Optimal Design of Infrared Wavelength‐Selective and Microwave Transmitting Bionic Metasurface

Abstract The radar and infrared (IR) compatible stealth technology is an important technology in the military field. Inspired by the special triangular‐shaped hairs from the Saharan silver ants, a bionic structure with IR wavelength‐selective emission and large microwave transmission simultaneously is presented. An algorithm based on the combination of Bayesian optimization and finite different time domain method is proposed for optimal design. The proposed structure is an indium tin oxide (ITO)‐hairs/ITO‐film/PET‐substrate structure. The IR wavelength‐selectivity is reached by the hair covered ITO film, and the microwave transmission is realized by patterning gap arrays on continuous films. After optimal calculation, the optimal bionic structure is obtained. The change of the structural parameters of the meta‐atom will lead to a change in microwave transmission. When p = 0.1 mm and w = 0.9 mm, the maximum and minimum transmittivity of the infrared stealth layer (IRSL) in 2–20 GHz are 0.972 and 0.764, respectively, while the estimated emissivity in 3–5, 5–8, and 8–14 µm wavebands are 0.592, 0.730, and 0.373, respectively. It illustrates that the IRSL maintains IR wavelength‐selective emission while maintaining high microwave transmission. This study provides a strategy for bionic structure applied in compatible stealth.