Exact analysis of class DE amplifier with FM and PWM control <Abstract> The control of class DE ampli er is the im- portant probrem since the switching of the ampli er does not satisfy class E switching condition when load resistance varies from initial designed values. Therefore, some of con- trol schemes of class DE ampli er were proposed. However, the changes of the output voltage and power conversion ef- ciency by using the controls can be measured only exper- imentally and thus, they cannot be found theoretically. In this paper, an exact analysis of class DE ampli er with FM and PWM control schemes is presented. From the anal- ysis, we can derive the output voltage, power conversion eciency and so on theoretically. Moreover, the frequency and duty ratio to keep the constant output voltage can be found when the load resistance and input voltage vary. We indicate that the theoretical predictions agree with the ex- perimental results qualitatively. Measured eciency is over 94 % with 1.0 MHz and 1.8W output. |