Fully Compensated Self-Resonant Coil with Low E-field and Low Profile for Consumer Electronics Wireless Charging

Abstract

This paper details a fully compensated self-resonant coil (FSRC) with series LC resonance and reduced surface electric field for application in wireless power transfer for consumer electronics. By having a repeated series LC connection along the entire coil trace, the proposed series resonant structure achieves high-Q, low E-field, and thin profile simultaneously. The impact of ferrite shielding is also studied. Different E-field compensation coil geometries are studied, and a systematic design method is presented for optimal coil performance. Experimental tests verify the coil function, modeling, and design.