NSGA-II-driven design of a multispectral compatible metasurface with broadband microwave polarization conversion and low infrared emissivity

Given the conflict between high microwave absorption and low infrared emissivity performance in electromagnetic-controlled metasurface design, achieving multispectral compatibility between low microwave reflectivity and low infrared emissivity remains challenging. Leveraging the non-dominated sorting genetic algorithm II (NSGA-II), this study presents a three-layer lightweight metasurface comprising a metal-patterned F4B substrate with a metal backplate, designed to achieve simultaneous ultra-wideband polarization conversion and low infrared emissivity. The NSGA-II is employed to engineer distinct electrical lengths along the two orthogonal decomposition components of the incident electromagnetic wave, enabling dominant resonant mode conversion across multiple frequency bands, which facilitates efficient broadband polarization conversion while maintaining low infrared emissivity. Simulation results show that the polarization conversion efficiency is greater than 90% in the 7.7–12.1 GHz band, and the experimentally measured mean infrared emissivity is 0.36, which is close to the theoretical value with angular stability. This feature enables it to be directly applied to the stealth coating of military targets and the field of polarization multiplexing communication, doubling the transmission channel capacity.