A Wideband Frequency Selective Surface EM Absorber using Lossy Material for X and Ku band Applications

A wideband frequency selective surface (FSS) absorber implementing lossy ink layer for electromagnetic absorption is presented in this paper. The absorber is designed on a metallic ground plane which acts as reflector. A thin layer of lossy ink material is used in the form of double square loops which serves as an absorber at the top surface of the substrate. The FSS unit cell has an overall size of
$18\mathbf{mm x }18\mathbf{mm x }0.8\mathbf{mm}$
with outer and inner square loops whose dimensions are 15mm and 10 mm, respectively. The results show that the proposed absorber operates between 8 GHz to 14 GHz covering X and lower Ku bands. It is shown that this design provides a fractional bandwidth of 54.5% and 98% absorptivity in the whole band. The wideband and high absorptivity of the proposed FSS absorber demonstrates its potential for electronic warfare and other strategic applications.