Title :
A Distortion-Cancelled Doherty High-Power Amplifier Using 28-V GaAs Heterojunction FETs for W-CDMA Base Stations
Author :
Takenaka, Isao ; Ishikura, Kohji ; Takahashi, Hidemasa ; Hasegawa, Kouichi ; Ueda, Takashi ; Kurihara, Toshimichi ; Asano, Kazunori ; Iwata, Naotaka
Author_Institution :
NEC Electron. Corp., Shiga
Abstract :
An L/S-band 330-W distortion-cancelled Doherty GaAs field-effect transistor (FET) amplifier has been successfully developed optimizing the main and peak amplifiers load impedance shift. The amplifier employed a pair of 28-V operation 150-W GaAs heterojunction FETs. It demonstrated low third-order intermodulation of -37 dBc with a drain efficiency of 42% at an output power of 49 dBm around 6-dB backoff level under the two-carrier wideband code-division multiple-access (W-CDMA) signals of 2.135 and 2.145 GHz. To our knowledge, these represent the best results ever reported among the simple high-power FET amplifiers for W-CDMA base stations. In addition, we proposed the evaluation techniques to obtain each AM-AM and AM-PM characteristics of the main and peak amplifiers in an operating Doherty amplifier, and have experimentally proven the distortion cancellation effect in the GaAs FET Doherty amplifier
Keywords :
III-V semiconductors; UHF power amplifiers; code division multiple access; field effect transistor circuits; gallium compounds; microwave power amplifiers; 150 W; 2.135 GHz; 2.145 GHz; 28 V; 330 W; FET Doherty amplifier; GaAs; L band; S band; W-CDMA base stations; distortion cancellation effect; high-power amplifiers; third-order intermodulation; Base stations; Broadband amplifiers; FETs; Gallium arsenide; Heterojunctions; High power amplifiers; Impedance; Multiaccess communication; Operational amplifiers; Power generation; Distortion cancellation; Doherty amplifier; efficiency; heterojunction field-effect transistors (HFETs); high power; wideband code division multiple access (W-CDMA);
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
DOI :
10.1109/TMTT.2006.883606
