Hybrid planar Litz coil optimization for phone wireless power transfer

This paper proposes an innovative receiver coil structure for wireless power charging suitable for portable devices with thickness constraint. Litz wires represent the best solution for high-efficiency wireless power transfer coil but cannot be implemented in a thin structure. In this paper will be presented and optimized planar Litz structures with narrow profile. The performances of the coils were tested with the measurements in a wireless power transfer system in alignment and misalignment conditions.