Characteristic-mode analysis of coupled split-ring resonators

The coupling between closely spaced split-ring resonators, when employed as sub-components of electromagnetic structures, is an important feature often leveraged upon to provide bulk material properties. In its contribution, this paper employs characteristic-mode analysis (CMA) to examine modal interactions intrinsic to the coupling between a pair of split-ring resonators. The analysis reveals the influence of feed impedance and rotational orientation of a pair of coupled SRRs on the excited resonant modes, which, in turn, determine the power transfer levels between both SRRs and the frequencies at which these occur. The insights provided suggest the aptness of rotational orientation and feed impedance as critical design parameters for the realization of SRR-based magneto-inductive waveguides and wireless power transfer setups.