A 19W high-efficiency wide-band CMOS-GaN class-E Chireix RF outphasing power amplifier

Abstract

A class-E Chireix outphasing power amplifier is presented that enables high efficiency across a wide power back-off range and RF bandwidth. In this design the Chireix compensation elements and class-E loading conditions are provided by an asymmetric coupled-line power combiner. The class-E operated GaN HEMT switches are driven by high-speed, high-voltage CMOS drivers, implemented in a standard 65nm process technology. The proposed concept demonstrates 51.6% system average power efficiency and 65.1% average drain efficiency for a 7.5dB PAR WCDMA signal at 1.95GHz, while meeting the ACLR specifications. Moreover, the PA demonstrated more than 60% drain efficiency across a 6dB power back-off range and up to 19W peak power between 1800–2050MHz.