A doherty power amplifier design approach for matched transistor without simulation model

This article proposes for the first time a method for designing Doherty power amplifier(DPA) based on matched transistors without simulation model. In the design process of DPA, it is necessary to determine the transmission phase of the output matching network of the transistor. To this end, we first propose a method for extracting the transmission phase of the output matching network of the transistor from the perspective of circuit theory. In addition, to design DPA more accurately, we analyze the influence of the optimal impedance at the saturation state and the transmission phase of the main and peak matching networks on the backoff impedance. Finally, based on an internally matched transistor HEG028C, a DPA operating in the C-band was designed. The measured results showed that the operating frequency of the DPA was 4.2–4.8 GHz, the output power was between 44.4 dBm-46 dBm, the saturation efficiency was between 53.2 % −60.5 %, and the 6 dB backoff efficiency was 40 % −46.5 %. The experimental results demonstrate the effectiveness of the proposed design method.