Metamaterial made of BC-SRRs with randomly dispersed resonance frequencies

This paper reports on an investigation of a metamaterial designed as a 3D system of broad side coupled split ring resonators. Imperfections in the fabrication process cause dispersion of the geometrical and material parameters of the resonators, and thus dispersion of their resonance frequencies. Homogenization of a 3D cubic lattice of these imperfect resonators reveals that the resulting resonance frequency band of the effective permeability is significantly widened, but at the cost of reducing its magnitude or even completely disappearing the negative values of its real part. An experiment performed in the rectangular waveguide verifies the theoretical predictions.