LAUSR

This article presents the design of a broadband high‐efficiency power amplifier (PA) with a compact coupling structure. In theory, the output matching network impedance expression based on the compact coupling structure is derived. According to the load impedance range of the class EFJ PA, the coupling structure is deduced to meet the impedance range of the class EFJ PA. This structure can realize the two functions of impedance transformation and harmonic impedance control. In order to further expand the bandwidth and improve the drain efficiency, the step impedance matching method is used to design the input matching network. To verify this design approach, a broadband high‐efficiency PA over a 115% bandwidth from 0.8 to 3.0 GHz is designed. The measured results show that the PA delivers output power of 40–42.2 dBm with the drain efficiency of 62%–73% and gain of 10–12.2 dB in the target band. The test results are good consistent with the simulated ones.