Coded Metasurfaces for Two Dimensional Steering and Splitting of Incident Radiation

This paper presents the design and analysis of 2- bit and 1-bit digitally coded reflective metasurfaces (DCRM) for two-dimensional (2D) beam-steering and beam-splitting applications. Using MATLAB, we first calculate the phase coding information for a metasurface of size $10\lambda_{0}\times 10\lambda_{0}$ (where $\lambda_{0}$ is the free space wavelength at 5.9 GHz) to get a desired direction of reflected beam for both 1D and 2D beam steering using MATLAB, considering normally incident plane wave. Subsequently, we develop the complete metasurface structure using a full-wave solver (CST MWS) and observe the corresponding far-field scattering patterns. It is observed that the 2-bit DCRM achieves zero steering error with a half power beam width (HPBW) of $5^{o}$. Furthermore, We demonstrate the beam-splitting functionality for generating multiple beams in desired directions using a 1-bit DCRM. Moreover, we report the aperture sizes for DCRMs that achieve highly focused beam-steering with HPBW of $2^{o}$ & $3^{o}$, a directivity of 35.4 dBi & 30. 5dBi, and the SLL of −10.77 dB & −12.71 dB, respectively.