A Transmitter-Embedded Metasurface-Based Wireless Power Transfer System for Extended-Distance Applications

Portability and efficiency are crucial parameters in wireless power transfer (WPT) systems for extended-distance wireless applications. However, these systems often face challenges of low efficiency and mutual inductance. Generalized solutions employ ferrite, intermediate coils, metamaterials, or increasing operating frequency to address these issues. However, those solutions always lead to poor portability with extra weight and volume, except for increasing the operating frequency. To tackle these challenges, this article proposes a transmitter-embedded metasurface (TEMS) for the WPT system. The design aims to increase efficiency and the coupling coefficient under high operating frequency while maintaining a lightweight and occupying no extra volume, based on the negative permeability property. The L/C-based mathematical model and parametric investigations are conducted to explore the negative permeability property of TEMS. A prototype of the TEMS-based WPT system is implemented to validate the effect of TEMS on efficiency and coupling coefficient enhancement. The experimental results demonstrate that the proposed design can increase efficiency by at least 14.5% over transfer distances longer than 125 mm.