Analysis and design of a class E current-driven rectifier for 1 MHz wireless power transfer system

The paper presents the design of the class E current-driven rectifier, which is intended for operation in the wireless power transmission system, as well as the concept of selection of the rectifier parameters which allows the operation with high efficiency. The selection of the rectifier parameters was performed with a view to the use of the existing wireless power transmission (WPT) system. The procedure for selection of the rectifier parameters has been proposed to enable its optimal use in reference to the system parameters given already at the design stage, ie; load resistance and the coil magnetic coupling factor (distance between coils). In order to verify the correctness of the procedure for selection of the parameters, the numerical model of the system which consists of the class E resonance inverter, the air-core transformer and the designed E class rectifier system was developed in the LTspice environment. Simulation tests and analysis of the obtained calculation results were performed. Based on the simulation results, a prototype of the class E rectifier system which cooperates with the existing wireless power transmission system supplied from the class E inverter was developed. The obtained results of laboratory measurements demonstrated a high compliance with the simulation results, thus, confirming the correctness of the proposed design procedure and the high operating efficiency of the rectifier system.