▎ 摘　　要

In this paper, terahertz (THz) tunable high-sensitive refractive index sensors based on single and double ring graphene metasurfaces are proposed and investigated by the full-wave simulation based on the Finite Element Method (FEM) and by the calculation through a generalized circuit model introduced for the sensor structures. The absorption spectra of the single and double ring sensors for various refractive indices have achieved. Good agreement is observed between the results of the circuit model and those of the full-wave simulations. The proposed sensor can be used as a platform for the design of the sensors needed in multiple chemical and biomedical systems.