Novel optimization method of single square FSS impinged and cascaded radar absorbing composites

Abstract

It is well known that radar absorbing potentiality of existing magneto-dielectric composites can be significantly enhanced by the application of frequency selective surface (FSS) and cascaded electromagnetic (EM) structures. But the optimization of such complex EM structures and validation of the adopted optimization strategy is still a very challenging task for the researchers. Therefore, in this study, an effective effort has been made for the optimization and the corresponding validation for Single Square FSS (SS-FSS) impinged and cascaded radar wave absorbers using advanced computational EM software's like FEldberechnung furKorper mit beliebigerOberflache - a German acronym (FEKO) and high frequency structure simulator (HFSS). In addition, a critical analysis of dielectric constant (epsilon) has been carried out to select the best combination of composites for the development of efficient radar wave absorbers. A comparison between optimized and simulated results have been carried out to examine the effect of advanced EM approaches over reflection loss (RL) characteristics of composite radar absorbing materials (CRAMs). A rapid change in radar absorption properties of composites has been observed after the application of SSFSS and cascading. A SS-FSS impinged composite has been found to provide a wide absorption bandwidth of 3.6GHz at X-band. A cascaded absorber having layer thickness 1.8mm provides a peak RL of -42.6dB at 10.6GHz with an absorption bandwidth of 2.5GHz. The strong agreement between mathematical model, HFSS and FEKO results clearly reflects the efficiency of adopted approach for distinct practical EM applications.