Design of Polarization Conversion Metasurfaces with Low-Scattering Multi-Beam and Multi-Polarization

This paper proposes two types of phase gradient metasurfaces, named as non-centrosymmetric beam metasurface (NCSM) and centrosymmetric beam metasurface (CSM), which exhibit remarkable performance in reducing radar cross-section (RCS). For the NCSM, when a circularly polarized (CP) wave is incident, it scatters incident wave into 45 beams accompanied by polarization conversion. When a linearly polarized (LP) wave is incident, the NCSM can generate total of 90 beams, including 45 left-circularly polarized (LCP) beams and 45 right-circularly polarized (RCP) beams. In contrast, when either CP or LP waves are incident on a CSM, it scatters incident wave into 36 beams and simultaneously achieves polarization conversion. The NCSM achieves over 10 dB multi-polarization RCS reduction across frequency range from 14.3 GHz to 33.4 GHz (80.1% relative bandwidth). Similarly, the CSM achieves over 10 dB multi-polarization RCS reduction within a frequency range from 14.9 GHz to 33.5 GHz (76.8% relative bandwidth). The proposed metasurfaces provide an efficient way to achieve multi-polarization RCS reduction, which can be adapted to the complex radar detection environment.