A 20-W Chireix Outphasing Transmitter for WCDMA Base Stations

Abstract

A Chireix outphasing transmitter for Band I wideband code-division multiple-access base stations was implemented using a nonisolating power combiner and two high-efficiency saturated class-B power amplifiers for 20-W single-carrier power levels. Novel adaptive background calibration algorithms were developed and demonstrated for the mismatch calibration and phase predistortion of the two transmitter chains. The complete demonstrator was able to achieve an average efficiency of 30% for a 3GPP TestModel64 signal, measured at a channel output power of 20 W and an adjacent channel power ratio of -45 dB.