A Design Methodology of Class-E/F3 Power Amplifier Considering Linear External and Nonlinear Drain–Source Capacitance

A single-ended Class-E/Fn power amplifier (PA) with linear external and nonlinear drain-to-source (intrinsic) capacitances is designed and analyzed to achieve optimum operation. The effects of nonlinear intrinsic and linear external capacitance at high and low frequencies increase, respectively. The different specifications of the Class-E/F
₃
PA are shown versus the external and intrinsic capacitances. A Class-E/F
₃
amplifier at 4-MHz frequency, based on the theoretical results, is analyzed, simulated, and fabricated. The efficiency, power gain, and output power versus the input power are presented as well. The measured results are close to the analytical derivations at optimum conditions of zero-voltage switching and zero-voltage-derivative switching.