Design of a Doherty Amplifier with Digital Predistortion for WCDMA Base Station

摘要

This paper presents a RF high-power Doherty amplifier with digital predistortion for improving the efficiency and linearity of a 20W power amplifier used in wide band code division multiple access (WCDMA) basestation applications. A fully digital baseband predistorter is used to improve the linearity of the amplifier over the whole input power range.This results in an improvement of the linearity of the Doherty amplifier without degrading its power efficiency. Experimental validation with 2 WCDMA carriers at 2100 MHz was applied to the system, and the results show about 30 dB reduction of ACLR at 5 MHz offset.