Investigating the Improved Microwave Absorption Bandwidth in Fe/ZnO Composite-Backed Cross-Dipole FSS: A Critical Analysis

The performance of magneto-dielectric composites to absorb microwave energy can be significantly increased by imprinting frequency selective surface (FSS) features on them, as is well known. However, optimizing such FSS absorbers remains a challenging endeavor. In order to achieve this, a critical examination of the effects of cross-dipole FSS structural parameters on the frequency response and bandwidth performances of composite material backed FSS absorber has been undertaken in this study. This work uses the High-Frequency Structural Simulator (HFSS) numerical simulation software in 8 – 18 GHz frequency range. The impact of cross-dipole length, width, and composite material substrate thickness on the microwave absorption performance of the Fe/ZnO composite-backed cross-dipole FSS was analyzed in this study. The absorption bandwidth of the composite absorbing material layer was significantly expanded from 5.17 (11.43-16.6) GHz to 8.22 (8.64-16.86) GHz by imprinting Cross-dipole FSS with a 2.5 mm coating thickness. The proposed FSS absorber's absorption behavior has also been explained through the analysis of surface current distribution. The conclusion will aid in the design of highly efficient cross-dipole FSS microwave absorber.