Doherty power amplifier with feedforward linearization

This paper presents a high efficiency feedforward power amplifier with Doherty technique for multi-carrier GSM base-station. The main Doherty power amplifier (DPA) was designed with third-order intermodulation distortion (IMD3) cancellation technique and tunable power division for optimized linearity and efficiency. The error amplifier was selected based on IMD3 analysis for higher efficiency. Two tone test show the amplifier has an efficiency of 27.2% and an IMD3 below -62.5 dBc at 80 W overall output power, the efficiency is much higher than traditional feedforward amplifiers.