Class E tuned power amplifier with nonsinusoidal output voltage

An analysis is presented of the amplifier for a limiting case when the load network does not contain a series-resonant output circuit and the output voltage is non-sinusoidal. For optimum operation with any switch-duty ratio, the author has determined the current and voltage waveforms, the collector current and collector-emitter peak values, the output power, the power-output capability, and the load-network component values. The spectrum of the output voltage is given for a switch-duty ratio of 0.25, 0.5, and 0.75. Close-approximation equations are given for transistor power losses and collector efficiency. The experimental and theoretical results are in very good agreement. The measured collector efficiency is 95%. The circuit has practical applications, e.g., in high-efficiency switching-mode DC-to-DC converters used in DC power supplies for microcomputers or communication equipment.