Low-loss near-zero-index metamaterial based on a single board for broadband electromagnetic-wave switches

Zero-index metamaterials have excellent potential for applications in electromagnetic devices, but severely suffering from inadequate bandwidth or high loss. Here we present an easy-fabricating zero-index metamaterial, composed of the wires on the surface and through the substrate. The near-zero-index metamaterial presents a low loss in the wide frequency range from 10.72 GHz to 11.4 GHz. A general approach of low-loss near-zero refraction is proposed based on the relationship between electric plasma frequency and magnetic plasma frequency, which provides an effective way for governing electromagnetic loss of metamaterials. The near-zero-index metamaterial can service as the broadband electromagnetic-wave switch covering the range of 10.5 GHz to 11.54 GHz, with a relative transmission ratio up to 97.8%.