Class F rectifier RF-DC conversion efficiency analysis

Abstract

In this paper, an analytical model for the Class F rectifier RF-DC conversion efficiency is presented. This model is based on the Class F voltage and current waveforms in the time domain, and analyzes three kinds of power losses due to the diode series resistor, junction capacitor and built-in potential. Closed-form equations are derived to calculate the Class F rectifier efficiency at various input power levels. This model can well predict the efficiency improvement due to the Class F harmonic termination. A 900 MHz Class F rectifier is designed with the highest measured efficiency of 80.4%, and the measurement results agree well with the proposed model calculation.