Multilayer Gradient Perforated Radar Absorbing Structure for Stealth Applications
Ravi Yadav, Ravi Panwar
Abstract
In the exploration of broadband radar absorbing structure (RAS), a new kind of multilayer gradient perforated RAS constituted of magnetic iron metal (Fe) and silicon carbide (SiC) is examined utilizing a top-down fabrication technique and metaheuristic grey wolf optimization (GWO) algorithm. The investigation of proposed structures and magneto-dielectric study of samples is carried out in 8.2–12.4 GHz (i.e., <inline-formula> <tex-math notation="LaTeX">${X}$ </tex-math></inline-formula>-band). Distinct single and multilayered RASs are optimized using the GWO algorithm under certain restrictive conditions. In addition, the GWO algorithm is reinforced with a fitness function (FF) to acquire maximum bandwidth below −10 dB threshold (<i>RC</i> <inline-formula> <tex-math notation="LaTeX">$\le -10$ </tex-math></inline-formula> dB) in various oblique angles of incidence with a minimum coating thickness (<inline-formula> <tex-math notation="LaTeX">${t} \le2.0$ </tex-math></inline-formula> mm). Among all investigated RASs, triple-layer gradient perforated structure (TLGPS) is found to be effective which fulfills the lightweight, broadband, and angular stable behavior of an efficient absorber. TLGPS has considerably exhibited the concept of impedance gradient which assists in triumph broadband radar absorbing materials (RAMs) for low observable applications.