Uniform near magnetic field generated by metasurface-based resonator for wireless power transfer

Abstract

The modern platforms capable of generating uniform magnetic fields for wireless charging multiple electronic devices have attracted considerable interest in the wireless power transfer realm. This paper proposes a metasurface-based transmitting resonator consisting of two orthogonally placed parallel copper wires layers separated by a high permittivity dielectric layer. The proposed structure of the transmitting resonator allows for generating a uniform magnetic field above the surface. The theoretically estimated minimum coefficient of magnetic field variation is 8.2 % over the central resonator working area with the size of 30 cm × 30 cm, which is sufficient to charge several devices at once. The calculated maximum achievable power transfer efficiency reaches 93.4 %. The simulated value of the resonator’s peak specific absorption rate is twice decreased compared to other metasurface-based designs. The proposed structure could transfer more power under the same safety limitation.