Design and Analysis of Terahertz Wave Tunable Metamaterial with High Refractive Index

Metamaterials are a class of artificially designed artificial composite materials with periodic arrangement of sub-wavelength structure. Because of their unique properties that are not found in nature, metamaterials are of great research value and have aroused extensive research interests of researchers. Here, a two-sided square metal metamaterial structure is designed. The structure is composed of double-sided metal box, base and silicon. A layer of silicon material is plated on the edge of the square metal box, and the purpose of the material refractive index can be tunable by adjusting the electrical conductivity of silicon. Through the S-parameter extraction algorithm, the effective refractive index of the material can be adjusted from 0 to 25 in 0THz 4THz band. The influence of silicon conductivity on effective permittivity, permeability, impedance and refractive index and its changing trend are revealed. At the same time, the influence of different base size and metal width on the relative refractive index of the material and its variation trend under different silicon conductivity are further compared. We can further adjust the equivalent refractive index of the metamaterial by changing the base size or changing the width of the square metal frame.