Genetic Programming in Designing Advanced Metamaterial Absorbers

Abstract

Metamaterials are artificial materials that possess properties otherwise not found in nature. The current state of metamaterial absorbers (MMA) in the lower gigahertz frequency (1-11 GHz) is sparse and commonly resides in the X-band (8-12 GHz). Typical 2D MMA have topologies designed by trial and error and are either compact with discrete operational frequencies or bulky and lossy to achieve broadband performance. Hybrid genetic programming (HGP) is proposed to create new compact design topologies in the lower gigahertz frequency with new material development. HGP can create new topologies optimized per input parameters, such as low frequency and high broadband absorptivity. These designs are built and simulated in Ansys High-Frequency Simulation Software (HFSS) and evaluated by HGP. Additional topologies, such as graphene and resistive sheet patterning, and resistive sheet insert, are explored and implemented with HGP to create compact, low-gigahertz frequency and high-absorptivity MMAs. The graphene-based and resistive sheet-based patterned designs achieved 80% bandwidth above 80% absorptivity from 4.6 to 11 GHz, up to 15 GHz, and from 3.83 to 9.13 GHz, respectively. Preliminary measurements of a fabricated resistive sheet insert design aligned with simulated results.