Normal-incidence left-handed metamaterials based on symmetrically connected split-ring resonators

Normal-incidence left-handed metamaterials (LHMs) based on symmetrically connected split-ring resonators (SC-SRRs) were proposed and investigated numerically and experimentally. The SC-SRR, which can be easily fabricated by conventional printed circuit board technology, is composed of metallic patterns connected by metalized vias through the dielectric substrate. Under normal incidence, SC-SRR exhibits strong magnetic response, leading to negative permeability. By combing SC-SRRs with metallic wires, a normal-incidence LHM was realized. Both the simulation and experiment results demonstrated left-handed properties of the SC-SRR/wire LHM. The design method paved new ways of realizing magnetic and even electric metamaterials.