Analysis of Class DE Amplifier With Nonlinear Shunt Capacitances at Any Grading Coefficient for High $\displaystyle Q$ and 25 $\displaystyle $ % Duty Ratio

Abstract

This paper gives analytical expressions for the class disruptive effect (DE) amplifier with nonlinear shunt capacitances at any grading coefficient m of the MOSFET body junction diode at a high value of the loaded quality factor Q of the output resonant circuit, zero equivalent series resistance of all the components, and switch-on duty ratio D=0.25. No external shunt capacitance is used in the analysis of the class DE amplifier. The grading coefficient determines the degree of nonlinearity of the MOSFET shunt capacitances. When the grading coefficient is different from the design specifications, the waveforms of the switch voltages do not satisfy the class E switching conditions, reducing the power conversion efficiency. Therefore, the grading coefficient m is an important parameter to satisfy the class E switching conditions. It is shown analytically that the dc supply voltage and current are always proportional to the amplitude of the output voltage and current. The output power capability is never affected by any nonlinearity of the shunt capacitances. We obtain analytical design equations, which are validated by PSPICE simulations and laboratory experiments considered with the gate-drain capacitance effect.