Design of a Near-Zero Refractive-Index Metamaterial Unit for Electromagnetic Cloaking

A novel near-zero refractive-index metamaterial unit is proposed. The basic structure of the proposed unit consists of two face-to-face E-type microstrip lines, both of which connect to a background microstrip line by the corresponding vias on the E-type microstrip lines crossbar. The retrieved refractive-index, equivalent permittivity and permeability from scattering parameters are calculated. The results show that the real part of the refractive-index as well as the equivalent permittivity is near zero at 10.5-14.5 GHz. A rectangular electromagnetic invisible cloak is designed and simulated based on the proposed metamaterial unit. The simulated results show that the rectangular cloak can make the pure copper cylinder electromagnetic invisible.