Novel broadband terahertz negative refractive index metamaterials: Analysis and experiment

Broadband planar and non-planar negative refractive index (NRI) metamaterial (MTM) designs consisting of a periodically arranged split ring resonator and wire structures are developed in the terahertz (THz) frequency regime using the Finite-Difference Time-Domain (FDTD) method. The novel MTM designs generate a broad negative index of refraction (NIR) passband approximately two and a half times higher than those of the conventional SRR/wire structures, by using the same dimensions. Numerical simulations of wedge-and triangle-shaped metamaterials are used to prove the negative refractive index of the models. The fabricated MTMs exhibit passband characteristics which are in good agreement with the model results. The parametric studies of correlated factors further support these outcomes.