Critical analysis of fractal FSS with heterogeneous composite to enhance microwave absorption for stealth application

Abstract

Nowadays there is a stringent need to develop an absorber that can provide good absorption with wide bandwidth and lower coating thickness. In this study, a critical analysis has been carried out over three different kind of absorbing structures, i.e., double layer, fractal Frequency Selective Surface (FSS) integrated, and fractal FSS sandwiched absorbers for achieving good absorption with thickness (t ≤ 1.5 mm) and bandwidth (RL ≤ 10 dB). The selection of suitable composite, layer preferences, and thickness has been optimized using genetic algorithm (GA) on the basis of effective complex dielectric permittivity and magnetic permeability of the synthesized heterogeneous composites. The Sierpinski carpet fractal FSS sandwiched double layer absorber (t = 1.3 mm) shows a strongest RL of 41.29 dB at 8.7 GHz with broad bandwidth of 3.1 GHz in the range of 8.2 to 11.3 GHz. The developed thin and broadband absorber provides an effective and feasible solution for stealth application.