Extended operation of class-F power amplifiers using input waveform engineering

Starting from the mathematical bases of waveform engineering, this contribution demonstrates the effectiveness of class-F power amplifier design in different bias conditions, provided the correct harmonic content is presented at the input. To validate the theoretical assumptions, low-frequency multi-harmonic load-pull measurements are carried out on a 1-mm gate periphery GaN HEMT, giving an experimental proof of the validity of the extended harmonic manipulation approach.