Conformal and polarization adjustable cloaking metasurface utilizing graphene with low radar cross section for terahertz applications

Abstract

Metamaterials with precisely chosen negative permittivity and permeability are preferable to cloak the target without scattering. In this work, a metasurface is designed by using graphene as conducting material to cloak a target cylinder under the instancing of TM and TE polarized waves in terahertz range of frequencies. The electric sheet impedance and magnetic sheet admittance played the crucial role to achieve the cloaking with good scattering reduction. Various incident angles are simulated and analyzed for obtaining the good radar cross section (RCS). The proposed metasurface resonates at three different frequencies in terahertz range of 3.8 THz, 9 THz and 13.8 THz and the bandwidth of the three resonating frequencies are 3.5–4.58 THZ, 8.8–9.5 THz and 13–14.98 THz respectively. In addition, the parametric analysis of chemical potential and relaxation time shows effective results in scattering reduction. The monostatic and bistatic RCS are simulated, which results high scattering reduction under different polarizations of different incident angles. The proposed structure is adjustable to various angle of incidence with less than 40 dB scattering reduction for various selected frequencies.