Efficient Wireless Power Transfer System for Mobile Devices: Asymmetric and Planar Magnetic Resonance Coupling Scheme

This paper presents an asymmetric, doublelayered, and fully planar magnetic resonance coupling-based (MRC) wireless power transfer (WPT) system that operates at 13.56 MHz. The transmitter is designed on a FR-4 substrate measuring 100 mm × 100 mm, while the receiver is developed on a flexible polyimide substrate with a footprint of 50 mm × 50 mm. Complete planarization is achieved by applying printed spiral coils on both the transmitter and receiver. At a separation distance of 60 mm between the transmitting and receiving coils, a maximum measured efficiency of 67% was attained. The thinness of the polyimide substrate allows the receiving unit to be compact, making it easily compatible with various mobile charging devices.