A NEW WIDEBAND NEGATIVE-REFRACTIVE-INDEX METAMATERIAL

This paper reveals the design and analysis of a new wideband negative-refractive-index (NRI) metamaterial unit cell. The proposed metamaterial unit-cell exhibits resonance in the C-band and displays negative permittivity and permeability there with a wideband NRI property. It also shows a wider negative peak of the refractive index in the major area of the C- and X-band and minor area of the S- and K-u-band, and a maximum 3-GHz negative bandwidth was achieved compared to the reference metamaterial. In the basic design, a square-shaped copper resonator was constructed with a metal strip on the FR-4 substrate material. The measured result was presented and it shows good conformity with the simulated result. Moreover, an analysis was performed with the same design by replacing the substrate material with the popular Rogers RT 6010 instead of the FR-4 material and then it shows NRI properties in the C-, X- and K-u-band.