Optimization of Broadband Microwave Absorber Using Genetic Algorithm

Abstract

In recent years, scientists have been focusing on coding metamaterials absorbers to take full advantage of digital technology. This technology is mostly based on the fact that the absorption spectrum of a full-sized metamaterial varies with the different number and position of the defect elements in conventional unit cells (UCs) in it. However, both of their traditional methods namely simple random sample and combination of fundamental meta-block struggle with the enormous number of possible configurations especially when the number of UCs increases. In this article, we represent 5 configurations with different numbers of UCs, 2x2, 3x3, 4x4, 5x5, and 6x6 UCs, all of which maintain average absorption higher than 90% over a 10 GHz wide frequency range of interest between 17 GHz and 27 GHz. These results are obtained by using a genetic algorithm to generate configurations with higher optical loss through the process. Comparing to the conventional methods' result, our approach has achieved a significant improvement in the absorption spectrum. Furthermore, our methods could be applied to more structures with different sizes and numbers of UCs, thus provided a reliable tool to design practical metamaterials that serve the real work demands.