Interaction of twisted split ring resonators

We study the dynamics of two microwave split ring resonators broadside coupled to each other, varying twist angle between them, as shown in Fig. 1(a). A similar system operating at near infra-red frequencies was presented in [1]. We show our experimental and numerical results in Fig. 1(b). For = 0, there are two resonances _S and _AS, and by inspection of the currents in the rings we verify that these correspond to the expected symmetric and anti-symmetric modes. As increases, _AS increases and _S decreases, reaching their maximum and minimum values respectively at = 180. For our chosen parameters the resonances appear to cross at _c 33, in contrast to [1], where an avoided crossing of resonances was reported.