Wide Bandwidth Angular Insensitive Metamaterial Absorber for X Band Application

A wide band-angular insensitive metamaterial absorber at X band is presented in this paper. The metamaterial structure is fabricated on FR4 substrate with a dielectric constant of 4.4 and a loss tangent of 0.02. The proposed absorber exhibits a broad bandwidth of 2.84GHz from 7.7GHz to 10.54GHz with more than 90% absorptivity with almost perfect absorption at 7.87GHz, 8.83GHz and 10.12GHz. The simulation result shows that the proposed structure is angular insensitive and can absorb electromagnetic waves impinging at an angle up to 50°. The double negative metamaterial behavior of the absorber in the proposed band is proved using the NRW method. The structure is fabricated using photolithography and tested using the bi-static measurement method. The proposed absorber can be utilized for stealth applications in the military domain.