Broadband and Wide-Angle Absorber Based on Indium Tin Oxide Films

In this paper, we propose a novel broadband and wide-angle absorber constructed from indium tin oxide (ITO) films, designed via a multi-objective optimization algorithm. The absorber, based on a lossy frequency selective surface with multiple layers, utilizes multilayer absorption equations and equivalent circuit models to calculate its absorptive properties. Addressing issues of bandwidth and thickness imbalance in the structure, the optimization algorithm adjusts the geometric dimensions and sheet resistance parameters. The resulting multilayer absorber achieves a 90% absorption bandwidth across a frequency range of 2-18 GHz and supports incidence angle up to 45 degrees. Remarkably, its overall thickness corresponds to only 0.133 times the wavelength, rendering it highly suitable for applications in stealth technology and electromagnetic shielding.