Optimization of Planar Strongly Coupled Wireless Power Transfer System for Biomedical Applications

Strongly coupled four-coil wireless power transfer (WPT) system is presented in this letter. Conformal architecture is used for both transmitter (TX) and receiver (RX) coils. Thus, a high mutual coupling coefficient is achieved between the coplanar coils. Furthermore, the quality factors of primary and secondary coils are improved. The proposed WPT system features a compact structure for biomedical applications and provides a measured efficiency greater than 79% when the distance between the TX and RX is 10 mm at a resonance frequency of 13.56 MHz. The designed system is also simulated for 10 mm human tissue medium using HFSS, which generates a power transfer efficiency of 55.1%. The simulated results are also verified by experimentation.