Simultaneous three-harmonics matched power amplifier with 84.1% drain efficiency at 915 MHz for microwave power transfer

The efficiency of power amplifiers (PAs) is quite critical for microwave power transfer (MPT) systems. Among the developed PAs, Class-F PA is one of the competitive candidates due to its high efficiency. However, conventional harmonic suppression networks for Class-F PA rely on the simple control of the first and the second harmonics by independent open/short microstrip line. In​ this study we propose a simultaneous three-harmonic matching network which provides better harmonic matching at the output port of the GaN HEMT. A 915 MHz PA is designed, achieving a simulated peak drain efficiency (DE) of 86.6% and measured DE of 84.1% at 38.5 dBm output power. The design demonstrates superior harmonic matching compared to traditional Class-F PAs.