High Efficiency GaN HEMT Class F Power Amplifier for S-band Telemetry Application

Design of a high power, high efficiency GaN HEMT based Class F power amplifier with harmonic termination network, operational at 2.1 GHz, has been presented in this paper. Optimum source and load impedances for fundamental tone, 2nd and 3rd harmonics were extracted using load and source pull analysis. Effect of with and without harmonic termination on the performance of class F power amplifier is investigated in term of output power, power added efficiency and drain bias variation. Proposed class F power amplifier is fabricated using RT/Duroid 5870 of 20 mil thickness. Designed structure possess power added efficiency of 72% with high output power of 36.3 dBm. In order to further enhance efficiency of power amplifier, it was operated at lower drain bias current resulting in efficiency enhancement of 6% with no significant change in output power performance.