Reference Design for an 802.11b/g RF Front

Maxim > Design Support > Technical Documents > Reference Designs > Wireless and RF > APP 4156
Keywords: RF, WLAN, IEEE, 802.11b/g, MAX2830
REFERENCE DESIGN 4156 INCLUDES: Tested Circuit Board Available Description Test Data Reference Design for an 802.11b/g RF Front-End
Module Using the MAX2830
Mar 27, 2008
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Abstract: This module uses the highly integrated MAX2830 RF
transceiver. It is a complete RF front-end solution that meets the WLAN - Wireless Home
- Application Notes and Tutorials
IEEESM 802.11b/g standard. The transmitter can deliver more than
15dBm Tx power at EVM < 5.6% with a 54Mbps OFDM 802.11g signal. - EV Kit Software
The receiver can provide an IQ signal EVM < 9% with a -74.5dBm
- Technical Support
54Mbps OFDM 802.11g signal.
Click here for an overview of the wireless
components used in a typical radio
transceiver.
Figure 1. The reference design board shows the MAX2830 in an 802.11b/g RF front-end module.
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Important Design Features
Cascaded Receive Noise Figure of 6dB
Low Phase Noise of -95dBc/Hz at 10kHz Offset
Rx EVM < 9% at -74.5dBm with an 802.11g 54Mbps OFDM Signal
95dB Receive Gain Control Range (32dB RF and 63dB BB VGA)
Tx EVM < 5.6% at 15dBm Output Power with an 802.11g 54Mbps OFDM Signal
25dB Transmit Gain Control Range
Supports Full-Range 802.11b/g Data Rates
Small 11mm x 16mm Size
Low BOM Cost
Figure 2. Block diagram for the 802.11 b/g RF module.
Lab Measurements
DC Performance
VBATT = +3.3V, VCC = +2.85V, TA = +25°C
Parameter
Test Condition
Meas. Unit
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Shutdown Supply Current
10
µA
Standby Supply Current
PLL, VCO, LO Generator ON 28
mA
Receive Supply Current
65
mA
Transmit Supply Current POUT = 15dBm
289
mA
Receive Summary
VBATT = +3.3V, VCC = +2.85V, fRF = 2437MHz, RF input = 802.11a, 64QAM, 54MBps at antenna,
VOUT = 112mV RMS at RXI and RXQ baseband outputs, RXHP = 0, TA = +25°C
Parameter
Test Condition
Meas.
Frequency Range
Unit
2.4 to 2.5 GHz
Max Gain, VGA adjusted for VOUT = 112mV RMS , PIN = -65dBm 3.9
Receive EVM
Mid Gain, VGA adjusted for VOUT = 112mV RMS , PIN = -45dBm 2.5
%
Min Gain, VGA adjusted for VOUT = 112mV RMS , PIN = -10dBm 2.7
Sensitivity
Receive EVM = 9%
Antenna 1
-73
Antenna 2
-74.5
dBm
Transmit Summary
VBATT = +3.3V, VCC = +2.85V, fRF = 2437MHz, baseband inputs = 110mV RMS , 802.11a, 64QAM,
54MBps, Tx output measured at Antenna 1, RXHP = 0, TA = +25°C
Parameter
Test Condition
Meas. Unit
Maximum Transmit
Output
Tx VGA adjusted for EVM = 5.6%, Tx VGA = -4dB
15
ACPR
Tx VGA set for EVM < 5.6%, channel BW =
20MHz
f OFFSET =
20MHz
36
fOFFSET =
40MHz
55
fOFFSET =
60MHz
60
dBm
dBc
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Figure 3. Phase noise plot of the reference design.
Detailed Description
The MAX2830 is a single-chip, single-band, Dual Mode™ direct-convert transceiver designed for a
2.4GHz 802.11b/g (OFDM and CCK) WLAN application. The device integrates all the circuitry required to
implement the complete RF transceiver function: PA, T/R switch, antenna diversity switch, LNA, 50Ω
matching components, sigma-delta fractional synthesizer, crystal oscillator, and unique I/Q amplitude and
phase-error calibration circuits. The device also eliminates the need for external SAW filters by
implementing on-chip monolithic filters for both receiver and transmitter. The baseband Tx and Rx filters
are optimized to meet the 802.11g IEEE standard. With an additional RF filter and several passive
components, one can form a complete 802.11b/g WLAN RF front-end solution that delivers high
performance within a small form factor and low price.
Application Note Links
Application note 3630, "Power Supply and Ground Design for a WiFi Transceiver"
Dual Mode is a trademark of Maxim Integrated Products, Inc.
IEEE is a registered service mark of the Institute of Electrical and Electronics Engineers, Inc.
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Related Parts
MAX2830
2.4GHz to 2.5GHz 802.11g/b RF Transceiver with PA and
Rx/Tx/Diversity Switch
More Information
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For Samples: http://www.maximintegrated.com/samples
Other Questions and Comments: http://www.maximintegrated.com/contact
Application Note 4156: http://www.maximintegrated.com/an4156
REFERENCE DESIGN 4156, AN4156, AN 4156, APP4156, Appnote4156, Appnote 4156
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