Investigation of the dynamic load modulation of an inverse class-F power amplifier with an adaptive matching network

This paper presents a 10 Watt gallium nitride (GaN) based inverse class-F power amplifier with dynamic load modulation. The designed power amplifier uses an adaptive output matching network, which is realized using MEMS switches (micro electro mechanical systems), for the enhancement of the power added efficiency over the dynamic output range. Through the load modulation achieved by the adaptive matching network an efficiency enhancement of approximately 30 pp (percentage point) at 10-dB-back-off at the drain of the transistor is achieved compared to a power amplifier without load modulation. Through the use of an in situ measurement approach in-depth investigations of the working principle of the realized amplifier and adaptive matching network are possible.