Coupling of split ring resonators in a mu-negative volumetric metamaterial

This paper presents an experimental and theoretical study of the coupling of split ring resonators, and aims to show ways to widen the frequency band of the response of mu-negative metamaterials. The behaviour of these metamaterials is theoretically described in terms of coupled resonant circuits theory. In particular the coupling is studied on pairs of split ring resonators and systems containing the greater number of resonators. Widening of the metamaterial response frequency band is caused primarily by dispersion of the resonant frequencies of the particular resonators, and to a minor extent by mutual coupling. The more particles participate in the tested system, the wider the frequency band of the system response. The requirement to obtain an isotropic medium is taken into account.