Analysis on maximum operating frequency of subharmonic Class-E amplifier at any duty ratio

This paper presents that the maximum operating frequency of sub-harmonic Class-E amplifier not only depends on the transistor duty ratio, but also relies on the slope of switch voltage when the transistor turns on. When dc supply voltage, output power and shunt capacitance are specified, the maximum operating frequency increases as the slope of switch voltage increases. On the contrary, it increases as the transistor duty ratio declines.