A resonant voltage multiplier for long-range inductive power transmission

Abstract

A switch-based technique has been presented for efficient inductive power transmission at large coupling distances. Unlike the conventional inductive link, in which the receiver (Rx) LC-tank is utilized as a voltage source, the proposed link switches the Rx LC-tank in a novel fashion to act as a current source. Therefore, the voltage across the load (R L ) can be significantly larger than the Rx LC-tank voltage. This enables the design of integrated voltage multipliers without additional off-chip capacitors and diodes, which are needed in conventional voltage multipliers. In the proposed link, the energy is first stored in the Rx coil by shorting the Rx LC-tank for several power carrier cycles. At the peak of Rx coil current, the coil energy is then transferred to the load capacitance and R L . In simulations, the proposed inductive link was capable of achieving a DC voltage of 5.7 V across R L of 100 kΩ while the peak of maximum AC voltage across the Rx coil was 1 V at the operation frequency of 1 MHz.