Implementation of Constant Current Performance of 13.56MHz Wireless Power Transfer System

The constant current to charge a battery is an important topic in wireless power transfer system. To acquire high efficiency and high frequency operation, the paper proposes an approach to design the WPT system by using class-E ² topology. The module components such as power amplifier, coupling coil and rectifier are carefully design to achieve the constant current operation. To verify the proposed approach, a 13.56MHz WPT system is implementation in this work. Measurement demonstrates the output currents are 0.384 A and 0.339 A at 10Ω and 50 Ω, respectively. The current variation is 6.2 % in the proposed system.