Highly efficient operation modes in GaN power transistors delivering upwards of 81% efficiency and 12W output power

This paper investigates the development of an inverse class-F design procedure for obtaining very high efficiency performance at high power levels. RF waveform engineering was used to obtain high efficiency inverse class-F waveforms at the device current-generator plane. Drain efficiencies above 81% have been achieved at 0.9 and 2.1GHz for a wide band-gap gallium nitride (GaN) HEMT transistor and 12W fundamental output power. Investigations into improvements in drain efficiency through increases in drain bias voltage have yielded drain efficiencies of up to 84% at 2.1GHz. To the author’s knowledge, the efficiencies presented in this study are the highest published, measured efficiencies of a high power GaN HEMT at these frequencies.