Transistor power losses in the class E tuned power amplifier

Abstract

The class E switching-mode tuned power amplifier offers efficiency approaching 100 percent. It is especially applicable at high frequencies because it minimizes the power dissipated during the switching transitions, even if the switching time is an appreciable fraction of the signal period. When the amplifier is properly loaded and tuned, power losses are caused primarily by active-device saturation voltage and resistance, nonzero switching time, and lead inductance. An accurate estimation of the dissipated power is presented giving more accurate circuit and thermal designs.