Positioning-Free Resonant Wireless Power Transmission Sheet With Staggered Repeater Coil Array (SRCA)

A magnetically resonant wireless power transmission sheet (WPTS) on a printed circuit board is developed. WPTS wirelessly supplies the power to electronic devices including the wearable wireless healthcare devices anywhere on the sheet with high efficiency. In order to increase a power transmission efficiency degraded by a misalignment of a receiver coil, a transmitter coil array and a proposed staggered repeater coil array (SRCA) are stacked in WPTS. One transmitter coil closest to the receiver coil and the surrounding four repeater coils are selectively activated based on the result of a position detection of the receiver coil. By adding SRCA to the transmitter coil array, the measured power transmission efficiency at the worst-case misalignment increases from 4.8% to 64% at a distance of 15 mm between the transmitter and receiver coils with a diameter of 40 mm. The measured results are verified by electromagnetic simulations.