In this paper, a broadband power amplifier with high efficiency and output power based on GaN HEMT is presented. The design of broadband matching network, transistor package modeling is presented and a simulation strategy is proposed to increase the simulation accuracy. According to measured results, the PA module shows a linear gain of 10~13 dB during 1.9-4 GHz, the efficiency can reach 74.5% and the maximum output power reaches 33.2 Watt. For a 5-MHz WCDMA signal, the designed power