Design of a Mu-Near-Zero metamaterial for reducing the backward magnetic flux leakage of a wireless power transfer system

摘要

This study proposed a design for a metamaterial that has the Mu-Near-Zero property in a certain frequency band in order to reduce the magnetic flux leakage of a wireless power transfer system. The proposed structure had spiral coils arranged in a strip line on a dielectric substrate and used a capacitor connected in parallel to induce magnetic resonance and attain the Mu-Near-Zero property. In this way, magnetic fields are reflected and thus become less likely to leak to the rear of the coils. To verify the performance of the proposed structure, the designed metamaterial was positioned at the rear of the transmission coil, and the efficiency of the transmission and receiver coils and the strength of the leaking magnetic fields were observed. The transmission efficiency at a 0.3 m distance between the transmission and receiver coils was 40.8%, which was similar to that of the conventional structures, and the reduction of magnetic flux leakage improved by a maximum of 79.7%.