Research on beam manipulate and RCS reduction based on terahertz ultra-wideband polarization conversion metasurface

Abstract Metasurfaces exhibit promising capacities in the manipulation of electromagnetic (EM) waves, as to diverse dimensions like amplitude, phase, and polarization. Despite many methods have been used to improve regulatory capabilities of EM waves, the efficiency and working bandwidth has yet to be developed. In this paper, an ultra-wideband and high-efficiency reflective polarization converter metasurface (PCM) is proposed. Both theoretical analysis and simulation results show that the polarization conversion ratio (PCR) is above 89% in the ultra-wideband from 2.28 THz to 6.75 THz, and the relative bandwidth reaches 99%. Moreover, the multi-bit digital coding metasurface elements are designed by using Pancharatnam–Berry (PB) phase principle. The coding metasurface arrays are designed by using different coding sequences, which can be used to realize the free adjustment of scattering angle of the reflected EM waves. In addition, the radar cross section (RCS) reduction performances of the designed metasurface array antennas based on different coding elements are studied. The results present that it can significantly reduce the RCS by −20 dB over a wide frequency range from 2.1 THz to 6.9 THz. The proposed metasurface has great application potential in manipulation of terahertz wave and contributes to RCS reduction.