A wireless power transfer system based on class E amplifier

In this paper, a wireless power system based on class E amplifier is constructed, and the mathematical model based on inductive coupling between transmitting and receiving windings are built subsequently. The values of some components for transmitter are optimized precisely according to the optimal working point of load resistance. Formulas for the optimal transmitter, receiver, and class E components are derived given a set of constraints on the load resistance, inductance values of the coupler, the phase angle and quality factor of load impedance, and drain voltage waveform. Moreover, the simulation is fulfilled to verify the method to calculate parameters. Using a separating transformer with a pot type ferrite core and a series-parallel arrangement for load impedance transformer, A wireless power transfer system based an open loop class E amplifier has been built and experimental results show that the system has desirable performance, including a power delivery of 4.2W with the distance is 10mm, and the peak efficiency of system is over 72%.