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AN-826
APPLICATION NOTE
One Technology Way • P. O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel : 781.329.4700 • Fax: 781.461.3113 • www.analog.com
A 2.4 GHz WiMAX Direct Conversion Transmitter
by Cecile Masse and Qui Luu
Rev. B | Page 1 of 16
FEATURES
Direct conversion transmit chain
Tx radio using 5 chips
Dual AD9862 MxFE, 14-bit DAC, 128 MSPS, with
programmable full-scale current
3 GHz quadrature modulator ADL5373
2.7 GHz VGA ADL5330 with 50 dB of power control range
4 GHz fractional-N synthesizer ADF4153
3 GHz RMS power detector AD8362
Supports 10 MHz channel bandwidth with 1024-subcarriers
OFDM
Supports QPSK, 16 QAM, and 64 QAM OFDMA
Transmitter output power: 13 dBm maximum, CW
EVM 64 QAM OFDM: 1.2% @ −3 dBm output
Transmitter noise at 20 MHz offset: −142.5 dBm/Hz @ −1 dBm
Precise output rms power control
Dual-supply operation: 5 V @ 380 mA, 3.3 V @ 165 mA
APPLICATIONS
WiBro/WiMAX 5 V CPE and base stations
DAC
DAC
ADC
ADC
AD8362
0°
90°
FRACTIONAL-N
SYNTHESIZER
ADF4153
A
D9860/AD9862
MxFE
RMS POWER
DETECTOR
RF VGA
ADL5330
IQ MODULATOR
ADL5373
05790-001
Figure 1. Direct Conversion Transmitter
