Design of Asymmetric Doherty Power Amplifier Based on 3-Port Output Combinational Network

To achieve better performance, this paper proposes a Doherty power amplifier (DPA) design method based on 3-port theory on the basis of traditional asymmetric DPA. In this design method, the asymmetric DPA output matching network is regarded as a whole, and the 3-port output combinational network analysis method is adopted to design it, so as to maximize the efficiency at output power back-off (OPBO). To verify the design method, a 3.4-3.6 GHz asymmetric DPA using 10 and 30W GaN HEMT is designed. Measurement results show that the efficiencies at saturation power and 12 dB OPBO are higher than 68% and 50% respectively over the entire frequency range.