  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.
