Transmitted Electromagnetic Beam Steering of Pyramid All‐Dielectric Encoding Surface Microstructure

Abstract A transmission‐type all‐medium element is proposed to construct a coded metasurface. Due to the single‐layer metasurface unit structure, large reflection loss will be caused when the base plane is incident. In order to improve the efficiency of the coded metasurface device and reduce the reflection loss, the authors propose a double‐sided metasurface digital unit structure and introduces a wideband anti‐reflection pyramid microstructure to achieve significantly improved transmission characteristics. The optimized unit structure is coded and the coded metasurface is constructed. Different coding metasurface sequences are constructed based on 1‐bit, 2‐bit, and 3‐bit digital coding units. According to generalized Snell's law, the number of transmitted beams can be controlled. The authors introduce complex code addition theory to construct multifunctional beam control metasurface. Based on the far field scattering theory of metasurface, the addition theory of different sequences of transmission‐coded metasurface is analyzed. The addition operation of the superposition of two sets of symmetric double beams and two sets of ordinary double beams can be realized. Based on the analysis of far‐field scattering characteristics, the multifunctional coded metasurface is demonstrated, that is, multiple functions are simultaneously superimposed in one array without interference.