A Compact Wideband CSRR near Zero Refractive Index and Epsilon Negative Metamaterial for Wearable Microwave Applications

A complementary split-ring resonator (CSRR) decagonal shaped textile-based single-negative metamaterial (MTM), considering a frequency range from 1 to 15 GHz, is presented in this paper. Seven different unit cell arrays (i.e., 1 1, 1 2, 1 3, 2 1, 2 2, 1 3 and 3 3) are analysed to evaluate the effects of the unit-cell arrays on the resonance frequencies of the MTM. The designed unit cell arrays exhibit average negative permittivity bandwidth of 12.87 GHz (from 1 to 12.87 GHz) and an average near-zero-refractive-index (NZRI) bandwidth of 11.98 GHz (from 1.015 to 12.995 GHz). Simultaneous negative permittivity and NZRI results at L, S, C, X and Ku frequency bands indicate the proposed MTM is suitable for various wearable applications in these frequency regimes.