Application of sandwiched sierpinski carpet fractal FSS for performance enhancement of microwave absorbing composite

Abstract

Stealth applications require that an absorber should not only provide wide absorption bandwidth, but should also be as thin as possible. Therefore, the main aim of this paper is to develop an efficient microwave absorber with lower thickness (t < 1.5 mm) along with effective absorption bandwidth for reflection loss (RL) < −10 dB. The goal has been achieved with the application of fractal FSS (FFSS) sandwiched between the optimized layers of microwave absorbing composites (MACs). The higher iterated Sierpinski carpet FFSS sandwiched MAC has been designed using Ansoft HFSS and experimentally verified. The numbers of MAC layers are restricted up to only two layers as per the feasibility for its successful practical implementation. The design process encompasses the proper optimization of MAC layer thickness and FFSS dimension that minimize at the same time the RL over a specified range of frequencies. The Sierpinski carpet FFSS sandwiched double layer MAC (t = 1.5 mm) shows a strongest RL of −14.5 dB at 11.3 GHz with −10 dB absorption bandwidth of 3.0 GHz. The obtained result reflects the potential of FFSS sandwiched MAC for distinct EM applications.