Multimodal Resonance in Strongly Coupled Inductor Arrays

TL;DR

This paper explores the multi-resonant phenomena in strongly coupled inductor arrays, demonstrating their potential for advanced sensing applications through theoretical, simulation, and experimental validation.

Contribution

It introduces eigen-formulae for resonant frequencies in over-coupled inductive arrays and validates multi-modal resonance effects for sensing and magnetic field shaping.

Findings

Multi-modal resonant frequencies are confirmed experimentally.

Eigen-formulae accurately predict resonant modes.

Strong coupling enables novel inductive sensing designs.

Abstract

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 paper introduces, validates and evaluates the unique multi-resonant phenomena predicted by circuit theory for over-coupled inductive arrays, and presents eigen-formulae for calculating resonant frequencies and voltage modes within passively excited arrays. Finite-element simulations and experimental results demonstrate the validity of the multi-modal resonant principles for strongly-coupled inductor arrays. The results confirm the distinctive multi-modal 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 over-coupling and exploiting their potential magnetic field shaping.