Analysis of Class-DE Amplifier With Linear and Nonlinear Shunt Capacitances at 25% Duty Ratio

The class-E zero-voltage switching/zero-derivative switching operation within class-DE amplifiers can be easily achieved by adding external shunt capacitances. This paper gives the analytical expressions for the designs of the class-DE amplifiers with the shunt capacitances composed of linear and nonlinear capacitances for any grading coefficient m of MOSFET body junction diodes at the switch-on duty ratio D=0.25 . In the analysis, an equivalent linear shunt capacitance of the nonlinear MOSFET drain-source parasitic capacitances is derived. Analytical results show good agreements with the simulation and experimental ones, which validate our analysis.