A compact CRLH metamaterial with wide band negative index characteristics

Metamaterials are the artificial materials that may have a negative refractive index and results in extraordinary properties which are not found in nature. This research focusses on designing a compact-sized artificial material for negative characteristics of permittivity, permeability and refractive index over the wide range of frequencies. The metamaterial design is evaluated for single negative, double negative and double positive behaviours over a broad range of frequencies to investigate the gap and gapless transitions from backward to forward wave propagation. The dispersion diagram of the material is also investigated for left or right hand behaviour of the material. The equivalent circuit diagrams along with circuit simulations of the parameters are also presented for detailed analysis and understanding. The designed metamaterial behaves like a double negative material for low frequencies and double positive material for high frequencies. The approach is verified using CST microwave studio simulation and the results obtained are validated using the rectangular waveguide measurement method.