Comments on "class-E, Class-C, and Class-F Power Amplifier Based Upon a Finite Number of Harmonics"

Abstract

Anamarija Juhas and Ladislav A. Novak present their views on class-E, class-C, and class-F power amplifiers (PA) based on a finite number of harmonics. They state that the maximum attainable efficiencies of finite harmonic class C differ from maximum attainable efficiencies of finite harmonic class-F PAs. The best way to prove that difference between efficiencies of finite harmonic class-C and class-F exists, is to solve the problem in closed analytical form. They provide closed form for maximum attainable efficiency of finite harmonic class-C using the Fejer's result. They have also considered maximally flat nonnegative waveforms to solve the problem. Another reason for including such waveforms is that a finite harmonic class-C PA with maximally flat current waveform has higher power-output than a finite harmonic class-C PA with optimal waveform with the same number of harmonics.