Combined Phase Coding of PB-metasurfaces with OAM Generation for Wide-angle RCS Reduction

The phase mechanism of broadband and wide-angle RCS reduction (RCSR), based on the complication of phase profiles of metasurfaces (MS) with orbital angular momentum (OAM), is examined. Patcharatnam-Berry metasurfaces are designed from meta-particles in the form of rectangular patches with rectangular cutouts. The scattering characteristics of MSs made of the same number of meta-particles having different phase profiles are compared: a profile with an azimuthal phase gradient, generating broadband vortex scattering with OAM; profiles with radial and linear phase gradients and anomalous scattering; modified parabolic phase profiles with wide-angle scattering; and various combined phase profiles. The simulation showed the advantages of phase profiles combined with OAM. The scattering patterns of the co-polarized MS field in these cases have a funnel-shaped vortex character. The far-field phase in the vortex region depends not only on the azimuthal but also on the meridional observation angles. MSs implement broadband, wider-angle diffuse scattering, which is important for RCSR.