CMOS RF Class AB Amplifier Design with High Linearity

CMOS radio frequency class AB power amplifiers are widely used in single chip wireless solutions. Efficiency is analyzed under constant maximum current and linearity analysis by using normalization method of input voltage. High linearity is achieved with the compensation between system gain and MOS transconductance, both are nonlinear. A two stage RF class AB power amplifier is designed based on TSMC 0.18 μm CMOS mixed-signal process. With a differential input and a signal-end output, this RF power amplifier works in the frequency band of 804~940 MHz under operating voltage of 3 V. Simulation shows:the gain is 11 dB, the P1 dB is 17.2 dBm, the OIP3 is 18.2 dBm and the PAE is 37%.