Genetic algorithm-enabled on-demand co-design of optically transparent metamaterial for multispectral stealth applications.

This paper proposes a genetic algorithm (GA)-enabled co-design method for the development of metamaterials with on-demand microwave reflectivity and infrared (IR) emissivity. First, we proposed a multilayered metamaterial based on metasurface with hexagonal patch and ring patterns. An equivalent circuit model (ECM) was then established to model the microwave reflectivity of the metamaterial. To achieve broadband low microwave reflectivity, a GA based on this ECM was adopted to optimize the structural parameters of the metamaterial. A co-design task was accomplished by setting a judgment condition in the algorithm for low IR emissivity. With the help of GA, a metamaterial with broadband low microwave reflectivity and low IR emissivity was designed. Subsequently, a prototype metamaterial was fabricated by patterning optically transparent indium tin oxide films. The calculated, simulated, and measured results agreed well. The co-designed metamaterial had an IR emissivity of 0.15 within the spectral range of 3-14 µm, -10 dB microwave reflectivity at frequencies of 3.1-32.2 GHz, and transparency in the visible band. The proposed co-design method will benefit the design and application of multispectral stealth metamaterials.