Effect of nonuniform-defect split ring resonators on the left-handed metamaterials

We have investigated the defect effect in three-dimensional (3-D) left-handed metamaterials, consisting of an array of repeated unit cells of copper wires and hexagon split ring resonators (SRRs) on strips of standard circuit board material. By measuring the X-band transmission through this metamaterial with different point- and linear-defected SRRs, we find that the resonance frequency, its value and passband of transmission peaks, changes markedly. It is suggested that such tunable left-handed properties may arise from the symmetry breaking of SRRs in the metamaterials.