A variable gain and output power CMOS PA with combination switch controls

A variable gain and output power CMOS power amplifier is presented in this paper. With combination switch controls of three cascode devices in the driver stage, the power amplifier can achieve a variable power gain and output power (seven types). The power amplifier was fabricated in 0.35-μm standard CMOS process, and is able to deliver a power gain of 10.5~27 dB and an output P1dB (1-dB compression point) of 9.3~20.3dBm together with a PAE (power-added-efficiency) of 4.1~36.5% at 915MHz frequency and 3.3V supply respectively.