Design of WPT RF Power Supply Based on Dual Directional Coupler and Capacitor Array Impedance Matching Network

In the engineering use of a magnetically coupled resonant radio energy transmission system, both the resonant frequency and the optimal load impedance will be varied because of the external conditions. In view of the above problems, this paper proposes an RF power supply with adjustable frequency and optimal load impedance, in order to achieve efficient power transmission for different frequency radio energy transmission systems and different load conditions. The RF power supply is mainly composed of a frequency controllable signal generator, a Class E power amplifier circuit, a dynamic impedance matching network, a load detection circuit and a controller. Through the above parts, the load tracking of the RF power supply can be realized, and the higher output efficiency can be realized under the condition of changing the working frequency and the load. Finally, the feasibility of the proposed RF power supply is verified through experiments. The experimental results show that the RF power supply can automatically track changes in the operating frequency and load range, and the output efficiency can be maintained at more than 75%.