Broadband 15-dB RCS Reduction Optimized Coding Metasurface Based on Flexible Polarization Converter

Metasurfaces have attracted significant attention due to their powerful capabilities to control the characteristics of electromagnetic (EM) waves flexibly and rapidly. Despite much effort to enhance their performance, metasurfaces remain constrained in optical transparency, flexibility and operating bandwidth. Herein, we have design a flexible metasurface that is capable of operating over an ultrawideband frequency range of 86% with an optical-transparency up to 65.29%. First, a cross-polarization converter (CPC) is design that converts the linearly polarized incident EM wave into its orthogonal component ranging from 14.5 to 36.5 GHz. Moreover, the underlying mechanisms of CPC is analyzed in detail. Next, utilizing Pancharatnam-Berry (PB) phase principle, meta-atom “1” is formed and the layout of the coding metasurface is obtained through genetic algorithm (GA) for radar cross section (RCS) reduction. According to the simulation results, the proposed metasurface can achieve more than 15 dB RCS reduction in the frequency range of 15.4 to 34.3 GHz. Additionally, the RCS reduction performance is evaluated on curved surfaces, demonstrating stable behavior even at a central bending angle of π. Experimental results show good agreement with simulations, validating the effectiveness of the proposed design. Owing to its transparency, flexibility, and broadband characteristics, the proposed metasurface yields promising potential in multifunctional stealth applications.