Title :
A 240 W Doherty GaAs power FET amplifier with high efficiency and low distortion for W-CDMA base stations
Author :
Takenaka, I. ; Takahashi, H. ; Ishikura, K. ; Hasegawa, K. ; Asano, K. ; Kanamori, M.
Author_Institution :
NEC Compound Semicond. Devices Ltd., Shiga, Japan
Abstract :
An L/S-band 240 W Doherty GaAs FET amplifier with high efficiency and low distortion has been successfully developed. The amplifier employed a simple 2-way Doherty configuration to our plastic-packaged GaAs heterojunction FETs (HJFETs). We optimized load impedance shift of the main and the peak amplifiers as a function of input power level utilizing load-pull measurement and large signal simulation. The developed Doherty amplifier demonstrated low adjacent channel leakage power ratio (ACPR) of less than -34 dBc with a power-added efficiency (PAE) of 34% at an output power (Pout) of 45 dBm with a W-CDMA signal at 2.14 GHz. It also showed 53.8 dBm saturation output power with 11.2 dB linear gain. It achieved efficiency enhancement more than 11% compared to the conventional push-pull configuration under the same ACPR conditions. To our knowledge, these represent the best results ever reported among the high power FET amplifiers for W-CDMA base stations.
Keywords :
III-V semiconductors; code division multiple access; distortion; gallium arsenide; junction gate field effect transistors; network synthesis; plastic packaging; power amplifiers; power field effect transistors; semiconductor device models; 11.2 dB; 2.14 GHz; 240 W; Doherty GaAs power FET amplifier; GaAs; GaAs heterojunction FET; JFET; W-CDMA base stations; adjacent channel leakage power ratio; channel leakage power ratio; conventional push pull configuration; load impedance shift; load pull measurement; plastic package; power added efficiency; signal simulation; Base stations; Distortion measurement; FETs; Gallium arsenide; Heterojunctions; High power amplifiers; Impedance; Multiaccess communication; Power amplifiers; Power generation;
Conference_Titel :
Microwave Symposium Digest, 2004 IEEE MTT-S International
Print_ISBN :
0-7803-8331-1
DOI :
10.1109/MWSYM.2004.1336031
