Abstract: 5G and beyond communication systems need wider bandwidth compared to 4G communication system. To break through the narrow band limitation of conventional Doherty power amplifier, a method was proposed to broaden the bandwidth. Two impedance matching was used to design output matching circuit of main power amplifier properly, and the post-matching structure was used to optimize the power synthesis network. A simple and wideband circuit structure of Doherty power amplifier was formed. To verify the proposed method, the 3.3-3.7 GHz Doherty power amplifier with GaN transistors CGH40010 was designed and measured. The measurement results show that the designed Doherty power amplifier has bandwidth ranging from 3.3 to 3.7 GHz with saturated power of 43.2-44.5 dBm and saturated gain of 8-11 dB. The drain efficiencies at saturation and 6 dB output power back-off level are 67%-76% and 42%-56%, respectively.