Pancharatnam-Berry metasurface for terahertz wave radar cross section reduction

The digital coding metasurfaces need several kinds of meta-particle structures to obtain corresponding electromagnetic wave responses and require time-consuming optimization. In this paper, we present train-symbol-shaped meta-particles with various orientations utilizing Pancharatnam-Berry (PB) phase to achieve 1-, 2-, and 3-bit digital coding metasurfaces. Terahertz wave scattering patterns of the coding metasurfaces with regular and random sequences are given and discussed. They have strongly suppressed backward scattering with approximately -13.5 dB radar cross section (RCS) reduction in a wide band range from 0.85 THz to 1.6 THz. The proposed digital coding metasurfaces provide a simple way and new opportunities for manipulating terahertz wave scattering with polarization independence.