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 2.1 GHz for a wide band-gap gallium nitride (GaN) HEMT transistor and 12 W fundamental output power. Investigations into improvements in drain efficiency through increases in drain bias voltage have yielded drain efficiencies of up to 84% at 2.1 GHz. To the authorpsilas knowledge, the efficiencies presented in this study are the highest published, measured efficiencies of a high power GaN HEMT at these frequencies.