Manipulating terahertz wave and reducing radar cross section (RCS) by combining a Pancharatnam-Berry phase with a coding metasurface

We propose a kind of coding metasurface of an 'M'-shaped metallic pattern coding particle, which can realize the flexible manipulation of terahertz waves and reduce radar cross sections effectively. In this paper, eight kinds of coding particles are obtained by rotating the 'M'-shaped pattern using the Pancharatnam-Berry phase theory. We design three different coding sequences of 3-bit coding metasurfaces and manipulate the incident terahertz wave to produce two, four and six beams of the reflected terahertz wave, respectively. Both theoretically calculated and numerically simulated scattering patterns of the designed coding metasurfaces demonstrate the expected manipulations. In addition, compared with the bare metal plate, the designed random coding metasurfaces can reduce the radar cross section by at least -10 dB at the frequency range 0.7-1.45 THz.