Polarization-angle insensitive metamaterial absorber for wide incident angles

In this paper, a polarization angle insensitive metamaterial absorber which works for wide incident angles has been proposed for C-band applications. A unit cell of the proposed absorber has an etched Jerusalem Cross (JC) inside a circle at the center of the square patch and four semi circles are rotated around the center circle by 90° each. Absorptivity of the proposed structure at 5.1 GHz is close to 95 % for all the polarization angles under normal incidence. This polarization insensitivity nature is due to the vertically and horizontally symmetric structure of the unit cell. The four semi circles used in the resonator provides incidence angle insensitivity. The angular insensitivity is studied at different radius of four semi circles. When the radius of the semi circles is 3.2 mm, the simulated absorptivity is higher than 90% and the frequency variation is less than 0.95% for incident angles up to 60°.