Wideband low-RCS polarization conversion coding metasurface optimized by quantum genetic algorithm

Abstract A wideband low radar cross section (RCS) coding metasurface is designed using an integrated methodology. First, a polarization conversion metasurface (PCM) unit cell with a 16 × 16 pixel structure is optimized employing a quantum genetic algorithm (QGA), achieving a polarization conversion ratio (PCR) over 90% from 7.9 to 22.3 GHz. Then, by rotating this optimized unit cell 90°, a 1-bit coding metasurface pair with a 180° phase difference is constructed. Based on antenna array theory, the spatial distribution of these 1-bit units on a larger array is subsequently optimized via QGA to produce low-RCS scattering performance. The resulting coding metasurface attains over 10 dB of RCS reduction from 8.2 to 22.3 GHz and maintains stable performance under oblique incidence up to 30°. This unified QGA-based design framework enables automated co-optimization of both the pixel-level PCM structure and the large-scale coding sequence, significantly improving design efficiency. The optimized metasurface is fabricated and experimentally validated, with measured results showing good agreement with simulations. The proposed approach simplifies the design process for a low-RCS coding metasurface based on PCMs and offers a valuable framework for applications in stealth and high-performance communication.