Manipulation of Terahertz Wave Using Coding Pancharatnam-Berry Phase Metasurface

Coding metasurface offers a promising way for manipulating electromagnetic waves using several structural metaparticles or changing the metaparticle geometry parameters. It leads to time-consuming optimization in multibit coding designs. Different from the previous conventional coding metasurface, both Pancharatnam-Berry (PB) phase and the predesigned coding sequences in the coding elements are used to manipulate terahertz wave, which becomes more flexible. In this paper, a multibit digital coding metasurface is constructed using the PB phase based on a same size metaparticle with various orientations. Both theoretically calculated and numerically simulated scattering patterns of the designed coding PB phase metasurfaces demonstrate the expected manipulations. The designed coding metasurfaces having polarization dependance for left circularly, right circularly, and linearly polarized waves are confirmed. The maximum bandwidth of a radar cross section reduction of approaching -10 B is 0.8 THz (range from 0.8 to 1.6 THz).