Title :
A 330W Distortion-Cancelled Doherty 28V GaAs HJFET Amplifier with 42% Efficiency for W-CDMA Base Stations
Author :
Takenaka, I. ; Ishikura, K. ; Takahashi, H. ; Hasegawa, K. ; Ueda, T. ; Kurihara, T. ; Asano, K. ; Iwata, N.
Author_Institution :
NEC Compound Semicond. Devices, Ltd., Shiga
Abstract :
An L/S-band 330W distortion-cancelled Doherty GaAs FET amplifier has been successfully developed optimizing the main and the peak amplifiers load impedance shift. The amplifier employed a pair of 28V operation 150W GaAs heterojunction FETs. It demonstrated low third order intermodulation of -37dBc with a drain efficiency of 42% at an output power of 49dBm around 6dB back-off level under the two-carrier W-CDMA signals of 2.135GHz and 2.145GHz. To our knowledge, these represent the best results ever reported among the simple high power FET amplifiers for W-CDMA base stations. Moreover, we proposed the evaluation techniques to obtain each AM-AM and AM-PM characteristics of the main and the peak amplifiers in an operating Doherty amplifier, and for the first time, experimentally proved the distortion cancellation effect in the GaAs FET Doherty amplifier
Keywords :
III-V semiconductors; code division multiple access; distortion; field effect integrated circuits; gallium arsenide; microwave power amplifiers; 150 W; 2.135 GHz; 2.145 GHz; 28 V; 330 W; Doherty HJFET amplifier; GaAs; WCDMA base stations; distortion cancellation effect; distortion-cancelled amplifier; heterojunction FET; third order intermodulation; two-carrier W-CDMA signals; Base stations; FETs; Gallium arsenide; Heterojunctions; High power amplifiers; Impedance; Multiaccess communication; Operational amplifiers; Power amplifiers; Power generation; Doherty amplifier; W-CDMA; distortion cancellation; efficiency; heterojunction FETs; high power;
Conference_Titel :
Microwave Symposium Digest, 2006. IEEE MTT-S International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-9541-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2006.249498
