▎ 摘　　要

We present a numerical analysis of the polarization-insensitive squared spiral-shaped graphene-based tunable metasurface for the high performance of the reflection control. The proposed structure is investigated for the normal and complementary behavior of the graphene surface. The proposed metasurface structure is tuned by applying external biasing potential which will ultimately control the conductivity of the graphene sheet. The transmittance, reflectance, effective refractive index and polarization variation in the reflected wave are investigated for the frequency range of 1-3 THz. The proposed design also investigated the wide-angle incidence response. The proposed structure is tunable over graphene chemical potential range of 0.1-0.9 eV. The proposed metasurface structure is the polarization-insensitive for X- and Y-polarized TE- and TM-excited modes. The behavior and numerical results of the metamaterial structure can be applied to design various photonic components like a polarizer, THz filters, frequency-selective surface, sensors, modulators, etc.