An inverse class-F GaN HEMT power amplifier with 78% PAE at 3.5 GHz

This paper presents the design and implementation of an inverse class F power amplifier (PA) using a high power GaN HEMT transistor. For a 3.5 GHz continuous wave (CW) signal, the measurement results show state-of-the-art power-added efficiency (PAE) of 78%, a drain efficiency of 82%, a gain of 12 dB, and an output power of 11 W. Moreover, drain efficiency is maintained over 60% and the output power level is higher than 10 W over 300 MHz bandwidth. To our knowledge, the presented power amplifier represents the highest efficiency for all switching mode PAs that have been reported for high power applications at frequencies above 2 GHz.