Efficiency comparison between highly efficient class-F and inverse class-F power amplifiers

A quantitative explanation of the better efficiency and a design guide for optimizing the output power and efficiency of inverse class-F amplifiers over class-F amplifiers, is presented. The efficiency equations of the inverse class-F and class-F amplifiers are derived using ideal time-domain waveforms. The results show that the inverse class-F amplifiers have square-wave current and half-sinusoidal voltage signals and these ideal waveforms of class-F amplifiers are analyzed by Fourier series expansion. The performances of the two amplifiers are assessed by MATLAB, which shows that the inverse class-F amplifier is better than the class-F amplifier with increasing time-domain dc voltage waveform. The output matching network for the inverse class-F amplifier is designed for optimum performance with the harmonic control network and amplifier design is simulated to probe the voltage and current signals.