Ultra-wideband polarization- and angle-insensitive metamaterial absorber based on multilayer resistive ink

An ultra-wideband metamaterial absorber (MA) consisting of three layers of resistive ink separated by two layers of polymethacrylimide is proposed. The results of full-wave simulation show that the absorptivity is high up to 95% with a bandwidth ratio of 1:9.73 over the wide frequency range from 4.20 to 40.87 GHz, covering the whole C, X, Ku, K, and Ka bands. Moreover, the MA is insensitive to polarization and exhibits wide-angle stability, which is investigated by the full-wave simulation results as well as the analysis of multi-reflection interference theory. The fabricated prototype with a single unit cell of 0.081 g is tested using free-space measurement in an anechoic chamber, and the measured results are in good agreement with the simulation results, which prove the robustness of the design and indicates a practical application prospect of the proposed ultra-wideband MA with lightweight, simple, and compact structure.