An Ultrathin Wideband Microwave Metamaterial Absorber Based on Frequency Selective Surface

Abstract This article introduces a frequency‐selective surface‐based metamaterial absorber with small thickness and large bandwidth. The structure having an overall thickness of only 2 mm is manufactured on an FR4 substrate, and the size of the repeating unit is 10 mm × 10 mm. When electromagnetic waves incident perpendicularly on the absorber, it has an absorption bandwidth of 8.64 GHz (from 9.16 to 17.8 GHz), covering most of the X‐band and Ku‐band. Results show that the lowest absorption rate reaches 91.5% while the highest is 99.85%, and the full width half maxima (FWHM) bandwidth is 10.5 GHz (from 8.8 to19.3 GHz). Thanks to extensive simulations, the structure is optimized. Furthermore, the electromagnetic parameters ε eff and μ eff images are drawn to illustrate the absorption mechanism, and the current images of the top and bottom layers are drawn to further support absorption mechanism. Finally, experiments are conducted to verify the absorption capacity of the structure as electromagnetic waves incident perpendicularly.