Wide-Angle, Ultra-Broadband, Linear-to-Circular Polarization Conversion Reflectarray Based on Metasurface with RCS Reduction

In this paper, we propose an ultra-broadband linear-to-circular polarization conversion reflectarray with wide angular stability based on metasurface. The unit cell consist of a leaf-shaped symmetric structure consisting of parallel short truncated lines printed on a grounded dielectric substrate. Numerical analyses show that the reflectarray composed of such units is capable of converting linearly polarized (LP) incident wave into circularly polarized (CP) reflected wave. The y-polarized incident wave is converted into right-hand circularly polarized (RHCP) wave by reflectarray and x-polarized incident wave is converted into left-hand circularly polarized (LHCP) wave. Under normal incidence conditions, the relative bandwidths of the normalized ellipticity and axial ratio (AR) reach 82.7% and 83.2%, respectively, which completely cover the X-band. The reflectarray is stable over wide frequency range even at incidence angle up to 40°. The application in radar cross section (RCS) reduction is also verified, and the results show that the designed unit cell has potential applications in the field of RCS reduction.