Current scaled Doherty amplifier for high efficiency and high linearity

摘要

In this paper, a novel Doherty power amplifier (PA) design method that enables high efficiency and high linearity simultaneously is developed. The output combiner network parameters are solved to satisfy boundary conditions required for high efficiency, and linear gain and phase responses. The proposed method is experimentally verified by a 2.14 GHz prototype PA, fabricated using two identical 15 W GaN HEMT devices. For a 8.6 dB peak to average power ratio 10 MHz LTE signal, the PA presents an average power added efficiency of 40%, and an adjacent power leakage ratio of -41 dBc without any linearization.