Designing Thinner Broadband Multilayer Radar Absorbing Material Through Novel Formulation of Cost Function

Modern military and civic applications require broadband microwave multilayer radar absorbing material (MRAM), which typically consists of multiple layers that increase the thickness of platforms like aircraft, ships, and vehicles, thereby adding to their weight. To address this, MRAM design methods strive to optimize layer parameters to reduce thickness. In this article, we emphasize the importance of the cost function used in the optimization process, which can significantly affect the outcomes. This article investigates the impact of common cost function formulations on achieving global optima and proposes a new cost function that produces thinner MRAM designs without increasing algorithmic complexity. The new formulation works as a two-step optimizer and yields thinner results. The article compares the results for twelve different MRAMs with those of previous literature, and achieves maximum and minimum thickness reductions of 22.9562% and 0.009%, respectively. The findings highlight that the cost function formulation significantly impacts the design outcome and can be used to obtain thinner designs. Additionally, the proposed approach is more effective than other commonly used formulations for finding the optimal layer sequence and minimizing thickness using a given search algorithm