Analysis and Design of Finite Input Inductance Class-E Inverters with Variable Complex Loads

This paper presents a detailed analysis and design method of the Class-E inverter with finite input inductance under arbitrary complex loads based on the first harmonic approximation. The analytic results show that the inverter can achieve ZVS with a wide range of complex loads with proper resonant network design. The model established allows designers to plot the theoretical ZVS load impedance region for specific design parameters directly in the complex plane. Subsequently a design method for the inverter to achieve high efficiency operation under variable complex loads is developed. This method thus allows the Class-E inverter to be used in an application in which the load resistance varies as well as the reactance. The effectiveness of the proposed method is verified by a 13.56 MHz Class-E inverter prototype.