Analysis and design of class E power amplifier with nonlinear parasitic capacitance at any duty ratio

The nominal operating condition of Class E power amplifiers with parallel-connected nonlinear parasitic capacitance and linear capacitance at any duty ratio has been studied in this article. Basic design equations are derived analytically. Using these equations, the component values for ensuring nominal operation at any given duty ratio can be conveniently found. Furthermore, the design equations highlight several important practical constraints, which help develop effective designs for improving the performance of practical Class E amplifiers. Finally, a design example is provided for verification. Both PSPICE simulation and experimental measurements are presented.