Resonant-Based Wireless Power Transfer System Using Electric Coupling for Transparent Wearable Devices and Null Power Points

SIMPLE SUMMARY: Wireless power transfer using electric coupling can deliver the power by electric field between two metal plates, and a copper plate is generally used for metal material. This study presents that a transparent and flexible metal mesh material can replace the existing copper plate in resonance-based wireless power transfer using electric coupling. In wireless power transfer using electric coupling, a phenomenon called null power point occurs depending on the relative positions of the transmitter and receiver, which negatively affects the efficiency of power transfer. This study also clarified the reason for the occurrence of null power points in the power transfer process. ABSTRACT: This study provides information on the transfer efficiency of four-plate-structured copper plate and metal mesh sheet couplers, the cause of null-power point. The couplers are compared based on the equivalent circuit model analysis, experimental results of fabricated couplers, and simulation results of the High-Frequency Structure Simulator (HFSS) tool. It was confirmed that the metal mesh material exhibits the same performance as the existing copper plate and can be fully used as a coupler material for the electrical resonance wireless power transfer system. In addition, the null-power point phenomenon is only determined by the main coupling and cross coupling between the transmitter and receiver, which are most dominantly affected by the coupler structure.