Optimization of multilayer absorbers using the bald eagle optimization algorithm

Abstract

Electromagnetic (EM) absorbers have several uses in today's military and civilian industries, and there is a growing demand for microwave absorbers with good absorption characteristics and thin layer structures over a broad frequency range (FR) within a specific EM spectrum band. This study aimed to find the most suitable design using different material sets, using the recently introduced Bald Eagle Search Optimization Algorithm (BESOA) to design a multilayer EM absorber for the required FR. An FR of 1 to 20 GHz was considered, and the multilayer absorbers were designed for 2-8 GHz, 12-18 GHz, 2-18 GHz, and 1-20 GHz FRs. For various incidence angles between 30 & DEG; and 75 & DEG; and polarizations (TE and TM) in chosen FRs, comparisons were made with the Improved Particle Swarm Optimization (PSO), Differential Evolution (DE), Central Force Optimization (CFO), Lightning Search Algorithm (LSA), Double Stage Ant Bee Colony (DS-ABC) and other optimization algorithms found in the literature. The optimization algorithms that were used to design MMAs in the literature aim to construct the absorber with the lowest maximum reflection coefficient (RC) in the given FR and the thinnest thickness by selecting suitable material layers from a predefined database. The numerical and visual comparisons show that the obtained designs have the lowest maximum RC with the thinnest overall thickness compared to those in the literature. Numerical best results are presented for each variation obtained as a result of the optimization.