Switchable function GaN power amplifier/rectifier

Abstract

This letter proposes a switchable function power amplifier/rectifier using a GaN transistor. A dc single-pole double-throw switch is used to switch between the working mode of the circuit from power amplifier (PA) to rectifier and vice-versa, which greatly reduces the complexity of the circuit. A feedback network with an impedance close to infinity and the input port of the PA always terminated to 50 Ω are utilized to achieve consistent impedance conditions in both PA mode and rectifier mode. Class-F−1 operation is employed to design the PA/rectifier module. For validation, a PA/rectifier operating at 2.4 GHz is designed and fabricated using a CGH40010F GaN transistor. Measurements show that the implemented module can realize efficiency of over 70% regardless of operating in PA mode or in rectifier mode. Meanwhile, the application of the GaN transistor greatly increases the power capacity of the RF-DC rectifier mode, which is promising in bi-directional wireless high-power application scenarios such as enhanced drone airborne capability. To the best of the authors knowledge, this is the first realization of a switchable PA/rectifier module based on a GaN transistor.