Article ID: 11.20140147
This paper presents versatile formulas that characterize wireless power transfer schemes in arbitrary coupling topologies. Maximum available coupling efficiency is formulated in two-port immittance matrix domain invariant to source and load conditions. Key performance index k-Q product is extended to general cases even where resonance or filtering model is inapplicable. Typical capacitive- and inductive-coupling schemes are shown with their k-Q product instances.