Experimental demonstration of the equivalence of inductive and strongly coupled magnetic resonance wireless power transfer

• Published in: Applied physics letters Vol. 102; no. 5
• Main Authors: Ricketts, David S., Chabalko, Matthew J., Hillenius, Andrew
• Format: Journal Article
• Language: English
• Published: 04-02-2013
• Subjects: Coiling; Equivalence; Impedance; Impedance matching; Magnetic induction; Magnetic resonance; Power transfer; Transformations
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4788748

In this work, we show experimentally that wireless power transfer (WPT) using strongly coupled magnetic resonance (SCMR) and traditional induction are equivalent. We demonstrate that for a given coil separation, and to within 4%, strongly coupled magnetic resonance and traditional induction produce the same theoretical efficiency of wireless power transfer versus distance. Moreover, we show that the difference between traditional induction and strongly coupled magnetic resonance is in the implementation of the impedance matching network where strongly coupled magnetic resonance uses the mini-loop impedance match. The mini-loop impedance mach provides a low-loss, high-ratio impedance transformation that makes it desirable for longer distance wireless power transfer, where large impedance transformations are needed to maximize power transfer.