WiBro Reference Design with the MAX2837

Maxim > Design Support > Technical Documents > Reference Designs > Wireless and RF > APP 4274
Keywords: Wibro, MAX2837, 2.3GHz, 2.4GHz, CPE, CardBus, card bus, miniPCI, wman, WMAN
REFERENCE DESIGN 4274 INCLUDES: Tested Circuit Board Available Description Test Data WiBro Reference Design with the MAX2837
Sep 11, 2008
More Information
Abstract: The WiBro™ reference design is a complete RF front-end
- Wireless Home
solution designed to meet requirements for the WiBro 2.3GHz to
2.4GHz mobile WMAN (Wireless Metropolitan Area Network) standard. - Application Notes and Tutorials
This reference design uses the MAX2837 direct-conversion transceiver - EV Kit Software
and demonstrates a complete WiBro single-band RF-to-baseband
- Technical Support
solution. It serves as a platform for designs in multiple form factors such as CardBus, miniPCI, and custom CPE modules. The design can be easily adapted for WiBro-only 3.3V
laptop applications, or WiBro-only 5.0V CPE applications.
Click here for an overview of the wireless
components used in a typical radio
transceiver.
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Figure 1.The WiBro reference design features the MAX2837 direct-conversion transceiver.
Important Design Features
Complete RF-to-Baseband WiBro Solution
+23dBm Transmit Power at 5% EVM and Meets Spectral Mask Requirements
-79dBm Receive Sensitivity at 10% EVM
60dB of Transmit Gain-Control Range
94dB of Receive Gain-Control Range
Optimized Low-Current Modes
More detailed image (PDF, 324kB)
Figure 2. Block diagram for the WiBro reference design.
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Lab Measurements
Supply Current Summary
VBATT = +3.6V, VCC = +2.85V, TA = +25°C
Parameter
Test Conditions
Shutdown Supply
Current
MAX2837 and PA in shutdown; regulators and VCTCXO still
1.8
active
mA
Idle Supply Current
MAX2837 in idle mode; PA in shutdown; regulators and
VCTCXO active
34.8
mA
Transmit Supply
Current
16 QAM, ¾ FEC coding rate, POUT = +24dBm, EVM = 5%
392.6
mA
Low-current mode
79
Nominal current mode
96.2
Receive Supply
Current In
Measured Units
mA
Receive Summary
VBATT = +3.6V, VCC = +2.85V, fRF = 2347MHz, VOUT = 90mVRMS , WiBro signal, RF specs are
antenna referred, TA = +25°C
Parameter
Test Conditions
Measured Units
I channels
6.8
Q channels
4.5
VGA Gain Step Size
2
dB
Receive Gain-Control Range
Max to min VGA gain
61.7
dB
Attenuation from 0dB to -16dB
-15.9
Attenuation from 0dB to -32dB
32.1
DC Offset
Receive LNA Gain Step
LNA gain = 0dB
-5.2
LNA gain = -16dB
-5.3
LNA gain = -32dB
-3
Gain Variation over Temperature
TA = -40°C to +85°C
Gain Variation over Frequency
fLO = 2304MHz to fLO = 2396MHz
0.2
64 QAM, ¾ FEC coding rate, 10% EVM at
sensitivity
-79.8
16 QAM, ¾ FEC coding rate, 20% EVM at
sensitivity
-90.7
64 QAM, ¾ FEC coding rate, 10% EVM at
sensitivity
-80.4
Sensitivity at Low Supply Current¹
Sensitivity at Nominal Supply
Current¹
mV
dB
dB
dB
dBm
dBm
16 QAM, ¾ FEC coding rate, 20% EVM at
-91.3
sensitivity
¹Rx EVM limits are at BB I/Q Rx outputs, and are given in the IEEE® 802.16e specification Table 338,
"Receiver SNR Assumptions." The assumption is that this EVM for this modulation rate is sufficient to
meet 1e-6 BER.
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Transmit Summary
VBATT = +3.6V, VCC = +2.85V, fRF = 2347MHz, VIN = 90mVRMS , WiBro signal, RF specs are antenna
referred, TA = +25°C
Parameter
Test Conditions
Measured Units
LO Leakage
Q = 640/352µA, I = 576/416µA
-39.6
dBc
Sideband Suppression
I/Q phase = -0.5°
-52.5
dBc
Transmit Power-Control
Range
Including PA gain step
64.5
dB
Gain Variation over
Frequency
fLO = 2304MHz to fLO = 2396MHz
1.9
dB
16 QAM, ¾ FEC coding rate, POUT = +24dBm, meeting
spectral mask
4.1
16 QAM, ¾ FEC coding rate, POUT = +23dBm, meeting
spectral mask
3.5
Transmit EVM
%
Transmit Operating Characteristics
Figure 3. Output EVM for the reference design. The WiBro reference design delivers more than 23dBm
of output power at the antenna, while meeting the required EVM specification of 5.5% over the entire
2.3GHz to 2.4GHz band.
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Figure 4. Transmit capture for the reference design. This capture shows the transmit spectrum, EVM
constellation, and spectrum of the reference design at 23dBm of output power at the antenna. Measured
EVM = 3.9% at 23dBm at 2.347GHz.
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Figure 5. 2.35GHz, 10MHz spectral mask using ETSI-EN-301-021F mask. This capture shows that the
WiBro reference design meets the ETSI-EN-301-021F spectral mask at 23dBm of output power at the
antenna.
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Figure 6. Receive gain characteristic across the 2.3GHz to 2.4GHz band. Gain variation over frequency
is less than 0.2dB. Gain-control range, not including LNA gain steps, is 62dB, approximately 2dB per
gain step.
Figure 7. Gain characteristic across three LNA gain attenuations and temperatures. Gain variation over
temperature for LNA attenuations 0dB and -16dB is approximately 5dB, and roughly 3dB for -32dB gain
attenuation.
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Detailed Description
The WiBro reference design includes the following components: MAX2837 direct-conversion transceiver,
Micro Mobio MMPA372X PA, MAX8510 regulators, Murata balanced-to-unbalanced SAW bandpass
filters, Hexawave HWS466 SPDT Tx/Rx switch, and Vishay Si1563DH load switch.
The MAX2837 is a single-chip, wideband, direct-conversion transceiver designed for 2.3GHz to 2.7GHz
WiBro and WiMax radios. The transceiver is fully equipped with an on-chip broadband VCO, fast settling
sigma delta RF synthesizer, crystal oscillator, programmable lowpass filters, proprietary DC offset
cancellation, I/Q error and carrier leakage detection circuits. The MAX2837 offers less than 1.4% of
transmit EVM at -3dBm driver output power, and receive sensitivity better than -79dBm. When integrated
with the MMPA372X PA and Murata BPF, the reference design can deliver at least 23dBm of output
power at the antenna, while meeting WiBro EVM and spectral-mask requirements with margin.
IEEE is a registered service mark of the Institute of Electrical and Electronics Engineers, Inc.
WiBro is a registered trademark of the Telecommunications Technology Association.
WiMAX is a registered certification mark and registered service mark of the WiMAX Forum.
Related Parts
MAX2837
2.3GHz to 2.7GHz Wireless Broadband RF Transceiver
Free Samples More Information
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Application Note 4274: http://www.maximintegrated.com/an4274
REFERENCE DESIGN 4274, AN4274, AN 4274, APP4274, Appnote4274, Appnote 4274
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