Switch-less-impedance-matching type W-CDMA power amplifier with improved efficiency and linearity under low power operation

Author

Tanoue, Tomonori ; Ohnishi, Masami ; Matsumoto, Hidetoshi

Author_Institution

Central Res. Lab., Hitachi Ltd., Tokyo, Japan

fYear

2005

fDate

12-17 June 2005

Abstract

A W-CDMA power amplifier with new impedance matching technique, Switch-Less Impedance Matching (SLIM), is fabricated to improve the efficiency and linearity of a power amplifier at medium- to low-power ranges. In a SLIM amplifier, two amplifiers with different saturation powers are connected in parallel, and operated alternately without switches in the signal path. At its full power of 25.6 dBm, fabricated SLIM amplifier module exhibited power added efficiency of 38% with ACPR of -40 dBc, which is comparable to existing PAs for W-CDMA. Furthermore, at 15 dBm, its power added efficiency is as much as 12% with ACPR of -42 dBc. Throughout its output power range up to 25.6 dBm, the SLIM PA can provide very high linearity of under -40 dBc ACPR. Furthermore, the efficiency of 12% is not possible from a single amplifier with fixed load impedance.

Keywords

code division multiple access; impedance matching; low-power electronics; power amplifiers; 12 percent; 38 percent; ACPR; SLIM amplifier module; W-CDMA power amplifier; fixed load impedance; high linearity; power added efficiency; signal path; switch-less-impedance-matching type amplifier; Impedance matching; Linearity; Multiaccess communication; Operational amplifiers; Power amplifiers; Power transistors; Radio frequency; Switches; Telephone sets; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 2005 IEEE MTT-S International

ISSN

01490-645X

Print_ISBN

0-7803-8845-3

Type

conf

DOI

10.1109/MWSYM.2005.1516693

Filename

1516693