Multimodal Resonance in Strongly Coupled Inductor Arrays

Magnetic resonance coupling (MRC) is widely used for wireless power transfer (WPT) applications, but little work has explored how MRC phenomena could be exploited for sensing applications. This article introduces, validates, and evaluates the unique multiresonant phenomena predicted by circuit theory for overcoupled inductive arrays and presents eigenformulae for calculating resonant frequencies and voltage modes within passively excited arrays. Finite-element simulations and experimental results demonstrate the validity of the multimodal resonant principles for strongly coupled inductor arrays. The results confirm the distinctive multimodal resonant frequencies these arrays exhibit, corresponding to the specific magnetic excitation “modes” (comparable to vibrational modes in multi-degree-of-freedom systems). The theoretical and finite-element models presented offer a framework for designing and optimizing novel inductive sensing arrays, capitalizing on the unique resonant effects of overcoupling and exploiting their potential magnetic field shaping capacity.