Conformal Magnetic Metasurface for Wireless Power Transfer with Multi-Receiver and Multi-Frequency Capabilities

This paper presents a conformal magnetic metasurface for multi-frequency and multi-receiver resonant inductive Wireless Power Transfer systems. The proposed metasurface is excited by a spiral transmitter which operates at different frequencies, fully integrated in the center of the conformal array structure, thus resulting in a compact design. In turn, the metasurface is employed to wirelessly deliver power to four receivers that are spatially distributed at distinct locations. The receivers resonate at the ISM frequencies of 6.78 MHz, 13.56MHz, 27.12 MHz and 40.68 MHz, respectively. After performing accurate full-wave simulations, the conceived conformal metasurface proved effective in distributing power to multiple loads in conditions of distant and non-coaxial coils, avoiding interferences by relying on the frequency coding capability. Moreover, the possibility to design conformal geometries enables the investigated system to adapt to various applications, realizing ultra-thin and flexible devices.