.
1--+--+--t---t--+--+--t--+-+-----1f--i
-10
I
~YPICAl~REaUE~CYRESP~NSEEX~URSIONI
LIMITS
I I •
1--+--+--t---t--+--+--t--+-+-----1f--i
-10
-..--f---+--+--+--+--+---+--+--+----;--i
-!.,...---
I
-00
-120
1--+-+-+---+-+-+--1--+-.j-.....If--i
, kHI I SPECIFIE!? I
I
,...-f--+-~_-oof--
F -
I--H
I
10 12
FReQUENCY'
GHI
I
'4 16 18 20
Figure
3.
Typical Frequency Response and
A verageNoise Level Versus Input Frequency
22
INPUT 500 0.01 TO 22 GHz
Input connector: Precision type N female
Input Impedance
Input attenuator at 0 dB: 50 ohms nominal
SWR: < 1.5
0.01 to 1.8 GHz
<2.0
1.7 to 22 GHz (at analyzertuned frequency)
Input attenuator at 10 dB or more: 50 ohms nominal
SWR: < 1.3
0.01 to 1.8 GHz
<2.0
1.7to22GHz
LO Emission (2.00 to 4.46 GHz):
< - 60 dBm 0.01 to 1.8 GHz
< -SOdBm 1.7t022GHz
Input Protection (For input signals from .01 to 22 GHz)
0.01 to 1.8 GHz Frequency Band: Internal diode limiter.
1.7 to 22 GHz Frequency Bands: Saturation of YIG filter (preselector) occurs at total input signal power levels below input mixer damage.
SMA female connector is a port for 321.4 MHz IF input signals and bias current. Internal gain adjustments have a range of 10 to 45 dB.
SWEEP SOURCE
Manual: Sweep determined by front panel control: continuously settable across CRT in either direction.
External: Sweep determined by 0 to
+
10V external signal applied to External Sweep input on rear panel.
Blanking is controlled by signal at Blanking Input.
Operation in Digital Storage Display mode with External sweep requires a Retrace signal input to rear panel
Retrace Input connector.
Internal: Sweep generated from internal sweep generator.
SWEEP TRIGGER
Free Run: Sweep triggered repetitively by internal source.
Line: Sweep triggered by power line frequency.
Video: Sweep internally triggered by detected waveform of input signal (signal amplitude of 0.5 division peak-topeak required on CRT display).
Trigger Level: Sets the level of the sweep trigger signal, whether it is the displayed trace (Video mode) or an external trigger input (Ext mode).
External Trigger: Sweep triggering determined by signal input (between
+
1 and
+
10 volts) to rear panel BNC connector.
Single: Sweep triggered or reset by front panel
Start/Reset pushbutton.
Start/Reset: Triggers sweep in Single sweep mode. Can also reset any internal sweep to left edge of display.
Model 8569B
General Information
Table
1-2 HP Model 8569B Supplemental Characteristics (4 of 4)
Plotter Interface
Log: < 0.1 dB/dB, max error < 1 dB
Linear: < 0.1 division
V, and Z Axis Outputs: These outputs are compatible with and may be used to drive all current HP XV recorders (using positive pencoils or TIL penlift input) and CRT monitors.
Horizontal Sweep Output (X axis): A voltage proportional to the horizontal sweep of the CRT trace which ranges from - 5V for the left graticule edge to
+
5V for the right graticule edge. Output impedance is 5 kohms.
Vertical Output (V axis): Detected video output proportional to vertical deflection of the CRT trace. Output increases 100 mV/div from 0 to 800 mV (from a 50 ohm source) for a full 8-division deflection. Output impedance is 50 ohms.
Blank (Penlift or Z axis) Output: A blanking output, 15V from 10 kohms, Which occurs during CRT retrace or when sweeping beyond band edges. Otherwise output is low at OV with a 10 ohm output impedance for a normal or unblanked trace (pen down).
Blanking Input: Permits remote Z axis control of CRT with TIL levels; normal < 0.5V or open circuit, blank
> 2V. Input impedance is 10 kohms. Note that in Digital
Storage mode, Blanking input does not directly blank the CRT; instead it sets blank bits in the trace memory so that the appropriate parts of the trace are blanked during the CRT refresh cycle.
Caution: maximum input is ±40V.
External Sweep Input: When the front panel Sweep
Source switch is set to the EXT mode, a 0 to 10V ramp will sweep the analyzer through the frequency range determined by front panel Tuning and Frequency Span/Div controls. Input impedance is 100 kohms.
Caution: maximum input ± 40V.
Retrace Input: Required for operation in Digital Storage
Display mode if External Sweep is used. Normal level
<O.5V, blank (retrace) level >2V. Input impedance is 10 kohms.
Caution: maximum input is
±
40V
External Trigger Input: With the Sweep Trigger in EXT mode, a signal will trigger a sweep on the signal's positive slope between + 1 and + 10 volts according to the setting of the Trigger Level control. 100 kohms input impedance, de coupled.
Caution: maximum input
±
40V.
21.4 MHz IF Output: A 50 ohm, 21.4 MHz output linearly related to the RF input to the analyzer. Bandwidth controlled by the analyzer's Resolution Bandwidth setting; amplitude controlled by the Input Attenuator, IF gain vernier and first 6 IF Reference Level step gain positions
(-10 through - 60 dBm level with 0 dB input attenuation). Output is approximately - 10 dBm from 50 ohms for full scale signals on the CRT.
First LO Output: Connector is SMA Female, 50 ohms.
Terminate in a 50 ohm load When not in use.
Frequency: 2.00 to 4.46 GHz
Power Level: typically
+
8 dBm minimum
Stability (Typical residual FM):
Stabilized: 30 Hz pop
Unstabilized: 2 kHz pop
External Mixing Bias: -5 mA to +5 mA Onto 500 D.s) output from the EXT MIX ING IF INPUT port. Maximum short circuit current limits: ±9 mA, maximum open circuit voltage limits: ±3 volts.
Aux B: Used during factory calibration.
CATHODE RAY TUBE
Type: Post deflection accelerator, approximately 11.5 kV accelerating potential, aluminized P31 phosphor, electrostatic focus and deflection.
Graticule: Internal 8 x 10 division. 1 division vertically is
1 centimeter, 1 division horizontally is 1.2.centimeters.
There are 5 subdivisions per each major division.
Annotation: Major control settings are annotated on
CRT.
Viewing Area: Approximately 9.6 centimeters vertically by 11 centimeters horizontally (3.8 inches by 4.7 inches).
1-11
General Information
Model 8569B
1-12
HP PART NO. 08565-60100
Figure
1-3. Service Accessories Package (1 of 2)
Model 8569B General Information
!
Jillillllil
Item Description
C
D
HP Part
Number
•
0
Extender board, 6 pin (12 conductors)
•
Extender board, 15 pin (30 conductors)
Extender board, 22 pin (44 conductors)
0
•
•
•
Wrench, 15/64 inch open end
Adapter, SMA male to male
Wrench, 5/16 inch slotted box end/open end
Adapter, BNC female to SMA male
•
Alignment tool
•
Test cable, subminiature (SMC) female to BNC male
(36 inches long)
8
7
8
8
3
9
6
7
08505-60109
08505-60041
08565-60107
871O'{)946
1250-1158
08555-20097
1250-1200
871O.{)630
11592-60001
•
CD
Alignment tool, non-metallic
4 871O.{)033
•
Adapter, BNC female to SMC female (used to measure
3 08565-60087 second LO output)
Connector extractor
6 8710.{)580
•
Tuning tool (consists of modified 5/16 inch nut driver
6 08555-60107 with modified No. 10 Allen driver)
•
Extender board, 40 pin (80 conductors)
9 08569-60013
Figure
1-3. Service Accessories Package (2 of 2)
1-13
Synthesized Signal
Generator
Frequency Counter
Electronic Counter
Power Meter
Power Meter
Power Sensor
Power Sensor
Power Sensor
Power Sensor
Spectrum Analyzer
Tracking Generator
Sweep Oscillator
1-14
General Information
Instrument
Digital Voltmeter
Oscilloscope
Probe
Probe
Probe
Function Generator
Comb Generator
Signal Generator
Model 8569B
Table 1-3. Recommended Test Equipment (1 of 3)
Critical Specifications
Range: -IOOOV to +1OOOV
Accuracy: ±O.004% of reading pluse 0.001 % of range
Input Impedance: 10 Meg ohms
Frequency: 100 MHz
10: 1 Divider
1: 1 Divider
High Voltage, 4 kV
Amplitude: 0 to +1OVpop sine wave with de offset
Frequency: 1 to 5 kHz
Frequency Markers: 10 and 100 MHz
Increments up to 5 GHz
Frequency: 50 to 500 MHz
Modulation Frequency: 100 kHz
Modulation Deviation: 1% of lowest frequency in range
Frequency Resolution: 2 Hz
Recommended Model
HP 3455A
HP1741A
HP 10004D
HP 10007D
HP 34111A
HP 3312A
HP 8406A
HP 8640B, Opt. 001
HP8662A
Use*
P,A,T
A,T
A,T
A,T
A,T
P,A,T
P,A
P,A,T
P
Range: .01 to 24.5 GHz
Time Interval Counter Function
Range: -20 to +10 dBm
Recorder Output: 1V = full scale
Frequency Range: .05 to 26.5 GHz
Frequency Range: 12.4-18.0 GHz
Frequency Range: .01-18 GHz
Frequency Range: 18.0-26.5 GHz
Frequency: 300 MHz
Frequency: 300 MHz
Mainframe for RF Plug-in
HP 5342A, Opt. 005
HP 5300A/5302A
HP435B
HP432A
HP 8485A
HPP486C
HP 8481 A, Opt. C03
HPK486C
HP 140T/8552B/8554B
HP 8444A, Opt. 059
HP 8350A
P,A,T
P,A,T
P,A,T
P,A,T
A,T
A,T
P,A,T
A
P,A,T
A,T
P,A,T
Model 8569B
Instrument
Sweep Oscillator
RF Plug-in
RF Plug-in
RF Plug-in
Synchronizer
DC Power Supply
Termination
Mixer
Power Splitter
Crystal Detector
Attenuator
Attenuator
Step Attenuator
Attenuator
Step Attenuator
Adapter
(2 required)**
Adapter
Adapter (2 required)
Adapter
General Information
Table 1-3. Recommended Test Equipment (2 of 3)
Critical Specifications
Mainframe for RF Plug-in
(Alternate for HP 8350A)
Frequency: .01 to 26.5 GHz
Frequency: .01 to 2.4 GHz
Frequency: 2 to 22 GHz
Residual FM: <30 kHz in 10kHz Bandwidth
No Substitute
4 to 6 volts de (Floating)
Frequency: de to 18 GHz
Impedance: 50 ohms
Connector: Type N Male
Input Frequency: 23 GHz
Frequency: 2 to 18 GHz
Attenuation: 6 dB each arm
Connectors: Type N Female Input APC-7 Outputs
Frequency: .1 to 22 GHz
Input Connector: APC-3.5
Attenuation: 10 dB ±0.5 dB
Frequency: .01 to 18 GHz
Connectors: Type N
Frequency Range: 12.4-18 GHz
Attenuation: 0 to 12 dB in 1-dB steps
Frequency: 100 MHz, Calibrated
Frequency Range: 18.0-26.5 GHz
Attenuation: 0 to 120 dB in lO-dB steps
Frequency: 100 MHz, Calibrated
Waveguide to SMA Jack
Recommended Model
HP 8620C
HP 83595A
HP 86222A
HP 86290A, Opt. H08
HP 8709A, Opt. H10
HP 62l4A
HP 909A, Opt. 012
HP 11517 A, Opt. E03
HP 11667 A, Opt. 002
HP 33330C
HP 8491B, Opt. 010
HPP382C
HP 355C, Opt. H80
HP K382C
HP 355D, Opt. H80
Narda 4608
Use*
P,A,T
A,T
P,A
P,A,T
P
P,A
A
P,A
A
P,A
P,A
A
A
P
P,A,T
P,A
Type N Female to BNC Male
Type N Male to BNC Female
Type N Plug to SMA Jack
HP 1250-0077
HP 1250-0780
HP 1250-1250
P
P,T
P,T
1-15
Instrument
Adapter**
Adapter
Adapter
Adapter
Adapter
Adapter
Adapter (2 required)
Cable Assembly
Cable Assembly
BNC Short
BNC Tee
Test Cable**
Diplexer
Directional Coupler
Directional Coupler
General Information Model 8569B
Table 1-3. Recommended Test Equipment (3 of 3)
Critical Specifications
BNC Female to SMC Female
K-Band to R-Band; for use with
HP 11517 A Mixer
APC-7 to Type N Female
APe-7 to Type N Male
APe-7 to SMA Female
Type N Female to SMA Female
Type N Male to SMA Female
SMA Plug both ends
Type N Connector both ends
Impedance: 50 ohms
Connectors: BNC Jack and Plug
SMA Female to BNC Male
No Substitute
Frequency Range: 12.4-18.0 GHz
Frequency Range: 18.0-26.5 GHz
Recommended Model
HP 08565-60087
HP l1519A
HP 11524A
HP 11525A
HP 11534A
HP 86290-60005
HP 1250-1404
HP 8120-1578
HP 11500A
HP 1250-0774
HP 1250-0781
HP 11592-60001
HP 5086-7721
HPP752C
HPK752C
Use*
A,T
P
P,A
P,A
P,A
P,A
P,A
P,T
P,T
P,T
P,T
A
A
P
*p
=
Performance Test; A
=
Adjustment; T
=
Troubleshooting
**These parts are included in Service Accessories Package; HP Part Number 08565-60100
***Only one required if HP 86290A. Opt. H08 used
1-16
Installation and Operation Verification
Model 8569B
SECTION II
INSTALLATION AND OPERATION VERIFICATION
2-2.
This section includes information about the initial inspection, preparation for use, storage and shipment, and operation verification for the HP
Model 8569B.
2-4.
Inspect the shipping container for damage.
If the shipping container or cushioning material is damaged, it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically. The contents of the shipment should be as shown in Figure 1-1. The electrical performance is checked by the operation verification procedure in this section.
If the contents are incomplete, if there is mechanical damage or defect, or if the instrument does not pass the operation verification test, notify the nearest Hewlett-Packard office. Keep the shipping materials for inspection by the carrier. The HP office will arrange for repair or replacement without waiting for a claim settlement.
2-7.
The HP Model 8569B requires a power source of
100, 120,220, or 240 Vac
+
5OJo
-10%,48-66
Hz.
Power consumption is less than
220 volt-amperes.
The Option 400 permits operation on line frequencies of 50, 60, and 400 Hz at the voltages specified above.
WARNING
I
2-9.
Select the line voltage and fuse as follows:
1.
Measure the ac line voltage.
2.
See Figure 2-1.
At the power line module (rear panel), select the line voltage
(l00v, 120V, 220V, or 240V) closest to the voltage measured in step
1.
Line voltage must be within
+
5
% or -
10% of the voltage setting.
If it is not, use an autotransformer between the ac source and the instrument.
3.
Make sure the correct fuse is installed in the fuse holder. The required fuse rating for each line voltage is indicated below the power line module.
In accordance with international safety standards, this instrument is equipped with a three-wire power cable. When connected to the appropriate power line outlet, this cable grounds the instrument cabinet. Table 2-1 shows the styles of plugs available on power cables supplied with HP instruments.
2-1
Installation and Operation Verification Model 8569B
Plug
Tvpe,"
Cable,* HP
AC Source End Part Number
C
D
250V
8120-1351
8120-1703
0
6
Table
2-1.
A
C
Power Cables Available
Plug Description,
Instrument End
Straight
90°
Length cm (inches)
229 (90)
229 (90)
Color
Country of Use
Mint Gray United Kingdom,
Mint Gray Cyprus, Nigeria,
Rhodesia,
Singapore, South
Africa, India
BS1363A
250V
@
8120-3169
8120~696
NZSS198/ASC112
250V
@
N L
CEE7·Y11
8120-1689 7
8120·1692 2
0
4
125V
~
NEMA5·15P
8120-1348
8120-1398
8120-1754
8120-1378
8120·1521 6
8120-1676 2
7
1
5
5
250V
8120-2104 3
Straight
90°
Straight
90°
Straight
90°
Straight
Straight
90°
Straight
Straight
201 (79)
221 (87)
201 (79)
201 (79)
293 (80)
203 (80)
91 (36)
203 (80)
203 (80)
91 (36)
Mint Gray East and West
Mint Gray Europe, Saudi
Arabia, Egypt,
South Africa,
India, (unpolarized in many nations)
Black
Black
United States,
Canada,Japan
Black (IOOY or 200Y),
Jade Gray Mexico, Philip-
Jade Gray pines, Taiwan
Jade Gray
201 (79)
Gray
Gray
Gray
Australia, New
Zealand
Switzerland
SEV1011
1959·24507 Type12
220V
8120·1957
8120-2956
2
3
Straight
90°
201 (79)
201 (79)
Gray
Gray
Denmark
2-2
DHCK 107
*Part number shown for source end plug is industry identifier for plug only. Number shown for cable is HP Part
E
Number for complete cable including plugs.
=
Earth Ground; L
=
Line; N
=
Neutral
Model 8569B
I
WARNING
I
If this instrument is to be energized through an autotransformer, make sure the common terminal of the autotransformer is connected to the protective earth contact of the power source outlet socket.
Any interruption of the protective ground, inside or outside the instrument, can make it a shock hazard.
2-12.
Mating Connectors
2-13.
All mating connectors on the HP Model
8569B Spectrum Analyzer have standard Hewlett-
Packard part numbers and are readily available.
2-14.
Operating Environment
2·15.
Temperature.
The instrument may be operated in tempertures from
O°C to
+
55°C.
2·16.
Humidity.
The instrument may be operated in environments with humidity from 5070 to 95% at O°C to 40°C.
However, the instrument should also be protected from temperature extremes that cause internal condensation.
2·17.
Altitude.
The instrument may be operated at altitudes up to 4572 meters (15,000 feet).
Installation and Operation Verification
2·18.
Bench Operation
2-19.
The cabinet of the instrument has plastic feet and foldaway tilt stands for convenience in bench operation. The tilt stands raise the front of the instrument for easier viewing of the control panel.
The plastic feet are shaped to make full width modular instruments self-aligningwhen stacked.
2·20.
Rack Mounting (Options 908 and 913)
2-21.
Instruments with Option 908 are shipped with a Rack Flange Kit, which supplies necessary hardware, with installation instructions, for mounting the instrument on a rack whose spacing is 482.6 mm (19 inches). Installation instructions are also given in Figure 2-2. See Table 2-2 for HP part numbers.
2-22.
Instruments with Option 913 are shipped with a Rack Flange/Front Handle Kit, which supplies necessary hardware, with installation instructions, for the addition of front handles and mounting the instrument on a rack whose spacing is 482.6 mm (19 inches). Installation instructions are also given in Figure 2-2. See Table 2-2 for HP part numbers.
2·23.
Front Handles
2-24.
Instruments are shipped with a Front Handle
Kit, which supplies necesary hardware, with installation instructions, for mounting front handles on the instrument. See Figure 2-2 for installation instructions.
Table
2-2.
Rack-Mounting Kits for HP 8569B
C
D
HP Part
Number
Quantity Description
OPTION 908
Rack Flange
Machine Screw, Pan Head,
8·32 x 0.375 inch
OPTION 913
Handle Assembly
Rack Flange
Machine Screw, Pan Head,
8·32 x 0.625 inch
0
2
8
8
7
502008863
2510.0193
5060·9900
502008875
2510.0194
2
2
8
2
8
2-3
Installation and Operation Verification
RECEPTACLE FOR PRIMARY POWER CORD
Model 8569B
PC SELECTOR BOARD SHOWN POSITIONED
FOR 115/120 VAC POWER LINE.
OPERATING VOLTAGE APPEARS IN MODULE WINOOW.
SELECTION OF OPERATING VOLTAGE
1.
SLIDE OPEN POWER MODULE COVER DOOR
AND PUSH FUSE-PULL LEVER TO LEFT TO
REMOVE FUSE.
2.
PULL OUT VOLTAGE-5ELECTOR PC BOARD.
POSITION PC BOARD SO THAT VOLTAGE
NEAREST ACTUAL LINE VOLTAGE LEVEL
WILL APPEAR IN MODULE WINDOW. PUSH
BOARD BACK INTO ITSSLOT.
3. PUSH FUSE-PULL LEVER INTO ITSNORMAL
RIGHT-HAND POSITION.
4.
CHECK FUSE TO MAKE SURE IT IS OF COR-
RECT RATING AND TYPE FOR INPUT AC
LINE VOLTAGE. FUSE RATINGS FOR DIF-
FERENT LINE VOLTAGES ARE INDICATED
BELOW POWER MODULE.
5.
INSERT CORRECT FUSE IN FUSEHOLDER.
Figure 2-1. Line Voltage Selection with Power Module PC Board
Installation and Operation Verification Model 8569B
OPTION 908
RACK MOUNTING KIT
WITHOUT FRONT
HANDLES
(HP 5061-0078)
PAN HEAD
Machine Screw
/ / /
~
/
~
8-32 x 0.375"
_--..-,~
HP 2510-0193
-:
- : - :
~
/ /
e
4 places on each side of instrument.
RACK FLANGE
HP 5020-8863
Attach 1 on each side of instrument.
TRIM STRIP
(Each side of instrument) Remove from instrument before attaching flange.
OPTION 913
RACK MOUNTING KIT
WITH FRONT
HANDLES
(HP 5061-0084)
RACK FLANGE
HP 2510-0195
HP 5020-8875
---~~
(on each side of instrument).
*FRONT HANDLE
Trim Strip
HP 5020-8897
*FLAT-HEAD
Machine Screw
8-32 x
0.375"
LEFTSIDEDF
INSTRUMENT
"
~
<;
Y
.>.
T~", ~~
-~'"
FRONT OF
INSTRUMENT
y)
.~
/%f'/~Friil~
== .-: '
%?
/~/ ~
.XJ
-III_ -
*FRONT HANDLE ASSEMBLY
HP 5060-9900
REMOVE TRIM STRIPS AND
FLAT-HEAD MACHINE SCREWS
IF HANDLES ALREADY ON
INSTRUMENT.
*THESE ITEMS SUPPLIED WITH
THE FRONT HANDLES KIT. IF
INSTRUMENT ALREADY HAS
FRONT HANDLES, ORDER
JUST THE PAN HEAD MACH-
INE SCREWS (2510-0194)
AND FLANGES (5020-8875).
Figure
2-2. Attaching Rack Mounting Hardware and Handles
2-5
Installation and Operation Verification Model 8569B
2-6
Item Qty HP Part No.
Description
C
D
• e
8 7 9220-2733
FOAM PADS-TOP CORNER; BOTTOM CORNER
•
4
9211-2622
CARTON-INNER
4 3 4040-1738
BARS-SHIPPING, PLASTIC
8 9 2510-0103
SCREW-FOR ATTACHING SHIPPING BARS
(REMOVE HANDLES FOR SHIPMENT)
•
5 9211-2623 CARTON-OUTER
2
9
9220-2735
SIDE PADS, CORRUGATED CARDBOARD
2
9222-0069
BAG, PLASTIC
Figure
2-3.
Packaging for Shipment Using Factory Packaging Materials
Model 8569B
Installation and Operation Verification
2-25.
STORAGE AND SHIPMENT
2·26.
Environment
2-27.
The instrument may be stored or shipped in environments within the following limits:
Temperature
Humidity
Altitude
- 40°C to
+
75°C
5% to 95010 at O°C to 40°C
Up to 15,240 meters
(50,000 feet)
The .instrument should also be protected from temperature extremes that cause internal condensation.
2·28.
Packaging
2-29.
Original Packaging.
Containers and materials identical to those used in factory packaging are available through Hewlett-Packard offices. Figure 2-3 illustrates the proper method of packaging the instrument for shipment using factory packaging materials.
If the instrument is being returned to
Hewlett-Packard for servicing, attach a tag indicating the type of service required, return address, model number, and full serial number. A supply of these tags is provided at the end of this section. Also mark the container FRAGILE to assure careful handling. In any correspondence, refer to the instrument by model number and full serial number.
2·30.
Other Packaging.
The following general instructions should be used for repackaging with commercially available materials:
1.
Wrap the instrument in heavy paper or plastic.
If shipping to a Hewlett-Packard office or service center, attach a tag indicating the type of service required, return address, model number, and full serial number. A supply of these tags is provided at the end of this section.
2.
Use a strong shipping container. A double-wall carton made of 350-pound test material is adequate.
3.
Use enough shock-absorbing material (3-inch to
4-inch layer) around all sides of the instrument to provide firm cushion and prevent movement inside the container. Protect the control panel with cardboard.
4.
Seal the shipping container securely.
5.
Mark the shipping container FRAGILE to assure careful handling.
2·31.
OPERATION VERIFICATION
2-32.
The Operation Verification is designed to test only the most critical specifications and operating features of the instrument. It requires much less time and equipment than the complete performance tests listed in Section IV and is recommended for verification of overall instrument operation, either as part of incoming inspection or after repair. The Operation
Verification consists of the following tests:
• Operational Check
• Tuning Accuracy
• Frequency Span Width with Resolution Bandwidth Accuracy
• Amplitude Accuracy
2-7
Installation and Operation Verification
Model 8569B
EQUIPMENT:
Frequency Counter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. HP 5340A
Comb Generator HP 8406A
Power Meter
Power Sensor
Step Attenuator (10 dB/Step)
HP 435B
HP 8481A
HP 355D
1-3.
PROCEDURE:
1.
Perform front-panel adjustment procedure provided on pull-out card.
2.
Connect comb generator (100 MHz comb) to HP 8569B INPUT 500 connector. Set all normal (green) settings, except set TRACE A and TRACE B to STORE BLANK. Set FREQUENCY SPAN/DIV to 1
MHz and TUNING to 0.100 GHz. Verifyindication noted in Table 2-3for each setting shown.
SPECIFICATION:
Overall tuning accuracy of the digital frequency readout in any span mode:
Internal Mixing:
±
(5 MHz or 0.2070 of center frequency, whichever is greater, plus 20% of frequency span per division)
DESCRIPTION:
The tuning accuracy of the HP 8569B is verified by means of a comb generator at the first two FREQUENCY
BAND GHz settings. The CAL OUTPUT frequency is measured, and the HP 8569B is calibrated at 100 MHz.
The comb generator is then connected to the INPUT 500 connector of the HP 8569B, and the tuning accuracy is checked.
2-8
Model 8569B
Installation and Operation Verification
PROCEDURE:
1.
Connect frequency counter to spectrum analyzer CAL OUTPUT as shown in Figure 2-4. Set all normal
(green) settings, and other controls as follows:
TRACE A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. WRITE
TRACE B , . . . . . . . .. STORE BLANK
FREQUENCY BAND GHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .01 - 1.8
TUNING O.IOOGHz
INPUT AITEN
REF LEVEL dBm
10 dB
- 10
REFERENCE LEVEL FINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0
FREQUENCY SPAN/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 MHz
RESOLUTION BW
MIXING MODE
30 kHz
INT
POWER
METER
SPECTRUM ANALYZER
FREOUENCYCOUNTER
INPUT
10 Hz - 250 MHz
,
I
STEP
_ _
P~OWER
SENSOR __
: AITENUATOR :
I
,
1 ...'
I
,
COMB
GENERATOR
0 0 0
OUTPUT
Figure
2-4.
Operation Verification Test Setup
"
2-9
Installation and Operation Verification
Model8S69B
OPERATION VERIFICATION
2·34.
TUNING ACCURACY (Cont'd)
2.
Measure spectrum analyzer CAL OUTPUT frequency using frequency counter. Reading should be 100
MHz ± 0.01 MHz.
3.
Calibration of FREQUENCY GHz display is initially adjusted at 100 MHz. Connect CAL OUTPUT to
INPUT son and tune instrument to center signal on CRT display. FREQUENCY GHz readout should be
0.100.
If necessary, adjust FREQ CAL screwdriver adjustment for 0.100 on FREQUENCY GHz display.
Check that CTR annotation on CRT reads 100.0 MHz.
4.
Verifycalibration of FREQUENCY GHz display in other frequency bands as follows: a.
Tune instrument for an indication of 1.800 GHz on FREQUENCY GHz digital readout.
b.
Connect comb generator to spectrum analyzer INPUT 500 and tune instrument to center 1.8 GHz comb tooth on CRT display. FREQUENCY GHz readout must be 1.800 ±0.005 GHz.
c.
Select 1.7 - 4.1 FREQUENCY BAND GHz and set TUNING control for an indication of 3.000 GHz on FREQUENCY GHz readout.
d.
Center 3.0 GHz comb tooth on CRT display. FREQUENCY GHz readout must be 3.000 ±0.006
GHz.
e.
Set TUNING control for an indication of 4.000 GHz on FREQUENCY GHz readout.
f.
Center 4.0 GHz comb tooth on CRT display. FREQUENCY GHz readout must be 4.000 ±0.008
GHz.
2·35.
FREQUENCY SPAN WIDTH AND RESOLUTION BANDWIDTH ACCURACY
SPECIFICATION:
Span width accuracy: The frequency error for any two points on the display for spans from 500 MHz to 20 kHz/Div (unstabilized) is less than ± 5070 of the indicated separation; for stabilized spans 100 kHz/Div and less, the error is less than ± 15%.
Resolution bandwidth accuracy: Individual resolution bandwidth 3
dB
points:
± 15%.
DESCRIPTION:
A comb generator is used to check the span width and the CAL OUTPUT signal is used to check resolution bandwidth accuracy at different positions of the FREQUENCY SPAN/DIV and RESOLUTION
BW
controls.
By verifying the calibration of these controls, proper operation of the sweep circuits is also verified.
PROCEDURE:
1.
Connect comb generator to instrument INPUT 500.
2-10
Model 8569B
Installation and Operation Verification
OPERATION VERIFICATION
2·35.
FREQUENCY SPAN WIDTH AND RESOLUTION BANDWIDTH ACCURACY
(Cant'd)
2.
Set all normal (green) settings, and other controls as follows:
Spectrum Analyzer:
TRACE A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. WRITE
TRACE B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
STORE BLANK
FREQUENCY BAND GHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
.01 - 1.8
FREQUENCY SPAN/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
100 MHz
RESOLUTION BW
INPUT ATTEN
REF LEVEL dBm
TUNING
1 MHz (coupled)
10 dB
0
0.500 GHz
Comb Generator:
Comb frequency
Output amplitude
100 MHz
Optimum
3.
Tune spectrum analyzer to position one comb tooth at graticule reference line (far left).
4.
Note position of ninth spectral line (comb tooth).
It must be on eighth graticule line
±
0.4 division. (See
Figure 2-5.)
5.
Set FREQUENCY SPAN/DIV to 10 MHz (with RESOLUTION BW coupled) and comb generator to 10
MHz. Repeat steps 3 and 4.
6.
Set FREQUENCY SPAN/DIV to 1 MHz and comb generator to 1 MHz. Repeat steps 3 and 4.
FIRST
GRATICUl E
LINE
GRATICUl
REFERENC
LINE
COMB
SIGNALS
VF OFF
CTR
604.0 MHz SPAN 100 MHz/
RES BW 1 MHz
REF o dBm 10 dB/ ATTEN 10 dB SWP AUTO
--
~
---
I
-
V -
-...
---
FIRST
SPECTRAL
LINE
-
'V'Y
EIGHTH
GRATICUlE
LINE
NINTH
SPECTRAL
LINE
Figure
2-5.
Span Width Accuracy Measurement
2-11
Installation and Operation Verification Model 8569B
OPERATION VERIFICATION
2-35.
FREQUENCY SPAN WIDTH AND RESOLUTION BANDWIDTH ACCURACY (Cont'd)
NOTE
The wider FREQUENCY SPAN/DIV settings are checked using a comb gen-
The narrow FREQUENCY SPAN/DIV settings are checked by observing RESOLUTION BW accuracy as follows:
7.
Set FREQUENCY SPAN/DIV to .2 MHz, RESOLUTION BW to 1 MHz, and AMPLITUDE SCALE to
I dB.
8.
Connect spectrum analyzer CAL OUTPUT to INPUT 500 and tune spectrum analyzer to 0.100 GHz.
Center signal on display and use REFERENCE LEVEL controls to position peak of signal to REFER-
ENCE LEVEL line.
9.
Note width of signal three divisions below REFERENCE LEVEL line. Specification: 5 divisions ±0.75
division. Verification of the I MHz RESOLUTION BW setting verifies proper operation of the LC bandwidth filters.
10.
Set FREQUENCY SPAN/DIV to 10 kHz and RESOLUTION BW to 30 kHz.
11.
Repeat step 8 and note width of signal three divisions below REFERENCE LEVEL line. Specification: 3 divisions ± 0.45 division. Verification of the 30 kHz RESOLUTION BW setting verifies proper operation of the crystal bandwidth filters.
2-36_ AMPLITUDE ACCURACY
SPECIFICATIONS:
Calibrator Output: - 10 dBm ± 0.3 dB
Reference Level variation (Input Attenuator at 0 dB):
10 dB steps,
+
20°C to
+
30°C:
Oto -60dBm: <±0.5 dB o to - 90 dBm: < ± 1.0 dB
Vernier (0 to - 12 dB) continuous:
Maximum error < ± 0.5 dB, when read from REFERENCE LEVEL FINE control.
Input Attenuator (at preselector input, 70 dB range in 10 dB steps):
Step size variation (for steps from 0 to 60 dB):
Oto 60 dB, 0.01-18 GHz: <± 1.0dB
o to 40 dB, 0.01 - 22 GHz: < ± 1.5 dB
Maximum cumulative error: o to 60 dB, 0.01-18 GHz: < ±2.4 dB o to 40 dB, 0.01- 22 GHz: <±2.5 dB
2-12
Model 8569B
Installation and Operation Verification
OPERATION VERIFICATION
AMPLITUDE ACCURACY (Cont'd)
PROCEDURE:
1.
Set all normal (green) settings, and other controls as follows:
FREQUENCY SPAN/DIV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 MHz
RESOLUTION BW 30 kHz (coupled)
FREQUENCY BAND GHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .01 - 1.8
TUNING O.looGHz
INPUT ATTEN
REF LEVEL dBm
REFERENCE LEVEL FINE
10 dB
- 10
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 0
AMPLITUDE SCALE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1 dB LOG/DIV
2.
Measure CAL OUTPUT signal level with a power meter. Specification: - 10 dBm
0.3 dB.
3.
Connect 100 MHz CAL OUTPUT signal through 355D step attenuator (set to 0 dB) to INPUT 500 and tune spectrum analyzer to center signal on CRT display. Position peak of signal at REFERENCE LEVEL line with front-panel REF LEVEL CAL screwdriver adjustment.
4.
To verify correct operation of the REFERENCE LEVEL FINE (Vernier) control, set 355D step attenuator to 10 dB.
Set REFERENCE LEVEL FINE to -
9.
The peak of the signal on the CRT display should be one division below the REFERENCE LEVEL
±
0.5 division
«
±
0.5 dB). Return 355D step attenuator to
OdB.
5.
Set INPUT ATTEN to 70 dB, REF LEVEL dBm to 0, REFERENCE LEVEL FINE to - 8, RESOLU-
TION BW to 3 kHz, FREQUENCY SPANIDIV to 1 kHz, and VIDEO FILTER to .03. Center signal on
CRT display with TUNING control.
6.
Adjust REF LEVEL CAL to position signal peak two divisions below REFERENCE LEVEL line.
7.
Step instrument INPUT ATTEN from 70 to 0 dB while stepping 355D step attenuator from 0 to 70 dB
(maintain a total attenuation of 70 dB). For each 10 dB step, the signal amplitude should not change more than
1 dB from the previous step. The total amplitude variation (difference betwen maximum and minimum signal levelsover entire 70 dB range) should not exceed
2.4
dB.
8.
Adjust REF LEVEL CAL to position signal
two divisions below REFERENCE LEVEL line.
9.
Step instrument REF LEVEL dBm from -70 to -10 while stepping 355D step attenuator from 70 dB to
10 dB (maintain signal level approximately two divisions below REFERENCE LEVEL line
0.5 division
(±0.5dB).
2-13
Installation and Operation Verification
OPERATION VERIFICATION
Function
SWEEP SOURCE
SWEEP TRIGGER
SWEEP TIME/DIV
PRESELECTOR
PEAK
AUTO STABILIZER
(Blue FREQUENCY
SPAN/DIY settings)
Model 8569B
Table 2-3. Operational Check (1 of 3)
MAN
EXT
INT
LINE
VIDEO
Setting
EXT
SINGLE
Indication
Rotation of MANUAL SWEEP control varies position of trace on CRT display.
No sweep. Bright dot on lower left edge of CRT display.
Sweep visible on CRT display.
Sweep visible on CRT display.
Presence of CRT sweep is dependent on TRIGGER
LEVEL setting.
No CRT trace is visible.
One sweep is triggered when START/RESET pushbutton is pressed.
Sweep visible on CRT display.
FREE RUN
Slowly rotate control counterclockwise.
Sweep on CRT display becomes increasingly slower.
NOTE
Select 1.7-4.1 FREQUENCY BAND GHz and adjust TUNING control to center signal on CRT display.
Rotate over full range.
Signal amplitude varies. (Set control for maximum signal amplitude.)
NOTE
Set FREQUENCY SPAN/DIV to 100kHz and adjust FINE tuning control to center signal on CRT display.
OFF
(in)
ON
(out)
Tuning of signal with coarse TUNING control is continuous.
Tuning of signal with coarse TUNING control causes signal to jump off CRT display.
2-14
Model 8569B Installation and Operation Verification
Function
Table 2-3. Operational Check (2 of 3)
PERDIV
Setting Indication
NOTE
Set TRACE A to WRITE and FREQUENCY SPAN/DIV to 100MHz.
Signals are displayed at one-division intervals.
FREQUENCY SPAN
MODE
AMPLITUDE SCALE
(Center signal on
CRT display.)
NOTE
Set FREQUENCY SPAN/DIV to .2 MHz and adjust TUNING control to center signal on CRT display.
ZERO SPAN
FULL BAND
1.7-22 GHz SPAN
10 dB (LOG/DIV)
CRT trace is a straight line and FINE TUNING control affects signal amplitude.
Twenty-five comb teeth are visible and baseline marker position is determined by coarse TUNING control.
Baseline is displayed from left to right in five steps (see
Section III). Return to PER DIV.
10 dB change in REF LEVEL dBm changes signal amplitude by one division ±O.l division.
NOTE
Set REF LEVEL dBm and REFERENCE LEVEL FINE to position signal peak 0.5 division below REFERENCE LEVEL graticule line.
Center signal on CRT display with TUNING control.
5 dB (LOG/DIV)
2 dB (LOG/DIV)
1 dB (LOG/DIV)
LIN
Signal peak one division below REFERENCE LEVEL graticule line (±O.25 division).
Signal peak 2.5 divisions below REFERENCE LEVEL graticule line (±O.6 division).
Signal peak 5 divisions below REFERENCE LEVEL graticule line (±1.2 divisions).
Signal peak 3.5 divisions below REFERENCE LEVEL graticule line (±l.O division). Return to 10 dB.
2-15
Installation and Operation Verification
Function
TRACE A
TRACEB
TRACES A and B
STORE BLANK
TRACES A and B
STORE VIEW
SIG IDENT
CRT Annotation
VIDEO FILTER
Mode18569B
OPERATION VERIFICATION
Table
2-3. Operational Check (3 of 3)
Setting Indication
MAX HOLD Increase and then decrease signal amplitude. Maximum signal is held on CRT display.
STORE VIEW
Trace is held on CRT display and is not affected by changes in control settings.
Set TRACE A to WRITE and repeat checks described for TRACE A.
Analog signal is displayed without CRT annotation.
Set TRACE A to WRITE, then to STORE BLANK. With TRACE B set to WRITE, vary signal amplitude or position, then set TRACE B to STORE VIEW. Set
TRACE A to STORE VIEW. Both traces are displayed on CRT.
NOTE
Set TRACE A to WRITE and TRACE Bto STORE BLANK. Set
FREQUENCY SPAN/DIV to 1 MHz and RESOLUTION BW to
30 kHz. Center signal on CRT display with TUNING control.
Depressed
TRACE A to WRITE
Step through each switch position
Two signals on CRT display. Signal identifier signal is two divisions to left of comb tooth and is also lower in amplitude.
Control settings are displayed on CRT, and annotation changes as settings are changed.
Each step decreases baseline noise level and decreases sweep speed. Sweep speed increases when switching to
NOISE AVG position, and CRT trace is virtually a straight line.
2-16
Model 8569B Installation and Operation Verification
Hewlett-Packard Company
Mode18569B
Serial Number
Table
2-4.
Operation Verification Test Record
Tested by
Date
Results
Para.
No.
Min.
Actual
2-34
2-34.
2-35.
2-35.
2-36.
2-36.
2-36.
2-36.
Test Description
Calibrator Output Accuracy
2. 100 MHz
Tuning Accuracy
4b. 1.8 GHz
4d. 3.0 GHz
4f. 4.0 GHz
Span Width Accuracy
4. 100 MHz FREQUENCY SPAN/DIV
5. 10 MHz FREQUENCY SPAN/DIV
6. 1 MHz FREQUENCY SPAN/DIY
Resolution Bandwidth Accuracy
9. 1 MHz RESOLUTION BW
11. 30 kHz RESOLUTION BW
Calibrator Output Power
2. CAL OUTPUT Signal
Vernier (0-12 dB)
4. Vernier Accuracy
Input Attenuator Accuracy
7. Error Between Adjacent Settings
8. Error Over 60 dB Range
Reference Level Variation
9. Reference Level Variation in
LOG,O to -60 dB
99.99
1.795
2.994
3.992
-0.4 div
-0.4 div
-0.4 div
4.25 div
2.55 div
-10.3 dBm
0.5 div
Max.
1.805
3.006
4.008
+0.4 div
+0.4 div
+0.4 div
5.75 div
3.45 div
-9.7 dBm
1.5 div
±1.0 div
±2.4 div
±0.5 div
2-17/2-18
Mode18569B Operation
3·1.
INTRODUCTION
3-2.
This section is published separately as "8569B
Spectrum Analyzer Operation," HP Part Number
08569-90034.
It describes typical applications of signal analysis and provides detailed instructions for both local (front-panel) and remote (HP-IB) operation.
3-3.
A table of contents is provided at the beginning of this section.
3·4.
ROUTINE MAINTENANCE
3·5.
Fuses
3-6.
The HP 8569B has nine fuses, eight of which are internal. Only the ac line fuse, located at the back of the instrument, may be replaced by the operator.
The ac line cord should be disconnected from the power source, then the other end disconnected from the instrument. With the power cord removed, access the fuse compartment by sliding open the clear plastic cover on the power module. Remove the fuse by pulling the lever inside the fuse compartment.
Replace the blown fuse with a fuse of the correct rating and type for the ac line voltage selected. Fuse ratings for different voltages are indicated below the power module. Access to the other eight fuses requires removal of the covers of the instrument. The internal fuses should be replaced by a qualified service technician.
3·7.
Air Filter
3-8.
Inspect the air filter frequently and, if necessary, remove and clean it. To clean the filter, wash it in warm water and detergent. Thoroughly dry the filter before reinstalling it.
3-9.
Unrestricted air flow within the instrument lengthens component life. Keep the air filter clean.
3·10.
Calibration
3-11.
Performance tests (Section IV) should be performed every six months to ensure that the instrument meets the specifications listed in Section I.
3-1/3-2
HP
Part
Copyright ©1982, HEWLETT·PACKARD COMPANY
1424 FOUNTAIN GROVE PARKWAY,SANTA ROSA, CALIFORNIA, 95404, U.S.A.
No. 08589-90034
Printed: December 1982
4
Chapter
INTRODUCTION
Signal Analysis . . . . . . . . . . . . . . .
BASIC DESCRIPTION
2
3
OPERATING THE HP 8569B 3 tine Power On . . . . . . . . . . . . . . . . . . . . ..
3
Front Panel Adjustment Procedure. . . . . . . .. 3
Getting Started. . . . . . . . . . . . . . . . . . . . .. 4
FRONT PANEL OPERATION 8
Tuning 8
Frequency Span Mode . . . . . . . . . . . . . . . .. 8
Resolution Bandwidth . . . . . . . . . . . . . . .. 10
Reference Level . . . . . . . . . . . . . . . . . . .. 10
Digital Storage Display. . . . . . . . . . . . . . .. 13
Traces. . . . . . . . . . . . . . . . . . . . . . . . . .. 13
Trace Memory . . . . . . . . . . . . . . . . . . . .. 14
Direct Plotter Output. . . . . . . . . . . . . . . .. 17
SPECIAL TOPICS. . . . . . . . . . . . . . . . . . . .. 18
Maximum Dynamic Range
Improving Amplitude Measurement
" 18
Accuracy. . . . . . . . . . . . . . . . . . . . . .. 22
CRT Photography and X·Y Recording 22
External Mixer Operation . . . . . . . . . . . . .. 23
TYPICAL MEASUREMENTS . . . . . . . . . . . .. 26
Distortion . . . . . . . . . . . . . . . . . . . . . . .. 26
Modulation . . . . . . . . . . . . . . . . . . . . . .. 27
Noise . . . . . . . . . . . . . . . . . . . . . . . . . .. 31
Page
.
.
, 2
CONTENTS
Chapter
5
Page
Electromagnetic Interference (EMI) . . . . . .. 31
Swept-Frequency Response , 33
HP-IB REMOTE OPERATION. . . . . . . . . . . .. 35
APPENDIX A
OPERATING PRECAUTIONS
Low Impedance AC
DC Precautions .. :
"
38
38
, 38
, 38
APPENDIX B. . . . . . . . . . . . . . . . . . . . . . . . . . .. 39
THEORY OF OPERATION . . . . . . . . . . . . .. 39
System Description . . . .
, 39
RF Section. . . . . . . . . . . . . . . . . . . . . . .. 39
Automatic Stabilization Section , 39
IF Section . . . . . . . . . . . . . . . . . . . . . . .. 40
Digital Storage Display. . . . . . . . . . . . . . .. 40
Tuning Control Section , 40
APPENDIX C. . . . . . . . . . . . . . . . . . . . . . . . . . .. 43
AMPUTUDE CONVERSIONS , 43
Conversion Equations. . . . . . . . . . . . . . . .. 43
APPENDIX D , 44
OPTION STATUS INTERFACE . . . . . . . . . .. 44
APPENDIX E. . . . . . . . . . . . . . . . . . . . . . . . . . .. 45
SYNTAX REFERENCE GUIDE , 45
APPENDIX F. . . . . . . . . . . . . . . . . . . . . . . . . . .. 50
CONTROL GLOSSARY. . . . . . . . . . . . . . . .. 50 ii
SIGNAL ANALYSIS
The spectrum analyzer is a receiver that displays signals in the frequency domain. The CRT on the analyzer displays signal amplitude (A) on the vertical axis and frequency
(f) on the horizontal axis. A method of visualizing how a spectrum analyzer views the frequency domain is to picture a tunable bandpass filter that scans the frequency axis (see Figure 1). At any instant in time, the analyzer views only the signal it is tuned to receive, rejecting all others. In this way.
all the individual components of a signal are viewed separately. In comparison, an oscilloscope displays the signals in the time domain, and the amplitude displayed represents the vector sum of all signal components.
The purpose of this section is to acquaint the reader with the operation of the HP Model 8569B Spectrum Analyzer. Rather than discussing specific topics in detail, the reader is referred to existing application notes, which may be obtained by contacting your local Hewlett-
Packard Sales Office.
A
-:
AMPLITUDE-'-TIME
PLANE t o
<,
AMPLITUDE-FREQUENCY
'~')
i
I
A lJ~f
THE FREQUENCY-TIME DOMAINS a. Three-dimensional coordinltes showing time,frequency, andImplitude. The
Iddition of I fundlmentll Ind itssecond hlrmonic isshown ISIn eXlmple.
b. View seen inthe teA pllne.OnIn oscilloscope, only the composite f l
+ 2f l would be seen.
c. View seen in the f·A pllne. Note how the components of the composite signll
Ire clelrly seen here.
Figure
1.
Frequency and Time Domain
The HP 8569B (Figure 2) is a high-performance spectrum analyzer designed for ease of use. Most measurements can be made with just three controls once the normal
(green) settings are preset. The HP 8569B has absolute amplitude and frequency calibration from 0.01 to 22
GHz. The frequency span, bandwidth, and video filter are all coupled with automatic sweep to maintain a calibrated display and simplify use of the analyzer. Internal preselection eliminates most spurious responses to simplify signal identification. The preselector also extends the dynamic range of the analyzer and provides some protection for the input mixer.
The HP 8569B has a digital storage display system. All the information necessary to analyze a signal is displayed on the top portion of the CRT. The trace information for both Trace A and Trace B resides in a digital storage buffer which is updated at the sweep rate of the analyzer.
The information in this buffer is then displayed on the
CRT and automatically refreshed at a flicker-free rate.
Certain arithmetic and logical functions, such as digital averaging and normalization, can be performed on the trace values. The graticule, character, and trace information can be output directly to a digital plotter set for the listen only mode without the need for a controller. A controller connected via HP-IB may control the output or input of display information (e.g., trace values, text, control information).
The frequency range of the HP 8569B is 10 MHz to 22
GHz in direct coaxial input and 14.5 to 115 GHz when used with external mixers.
2
!
i i
I-
,
1
•
I
L~
Figure
2.
HP 8569B Spectrum Analyzer
LINE POWER ON
Before connecting the line power cord, make sure the proper line voltage and line fuse have been selected for the instrument. For complete information on power cords, voltage and fuse selection, refer to the HP 8569B Operation and Service Manual, Section II.
When LINE is switched ON, the instrument performs an automatic internal instrument check. This routine checks the operation of the system memory (RAM), system program memory (ROM), and the stroke memory (RAM), located in the analyzer's display section.
If the test routine fails partially or if the routine will not run at all, refer to the HP 8569B Operation and Service Manual,
Sections V and VIII.
Contained in the HP 8569B program memory (firmware) is a series of test patterns which aid in troubleshooting and in the adjustment of the analyzer. (Refer to HP
8569B Operation and Service. Manual, Sections V and
VIII.)
FRONT PANEL ADJUSTMENT PROCEDURE
The front panel adjustment optimizes the performance of the HP 8569B Spectrum Analyzer to obtain its specified accuracy. The following step-by-step procedure is recommended for adjusting the HP 8569B. A condensed procedure is also located on a pull-out INFORMATION
CARD attached to the analyzer.
Pre-adjustment settings
1.
Set normal (green) settings on analyzer (Table 1).
2.
Set FREQUENCY BAND GHz to 0.01 - 1.8.
3.
Set FREQUENCY SPAN/DIV to 1 MHz.
4.
Set INPUT ATIEN to 10 dB.
5.
Set REF LEVEL dBm to -10 and REFERENCE
LEVEL FINE to 0 dB.
Display Adjustments
1.
Adjust FOCUS characters.
0 for clearest control readout
2.
Press and hold in the the
IQ]
GRAT while pressing g
CLEAR/RESET to activate the Display Adjust line at top of screen as shown in Figure 3.
Figure
3.
Display Line Adjustment
3.
Adjust TRACE ALIGN
0 so that the displayed line is parallel to top graticule line.
4.
Adjust VERT POSN
0 to place display line on top graticule line (REFERENCE LEVEL).
5.
Adjust HORIZ POSN
0 to place center cross tick of displayed line at center of top graticule line.
6.
Press g
CLEAR/RESET to return normal display.
Frequency Adjustment
1.
Connect 100 MHz CAL OUTPUT signal to
INPUT.
2.
Center signal on CRT with TUNING control.
3.
Uncouple the RESOLUTION BW and set it to 10 kHz.
4.
Adjust FREQ CAL
0 to indicate 0.100 GHz on FREQUENCY GHz readout.
3
Amplitude Adjustment
1.
Center signal on CRT with TUNING control.
2.
While keeping signal centered on the CRT, reduce
FREQUENCY SPAN/DIV to 50 kHz.
3.
Set AMPLITUDE SCALE to
[Q]
1 dB •
4.
Adjust REF LEVEL CAL
0 to position the peak of the signal on the REFERENCE LEVEL
(top graticule line) of the CRT. Once the Front
Panel Adjustment Procedure is completed, the
CRT display should be similar to that shown in Figure4.
5.
Reset the AMPLITUDE SCALE to •
10 dB •
The HP 8569B is now calibrated for absolute frequency and amplitude measurement.
eTR 111'1.
8 MHz SPAN 50 kHz/
REF -18 dB.
1 dB/ ATTEN 8 dB
RES BW 18 kHz
SVP AUTo
-,
YFIFF
I
WARNING
I
This instrument and any device connected to It must be connected to power line ground. Failure to ensure proper grounding could cause a shock hazard to personnel or damage to the instrument.
Normal settings
The normal settings listed in Table 1 are used for the majority of measurements. For instance, 10 dB/division,
INT sweep, and AUTO sweep time positions are most often used and so are classified as normal settings. AU normal settings on the HP 8569B are colored green so the user can easily identify and set them initially.
I
Figure
4.
CAL OUTPUTSignIll
GETTING STARTED
The HP 8569B Spectrum Analyzer is a sensitive measuring instrument. To avoid damage to the instrument, do not exceed the following:
Absolute Maximum Inputs:'
Total RF Power:
+
30 dBm (1 watt) de or ac «<50 (}source impedance):
OV with 0 dB RF input attenuation «l amp)
±
7V with
~
10 dB RF input attenuation
«0.14 amp).
Peak Pulse Power:
+
50 dBm «10 /lSec pulse width, 0.01010 duty cycle) with
~20 dB INPUT ATTEN.
IFor more detailed information regarding Operating Precautions refer to Appendix A.
4
Table
1.
Normal Settings
Function
TRACEA,B
SAMPLE, DGTL AVG,
INP-B-+A
FREQUENCY SPAN/ON
RESOLUTION BW
FREQUENCY SPAN MODE
MIXING MODE
AMPLITUDE SCALE
VIDEO FILTER
SWEEP SOURCE
SWEEP TRIGGER
SWEEP TIME/DN
PRESELECTOR PEAK
Setting
•
WRITE
CD
OUT
OPTIMUM (Push in
to couple)
•
PERON
•
INT
•
10 dB
OFF
•
INT
FREE RUN
•
AUTO
•
Center in green area
With normal settings, most measurements can be made using only the TUNING, FREQUENCY SPAN/DIV and
REFERENCE LEVEL controls. The analyzer is calibrated for any combination of control settings as long as the UNCAL indicator is not displayed (refer to Chapter
2).
Three-Knob Operation
_ _ _
T " " ' H G ~
TUNING adjusts the center frequency of the analyzer.
It also positions the marker in the full band and 1.7 to 22 GHz span modes.
" , . . fR(QUE:NCY SPAN:JON 0
RtW~Ul'IOt>l 8W 0 llit+'U»'
~
FREQUENCY SPAN/DIV sets the horizontal frequency calibration on the CRT. An optimum resolution bandwidth is automatically selected for a given frequency span when two arrows are aligned.
: r- ......
HC.l£~;..,
0.1
The REFERENCE LEVEL con-
":,':~ trol sets the vertical amplitude calibration on the CRT. The REFER-
ENCE LEVEL (top graticule line) on the CRT represents an absolute power level (in dBm or dBIJV).
Changes in RF INPUT ATTEN will also change the indicated REFERENCE LEVEL.
Simplified Signal Analysis eAtOO1'Hl'
WO_h:
The internal CAL OUTPUT signal is a convenient source to demonstrate how fast and easily the HP 8569B can measure frequency and amplitude.
to
118,.,
, . 'I!
dO",\(
Start by presetting the green normal settings listed in
Table I. This sets the analyzer in its normal, three-knob operation mode. Now connect the CAL OUTPUT signal to the INPUT connector of the analyzer and begin the measurement procedure:
1.
Select the FREQUENCY BAND that includes the
100 MHz CAL OUTPUT signal (.01 - 1.8).
2.
Use the TUNING control to tune the 100 MHz signal to the center of the display. The FREQUENCY
SPAN/DIV control may be increased to facilitate tuning.
3.
Adjust the FREQUENCY SPAN/DIV control to achieve the desired resolution. Since there is no modulation on the CAL OUTPUT signal, a 1
MHz/Div span is sufficient. Retune the signal to the center of the display if necessary.
4.
Position the peak of the signal on the REFER-
ENCE LEVEL (top graticule line) of the CRT using the REFERENCE LEVEL control.
Since the CAL OUTPUT signal is the calibration reference for the analyzer, FREQUENCY GHz should read
0.100 GHz and the REFERENCE LEVEL should read
-10 dBm (Figure 5).
If not, adjust the FREQ CAL and the REF LEVEL CAL to obtain the correct reading.'
For this next example, let us suppose that the microwave source in the test setup (Figure 6) operates in C-band (4 to
'A complete front panel adjustment procedure is included in this chapter.
eTR laa. a MHz
REF -ie dB.
SPAN I MHzl la dBI
ATTEN a dB
RES BW iee kHz
SWP AUTO
VF OFF
I
\
I
\
/
\
I
Figure 5. CAL OUTPUTSignal
MICROWAVE SOURCE
.01 TO 8 GHz
0 0 0 0 9
• ' 0 0 e
co
EJBEI
BOD
0 0 0 0 0
GOeDe ",.,.+-,
0 0 0
~G
EjEl[;l
RF OUTPUT
SPECTRUM ANALYZER c
~.
~o~
000
000
00
@@ o •
C a::D D
OO~(i) ~~.C(i)
= e
0
0
INPUT
Figure
6. Microwave Source Test Setup
5
6
8 GHz). However, we do not know its exact output frequency. What, then, is the best way to locate a signal?
By using the full band feature of the HP 8569B, we can sweep an entire frequency band to search for a signal.
To view the microwave source in Figure 6 that operates in
C-band, select the 3.8 to 8.5 GHz Frequency Band. Position the tuning marker (which appears in the full band modes) under the signal to identify its frequency (Figure
7). Then by pushing the green PER DIV button, the signal at the marker will become the center frequency of the analyzer (Figure 8). In PER DIV mode, the desired frequency span can be adjusted with the FREQUENCY
SPAN/DIV control. Figure 9 illustrates the procedure for locating a signal.
MKR 5.
~2~~ GHz
SPAN FULL
REF -9 dB.
1~ dB/ ATTEN 2~ dB
RES BW 3 MHz
SWP AUTO
I
I
I
I
!
:
,
I
I i
I
I
I i
I i
I
I
I
,
I
I i
I i
I
I
VF OFF
Figure 7. TuningMarker in FULL BAND
OR
5.
~2~~
REF -9 dB.
GHz
1~
SPAN dB/
1~~ kHz/
ATTEN 2~ dB
RES BW
1~ kHz
SWP AUTO
VF OFF
.A .....
I
I
I
J.
l..
.,.<1.1.
!
/
7 \
!A.
..ill
7
\
\!.....
..
~
'"
LlI...1
Figure 8. PER DIV Mode
1
Set desired FREQUENCY BAND while in FULL BAND Frequency Span Mode
2
T U N l N G : - l , . . . FREQUENCY St>AN/DIV 0 " . - . REfERENCE LEV£L
RESOLUTION BW e
.,L PUSH 0
'-"'/' puu i»P~ic.
RA~jD
I HprHJlbM
II
I
J ;
I
..
•
,un.• i t j
II
I i
I
J
Ii
I
r---
AMPUTUOE I AlE----,
I
·-.-'O-L~ 1<lll/~1V'
I
;..,...-,...__--' ..........,....-,-__\-_ll ••• ~
TUNING Control sets marker which will be centerfntquencyin
PER DIVMODE
3
R_t to PER DIV and adjust
FREQUENCY
SPAN/DIV
4
Position signal on top REFERENCE
LEVEL line
Figure
9. Locating a Signal
7
CHAPTER 2
This chapter provides detailed descriptions of all frontpanel controls. Following each description, the relevant
HP-IB code is given. For additional HP-IB information, refer to Chapter 5 and Appendix E.
TUNING
----~
The TUNING control adjusts the
I center frequency of the analyzer.
In the full-band modes, the TUN-
ING control is used to locate an inverted marker on a particular signal. The FREQUENCY GHz readout on the front panel and the
CTR readout on the display indicate the center frequency of the analyzer or the frequency at the tuning marker. By pulling out the outer control, rapid tuning is enabled. Rapid tuning is especially useful when moving the tuning marker in full band modes. Normal tuning resumes when the knob is pushed in. When the analyzer is stabilized (frequency spans ::$100 kHz/Div), only FINE TUNING should be used to tune the analyzer.
If coarse tuning is desired, the AUTO STABILIZER can be disabled with the push button switch.
HP·IB Code:
CF (output center frequency)
FREQUENCY SPAN MODE
Four push button span modes are available on the HP 8569B:
ZERO SPAN, PER DIY, FULL
BAND, and 1.7-22 GHz SPAN.
An additional F (fullband) setting is available on the FREQUENCY SPAN/
DIV control knob. The full-band modes (FULL BAND,
F, and 1.7- 22 GHz) enable the analyzer to monitor the various frequency bands or to provide multiband coverage from 1.7 to 22 GHz. PER DIV mode is generally used for detailed signal analysis, and ZERO SPAN is used for time domain analysis. The following text explains the various FREQUENCY SPAN MOD~ settings in more detail.
HP·IB Code:
SP (output FREQUENCY SPAN/DIY)
8
Zero
Span
ZERO SPAN is used to recover the modulation on a carrier. In this mode, no sweep voltage is applied to the LO in the analyzer, so it operates as a manually tuned narrowband receiver. Carrier modulation is displayed in the time domain, and the calibrated SWEEP TIME/DIV control can be set manually to read the time variation of the signal. Selection of VIDEO trigger allows the sweep to be synchronized on the demodulated waveform. Figure 10 illustrates a demodulated AM carrier that was obtained with the analyzer in ZERO SPAN.
\If eH CT" l07.1iti,
REF -20 dllm
S'1lIl ZERO lIHEAR
~mH
10 dB l1£S IlW liti,
!III' s ....
cl
jl
\ 1\ \ \ / \ / \
1
' I \1 \
\1
\1
\1
\1
\Vl
V V V
\1
J
0
Figure 10. AM CarrierDemodulated in ZERO SPAN
Since the analyzer remains calibrated in ZERO SPAN, it is also possible to measure the amplitude and frequency of a CW signal. In this case, the CW signal appears as a horizontal line on the CRT. (See Figure 11.) Use a wide
RESOLUTION BW setting and disable the AUTO
STABLIZER for ease of tuning the signal.
The PER DIV mode enables the FREQUENCY SPAN/
DIV control to set the horizontal frequency calibration of the CRT. The calibrated FREQUENCY SPAN/DIV control is adjustable from 1 kHz/Div to 500 MHz/Div in a
1, 2, 5 sequence of steps.
An
F (full-band) position allows the entire frequency band selected to be scanned. Normally, the RESOLUTION BW is coupled _ to the
FREQUENCY SPAN/DIV so that the optimum RESO-
LUTION BW setting is automatically selected as the
FREQUENCY SPAN/DIV is adjusted.
CTR 2.3500
GHz SPAN ZERO
REF
~ dB.
1~ dB!
mEN 2~ dB
RES BW 3 MHz
SWP AUTO
VF OFF
The five frequency span modes available on the HP
8569B provide the user with maximum flexibility in making measurements. Table 2 summarizes the characteristics of each FREQUENCY SPAN MODE setting.
MKR 3.
1467 GHz SPAN FULL
REF -30 dB.
10 dB!
mEN 0 dB
RES BW
3
MHz
SWP AUTO
VF .003
Figure
11.
CW Measurement in ZERO SPAN
Full Band
The FULL BAND mode scans in one sweep the entire selected frequency band. A tuning marker, 3 MHz RES-
OLUTION BW and 0.003 VIDEO FILTER are automatically set in FULL BAND mode. Different frequency bands can be selected to look for unknown signals. Once a signal is located in a particular frequency band, the tuning marker can be positioned under the signal to identify its frequency (Figure 12). Then, by pushing PER DIY, the signal that was at the marker will be displayed at the center frequency on the CRT (Figure 13). The F position on the FREQUENCY SPAN/DIV control differs from the
FULL BAND push button in that it allows independent adjustment of the RESOLUTION BW and VIDEO
FILTER controls.
1.7 -22 GHz Span
A multiband sweep, available when the 1.7 - 22 GHz
SPAN push button is depressed, is useful for observing signal activity within a broad frequency range. A tuning marker can be used with rapid tuning to quickly identify the frequency of any signal in the 1.7 - 22 GHz range.
Figure 14 illustrates a typical display with the 1.7 - 22
GHz SPAN selected.
The stair-step baseline display in Figure 14 is the result of gain compensation applied to the higher frequency bands to maintain a calibrated amplitude display. Gain compensation is required because the higher frequency bands utilize higher LO harmonics of lower amplitude, yielding reduced sensitivity. To obtain the highest sensitivity from the analyzer, use the lowest FREQUENCY BAND GHz setting available when there is a frequency overlap. For instance, a 7 GHz signal can be measured in the 3.8 to 8.5
GHz band or the 5.8 to 12.9 GHz band. The sensitivity, however, is better in the 3.8 to 8.5 GHz band.
Figure
CTR 3.
1468 GHz SPAN 2 MHz!
REF -30 dB.
1~ dB!
mEN 0 dB
RES BW 10~ kHz
SWP ~UTO
VF OFF
I I
I
- -
,",
Figure
13. Analysis in PER DIV
MKR
REF
11. 6338 GHz SPAN I.
7-22 GHz RES BW 3 MHz
-6 dB.
10 dB!
mEN l~ dB SWP AUTO
VF .003
'-~
I
I
12.
Identifying a Signal in FULL BAND
I
----
Figure
14.1.7-22
GHz SPAN Mode
9
10
RESOLUTION BANDWIDTH
""FR£:~~~~:-':~O~ llfllolov'"
In OPTIMUM setting, the RESO-
LUTION BW is coupled to the
FREQUENCY SPAN/DIV by aligning the green markers _ and pushing the controls in. Once the controls are coupled at OPTI-
MUM, the best RESOLUTION
BW setting will be automatically chosen for any frequency span selected. The RESOLUTION BW control can also be coupled at a position other than OPTIMUM without loss of calibration of the spectrum analyzer. Calibration is always ensured when the UNCAL indication on the CRT annotation is not present.
For certain applications, independent control of the
RESOLUTION BW control may be desirable. When either control knob is pulled out, the RESOLUTION BW control is decoupled, allowing different RESOLUTION
BW settings to be selected. Figure 15 illustrates how an
AM signal with 200 kHz sidebands is displayed at various
RESOLUTION BW control settings. Note that the narrower resolution BW will yield increased sensitivity, since random noise decreases 10 dB for every reduction of Resolution BW by a factor of 10.
The SWEEP TIME/DIV control, when in AUTO position, will automatically select the proper sweep speed, whether the RESOLUTION BW control is coupled or uncoupled.
HP·IB Code:
RB (output RESOLUTION BW)
ZERO
SPAN
(Time Domain)
REFERENCE LEVEL
, . . . .
M~~~~~,t.(V~~
c
The main purpose of the REFER-
,,:'-: ENCE LEVEL control is to set the absolute power at the REFER-
ENCE LEVEL (top graticule line) on the CRT. When the peak of a signal is at the REFERENCE
LEVEL, its absolute level (in dBm or dB~
V) is indicated on the CRT annotation as well as on the REF-
ERENCE LEVEL control knob.
This characteristic of the analyzer is used to improve the amplitude measurement accuracy using IF substitution
(refer to Chapter 3).
The REFERENCE LEVEL control, combined with the
INPUT ATTEN control, has a range of 172 dB; from
- 112 dBm to
+
60 dBm, as shown in Figure 16a.
Although the REFERENCE LEVEL control is calibrated from
30 dBm to
60 dBm, signal levels should never exceed
30 dBm since that is the maximum power the analyzer can withstand without damage. In Figure 16b, the REFERENCE LEVEL control was adjusted to position the peak of f, on the REFERENCE LEVEL line of the CRT. The absolute power of f" then, is
+
30 dBm.
The level at f
2 can be read from the calibrated CRT displayas - 20 dBm; that is, 50 dB below
+
30 dBm, assuming a 10 dB/Div Amplitude Scale factor. The Amplitude
Scale factor can be set for 10 dB,S dB, 2 dB or 1 dB per division with respect to the REFERENCE LEVEL (top graticule line). The LIN scale factor sets the vertical calibration to volts with the bottom graticule line representing
If desired, a low-level signal can be positioned at
Table
2.
Frequency Span Modes
PER
DIV
•
(Close Analysis)
Full Band Modes
On Freq Span/Diy
Control
FULL
BAND
1.7-22
GHz
SPAN
TUNING
MARKER
FREQUENCY
SPAN
RESOLUTION
BANDWIDTH
NO
ZERO
(Manual Tune)
Selectable
NO
Selectable from 1 kHz/DIY to 500 MHz/DIV
OPTIMUM or Selectable
Selectable
YES
Depends on
FREQUENCY
BAND selected
Selectable
YES
Depends on
FREQUENCY
BAND selected
Fixed at
3 MHz
YES
1.7
to 22 GHz
Fixed at
3 MHz
VIDEO
FILTER
Selectable Selectable
Fixed at
0.003 x3 MHz
=9 kHz
Fixed at
0.003 x3 MHz
=9 kHz
the REFERENCE LEVEL line to read its power level directly on the CRT annotation. The signal f
J in Figure
16c is positioned on the REFERENCE LEVEL line to read - 80 dBm directly.
CTR 105.6 MHz
REF -10 dBm
SPAN 200 kHz/
10 dB/
ATTEN 0 dB
RES BW 100 kHz
SWP AUTO
VF OFF i i i
I
/
,
1
I
I
I
I/i\
,
I
!
Y
~
/i
I
\
\
I
<,
I r k-.
(a) 100 kHz RBW
- -
The REFERENCE LEVEL line on the CRT is determined by a combination of IF gain (REFERENCE
LEVEL control) and RF attenuation (INPUT ATTEN).
The outer control knob adjusts the IF gain in 10 dB steps.
A fine vernier knob provides continuous control from 0 to -12 dB.
'EFERENCE
Lf~~\,~
Pushing in the outer knob allows
• i selection of RF input attenuation
(blue numbers) from 0 to 70 dB. A reminder light is lit whenever 0 dB
INPUT ATTEN is selected.
Except for noise measurements or when maximum sensitivity is required, a minimum INPUT ATTEN setting of 10 dB should always be used to ensure a good SWR and to minimize uncertainties due to mismatches.
HP·IBCode:
RL (output REFERENCE LEVEL)
LG (output AMPLITUDE SCALE)
AT (output RF INPUT ATTENuation)
CTR
105.6 MHz
RE' -10 dBm
SPAN 200 kHz/
10 dB/ ATTEN 0 dB
RES BW 30 kHz
SWP AUTO
I
I
I
I i
I i
I
1 I
I i
1\ i i
I '\
I
I
II \
J
I \
I \
i
!
J'V
!
J
\
1\
V
\
1\)1\
!
,
!
VF OFF
I i
,,
(b) 30 kHz RBW
CTR 105.8 MHz
REF -10 dBm
SPAN 200 kHz/
10 dB/ ATTEN 0 dB,
RES BW 10 kHz
SWP AUTO
I I
I
I
I
I
I
I
I
1
VF OFF i i
I
I
Video Filter
~.
The VIDEO FILTER control is useful for observation of a low-level signal that is close to the noise level. Figure 17 illustrates how use of the VIDEO FILTER control allows measurement of low-level signals, that are close to the noise level.
A NOISE AVG position on the VIDEO FILTER control allows the analyzer to perform noise level measurements or to measure its own sensitivity (for a given RESOLU-
TION BW setting). The NOISE AVG position engages a
1 Hz low-pass filter to average the noise displayed on the
CRT. The sweep time of the analyzer increases to facilitate noise level measurements.' Another method of making noise and low-level signal measurements easily and accurately is to use
IQ]
~~~
(Digital Averaging) mode.
HP·IBCode:
VF (output VIDEO FILTER)
.-J
(e)
10kHz RBW
Figure
15. Resolving Modulation Sidebands
'Because of detector and log amplifier characteristics, 2.5 dB should be added to obtain the correct noise power reading.
Refer to Hewlett-Packard Application Notes 150-4 and 150-9 for details.
11
REF
LEVEL
(dBm)
+60
+50
+40
GMaximum
}-+3O
Input Level
+20
-90
-100
-110
(SENSITIVITY)
-120
-50
-60
-70
-80
+10
0
-10
-20
-30
-40
( a )
-30
-20
-10
0
INPUT
ATTEN fdBI
-80
-50
-40
REFERENCE
LEVEL RANGE
1172dBI
REFERENCE LEVEL
Figure 16. Reference Level
13
( C )
IIiIPUTATTEN
11
REFERENCE LEVEL
12
( b )
AMPLITUDE
SCALE
10dBIDIV
INPUTATTEN
AMPLITUDE
SCALE
10dBIDIV
CTR 2.4Bll7
GHz SPAN III
MHz/
REF -411 dB.
111 dB/ ATTEN II dB
RES BW
3llil kHz VF OFF
SWP AUTO eTR 2.41lil7
GHz SPAN III MHz/
REF -411 dB.
III dIl/
ATTEN II ell
RES BW 31!0
kHz
VF •ilil3
SWP AUTO
12
......
I
I
I
(I)
Vidlo Filter OFF (b) Video Filter BW
=
.003 x 300 kHz
=
900 Hz
Figure 17. Video Filtering
Sweep Time
__
~ ~_'_h_"_""
When SWEEP TIME/DIV is set to
AUTO, the sweep time is automatically adjusted for all FREQUENCY SPAN/
DIY, RESOLUTION BW, and VIDEO
FILTER settings to maintain a calibrated amplitude display. The effect of
the AUTO SWEEP TIME/DIV setting
may be observed by decreasing the VIDEO FILTER bandwidth setting. The sweep rate slows automatically to allow the narrow video filter bandwidths more time to respond. Calibrated sweep times from 2 jAsec/Div to 10 sec/Div are available when the SWEEP TIME/DIV control is not in AUTO. The faster sweep times (2 jAsec/Div to 1 msec/Div) are used only to display fast signal variations in the time domain (ZERO SPAN selected). At sweep speeds of 2 msec/Div and faster, a mixed mode is enabled in which the display characters and the illumination for the graticule remain digitally controlled while the displayed trace information is analog. At a sweep speed of 5 msec/Div, a mixed mode is enabled if the g
~~6L
, g
I':"~B, or g
:OAL~ push button is pressed. When the mixed mode is enabled, the trace information cannot be transferred digitally.
When the SWEEP TIME/DIV control is operated manually (not in AUTO) or in any full-band mode, care must be taken to ensure that amplitude calibration is maintained.
An uncalibrated display can easily be verified by the presence of the UNCAL readout in the CRT annotation. The SWEEP TIME/DIV control (AUTO or manual operation) will operate with any SWEEP TRIGGER setting as long as INT SWEEP SOURCE is selected.
Hp·IBCode:
ST (output SWEEP TIME/DIV or AUTO flag)
TS (take sweep)
SF (start sweep and set sweep flag)
MS (output value of sweep flag)
DIGITAL STORAGE DISPLAY
The spectrum analyzer CRT displays the signal response trace and all pertinent measurement data. The display information, provided at a flicker-free rate, can be stored for later reference. Certain arithmetic and signal processing functions such as MAX HOLD and digital averaging can be performed on the trace values.
The analyzer can output character information (Figure
18), or messages can be sent to the display via HP-IB.
Hp·IB Code:
LU,LL (input lower, upper line messages)
AU,AL (display lower, upper line control settings)
CS (output annotation)
TRACES
Two independent traces (A and B) may be stored and then displayed either separately or simultaneously.
Error Detection
UNCAL: Uncalibrated display. Gives indication of incompatible FREQUENCY SPAN, RESOLUTION
BW, VIDEO FILTER or SWEEP TIME/DIV settings when SWEEP TIME/DIV is not set to AUTO.
*: Invalid trace asterisk indicates that the displayed trace data has not been updated to reflect changes in control settings.
Display Error Messages: Provide feedback of incorrect control settings for the current measurement. (Display
Error Messages are discussed later in this chapter.)
Clear/Reset
CLEAR/RESET clears trace data from the CRT and resets sweep when the instrument is in a write mode.
I f[j1
MAX d f[j1
DGTL • n
U::::!J
HOLD an
U::::!J
AVG modes, the processed trace
IS cleared and the sequence restarted.
If a plot is in progress, it is aborted. During HP-IB operation, CLEAR/
RESET halts HP-IB communication and returns the display to front-panel control.
Trace Modes
Four mutually exclusive modes for Trace A and Trace B determine the manner in which the traces of the input signal are displayed.
Write Modes.
There are two write modes, in which the trace is updated, for Trace A and Trace B:
• WRITE displays the input signal response.
• MAX HOLD displays and holds the maximum responses of the input signal.
Store Modes.
There are two store modes, in which the trace remains unchanged, for Trace A and Trace B:
• STORE VIEW stores the current trace and displays it on the CRT.
• STORE BLANK stores the current trace and blanks it from the CRT display.
When both Trace A and Trace B are in STORE BLANK, a single analog trace is displayed.
HP·IBCode:
TA,TB (output Trace A, Trace B integer values)
BA,BB (output Trace A, Trace B byte values)
AP,BP (output Trace A, Trace B peak signal coordinates)
IA,IB (input Trace A, Trace B integer values)
13
~
~ ~
, ,
,
*
"
,
0
).
o
'e
NOTE: ITEMS 11 THROUGH 15 ARE ALTERNATE ANNOTATIONS
14
•
••
•
Item
•••
Center Frequency
Description
FREQUENCY SPAN/DIV setting
RESOLUTION Bandwidth setting
Video Filter setting
Reference Level setting
Amplitude Scale factor setting
Input Attenuator setting
Sweep Source· Sweep Time/DIV setting
••
••
Item
•••
Figure
18. CRT Annotation
Description
Sample mode indication
Trace invalid indication
Uncalibrated display indication
ANALOG DISPLAY mode indication
Marker Frequency in Full and
1.7-22
GHz Span modes
Reference Level (dB) at center graticule line
Digital Averaging indication
TRACE MEMORY
An understanding of the trace modes requires a description of trace memory and trace data transfer within the analyzer.
Display traces are not written directly to the CRT using the IF section video output (Figure 19). Instead, the video response is converted to digital information and stored in a trace memory which can then be transferred to the CRT display. The way in which the information is displayed depends upon the trace mode selected.
NOTE
It is important to understand the differ· ence between "sweep" and "refresh."
In "sweep," the spectrum analyzer sweeps across a frequency span and stores measured amplitude data In a trace memory.
In "refresh," display memory data Is fransferred to the CRT.
The video response is transferred into the trace memory at the sweep rate of the analyzer (selected sweep time).
The trace memory is written to the CRT display at a refresh rate of about 55
Hz.
This is rapid enough to prevent flickering of the trace on the CRT. Thus, trace intensities remain constant as analyzer sweep times are changed.
For write modes, the analyzer signal response is written into trace memory during the sweep, and the memory
RF
INPUT
RF/IF
SECTIONS
ANALOG
TO
DIGITAL
TRACE
CRT DISPLAY
MEMORIES
B
DIGITAL
TO
ANALOG
D:J
DATA DISPLAYED AT
RATE
DATA UPDATED AT
RATE
Figure
19. Data A cquisition and Transfer contents are displayed on the CRT. In store modes, the trace memory is not updated. The current memory data is saved and is either displayed blanked
[Q]
~r~~~
[Q] SJ~~E or
Signal Processing
One of two detection techniques can be selected for displaying trace information: Normal or Sample (Table' 3).
Table
3. Detection Techniques
Mode
Access Use
Normal Default Mode Most measurements when
Always selected peak amplitude of response if not in sample is desired mode or in analog display
Sample
[Q]
SAMPLE pushed in
Random Noise Level measurements
Digital Averaging (automatically selected)
Zero Frequency Spans for sweeptimes ;;;;'2 msec/
DIV for most time domain analysis
During a sweep, only a specified amount of time is available for writing data into each of the 481 trace memory addresses. In each one of these time periods, the positive
Peak detector obtains the maximum video signal excursions and stores this value into the trace memory address.
In the sample mode
([Q]
SAMPLE), the instantaneous signal value of the final analog-to-digital conversion for the time period is placed in memory (Figure 20).
In Figures 21 and 22, the same signal response is displayed with each trace detection mode.
HP-IBCode:
DM (output SAMPLE state)
Digital Averaging
[Q]
~~.;riL is a trace display routine that averages trace responses from sweep to sweep, thus averaging random noise without requiring a narrow video bandwidth. Maximum averaging is achieved after 64 sweeps. Both digital averaging and reduced video bandwidth are primarily used to improve the ability of the analyzer to measure low level signals by smoothing the noise response.
The advantage of digital averaging over narrowing the video filter is the ability for the user to view changes made to the amplitude or frequency scaling of the display while smoothing the noise response. For example, to display very low level signal responses, very narrow resolution and video bandwidths are required. The accompanying increase in sweep time can make measurements cumbersome. Digital averaging allows the display of low level signals without long sweep times. (Any change to control settings will cause the digital averaging process to be restarted.)
Display
Error
Message
If either Trace
[Q]
A or Trace B is in the-
:tto mode, an error message is displayed on the upper portion of the CRT.
15
VIDEO
POSITIVE
PEAK
DETECTOR
SAMPLE
TRACK
AND
HOLD f----
A TO D
\"ONVERTER
~
MEMORY
---.
D TO A
CONVERTER
I - -
CRT
DISPLAY
Figure 20. Detection SignalFlow
Digital Averaging Algorithm
The average of each amplitude point depends on the number of samples already taken and the last amplitude average. The exponentially weighted algorithm is expressed
Y
N
=
Y
N- 1
+
SN - Y N- 1
F where
Y N
SN the latest measurement average
Y N- 1
= the previous measurement average
= the current measurement
N
F sweep number
2INT(l+LOG
2(N»
In other words, the difference between the previous average and the current measurement is divided by F. The result is then added to the previous average to obtain the new average.
For each sweep when n>64, F (now 64) remains constant, and all new data is weighted by 1/64 and added to the average amplitude after the most recent measurement.
Therefore, the average follows only a slowly changing signal response.
HP·IBCode:
DO (output DOTL AVOstate) eTR 2.3799
GHz
SPAN 100
MHz/
REF -Ie dBt.
Ie dB/ ATTEN Ie dB
RES BW 1 MHz
SWP AUTO
VF OFF CTR 2.3799
GHz SPAN 100 MHz/
REF -Ie c&
Ie dB/ ATTEN Ie dB
RES BW 1 MHz
SWP .1
.ee!
VF OFF
SMPL
16
Figure
21.
NormalDetection Mode
---
Figure
22.
SampleDetection Mode
TraceArithmetic
Trace arithmetic can be used either for comparison of two traces or for normalization in swept frequency measurements.
Display
Error
Message
Trace B amplitude (measured in divisions from the bottom graticule) is subtracted from the input trace (Trace A), and the result is written into Trace A from sweep to sweep. Trace B must be in one of the
STORE modes.
If
.
. U
STORE
U
STORE
Trace B
IS not
III l!:::!J
VIEW or l!:::!J
BLANK, an error message is displayed in the upper portion of the CRT.
Trace arithmetic can be used to correct for the frequency response characteristics (flatness) of a swept measurement system. (Refer to Chapter 3 for more detail.)
Hp·IBCode:
NS (output INP - B....A state)
DIRECT PLOTTER OUTPUT
Graticule trace
[Q]
GRAT, character
[Q]
CHAR, and
[Q]
TRACE information can be output directly to a digital plotter through an HP-IB cable, without the need for a controller.
NOTE
If an Hp·IB controller is connected to the
Hp·IB output of the HP 8569B, place controller in reset state (terminate any running program) before the direct plot routine is executed.
Digital plotters can provide full-size copies - up to 11 by
16 inches (approximately 279 by 406 mm) with the HP
9872B- that are ideal for lab reports and that can be reproduced more easily than photographs.
The HP 7225A and HP 9872B are among the plotters that are directly compatible with the HP 8569B. (Most of the CRT illustrations in this manual were directly plotted with the HP 7225A.)
To generate a plot:
1.
Attach HP-IB cable from the HP-IB connector on the rear panel of the HP 8569B to the plotter rear panel HP-IB connector as shown in Figure 25.
2.
Establish the lower-left and upper-right limits on the plotter.
3.
Press and release le,
IQI
GRAT to plot graticu-
[Q]
CHAR to plot characters, and
[Q]
TRACE to plot trace data. (The plots may be run individually, or all three push buttons may be pressed immediately to run a complete plot of the total CRT display.)
To stop the direct plot routine, depress
[Q]
CLEAR/RESET •
DIGITAL PLOTTER SPECTRUM ANALYZER
.
:.f~F .
liiiii~oO
0 • C a::D
0 a:::c::c aa'~.o.
~
I:J
00D@
RF Sign.1
>-__...
Figure
23. Digital Plotter Setup
17
CHAPTER 3
MAXIMUM DYNAMIC RANGE
Dynamic range is defined as the ratio of the largest to the smallest signal that can be measured without any interference from analyzer distortion products or internal noise.
The maximum dynamic range occurs when the internally generated distortion of the analyzer is equal to its noise level (thus, the dynamic range is limited equally by both).
Mixer distortion, caused by a large signal at the mixer, changes non-linearly as the fundamental signal amplitude is changed. That is, for example, a 10 dB change in amplitude causes a 20 dB change in second-order distortion level and a 30 dB change in third-order distortion.
Therefore, the objective of the following discussion is to show that maximum dynamic range can be achieved by the judicious use of RF attenuation.
The maximum dynamic range of the HP 8569B can be determined by referring to Figure 26. Three types of curves are presented on the chart: sensitivity (solid line), second-order distortion (large dashed line), and thirdorder distortion (small dashed line). The sensitivity curves for the six internal frequency bands (0.01 - 22
GHz) are given for a 100 Hz bandwidth. To use the sensitivity curves for other resolution bandwidths, simply subtract 10 dB from the signal to noise reading for an increase in resolution bandwidth by a factor of 10. For example, a signal to noise ratio of 70 dB for a 100 Hz bandwidth would be 60 dB for a 1 kHz bandwidth. The second- and third-order distortion curves are dependent on whether the 0.01 to 1.8 GHz band or one of the preselected internal mixing bands is used. When more than one signal is at the
RF input to the mixer, the distortion curves are also dependent on signal separation. 1\\'0 vertical axes are used in Figure 26: Signal to Noise Ratio
(right side) and Spurious-Free Dynamic Range (left side).
The maximum dynamic range occurs at the intersection of the particular sensitivity curve and distortion curve under consideration. This point is obtained on the spectrum analyzer by adjusting the
RF input attenuauon to achieve the appropriate signal amplitude at the mixer.
1\vo major factors determine the maximum achievable dynamic range ofthe HP 8569B. They are:
18
1.
Signal level at the Input Mixer.
2.
Sensitivity of the analyzer (dependent on frequency band and resolution bandwidth).
These two factors are examined separately in the following paragraphs.
Mixer Level
The Mixer Level is simply the signal at the input minus the analyzer INPUT ATTEN setting. In equation form:
Mixer Level
=
Input Signal - INPUT ATTEN
The horizontal axis on the dynamic range chart represents the Mixer Level.
Dynamic range varies as a function of Mixer Level. In the
0.01 to 1.8 GHz range, the Mixer Level (for maximum dynamic range) should be approximately - 47 dBm when second-order distortion products are measured. Beyond this level, second-order distortion will increase 20 dB for every 10 dB increase in Input Signal. For third-order distortion measurements, the Mixer Level should be approximately - 37 dBm. In the preselected 1.7 to 22
GHz frequency range, dynamic range variation as a function of Mixer Level is not as critical. The maximum dynamic range in the preselected bands is achieved at a
Mixer Level of approximately - 7 dBm, which is the 1 dB gain compression level of the spectrum analyzer. This applies for both second- and third-order distortion products.
Example (see Figure 26).
Measure the third-order intermodulation distortion products of a device. The spectrum analyzer input signals are 1146 MHz and 1156 MHz and have an amplitude of
-10 dBm. Find the Mixer Level to obtain the maximum dynamic range, insuring that the distortion of the spectrum analyzer does not interfere with measuring the distortion products of the device.
Solution:
The Mixer Level to achieve the maximum dynamic range is approximately - 37 dBm (about - 40 dBm for each signal). Since this is a third-order measurement, use the small dashed third-order distortion curve applicable to the frequency range. Intersect this curve with the sensitiv-
ity curve that cover 0.01 to 1.8 GHz. The maximum dynamic range and optimum Mixer Level for a 100 Hz resolution bandwidth occurs at the intersection of the curves. The INPUT ATTEN control must therefore be set at 30dB (for a total power level at the mixer of - 37 dBm) to achieve this dynamic range (see Figure 26a).
Sensitivity
Spectrum analyzer sensitivity has been traditionally defined as the average noise level displayed on the analyzer. The average noise level of the HP 8569B is dependent on the resolution bandwidth and on the frequency band selected. Since the noise displayed on the analyzer is random, it is dependent on bandwidth; therefore, for every decade increase (decrease) in resolution bandwidth the average noise level increases (decreases) by 10 dB.
The HP 8569B uses harmonic mixing to achieve 22 GHz
(internal mixing) and 115 GHz (external mixing) frequency ranges. Thus, higher harmonic mixing modes
(corresponding to higher frequency bands) have higher average noise levels, causing spectrum analyzer sensitivity to decrease). Therefore, the best sensitivities are achieved on the lower frequency bands. Figure 26c shows how the
Signal to Noise Ratio is degraded with the higher frequency bands.
Preselection
Another factor to consider in determining maximum dynamic range, besides mixer level and sensitivity, is preselection. In comparing the distortion curves for the 1.7
to 22 GHz frequency range to the 0.01 to 1.8 GHz frequency range in Figure 26c, it can be seen that the dynamic range for the preselected band (1.7 to 22 GHz) is generally much greater when the signal separation is
~ 100 MHz. This benefit is due to the tracking preselector, a tunable bandpass filter that tracks the tuning of the analyzer. The preselector extends the dynamic range of the analyzer to measure a low level signal in the presence of a potentially interfering high level signal. Since the preselector tracks the tuning of the analyzer, it allows a signal to pass to the mixer when both preselector and analyzer are tuned to receive it. When the analyzer is tuned to the low-level harmonic, the preselector rejects the high-level fundamental, thus preventing internal distortion products from affecting the measurement. This condition is illustrated in Figure 24.
In the preselected frequency bands (1.7 to 22 GHz) the tracking bandpass filter has a nominal 50 MHz bandwidth and a worst case rejection of >60 dB
(60 dB - 18 to
22 GHz, 70 dB-I.7 to 18 GHz). For signal separation
~
100 MHz, the tracking filter will allow only one signal to pass to the mixer while simultaneously rejecting the other signal. This is illustrated in Figure 25. Since only one signal is seen at the mixer at any instant of time, the third-order distortion products of the analyzer are significantly reduced. Also, for larger signal separation, the preselector has more rejection and hence the dynamic range is greater.
Power . . . . - - - - - - - . ,
YIG Preselector
-------+, \
I \
I
\'1'
\
At time t2, the analyzer is tuned to receive 2fl.
The preselector also rejects fl. thereby eliminating this source of distortion.
P o w e r . - - - - - - - - . . . ,
YIG Preselector
-,t
,
,
\
,
\
\
\
--,....----~. .
Time
At time tj , the YIG preselector will allow fl to pass while rejecting f2 since f2-fl
100 MHz.
Figure
24. YIG Preselector Tuning
Figure
25.
YIG Preselector Passband
19
B5dB
- 37 dBm
MIXER LEVEL
(a)
':!
::;;
<!
Z c
LU o
Z
<!
0:
110dB
-7dBm
MIXER LEVEL
(b)
LU
LULU
0:",
'7z z<!
00:
....
-
0:::;;
.... z
!!1>-
0 0
20
30
40
50 - -....."
~
8, 601---+-' c::
III
70
1----+---+-.,
.~
E
III
~
80
1---+--+---+-
C
Q)
e
90
LL en
~
.g
100 tr:=±:::=±:::==i==:t::==t;--~
~
Q.
m
Sensitivity
110
(in
100
Hz
BW)
120
2nd Order Products - -
3rd Order Products ••••••••••
130
........................................
1.7
to 22 GHz (2nd and 3rd order)
Signal Separation
100 MHz
---
.......
.......
-80 -70 -60 -50 -40 -30 -20 -10 0* +10 +20 +30
Effective Input Level in dBm (Signal Level-Input Attenuation)
"Mixer levels above -7 dBm cause gain compression.
(e)
Figure
26.
Dynamic Range
The distortion curves for the 1.7 - 22 GHz frequency range are represented by a horizontal line. The line represents both the second- and third-order distortion curves, which theoretically have the same slope as the distortion curves in the non-preselected modes. However, the curves are represented as a horizontal line because the absolute levels of the internally generated distortion are generally well below the internally generated noise of the analyzer.
Example:
Measure the third-order inter modulation products of a microwave amplifier. The two output signals are - 10 dBm at 5.9 and 6.1 GHz. What is the maximum dynamic range of the analyzer?
Solution:
The maximum dynamic range is approximately 110 dB.
Note that the signal separation is 200 MHz; therefore, the second- and third-order distortion of the analyzer is represented by the distortion curve for the preselected band
(1.7 to 22 GHz with signal separation ~ 100 MHz). For a mixer input level of - 7 dBm ( - 10 dBm for each signal) the distortion curve is below the sensitivity curve of the analyzer; therefore, the dynamic range is determined by the intersection of the 3.8 - 8.5 GHz sensitivity curve with the - 7 dBm mixer level. The dynamic range of the analyzer is approximately 110 dB (see Figure 26b).
Other constraints:
When measuring distortion products associated with low-level input signals, the noise floor of the analyzer is the limitation. In this case, find the input signal level on the Mixer Level (horizontal) axis
(assuming INPUT AITEN is set to 0 dB) and go vertically to the appropriate sensitivity curve. The maximum obtainable dynamic range is read from the Signal to
Noise ratio (vertical) axis.
Dynamic Range Equations
The dynamic range chart shown in Figure 26 is based on the following equations for third- and second-order maximum dynamic range.
For third-order dB
=
12/3 (average noise level - TOI)
in
For second-order
SOl)
I indB
11/2 (average noise level -
The third-order intercept (TOI) is theoretically defined as the mixer level at which third-order distortion equals the fundamental signal level (a condition which never occurs because compression in the mixer occurs first). The second-order intercept (SOl) is theoretically defined as the mixer level at which second-order distortion equals the fundamental signal level. The intercept is calculated from the following equation:
Intercept
= mixer level - (distortion
(dBc»/N -
1 where N
= order or distortion
These equations are used to compute the best dynamic range for either third- or second-order distortion products and noise. The noise level is the displayed noise level for the resolution bandwidth and center frequency to be used, assuming 0 dB input attenuation.
Example: In measuring a 10.50 GHz signal and a 10.55
GHz signal in a 1 kHz resolution bandwidth, the typical sensitivity of the analyzer is - 100 dBm, assuming 0 dB input attenuation. The HP 8569B has a TOI of
5 dBm and SOl of
30 dBm for signal separations of <100
MHz. What is the maximum dynamic range?
Solution:
70 dB for third-order and 65 dB for second-order.
Third-order
=
1213 (-100 dBm -
5 dBm)
I
=
70 dB
Second-order
=
11/2 (-100 dBm -
30 dBm)\
=
65 dB
It is also possible to determine the value of total RF attenuation (internal or external) needed to obtain the maximum dynamic range for a given input power level from the following equations.
For third-order:
Atten
=
Input 2/3 TOI - 1/3 Noise Level
For second-order:
Atten
=
Input - 1/2 SOl - 1/2 Noise Level
For the same conditions as in the previous example, with total Input Signal Level of - 20 dBm, the RF attenuation should be set to:
Third-order:
Atten
= -
20 dBm -
2/3(
+
5 dBm) -
1/3(
-100 dBm)
= lOdB
21
Second-order:
Atten
= -
20 dBm - 1/2(
30 dBm) - 1I2( - 100dBm)
=
15 dB
Therefore, RF attenuation must be set to 10 dB to maximize third-order and 15 dB to maximize second-order dynamic range.
IMPROVING AMPLITUDE MEASUREMENT
ACCU·
RACY
The technique known as IF substitution can be used to improve measurement accuracy on the HP 8569B. The IF substitution method uses only the accurate IF gain of the analyzer to position the signal on the calibrated REFER-
ENCE LEVEL line. In this way, errors caused by CRT non-linearity, log amplifier, input attenuator, and bandwidth filter will be eliminated. The IF gain of the analyzer is controlled with the calibrated REFERENCE
LEVEL dBm control.
Amplitude Measurement with IF Substitution
The steps for achieving accurate amplitude measurements with IF substitution are as follows:
1.
Set the INPUT ATTEN control to 10 dB or greater.
This ensures a good input SWR to minimize mismatch errors.
2.
Set the FREQUENCY SPAN/DIV and RESOLU-
TION BW controls to the desired settings.
3.
Connect the CAL OUTPUT signal to the analyzer to verify calibration.
4.
Disconnect the CAL OUTPUT signal and connect the signal to be measured.
5.
Press the desired FREQUENCY BAND push button and use only the TUNING control to center the signal on the CRT.
6.
In the 1.7 to 22 GHz frequency range, adjust the
PRESELECTOR PEAK control to maximize the signal level."
The best broadband tracking performance of the preselector is normally obtained with the PRESELEcroR PEAK control centered in the green area. However, for accurate power measurement, the PRESELECTOR PEAK control should be adjusted to maximize signal level every time an amplitude measurement is made.
22
7.
Now, using only the REFERENCE LEVEL dBm control and vernier, position the peak of the signal on the REFERENCE LEVEL line of the CRT. The signal amplitude is indicated by the REF on the
CRT annotation.
When the IF substitution technique is used for amplitude measurements, the only remaining measurement uncertainties are due to the CAL OUTPUT signal, flatness, and REFERENCE LEVEL control accuracy of the analyzer. Uncertainties caused by log amplifier fidelity, CRT non-linearities, and RESOLUTION BW and INPUT
ATTEN switching errors have been eliminated because they were left unchanged throughout the measurement.
Further improvement in accuracy can be achieved by calibrating the analyzer at the same frequency to which the measurement will be made. This would eliminate any flatness uncertainties, and the measurement accuracy would be dependent only upon the accuracy of the calibration signal and the REFERENCE LEVEL control.
CRT PHOTOGRAPHY AND
X·Y
RECORDING
CRT Photography
The CRT annotation on the HP 8569B display provides an excellent means of information retention with the use of any compatible scope camera. Since the display has readouts for all major spectrum analyzer settings, the need for additional writing on the photograph is largely eliminated. Also, interference between trace and characters is not a problem because the character annotation is located on the upper portion of the display, outside the graticule (refer to Figure 27).
Figure
27.
CRT Display with Character Annotation
The photo in Figure 27 was taken with a camera that has variable shutter speed and f-stop. A step-by-step procedure for photography is given below. These steps are applicable with the HP 197B Option 006 or other compatible scope cameras.
Photography Procedure
1.
Set the HP 8569B SCALE INTEN and INTEN to the calibrated blue markings.
2.
Set the camera shutter to 2 seconds and the f-stop to 8.
3.
Push the
[b]
SJ~~E button on the analyzer to store the trace. This ensures the trace and the CRT frequency readout on the display will not change while the camera shutter is opened. Press shutter on camera to take picture.
In the mixed display mode (refer to Appendix B), a double exposure is needed to provide the best contrast between signal trace, graticule lines, and CRT annotation.
DoubleExposure Photography
1.
Set INTEN fully counter-clockwise.
2.
Set SCALE INTEN to calibrated blue markings.
3.
Set SWEEP TIME/DIV to AUTO.
4.
Set shutter speed to 2:2 sec and f-stop to 8.
5.
Press shutter on camera to take first exposure.
6.
Return SWEEP TIME/DIV to original setting.
7.
Set INTEN to the calibrated blue markings.
8.
Press
[b] SJ~~E
.
9.
Press shutter on camera to take second exposure.
To set up the initial focusing of the camera the user is referred to the Operation Section of the 197B Operation and Service Manual (HP Part Number 00197-90915).
Analog X-Y Recording
The HP 8569B is directly compatible with the HP line of
X-Y recorders as well as strip-chart and magnetic tape recorders. The VERTICAL OUTPUT, BLANK OUT-
PUT, and HORIZONTAL SWEEP OUTPUT are available from the rear panel of the analyzer.
As with digital plotters, X-Y recorders can provide full-size, high-resolution copies - up to 11 by 14 inches (approximately 279 to
356 mm) - that are more convenient than photographs for laboratory report folders. Figure 28 iilustrates a typical setup used for X-Y recording.
The bandwidth of most X-Y recorders is very narrow, typically 1 to 2 Hz. This narrow bandwidth requires a sweep rate that is slow enough for the recorder to fully respond to a signal. In general, a sweep rate of 2 sec div is sufficient for most X-Y recorders. The SINGLE or the
MANUAL sweep mode on the HP 8569B can be used to control the sweep.
x·y RECORDER
BLANK OUTPUT (PEN LIFT)
VERTICALOUTPUT
HORIZONTAL SWEEP OUTPUT
SIGNAL INPUT
----~----...."
Figure
28. X-Y Recorder
EXTERNAL MIXEROPERATION
Calibrated frequency coverage from 12.4 to 40 GHz can be achieved by using the HP 11517A Option E03 External Mixer. Coverage above 40 GHz can be accomplished with a variety of commercially available mixers. The HP
11517A must be used with the appropriate waveguide adapter listed in Table 4. The external mixer connects to the IF INPUT port on the front panel of the HP 8569B by means of a coaxial cable that has male SMA connectors. Selection of the EXT MIXING MODE and the corresponding FREQUENCY BAND allows frequency coverage in four ranges: 12.4 to 26.5 GHz, 21 to 44 GHz, 33 to 71 GHz, and 53 to 115GHz.
23
Table
4.
External Mixer Components
HP Model
Number
115l7A
11518A
11519A
11520A
Description
12.4-40
GHz
Mixer
12.4-18 GHz Adapter
18-26.5
GHz
Adapter
26.5-40
GHz
Adapter
HP Band
Designation
P
K
R
External mixers are used whenever the signal of interest is higher in frequency than the design limits of the coaxial input and internal mixer of the spectrum analyzer. Consider these four signals when using external mixers: the
RF input, the spectrum analyzer first LO, the bias current for the mixer diode, and the IF output of the mixer.
Some mixers have separate ports for each signal. One port is for the RF input. The other port is shared by the
LO power and DC bias current inputs, and IF output.
The HP 11517A is a two-port device. A diplexer (HP
Part Number 5086-7721) must be used to separate the DC current from the LO power. A test setup of the HP 8569B with the HP 11517A External Mixer and adapter, and the diplexer, is illustrated in Figure 29.
In operation, the HP 11517A External Mixer bypasses the input attenuator, preselector, and the internal mixer of the analyzer. Three things must be remembered when using the external mixer:
1.
The INPUT ATTEN has no effect on the input signals.
2.
Harmonic mixing responses must be properly identified, since there is no preselection in the EXT
MIXER bands. With a FREQUENCY SPAN/DIV of 100 MHz, the HP 8569B displays mixing product pairs. The correct pair is 642.8 MHz apart. The lower frequency product of the pair is the correct one. To check this, center this signal on the display.
Select FREQUENCY SPAN/DIV of 1 MHz and press the SIO IDENT button. The display should show two signals with 2 MHz separation.
3.
Amplitude measurements are uncalibrated unless steps are taken to calibrate the analyzer. Refer to
Section V, paragraph 5-31, in the HP 8569B Operation and Service Manual.
Signal Identification
To properly identify a signal on the CRT, the SIO IDENT push button on the HP 8569B is used. To use the SIO
IDENT, center the unknown response on the CRT. Then press the SIO IDENT push button and note whether the response resembles that shown in Figure 30.
If the
000
•••
TEST SOURCE
.
, ,
• •••
CTR 29. 279 GHz
SPAN 1 MHz/
REF -35 dBm 1~ dB/ ATTEN 2~ dB
RES BW
SWP
3~ kHz
AUTO
VF OFF
~J
,
~,
.•...
T .,
,,,.
'I"" ..." 'WI
Figure
29. External Mixer Test Setup
A DC bias is necessary to optimize single diode mixers for minimum conversion loss at the frequency of the RF input signal. The HP 8569B can supply negative or positive DC bias. For positive polarity mixers such as the HP
11517A, the bias can vary from 0 to
+
5 rnA.
For negative polarity mixers, the bias can vary from - 5 to 0 rnA.
24
-.Ll-
Hiltz
Figure 30. Signal Identifier
response moves to the left 2 MHz and drops in amplitude, it is the correct signal and its frequency is indicated on the display. When a signal cannot be identified in any of the EXT MIXER frequency bands, one of two conditions applies:
1.
The signal is not in the 12.4 to 115 GHz frequency range.
2.
The displayed response is a product generated by a harmonic of the Local Oscillator not utilized by the analyzer in displaying amplitude calibrated signals.
However, there is a displayed response on one or more of the frequency bands which will identify the signal correctly.
In either case the signal frequency can be approximated from the following equation: where
F,
=
NF
LO
±F
1F
F,
= input signal
N
= mixing mode
FLO = first local oscillator frequency
F1F = first intermediate frequency
(I)
The first step in calculating the input frequency is to calculate the actual mixing mode (NA) using the following equation.
N
A
2 MHz x N of frequency
Signal Shift (MHz) band selected
(2) where N
= harmonic mixing mode
N
A
= actual mixing mode
Signal Shift = signal shift on CRT in MHz with ON
The next step in the determination of F s, the actual input signal, is to calculate the local oscillator fundamental frequency. Referring to equation
(l), the LO fundamental frequency can be calculated from the value of F,
(obtained from CRT or LED center FREQUENCY GHz display), N (determined from the FREQUENCY BAND selected), and F1F(first Intermediate frequency of the HP
8569B which equals 321.4 MHz). The"
or " - " sign is determined by the polarity of the mixing mode of the frequency band selected.
For example,
If r, =
34.5 GHz
N
F1F
=
10+
=
321.4 MHz
From equation (1)
=
NFLO ± F'F
34.5 GHz
=
(10) x FLO
321.4 MHz
FLO
=
3.42 GHz
The final step is to calculate F, (the actual input signal) using equation
(I), and the value of FLO, N
A , and FIF. The
or "- " sign in this final calculation is determined by the direction of the signal shift. A shift to the left requires the"
sign, while a shift to the right requires the" -" sign.
Example:
A signal displayed on the HP 8569B has a center FRE-
QUENCY GHz readout of 38.00 GHz. When theg
'~~~T button is pressed, a second signal appears offset to the left by 4 MHz. What is the actual frequency of the signal?
Solution:
1.
Calculate N
A using equation (2) while noting that
38.00 GHz is within the 21 - 44 GHz band, which hasN
=
10+.
N
A
=
(2 MHz/4 MHz) x 10
2.
Calculate FLO using equation (1) using
F s
= 38.00 GHz (center FREQUENCY
GHz readout)
N
=
10 (corresponding to 21 - 44 GHz band)
F'F
=
321.4 MHz (EXT MIXER 1st
Intermediate frequency)
Therefore,
38.
0 GHz
=
10 x fLO
321.4 MHz
FLO
=
3.77 GHz
NOTE
FLO
can also be obtained from Tuning
Curves on Figure B·2.
25
DISTORTION
Distortion measurement is an area in which the spectrum analyzer makes a significant contribution. Two basic types of distortion are usually specified by the manufacturer: harmonic distortion and two-tone, thirdorder intermodulation distortion. The third-order intermodulation products are represented by: 2f
2f2 - f
1 where f
1 and f
2
1 f
2 and are the two-tone input signals.
The HP 8569B is capable of making a wide variety of distortion measurements with speed and precision. The instrument can measure harmonic distortion products greater than 100 dB down in the 1.7 to 22 GHz frequency range. Third-order intermodulation products can also be measured greater than 100 dB down, depending on signal separation and frequency range.
Amplifiers
All amplifiers generate some distortion at the output, and these distortion products can be significant if the amplifier is overdriven with a high-level input signal. The test setup in Figure 31 was used to measure the thirdorder intermodulation products of a microwave fieldeffect transistor (FET) amplifier. Directional couplers and attenuators were used to provide isolation between sources.
Figure 32 is a CRT plot of a two-tone, third-order intermodulation measurement. The third-order products (2f
1
- f
2 and 2f
2
f.) are below the two-tone signals (f, and f
2) .
Mixers
Mixers use the non-linear characteristics of an active or passive device to achieve a desired frequency conversion.
As a result some distortion at the output is due to the inherent non-linearity of the device. Figure 33 illustrates the test setup and CRT plot of a typical mixer measurement. Once the RF input and LO input signals were measured on the spectrum analyzer, from a single display, the following information was determined:
Conversion loss (SSB):
RFin - IF
=
(-25) - (-34)
=
9dB
LO to IF isolation:
LOin - LOOU'(lF)
= (+
5) - (- 38)
=
43 dB
I
CTR 1.
~472 GHz
REF ~ dBm 1~
SPAN 5 MHz!
dB!
ATTEN 4~ dB
RES BW 1 ~~ kHz
SWP AUTO
VF OFF
,
I
I'
Figure
32. Two-Tone, Third Order
Intermodulation Products
i u
I
'f
" SIGNAL SOURCE
Son
TERMINATION
" SIGNAL SOURCE
I,
10 dBPAD
-20 dB e •.•.•.•.•.•.•.•.•.•.•.
1.)
I,
10dBPAD
-20 dB
I, • I,
AMPLIFIER
Figure
31.
Two-Tone Test Setup
SPECTRUM ANALYZER
26
RF to IF isolation:
RF in -
RF out(IF)
25) - (- 54)
29 dB
Third-order distortion product (2 LO - RF):
-74 dBm at 360 MHz.
MKR 2.B81B GHz
REF 1~ dBm l~
SPAN FULL dB/ ATTEN 2~ dB
RES BW 3 MHz
SWP AUTO
VF OFF
I
CTR
262.0 MHz
REF -20 dBm
SPAN
5~
MHz/
10 dB/ ATTEN 0 dB
RES BW 300 kHz
SWP AUTO
-IF
T
LO
+IF
VF OFF
RF
2LO - RF
.~
RF Input
>-----.1
Mixer
RF=LO±IF
±IF
To
HP8569B
Figure
34.
Oscillator Fundamentaland Second Harmonic
NOTE
Consult AN 150-11 for more information on distortion measurements.
MODULATION
Amplitude Modulation
The wide dynamic range of the spectrum analyzer allows accurate measurement of modulation levels. A 0.06 percent modulation is a logarithmic ratio of 70 dB, which is easily measured with the HP 8569B. Figure 35 shows a signal with 2 percent AM displayed, a log ratio of 40 dB.
Figure
33.
Mixer Measurement
Oscillators
Distortion in oscillators may be harmonically or non-harmonically related to the fundamental frequency. Nonharmonic oscillator outputs are usually termed spurious.
Both harmonic and spurious outputs of an oscillator can be minimized with proper biasing and filtering techniques. The HP 8569B can monitor changes in distortion levels while modifications to the oscillator are made. In the full-band modes, a tuning marker can be located under any signal response to determine its frequency and, hence, its relationship to the fundamental frequency of the oscillator. Figure 34 is a CRT plot of the fundamental and second harmonic of an S-band (2 to 4 GHz) YIG oscillator. The internal preselect or of the HP 8569B enables the analyzer to measure a low-level harmonic in the presence of a high-level fundamental. The plot was obtained using the lQ] :o~~ capability of the analyzer to allow storage of the maximum deviations of the signals.
CTR sa
3 MHz SPAN 1~~ kHz!
RES 8W 3 kHz
VF OFF
REF -15 dBm 10 d8/ ATTEN 10 d8
SWP AUTO
I
I
I
I i i
I
III I
!
i i i
I
1 -
- + -
I
--
~
~ \-,..
Figure
35. 2%
AM
When the analyzer is used as a manually tuned receiver
(Zero Span), the AM signal is demodulated and viewed in the time domain. To demodulate an AM signal, uncouple the RESOLUTION BW and set it to a value at least twice the modulation frequency. Then set the
AMPLITUDE SCALE to LIN and center the signal,
27
horizontally and vertically, on the CRT. (Refer to
Figure 38.) By pressing ZERO SPAN and VIDEO triggering, and adjusting the TRIGGER LEVEL for a stable trace, the modulation will be displayed in the time domain. (Refer to Figure 37.) The time variation of the modulation signal can then be measured with the calibrated SWEEP TIME/DIV control.
The example shown in Figure 37 demonstrates sinusoidal amplitude modulation, which can be used for narrowband sine wave testing of components and systems.
When the modulation is not a pure sine wave use the HP
8569B to obtain signatures (reference responses) of random modulation for comparison or listen to the VERTI-
CAL OUTPUT with headphones (see Control Glossary).
The display can be output to a controller for statistical analysis of random amplitude modulation.
Frequency Modulation
For frequency modulated signals, parameters such as modulation frequency (f m ) , modulation index (m), peak frequency deviation of carrier (.£lf pea k) are all easily measured with the HP 8569B. The FM signal in Figure
38 was adjusted for the carrier null which corresponds to m
=
2.4 on the Bessel function. The modulation frequency f m , is 100 kHz, the frequency separation of the sidebands. The peak frequency deviation of the carrier
(.£lf peak) can be calculated using the following equation: m
=
.£Ifpeak f m or .£lfpeak
2.4 x 100 kHz
240 kHz
CTR 90.0 MHz
REF -10 dBm
SPAN 200 kHz/
10 dB/ mEN 10 dB
RES BW 3 kHz
SWP AUTO
I I I
I
I~l
I i
!
I
:
VF OFF
Figure
36. Linear Amplitude Display
28
Figure
37. Demodulated AM Signal in ZERO SPAN
II
I w w
IJ
\;J
I.,.J
vv
I,.JI.-
W
~
Figure
38. FM Signal
If the FM signal displayed does not correspond to a specific carrier or sideband null, then determination of the modulation index m, and final calculation of the peak frequency deviation Af"..u becomes much more complex and tedious. As with amplitude modulation, the display output can pass to a controller, then, by storing in the controller memory the values of certain analyzer characteristics (such as slope non-linearities of bandwidth filters) and by prompting the user to set certain controls,
.£If,,... can be measured directly, or calculated.
Although the HP 8569B does not have a built-in discriminator, FM signals can be demodulated by slope detection.
Rather than tuning the signal to the center of the CRT as in AM, the slope of the
IF
filter is tuned to the center of the CRT. At the slope of the IF filter, the frequency variation is converted to amplitude variation. In FM, the resolution bandwidth must be increased to yield a display similar to that shown in Figure 39 before switching to
ZERO SPAN. When ZERO SPAN is selected, the amplitude variation is detected by the analyzer and displayed in the time domain as shown in Figure 40.
Figure
39. Slope Detection ofFM Signal less than the PRF. In the pulse mode, there is more than one spectral line in the passband; i.e., the resolution bandwidth of the analyzer is greater than about twice the PRF.
Since a spectrum analyzer does not display the actual peak pulse power of the signal (a pulsed signal has its power distributed over a number of spectral components and each component represents a fraction of the peak pulse power), a correction or a desensitization factor must be added to the displayed main lobe power of the pulsed RF signal to obtain the peak pulse power.
The calculation of the desensitization factor depends on whether the analyzer is displaying the signal in the line or pulse mode.
-
(lR 6.
~4~~ GHz SPAN 2~~ kHz /
REF -l~ dB.
l~ dB/ ATTEN l~ dB
RES BW l~ kHz
SWP AUTO
I i
I
,
I
VF OFF
A
, V!
All
:
I~
A
I
111~
I
V
Figure 40. Demodulated FM Signal in ZERO SPAN
Pulsed RF
A pulsed RF signal is basically an RF signal which is turned on periodically for brief intervals of time. Some parameters to be determined in measuring pulsed RF signals are pulse repetition frequency (PRF), pulse width, duty cycle, on-off ratio of the modulator, and pulse power. Pulse power can refer to either the average power or to the peak power of the pulse.
The spectrum analyzer can display a pulsed RF signal in either of two modes, the line mode or the pulse mode.
The factor that determines the display mode is the number of spectral components or lines that are in the passband of the spectrum analyzer at anyone time. In the line mode, there is only one spectral component or line in the passband; i.e., the resolution bandwidth is
Figure
41. Line Spectrum
Line Mode
To obtain a line spectrum on the analyzer, the resolution bandwidth must be less than the PRE This ensures that individual spectral lines will be resolved. From the line spectrum shown in Figure 41, it is possible to measure the following parameters:
PRF
50 kHz (spacing between spectral lines)
Main lobe width = 800 kHz
Main lobe power
38 dBm
Then, from the above measurement, the following data can be calculated:
Pulse width
2
Main Lobe width
=
_ 2 _
=
2.5JLSec
800 kHz
Duty cycle
2PRF
Main Lobe width
=
2(50 kHz)
=
0.125
800 kHz
29
To determine the peak pulse power in a line spectrum, a pulse desensitization factor
(ad
must be added to the measured main lobe power. The desensitization factor is a function of the duty cycle and is represented by the following equation:
«t,
20 log x (duty cycle)
For duty cycle of 0.125, aL
18 dB. Hence the peak pulse power in Figure 43 is - 20 dBm.
Pulse Mode
To obtain a pulse spectrum on the analyzer, the resolution bandwidth of the analyzer must be set to greater than about twice the PRF, to ensure that more than one spectral line is within the passband of the analyzer. To find the peak pulse power in the pulse mode, add the pulse desensitization a p , which is a function of pulse width and spectrum analyzer impulse bandwidth, to the main lobe power.
Figure 44 illustrates a signal in the pulse spectrum mode.
As with the line spectrum, the pulse width can be determined from the main lobe width, while the impulse bandwidth is a characteristic of the analyzer.
a p
20 log (pulse width x Impulse BW)
For a pulse width of
2.5/Lsec
and an impulse bandwidth of 150 kHz,
a p
8 dB. The peak pulse power of the signal shown in Figure 44 then, is - 20 dBm.
A wider resolution bandwidth results when in pulse spectrum mode. The wider resolution bandwidth provides two advantages. First, the signal to noise ratio is increased because the pulse amplitude increases linearly with the resolution bandwidth (BW).
The random noise increases proportionally to the square root of the bandwidth (yBW ). The only limitation is that the bandwidth should be no greater than about 5 percent of the main lobe width. Secondly, faster sweep times can be used because of the wider resolution bandwidths. The
HP 8569B has a 3 MHz resolution BW which enables it to effectively display pulsed RF signals in the pulse mode.
The 3 MHz bandwidth, along with fast sweep times, also enables narrow pulse widths to be measured in the time domain. The demodulated pulse signal of Figure 42 is shown in Figure 43.
Few operating pulsed RF systems have ideal spectra.
Measurements can still be made regardless of the asymmetry of the spectrum. Examples of non-ideal spectra are found in digital communications and radar.
Since most radar systems do not have ideal spectra, the spectrum of a properly operating system is often stored
30 away for future reference. This reference or spectral signature can then be used to determine changes that would indicate potential problems. The HP 8569B has the capability of storing display information onto magnetic tape via HP-IB, or by directly plotting the information (hard copy) for use later (refer to Chapter 2).
In digital communications, one major concern is the limits placed on transmissions by regulatory agencies. When the HP 8569B is used with a controller, specification limits can be written directly on the CRT, making conformance testing less tedious.
An additional factor to consider when measuring pulsed
RF signals is the VIDEO FILTER control and the digital averaging capability of the spectrum analyzer. In general, the VIDEO FILTER and
[Q]
~~Ti should
Figure 42. Pulse Spectrum
Figure 43. Demodulated Pulsed RF Signal in ZERO SPAN
be OFF when measuring pulsed RF signals. Adding video filtering or digital averaging will desensitize a pulsed signal and limit its displayed amplitude.
Therefore, when monitoring pulsed signals in a fullband mode, it is important to use the F mode rather than the FULL BAND pushbutton mode. The FULL
BAND pushbutton mode automatically engages a 9 kHz video (0.003 x 3 MHz) filter which will limit the displayed amplitude of the pulse bandwidth.
NOTE
Consult AN 150-2 for more information on pulsed RF measurements.
NOISE
Applications involving noise measurements include oscillator noise (spectral purity), signal to noise ratio, and noise figure. The NOISE AVG position of the
VIDEO FILTER control and the digital averaging capability of the spectrum analyzer can be used to measure the analyzer sensitivity or noise power from
0.01 to 22 GHz.
The test setup in Figure 44 is used to make a swept noise figure measurement of an amplifier. First, the total gain of the amplifier under test and the pre-amp is determined. Then, the input of the amplifier is terminated and its noise power is measured. The noise figure of the amplifier is the theoretical noise power (KTB) minus the total gain plus the amplifier noise power. Figure 45 is a plot of an amplifier's noise power output.
Another technique, called the Y-Faetor Technique (refer to Figure 46), overcomes the problems associated with the analyzer's absolute accuracy by using a calibrated noise power standard such as the HP 346B excess noise source. By measuring the ratio of Powith the noise source on, to Po with noise source off (the test amplifier input terminated in Z; impedance), we can determine Noise
Figure to a much greater accuracy. Spectrum analyzer instrument errors in the measurement of Po
OnlP
0
Off are typically less than a few tenths of a dB, leading to measurement accuracies approaching those of a noise figure meter. Figure 47 shows the results of a Y-Factor measurement.
NOTE
Consult AN 150-4, AN 150-7 and AN
150-9 for more Information on noise measurements.
ELECTROMAGNETIC INTERFERENCE (EMI)
The objective of EMI measurements is to ensure compatibility between devices operating in the same vicinity.
I
I
SPECTRUM ANALYZER
I
I
I
I
Podill'
TEST AMP
I
I
I
~'>-+-:-
I
NFpre
....
I
I
Gpre
1-
PREAMP
SYSTEM
....
FA"
2 -
KTBGA
NFAldBI' 10 Log Po-10 Log KT-10 Log B -10 Log GA
10 Log Po' 10 LogPodill' - 10 LOll Gpre
(If
10 LogPo>Syrltm SoMitivity + 10 dB)
NFAldBI" 10 Log Podisp + 174dBm - 10 LOll B{GA + Gprel
Figure
44.
Measuring Noise Figure-Absolute Power Technique
31
MKR I.
5985 GHz SPAN FULL
REF -38 dBo.
18 dB/ ATTEN 8 dB
RES BW 3 MHz
SWP AUTO
VF .81
SMPL
~
I~ .~
~
Pt""V'
......
L-o...
Figure
45. Noise PowerMeasurement
,
1 - -
The HP 8569B, along with an appropriate transducer, is capable of measuring either conducted or radiated EMI and can also be used as a calibration tool for EMI susceptability testing. Figure 48 illustrates an equipment setup used for measuring radiated field strength.
The antenna in Figure 48 is used to convert the radiated field to a voltage for the analyzer to measure. The field strength is the analyzer reading plus the antenna correction factor. Figure 49 illustrates radiated interference as displayed on the HP 8569B.
Compatibility is also important for high-frequency circuits which are in close proximity to each other. In a multi-stage circuit, parasitic oscillation from one stage can couple to a nearby stage and cause unpredictable
I
SPECTRUM ANALYZER
, Podisp
I
I
I
I
I
I
NF pII
I
I
G pII
L
SYSTEM
~
NFAMEAS"ENR-IOlOG [
~
-I ]
Podilp Off
WhtfI
Podilp is
PDWIr Outin WIttS
Figure
46. Measuring Noise Figure - Y Factor Technique eTR 100.8
ItIz
SPAN 2Il lliz/
REF -511 dBo.
5 dB/ ATTEN 8 dB
RES BW 3llB kHz
VF .81
SWP AUTO
SIf'L
32
....
,
,I ~
~-
"T"1
~
, '''f f1'
Figure
47.
Y-Factor Measurement
Figure
48. Field Strength Test Setup
eTR 475. 4 MHz
REF -1o dB.
SP~N
100 MHz/
10 dB/ ATTEN 0 dB
RES BW 1 MHz
SWP ~UTO
VF OFF
With interface to a desktop computer, the HP 8569B spectrum analyzer automatically reformats the display to reflect such test limits as impulse bandwidth normalizations, antenna factor, or current probe corrections.
NOTE
Consult AN 150·10 and AN 142 for more information on EMI measurements.
-
I
~
[&n lhlill
.I
Figure
49. Radiated Interference behavior. A popular technique used to search for spurious radiation utilizes an inductive loop probe. The loop probe is a few turns of wire that attaches to the spectrum analyzer with a flexible coaxial cable. (Refer to Figure
50.)
SPECTRUM ANALYZER
Figure 50. Loop Probe
Various parts of the circuit can be 'probed' to identify the location as well as the frequencies and relative amplitudes of spurious signals. Once the spurious signal has been identified, design techniques can be implemented to reduce or eliminate the cause of interference.
When testing to detailed specifications (i.e, MIL-STD), it is the worst case limits or the peaks of the signals that are of concern.
IQl
:OAL~ can be used to store the maximum amplitudes of these signals for later comparison to specified limits.
SWEPT·FREQUENCY RESPONSE
Frequency response measurements are a common requirement for many system components such as filters, amplifiers, and mixers. The addition of an appropriate source to the spectrum analyzer makes a powerful system for stimulus response (swept-frequency) measurements.
The HP 8444A Option 059 is a tracking generator whose
RF output frequency follows (tracks) the tuning of the
HP 8569B Spectrum Analyzer over the frequency range of .0lD to 1.5 GHz. Since the first local oscillator from the spectrum analyzer is used as a reference by the tracking generator, the low residual FM of the spectrum analyzer is transferred to the tracking generator. The frequency spans of the two instruments are matched and synchronous, providing precise tracking between the two instruments. The equipment setup for this measurement is shown in Figure 51.
A significant advantage of the spectrum analyzer/tracking generator combination for swept measurements is the large dynamic range. The noise is bandwidth limited in the spectrum analyzer, and harmonics and spurious products are not limiting factors since the spectrum analyzer is always tuned to the fundamental of the tracking generator. The dynamic range for the tracking generator and spectrum analyzer extends from the output available, on the tracking generator to the noise floor on the analyzer.
For the HP 8569B/8444A Option 059 system, the dynamic range is generally greater than 100 dB. Figure 52 illustrates the large dynamic range that is possible using the HP 8444A Option 059 and the HP 8569B.
The system frequency response can be eliminated from the measurement results by using the
1Ql1~;B mode.
First, calibrate the system with a known standard (i.e., a through-line for transmission measurements). Then, store the displayed response in Trace B by using
. h rcJ1
STORE or rcJ1
STORE ( see
F' igure
53 ) N .
device under test, press INP - B....A (see Figure 53b). The displayed frequency response is that of device, not of system plus device (refer tq
Appendix D concerning position of reference line).
33
NOTE
Errors due to mismatch uncertainty are not removed from measurement by normallzatlon.
The 8444A Option 059 can be used with a counter to make accurate, highly sensitive and very selective frequency measurements of unknown signals. Providing a signal can be resolved on the spectrum analyzer, it can be counted. The system can count signals down to the sensitivity of the analyzer with the frequency accuracy several orders of magnitude better than the spectrum analyzer accuracy.
NOTE
Consult AN 150·3 and AN 150·13 for more Information on Swept·Frequency
Response measurements.
TRACKING
GENERATOR
Figure
51.
Swept Frequency Response Setup
CTR 157.2
lib: SPAN 2ll IIb:I
REF Bell.
III
eIll
mEN III ell
RES BW I kHz
SWP .5 eecl
\
\
\
VF .BI
\
-,
50dB
CTR 157.2
MHz SPAN 2ll !lttl
REF -51!
cL IB
cIll
mEN III ell
RES BW I kHz
SWP .1 eecl
VF . BI
\
......
---
./.r
f - -
45dB
(e) (b)
Figure
52.
Low Pass Filter Measurement with
95
dB ofRejection
CTR
75.3
lib: SPAN III IIb:I
REF 5 ell.
I 431
RES BW III kHz
2ll ell
SWP 11l...d
VF .1l1
CTR 75.3
lib: SPAN III IIb:I
REF Bell mEN
RES BW III kHz
2ll 43 SWP III .eel
t--...
I 431
-
".,.
<, r-,
VF .1l1
\
34
(e) Celibration-System Response
(b) Meesurement-Normelized Response
Figure
53.
Normalization of Frequency Response
This chapter discusses the requirements for remote operation of the spectrum analyzer using an HP_IB' controller.
General Description gramming capability of the instrument is further described by the three HP-IB messages in Table 6. Foremost among these messages is the data message, which is the primary method of communication between the analyzer and the controller. The responses of the analyzer to other messages are shown as well.
The HP 8569B digital storage display and sweep control can be accessed through HP-IB. The HP-IB connector is located on the rear panel (see Figure 54).
An
HP-IB interconnection cable (often supplied with the HP-IB Interface) is required to connect the analyzer to the controller
HP-IB interface.
Addressing the Spectrum Analyzer
Communication between instruments on the HP-IB requires that a unique address be assigned to each instrument. The address switch (Figure 55) on the rear panel of the analyzer is used to set the analyzer address.
Programming codes are summarized on the pull-out information card and in Table 5 of this section. A more detailed syntax summary can be found in Appendix E.
Programming information dealing with specific HP-IB controllers can be found in the
Introductory Operating
Guide
addressing that specific controller.
The instrument address is the binary number represented by the on (l) or off (0) states of the five switch segments
(AI through A5). For example, the address 18 is set when
A2 and A5 are on
(1) and the other switch segments are off (0).
Digital CRT Display Coordinates
Hp·IB Compatibility
The complete bus capability of the spectrum analyzer as defined in IEEE STD 488 (or the identical ANSI Standard MC 1.1), is presented following Table 6. The pro-
References to the CRT display coordinates (specifically, commands AP/BP, BAIBB, IA/IB, and TA/TB as listed in Table 5) will follow the layout in Figure 56.
'Hewlett-Packard Interface Bus, the Hewlett-Packard implementation of IEEE STD 488-1975 and ANSI STD,
Me
1.1,
"Digital Interface for Programmable Instrumentation."
Within the range of the graticule, there are a total of 481
X-axis values (0 to 480, with 48 points per division) and
801 Y-axis values (0 to 800, with 100 points per division).
Table 5. HP-IB Programming Codes
HP·IB Commands (Alphabetical Listing)
AL
Display lower line control settings
AP Output trace A peak signal coordinates
AT Output RF Input Attenuation
AU Display upper line control settings
BA Output trace A byte values
BB
Output trace B byte values
BP
Output trace B peak signal coordinates
CF
Output Center Frequency
CS
Output annotation
DG
Output display mode
DM
Output detection mode
IA
Input trace A integer values
I
B Input trace B integer values
LG Output Amplitude Scale
LL
LU
MS
NS
RB
RL
SF
SP
ST
TA
TB
TS
VF
Input lower line message
Input upper line message
Output value of sweep flag
Output INP-B-+A state
Output Resolution Bandwidth
Output Reference Level
Start sweep and set sweep flag
Output Frequency Span/Div
Output Sweep Time
Output trace A integer values
Output trace B integer values
Take sweep
Output Vfdeo Filter
35
•
-
'".
'.':"
...
..
Hp·IB INTERCONNECTION CABLE
(SUPPLIED WITH THE HP CONTROLLER
HP·IB INTERFACE OPTION)
HP·IB CONNECTOR
ADDRESS SWITCH
Figure
54.
HP 8569B with HP-IB Interconnect Cable
The Y-axis overrange values displayed above the top of the graticule are 801 to 820 for the trace output commands AP/BP, BA/BB, and TA/TB and 801 to 975 for the trace input commands lA/lB. (Values above 950 may be deflected off the top of the screen.)
Two lines of annotation near the top of the CRT display
" -e controlled by the labeling commands CS, LL/LU,
:.ldAL/AU.
Table 5 is a summary of the HP 8569B HP-IB Programming Codes. For more detailed information concerning the front-panel controls of the analyzer, refer to Chapter
2. For information on syntax requirements, refer to
AppendixE.
36
0 , - -
Figure
ADDRESS
16 + 2 -18
....
55.
Hp·IB Address Switch
A1-2'-1
A2 - 2' - 2
A3-2' -4
A4-:Z-' -8
AS -
2' - 16
Table 6. HP-IB Message Reference Table
HP-IB
Message
Data
Response
Information pertaining to the digital storage display is available to the bus. Trace data and display messages can be sent to the analyzer via HP-IB. Program instructions can initiate sweeps.
Related Commands and Controls*
Interface
Functions* n,1A
AHI,
SHI
Clear
Device clear; clear active traces and reset sweep.
DCL
SDC
DCI
Abort
Interface clear; unaddress instrument.
IFC n,1A
*Commands, Control lines and Interface Functions are defined in IEEE STD 488 (and the identical ANSI Standard
MCI.I). Complete HP-IB capability is: SHI, AHI, T7, TEO, L4, LEO, SRO, RLO, PPO, DCI, DTO, CO,E2.
0,975
0,820
"<,
0,800
480,975
VF
/
480,820
480,800
I I I I
I I
I I I
0,0
480,0
Figure 56. Display Coordinates
37
38
I
WARNING
I
This instrument and any device eonnected to it must be connected to power line ground. Failure to ensure proper grounding may cause a shock hazard to personnel or damage to the instrument.
The spectrum analyzer is a sensitive measuring instrument. To avoid damage to the instrument, do not exceed the following absolute maximum input levels:
Total RF power:
30 dBm
(l watt) de or ac «<500 source impedance):
OV with 0 dB input attenuation «1 amp); ± 7V with
~
10 dB input attenuation «0.14 amp).
Peak pulse power:
0.01010
50 dBm «10
IJsec
pulse width, duty cycle) with ~ 20 dB attenuation.
NOTE
Overdriving the Input with too much power, either peak or dc voltages, might damage the Input circuit and require expensive repairs.
If large de components are present with ac signals, a blocking capacitor should be used at the INPUT of the analyzer to eliminate the de components.
LOW IMPEDANCE AC
A source with much less than 500 nominal output impedance can produce excessivecurrent which might damage the input circuit of the analyzer.
DC PRECAUTIONS
The HP 8569B
cannot
accept dc voltages in
0 dB
INPUT
ATTEN. With 10 dB or greater INPUT ATTEN, small de voltages « ± 7V) can be accepted without damage if the total power (ac and de) does not exceed 1 watt.
The input is direct-eoupled and its de input resistance varies from 0 to 870, depending on the settings of INPUT
ATTEN and FREQUENCY BAND GHz controls. (See
Figure: A-I.)
OftOC
1.7 - 22 GHz
Step A~uetor
Mixer
Input
50ft
DC 0"""
(~10 sen
DC dB Input
A~)
87ft
DC
.01-1.8 GHz
Figure A»], DC Block Diagram
SYSTEM DESCRIPTION
The HP Model 8569B Spectrum Analyzer is basically an electronically swept superheterodyne receiver.
It has high sensitivity and selectivity, a wide, distortion-free dynamic range, and excellent flatness from 10 MHz to 22 GHz.
With external mixing, frequency coverage can be extended up to 115 GHz. The HP 8569B consists of an
RF and an IF section, an automatic stabilization and control section, and a digital storage display section. These sections will be discussed separately in this appendix. Figure B-1 is a simplified block diagram of the instrument.
RFSECTION
The RF section is composed of a 0 - 70 dB step attenuator, an automatic preselector, a tunable local oscillator
(LO), and a broadband mixer. The step attenuator at the input to the spectrum analyzer is used to control the signal level to the mixer for optimum dynamic range and signal-to-noise ratio. The automatic preselector consists of a low-pass filter from 0.01 to 1.8 GHz and a yttriumiron-garnet (YIG) tuned filter
(YTF) from 1.7 to 22 GHz.
Coaxial RF switches are used to switch to the proper filter, depending on the selected frequency band. The automatic preselector greatly reduces most image, multiple, and spurious responses of the analyzer and thus enhances its dynamic range. A transistorized YIG-tuned oscillator (YTO) with a fundamental tuning range of 2.05
to 4.46 GHz is used as the
La in this superheterodyne system.
The main IF in the HP 8569B is set at 321.4 MHz, and the first
La sweeps from 2.0 to 4.46 GHz. Therefore, from equation 1, F, would cover approximately 1.68 to
4.14 GHz in fundamental operation. With harmonic mixing, the frequency range is extended to 115 GHz, as shown in equation 2:
(2) where:
N(harmonic number)
=
1- , 2 - , 3 - , 4 + , 5 + , 6 + ,
10+,16+,26+
Each harmonic number creates a tuning curve, illustrated in Figure B-2. Signal frequencies from 0.01 to 1.8 and 1.7
to 22 GHz are converted by the broadband internal mixer to a 2050 MHz IF and a 321.4 MHz IF, respectively. In the 1.7 to 22 GHz frequency range, the YIG-tuned filter tracks a particular tuning curve and thus eliminates spurious responses resulting from harmonic mixing. From
14.5 to 115 GHz, an external waveguide mixer is used to convert the input signals to a 321.4 MHz IF, which is then further processed by the analyzer.
The basic frequency conversion equation for a heterodyne system is given in equation 1:
(1) where:
F,
= signal frequency
FLO
= local oscillator frequency
F
1F
= intermediate frequency
AUTOMATIC STABILIZATION SECTION
Many factors can limit the resolution of the spectrum analyzer. Among these are the stability and spectral purity of the local oscillator and the bandwidth and shape factor of the IF filter. Of these limitations, the most significant for microwave analyzers is usually the stability (residual FM or drift) of an oscillator. For this reason, the HP 8569B utilizes an automatic stabilization circuit that locks the ITO to a 1 MHz crystal reference oscillator. The lock is automatically engaged when frequency spans of 100 kHz/Div or less are selected. The
AUTO STABILIZER can be disabled by a push button switch located on the front panel. An added feature of the automatic stabilization circuit is the use of offset compensation to keep the signal of interest fixed on the
CRT during stabilization. The circuit is designed so that the ITO is not moved when it is locked to the reference oscillator. Since there is no frequency shift in the ITO, there is no shift in the displayed signal. This eliminates the need for the user to retune the signal on the CRT once the instrument has been stabilized.
39
IF SECTION
The IF section consists of components in the signal path after the first mixer. The output from the first mixer is either 2050 MHz (for the .01 to 1.8 GHz band), or 321.4
MHz (for all other bands). Signals at 321.4 MHz bypass the second converter, whereas a 2050 MHz signal would mix with the second LO at 1.7286 GHz to also produce a
321.4 MHz IF. At the third converter, the 321.4 MHz IF is amplified, filtered, and mixed with the third LO at 300
MHz to produce a final IF of 21.4 MHz. The output of the third converter goes to a variable gain amplifier, selectable bandpass filters, variable gain logarithmic amplifiers, and linear amplifiers.
It is then detected. The detected video signal goes through a selectable video filter before it is sent to the display for digital processing.
The IF bandpass filter, log and linear amplifiers, and video filter are all controllable from the front panel of the spectrum analyzer.
DIGITAL STORAGE DISPLAY
The Digital Storage Display section performs two major functions. The first, which is controlled by the CPU
(Central Processing Unit), is to acquire, process, and store display data in memory (referred to as Stroke Memory). The second, which is controlled by the counter, is to retrieve data from stroke memory and to display it on the
CRT.
The Z-Axis signal controls both the brightness and the blanking of the trace. The Digital Y Generator outputs stroke length information, which is then converted to a brightness signal. The signal is used so that long strokes will not be dimmer than short ones. All remaining blanking inputs and control logic inputs are combined to produce one blanking signal that controls the blanking of the
CRT. Generation of the display characters, seen on the top portion of the CRT, is accomplished by the Character
Generator (addresed by the Counter and Data Bus) and by the blanking circuitry.
The Digital Storage Display section also performs secondary functions that are integral to the operation of the instrument but are not necessarily involved with acquisition and display of X and Y signals.
Secondary functions performed by the CPU (with the
Input/Output Interface) include response to display control push buttons, interpretation of instrument control switches, and operation of the HP-IB Interface. The
CPU also plays a major role in the performance of an automatic internal instrument check routine, as well as other test routines that are used to adjust, verify correct operation, and troubleshoot the digital storage circuitry.
(Refer to the HP 8569B Operation and Service Manual,
Section VIII.)
TUNING CONTROLSECTION
The Tuning Control Section contains the Frequency Control, YIG Driver, Frequency Display Unit, Sweep Attenuator, and Sweep Generator.
Since the CPU can process only digital information, an
Analog to Digital Converter is provided to convert analog signals to digital information. The rate at which data is acquired varies with the instrument sweep speed, which is set by the Sweep Generator. During normal operation, the CPU alternately takes samples of the horizontal and vertical signals; the horizontal
(X) value determines the memory address at which the vertical (Y) value is stored.
The counter accesses Stroke Memory and transfers the acquired data into the Y Data Buffer. Control logic determines the time at which the Y Data Buffer will transfer its data to the Digital Y Generator, which converts the retrieved data to an analog voltage that is applied through the Y Amplifier to the vertical deflection plates of the CRT. The horizontal
(X) signal is generated by the
Digital X Generator. The Digital X Generator receives control signals, derived from the counter, and generates an appropriate ramp voltage that is amplified and applied to the horizontal deflection plates of the CRT.
40
The Sweep Generator provides a sweep voltage that is simultaneously applied to the horizontal
(X) deflection amplifier, data converter, and sweep attenuator. The sweep attenuator, controlled by the FREQUENCY
SPAN/DIV control, reduces the sweep voltage to the Frequency Control Unit to maintain a calibrated horizontal scale on the CRT. In addition, the tuning control voltage, which sets the center frequency of the analyzer, is also applied to the Frequency Control Unit, where it is summed with the attenuated sweep. The resultant signal is then applied to the YIG oscillator drivers. Both the
YTF and the YTO have separate YIG oscillator drivers which are basically voltage-to-current converters. A preselector peak adjustment is used to control the offset of the YTF YIG driver circuit. It is adjusted to eliminate any amplitude uncertainty due to nonlinear tracking between the YTF and the YTO. The Frequency Display Unit displays the frequency represented by the center of the CRT display.
RF SECTION
Input 50£1
.01-22 GHz
-~-+---'V)(;y--I::'::",
INPUT ATTEN
SIGNAL PATHS
1.7-22GHz
.01 -" 1.8 GHL
12.4-115GHz •••••••
Frequency
Control
Unit
( ) TUNING
u ru nq tabihz er
·:1
Mixer l l S E C O N O CONVERTER
-'
~'·""~4 HI~"'"''
____
-.;~
2.05 GHz
•••••
IL___
LPE - - - -
, :\
I '
___ .A
I
:~.~:
•
.:~~:.::
THIRD CONVERTER
E~-'
LO
_c9
300
MHz
IF SECTION , - - - - - - -
REFERENCE LEVEL
'----r----J--ch,I:J
I
Amplifier
(I
RESOLUTION BW
I
I
I
_1
I
I
I
FREQUENCY SPAN!OIV
Frequency
Control
Unit
.
- - - - - - - - - - - - - - - - , - - ,' - - - -
TUNING o
SWEEP TIME/OIV
_ _ _ _ _ _ _ IF SECTION - -
REFERENCE LEVEL
~""__
/ / - - - - - - - - - - - - - - - - - - - - - - - - DISPLAYSECTION
-----------------------~
VIDEO FI LTER
f
I
I
I
I
I
___1
FREQUENCY SPAN!DIV
- - -
- - - - -
Control
Gate
__ m P lf i " ~
Z
(Intensity) to
CRT
I
I
!
I
I
I
I
_
~ J~.V""'"
CRT
-'~l
')
Figure nt
HI' 8569B Block Diagram
41
42
-
IJl
:I:
C!J
N
10
90
80
70
60
50
40
30
20
120
110
100
....
V+
....
. /
/ '
....
....
'-
V
-
V
.,~.
fI'
0
'>~
fI'
. /
V
V'
~/
....
~
.......
' /
....
~
~
.......
~ ~
2\.0
~ r
I
12. 4- 26. 5 GHZ
I"
~
V
to--
---
~+
16+
L....-!+ fo
2.0
2.5
3.0
3.5
EXTERNAL
MIXER
RANGE
4.0
4.5
fLO
(GHz ) b. EXTERNAL MIXING
24
~
22
~
20
....
. /
V
N
18
16
14
-
-
y(
"'+-~/
V
V
. /
V
l~
I!>'
,.".
:I:
C!J
IJl
-
10
12
f - /
,.".
V
V
...."...,.
~
8
6
....
2 ffo
2.0
....
-
-
-
-
V
----
--
V
~
2.5
I B " ' G L -
~
1.7~4.1
01-1.8
3.0
GHZ
G~_
~
3.5
.--
......i""'"
1-
-
4.0
i"'"
/
V
10'
V
~
3-
.--.-
2-
....
1-
4+
4.5
5+
VIG-TUNED
FIL TER
LOW-I>ASS
FIL.TER
(GHz) fLO
INTERNAL MIXING
8.
321. 4MHz IF f
5
=n f
LO
± f
IF t - -
321.4MHz I F -
2050 MHz
IF - - - -
t - - -
Figure B-2. HP 8569B Tuning Curves
The HP Model 8569B Spectrum Analyzer reads signal levels in dBm. The following equations allow conversion from dBm to dBm V or dBV in a 500 system.
CONVERSION EQUATIONS
dBm
+
107 dB
= dB/-lV dBm
+
47 dB
= dBmV dBmV
+
60dB
= dBV
If it is desired to convert from logarithmic units to linear units, then the equations given below will be useful. Keep in mind that the logarithmic levels are all referenced to linear units.
To calculate a linear level, simply take the antilog of the logarithmic level.
dBm dBm to P(mW)
=
P
10 log-w' P
= dBm log-l--
1m 10 dBmV dBmV to V(mV)
=
V
20 log--, V
= dBmV log-l--
1 mV 20 dBp,V to V(p,V) dBp,V
=
20 log
V
- 1 p,
V' V
= log-l dB V
--p,-
20
Figure C-I can be used to convert from dBm to voltage in a 500 system.
Conversion from dBm to volts can be made whether the
AMPLITUDE SCALE is in LOG or LINear. To read voltage on the HP 8569B, position the signal on the REF-
ERENCE LEVEL line of the CRT. Read the REF
LEVEL in dBm and find its equivalent voltage from the conversion chart (Figure C-I). The REF LEVEL calibration can be changed from dBm to dB/-lV by means of an internal jumper (Appendix D).
That is:
dBm referenced to 1 mw
dBmV referenced to 1 mV
dB/-lV referenced to I/-lV dBm
-20 40
-30 30
-40 20
, , ;
V
-50 10
V
~:,..-
-60 0
,,;
V
-70 -10
~
:,..-
-80 -20
-90 -30
10mV
V
lOIlV l00mV lOO1JV
1 V
1mV
Voltage (rms)
Figure Col. Converison Cban - Converts from dBm to Voltage in
son
. /
~
~
~
,,~
10V
10mV
43
Certain options on the HP 8569B can be enabled by means of a single jumper per option.
The jumper socket (12) is part of the Option Status Interface, located on the A7 Input/Output Assembly. A diagram showing the location of J2 is shown in Figure D-I.
Figure D-l. Option Status Jumpers
~
WARNING'
Positioning of the option jumpers requires working on the instrument with protective covers removed and should be done only by a qualified service techni· cian who is aware of the potential shock hazard. To avoid electrical shock, the line
(mains) power cable should be
dtseon-
nected before removing the protective covers from the spectrum analyzer.
Four (4) options are available on the OPTION STATUS
INTERFACE.
I.
Minimum Resolution Bandwidth
Pin A to Pin I (100 Hz Bandwidth)"
Pin B to Pin 2 (I kHz Bandwidth)
NOTE
The Minimum Resolution Bandwidth option is not usable with Option 002 instruments.
2.
Display Units - Reference Level
Pin C to Pin 3 (dBm)·
Pin D to Pin 4
(dB~V)
3.
Display Resolution - Center Frequency
Pin E to Pin 5 (100 kHz)·
Pin F to Pin 6 (1 MHz)
4.
Reference Position for Normalized Response
(INP-B-A)
Pin G to Pin 7·
(Center Horizontal Graticule Line)
Pin H to Pin 8
(Top Horizontal Graticule Line)
·No connection needed, default condition.
44
This Syntax Reference Guide is intended to provide, in detail, the required forms of command to be used when addressing the analyzer from an external HP-IB controller, and to describe precisely the resulting HP-IB output from the analyzer. It is important to keep in mind that this guide is written from a controller point of view, as user-generated programs will always be executed in the controller, not in the spectrum analyzer.
A pictorial flow representation is used to delineate the sequence of bytes or blocks of traffic across the bus.
Literal ASCII characters are bold and shown in rounded envelopes. These are transmitted exactly as shown.
Items enclosed by rectangular boxes are blocks of bus traffic which require further explanation. Those used repeatedly are described immediately below; others are dealt with on a command by command basis.
I
Output
I
UNL TA21 LAI8: UNListen, Talk Address 21,
Listen Address 18 (analyzer factory-set select code=18) (ASCII code: ?U2)
Enter
UNL LA21 TAI8: UNListen, Listen Address 21,
Talk Address 18 (ASCII code: ?5R)
I
Additional Commands
I
Additional analyzer commands
(two letter mnemonics) may follow within the same "Output" statement
Note that data bytes passed across the bus originate from the controller (controller is talker) until an "Enter" block is transmitted at which time the analyzer generates any succeeding data (analyzer is talker).
In several cases, two commands are used in an identical fashion and are listed together. Each pair performs the same function either on lower or upper lines of text (e.g.,
AL and AU) or on Trace A or Trace B (e.g.,
AP and BP).
Only the usage of the first command listed is described; the second command may simply in substituted in its place.
A reference in a command description to a "digit" should be understood to be the ASCII code for the character
1,2,3,4,5,6,7,8,9,orO.
The analyzer is able to ignore extra delimiters such as
(carriage return) and
"'R l.f:
(linefeed) at several points in a command sequence to the analyzer.
On the other hand, every byte indicated as output from the analyzer, i.e., data which immediately follows an "Enter" block, must be read by the controller or the analyzer will not be able to resume normal operation.
All commands which return values to the controller, except for the binary transfer commands, BA, BB, and MS, are terminated by transmitting an LF with the interface bus line EOI (End or Identify) pulled true. The commands
BA, BB, and MS send no terminating LF, but the EOI line is pulled true during transmission of the fmal byte of the returned data sequence. (The final byte is the 962nd byte for BA and BB and is the only byte for MS.)
Pressing RESET on HP·IB controllers generates an interface clear (IFC) command on the bus, which unaddresses the analyzer.
In case an illegal two-character mnemonic is entered (i.e., one which is not part of the analyzer's command set), a message appears on the upper annotation line:
SYNTAX ERROR
To remove the message, send a command AU, or press
CLEAR/RESET and hold it in until the annotation returns to the control setting mode.
AL. AU
Display lower line, display upper line control settings
Y
Additional Commands
Returns labeling above graticule on CRT to the control setting mode after an LL or LU command. (AU = upper line, AL = lower line)
AP. BP Output coordinates of trace A, trace B peak x~: x,y coordinates (0-480, 0-820) of peak response on trace
(AP
= trace A,
BP = trace B). Format is two 3-digit numbers separated by a comma: d d d , d d d
L.--.J
L.--.J
x
Y
If the peak value occurs at two or more horizontal positions, the leftmost point is returned.
45
AT
Output RF Input Attenuation CS
Output annotation
AU
Atten:
See
AL
0 to 70 for Attenuation in dB
BA. BB
Output trace A, output trace B byte values
Ctrl settings: A 126·character string, represents two 63-<:haracter lines of control setting labels (or LL or LV generated labels) as they are displayed above the graticule on the analyzer CRT. Refer to LL, LV for a table of the character set.
OG Output display mode
BB
BP
CF
Trace out: 481 trace values (962 bytes) in doublebyte format (BA
= trace A, BB
= trace
B): value number ab
1 ab
2 ab
3 ab ab
480481 where a and b are 8-bit bytes. Ten bits are required to specify trace values from 0 to 820 display units. 800 represents full-scale deflection. 801-820 are overrange values. The first byte in each number (a) represents the most significant two bits. The second byte
(b) represents the least significant eight bits of this lO-bit value. For example, to represent 820, the pair of 8-bit bytes would be: a
=
00000011 b
=
00110100
Therefore, when a BA or BB command initiates a byte transfer over the interface, the resulting pairs of bytes must be recombined in the controller to yield meaningful data. Normally, the first byte is either shifted or rotated 8 bits to the left (or multiplied by 256 = 2
8
) and added to the second byte to effect the recombination.
See
BA
See AP
Output Center Frequency
Frequency: -50000000 to 22600000000 for
Center Frequency in Hz
OM
Flag:
=
0 for normal mode
=
I for Digital Average mode
Output detection mode
Flag: lA, IB
= 0 for Peak Detection mode
=
1 for Sample mode
Input trace A, input trace B integer values
Trace in: value number
Up to 481 values in the range 0-975.
Only the integer portion of the number is used. Values will be displayed at the appropriate levels on the CRT except negative values, which will be blanked. The trace values are to be separated by commas, the last value followed by a serni-colon except when a full 481 values are sent, in which case the final serni-colon is optional. For example, an input of 300 values would look like this: v, v, v,......
v, v;
2 3 299 300 where v
=
1 to 3 digits
A carriage return before the terminating linefeed is optional and is ignored. If the trace values and commas are sent as a string, do not attempt to send additional commands following in the same
'Outputstaternent.
46
IB
See
IA
RB
Output Resolution Bandwidth
LG
Output Amplitude Scale
Res BW: 100 to 3000000 for Resolution
Bandwidth in Hz
Ampl Scale:
=
10, 5, 2, or I for LOG scale (dB/ division)
= 0 for LINEAR scale
RL
Output Reference Level
LL, LU
Input lower line, input upper line message
Additional Commands
Text: Up to
63 ASCII characters to appear on upper line (LU) or lower line (LL) of labeling above graticule on CRT.
Term: An ASCII terminating character ETX,
4=,
~ or any byte in the range
to 31 decimal.
Ref Level:
=
60 to -112 for Reference Level in dBm
167 to -5 for Reference Level in dBpV*
=
172 to -172 for relative level of center graticule in dB with
INP-B-+AON
8569B Display Character Set
32-.63
M~5
H~~
!
II
*$%&' ( )
*+, -.
/0123456789:
<
>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ
,]A
'abcdefghjjklmnopqrstuvwxyz
:)~i
*Character 32 Is a blank
LU
MS
See
LL
Output value of sweep flag
SF Start sweep and set sweep flag
B---0
Y
Additional Commands
Triggers sweep, sets MS flag sweep, MS flag
=
1.
At completion of
=
O.
(SF may not be used when analyzer is in analog or mixed sweep mode.) During the sweep triggered by SF, the MS command may be used to test whether the sweep is in progress or complete. All other analyzer commands sent by the controller during the sweep for which the MS flag = 1 will be accepted and ignored by the analyzer. The MS command is the only command that has meaning during an SF·triggered sweep.
See the example at the end of this appendix.
NS
Flag: = 0 for sweep completed
= 1 for sweep in progress
The MS (mid-sweep) flag should be used only following an SF command and refers only to the single sweep triggered by that command. If the
MS flag is tested when there has been no SF command, the flag has no meaning and a zero value is returned.
SP
Span:
Output INP-B-+A state
Output Frequency Span/Div
=
1000 to 500000000 for Span in
Hz/division
0 for Zero Span
=
=
-1 for Full Span
-2 for 1.7-22 GHz Span
Flag: = 0 for INP-B-+A OFF
=
1 for INP-B-+A ON
*See Appendix D for conversion from dBm readout to dBpV.
47
ST Output Sweep Time/Div
Sweeptime:
= 2 to 10000000 for Sweeptime in ps/division
= -I for AUTO sweep
= -2 for MANual sweep
=
-3 for EXTernal sweep
EXAMPLE I
Two of these are SF and MS, which provide the user with additional flexibility in sweep control over that provided by the simpler TS command". When the analyzer receives the ASCII mnemonic TS, a sweep is triggered and no further commands are accepted until the sweep is finished. This allows a programmer to instruct the analyzer to obtain trace data for the current control settings and input signal conditions without interference from any subsequent commands.
TA,TB Output trace A, output trace B integer values
Trace out: value number
481 values in the range 000 to 820
(3 digits each including leading zeros), each value followed by a comma except the last value (1923 total bytes or
ASCII characters).
(TA = trace A, TB = trace B.) v, v, v,......
v, v;
2 3......
480 481 where v = 3 digits
To permit parallel usage of the controller and other
HP-
IB equipment while the analyzer is sweeping, followed by end-of-sweep program branching, use SF and MS.
Additional Code
TB See TA
TS
Take Sweep
B-----0 qAdditional commandsfJ
Triggers the analyzer to sweep and inhibits subsequent commands to the analyzer until that sweep is complete. Upon completion of the sweep, the analyzer resumes accepting commands normally. (TS may not be used when analyzer is in analog or mixed sweep mode.)
In the flow diagram, the SF instruction triggers a sweep and sets the MS flag = I. The block Additional Code might represent digital processing of trace data from a previous sweep, or the execution of a separate measurement involving the controller and other instruments on the interface bus.
If branching is desired at the end of the sweep (such as outputting the new trace data to the controller and triggering another sweep), the analyzer may be interrogated repeatedly to test the MS flag (the flag remains one for the duration of the sweep and then reverts to zero). Recognition of the zero condition leads to the 'End-of-Sweep branch' command.
VF Output Video Filter
Video Filter: =
3 to .003 for ratio of VF to Res BW
= -I for VF I Hz (noise average)
= -2 for VF OFF
It should be understood clearly that for the duration of an
SF-triggered sweep (i.e., so long as the MS flag=l) only the specific instruction MS should be sent to the analyzer; any other command sent to the analyzer will be read and discarded. Therefore, resume sending other commands only after the MS flag has returned a zero.
An understanding of the interaction among six of the commands will facilitate their proper utilization in a user's program.
48
·For this discussion the analyzer is assumed to be in singlesweep trigger mode while executing controller generated sweep instructions TS and SF.
EXAMPLE 2
The four remaining instructions requiring further explanation are two pairs; LL,LU and AL,AU. As LL with AL and
LU with AU perform identical functions for their respective lines (lower and upper), only LL and AL is discussed.
Two lines of annotation are displayed above the etched
CRT graticule. These may be the turn- on state in which the instrument control settings are displayed, or in a userenabled state where the labeling lines have been input through the use of LL and LU. To reset the labels to the control setting mode, AL and AU are provided. Thus, to place the label "8569A Spectrum Analyzer" on the lower line use:
B - - - - 0 - - ( S 5 6 9 B Spectrum
To subsequently reset the lower line to the control setting mode:
49
Front Panel
1.
LINE: AC line switch. Turns instrument primary power ON-OFF.
2.
FOCUS: Adjusts sharpness of CRT trace.
3.
TRACE ALIGN: Rotates trace about center of
CRT.
4.
HORIZ POSN: Adjusts horizontal position of
CRT trace.
5.
VERT POSN: Adjusts vertical position of CRT trace.
6.
CLEAR/RESET: Momentarily pressing CLEAR/
RESET clears trace data in WRITE and MAX
HOLD operation and resets sweep. Resets digital averaging routine to begin averaging of subsequent sweeps. Also resets INP - B-A. Aborts plot during plot mode. Clears display from HP-IB control.
Holding CLEAR/RESET push button for 2 seconds returns control settings annotation to CRT.
7.
TRACE A, B: Provides two independent digital traces in the following modes.
a.
WRITE: Displays current input signal with each sweep.
b.
MAX HOLD: Displays only the highest value of trace data over successive sweeps. Process restarted by pressing
[g]
CLEAR/RESET' c.
STORE VIEW: Stores current trace and displays it on CRT.
d.
STORE BLANK: Stores current trace without displaying it on CRT. When both STORE
BLANK buttons are pressed, analog display appears.
8.
SAMPLE: Selects sample detection mode for random noise measurements (see Chapter 2).
9.
DGTL AVG: Digitally averages trace data over successive sweeps. Maximum averaging achieved after
64 sweeps. Sample detection mode automatically selected.
50
10.
INP - B-A: Subtracts trace data stored in TRACE
B from input signal data and displays resulting data in Trace A. Normalized trace is at the center horizontal graticule line when input signal is equal to stored Trace B (see Chapter 2). Center line reference level (MID) changes to dB for relative measurements.
11.
PLOT: Provides control of HP-IB plotter set for
Listen Only mode. Display information is frozen on screen during plot. Use CLEAR/RESET to abort plot and return to local control.
a.
GRAT plots graticule.
b.
CHAR plots CRT control readouts or HP-IB entered message.
c.
TRACE plots displayed trace(s).
12.
SCALE INTEN: Adjusts background illumination for photography. Set to blue area for CRT photographs. Does not operate in ANALOG DSPL mode.
13.
INTEN: Adjusts brightness of CRT trace and characters. Set to the blue region for CRT photographs.
14.
1ST LO OUTPUT: A 2.0 to 4.46 GHz,
+
7 dBm nominal output coupled from first local oscillator.
Terminate with 500 load when not in use. (Refer to
Appendix B for information on La for each Frequency Band.)
15.
CAL OUTPUT: An internal 100 MHz, - 10 dBm
( +
97 dBIAV) calibration signal.
16.
SIG IDENT: Used to verify frequency of unknown signals. Especially useful in External Mixing bands.
17.
VIDEO FILTER: Selects post-detection, low-pass filters which smooth the trace by averaging random noise. The Video Filter bandwidth is equal to the
Resolution BW times the factor indicated on the control knob. The NOISE AVGposition is a fixed 1
Hz low-pass filter used for noise measurements only.
18.
FREQUENCY GHz: Displays the tuned center frequency of analyzer in PER DIV and ZERO SPAN.
In Full Band modes, displays frequency of the tuning marker.
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Frequency range: 10 MHz to 22 GHz
Digital display with two independent traces
HP-IB capability for controller interrogation
Internal preselection eliminates spurious images
Automatic sweep time for calibrated display
Trace normalization, maximum hold, digital averaging
Hard-copy record through plotter control
The frequency range is 10 MHz to 22 GHz in direct coaxial input and 12.4 to 115GHz when used with external mixers.
The HP 8569B has a digital display with two independent traces.
The internal preselection eliminates most spurious images and multiple responses to simplify signal identification, extends dynamic range, and provides protection for the input mixer.
The frequency span, bandwidth, and video filter are all coupled with automatic sweep time to maintain a calibrated display.
The signal processing controls include trace normalization, a maximum hold function, digital averaging, and trace storage.
How to remove the top and bottom covers of the device?
Specific instructions for removing the top and bottom covers are not available in the viewed document. The document includes information on spectrum analyzer operation, installation, safety, and some service procedures, but does not detail cover removal.
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