An exact analysis of Class-DE amplifier at any output Q

Previous papers on Class-DE power amplifiers are based on the assumption that the Q factor of the series-tuned circuit is high enough that the load current is sinusoidal. This paper presents a theoretical description of the Class-DE power amplifier in which the assumption of infinite Q is eliminated. Design and performance curves are given and discussed and a comparison with the previous known results, a practical tuning procedure, and practical limitations of the Class-DE circuit are also presented. Such an analysis is useful because low-Q circuits are appropriate for applications in which the harmonic content of the output is not important, e.g., in high-efficiency DC/DC converters, in providing RF energy for heating, for generation of plasmas, arcs, or sparks, for communications jamming, or for input driver to a higher power stage. Experimental results closely agree with the theoretical predictions.