A Viaed Double-Spiral Resonator for Broadband WPT in Human-Involved Environments

For most strongly coupled magnetic resonance (SCMR) wireless power transfer (WPT) systems, a common problem is the dramatic efficiency drops by surrounding highly dielectric objects like human body, caused by their limited system bandwidth. In this paper, a broadband SCMR system with viaed double-spiral resonator fabricated on PCB is proposed. The proposed design shows an over 15 % increase of bandwidth compared to a conventional system with single-sided resonators in both simulation and measurement, meanwhile the power transfer efficiency is not compromised. The broadband of the proposed structure leads to a system with a reduced susceptibility to ambient interference like human body. A simulation with a multi-layer human tissue model was conducted, successfully demonstrates the robustness of the proposed system in human-involved environments compared to that of a conventional system.