Design of a Capacitive Wireless Power Transfer Link with Minimal Receiver Circuitry

By applying capacitive coupling, wireless power transfer can be realized between a transmitter and a receiver. To maximize the power transfer, the default design is to construct resonant circuits by applying a compensation circuit, both at the transmitter and the receiver side. However, to obtain optimal power transfer at variable coupling, an impedance matching system or frequency tuning mechanism is necessary at the transmitter and receiver side, requiring data communication between both sides. We present a simple design of the capacitive link that reduces the receiver to the bare minimum: the capacitance plates and the load. All tuning for variable coupling occurs at the transmitter side, therefore lowering the costs and making data communication no longer necessary.