Electromagnetic multi-beam steering of matrix pattern-encoded metasurfaces

An electromagnetically encoded metasurface is a synthetic surface based on subwavelength unit particles, which can freely control the amplitude, phase and polarization direction of electromagnetic waves. Using digital states to characterize electromagnetic parameters directly links digital technology at the information level with metasurface technology at the physical level. This paper proposes a matrix encoding mode to realize the flexible control of the number of scattering beams and the scattering angle of the encoding metasurface. In order to reduce the ohmic loss of the metal structure metasurface, we propose to use the all-dielectric material cylindrical structure to construct the coding unit. In view of the encoding of metasurface sequences in one-dimensional direction, the scattering angle of THz beam can only be controlled in a single direction, but not the scattering azimuth in three-dimensional (3D) space. We use different matrix encoding modes to achieve multi-beam and multi-angle control of terahertz beams in 3D space. Based on the cross-coding mode, the multi-beam separation of the beam scattering main lobe is obtained, and the azimuth angle of each separated main lobe beam is flexibly controlled.