Wide-Angle and Polarization-Insensitive Symmetric Multiple Split Ring Metamaterial Absorber for Quad-Band Shielding

A metamaterial absorber is designed using a multiple split-ring structure that has symmetrical circular edge splits. The absorber is polarization-insensitive and shows peak of absorption in the quad-band. To support the design, an FR-4 substrate is used. The dimensions of the absorber are 0.119 λ by 0.119 λ. Results show an absorption rate above 99% at 2.75 GHz, 5.04 GHz, and 13.9 GHz, with absorption of 96.7% at a frequency of 8.54 GHz. The structure exhibits the same absorption at transverse electromagnetic excitation modes. The angle-insensitivity of the absorber occurs up to 90°. The unique structure of the absorber can block unwanted electromagnetic interference with magnitudes of 40.82 dB, 49.12 dB, 28.43 dB, and 51.57 dB at frequencies of 2.73 GHz, 5.04 GHz, 8.54 GHz, and 14.12 GHz, respectively. The design is also verified using the HFSS (High Frequency Structure Simulator) program and validated in the ADS (Advanced Design System) environment, which also exhibits four satellite (S, C, X, and Ku) bands.