Resonance properties of metallic ring systems

We review our recent efforts in understanding the resonance properties of metallic ring systems using a rigorous mode-expansion theory. In the quasi-static limit, we established a matrix-form circuit equation to calculate the frequencies and current distributions for all resonance modes in a ring system. We then applied the theory to study different split ring resonators (SRR). We show that the circuit equations can be analytically solved in the thin-wire limit. Our theoretical results were all successfully verified by finite-different-time-domain simulations on realistic systems and available experiments.