A GaN HEMT Class F Amplifier at 2 GHz With $>\,$80% PAE

A Class F amplifier has been designed, fabricated, and tested using a GaN HEMT transistor and hybrid printed circuit board (PCB) packaging. The amplifier has a peak power-added efficiency (PAE) of 85% with an output power of 16.5 W. A gate-connected field-plated and a source-connected field-plated device of the same size and layout were measured in this topology. An output power and drain efficiency tradeoff, dependant on the drain impedance at the fundamental frequency due to the on-state resistance, is explored. A comparison between Class F and Inverse F, given particular operating conditions for this device, is made.