Design and Optimization of Wireless Charging Drawer Coil for Smart Garments

In this letter, wireless charging chests suitable for smart garments are analyzed and optimized. The coil structure is optimized to generate a uniform magnetic field in a variety of drawer sizes. With the hybrid Helmholtz–solenoid coil structure, the variation of coupling factor is reduced from 78.2% to 26.4% as compared with solenoidal coil. Two design approaches for multidrawer chest are examined. In the first approach, the coils are optimized for individual drawers. In the second approach, the coils are optimized by considering the entire drawer chest. The measurement results show that the second approach further reduces the variation of charging current of receiver coils placed at different locations.