One-bit Coded Near-field Corrected Metasurface for Beam Steering Applications

In this paper, one-bit coded near-field corrected metasurface antennas for beam-steering applications are critically examined, with studies on various feeder antenna locations. Initially, the reflection phase profile necessary for 1-bit coded metasurface is analytically generated using MATLAB, which provides scattered beam in the desired direction of $\mathbf{2 0}$ degrees, for far-field illumination. Then, near-field correction factor considering feeder antenna position at a quarter wavelength height at 10 GHz is analytically computed using MATLAB. Subsequently, the one-bit coded metasurface is synthesized in Ansys EM solver using MATLAB HFSS API, considering patch-type unit cells. Furthermore, effect of half wavelength dipole antenna as feeder for this fixed metasurface is explored, considering different heights quarter wavelength, half-wavelength and one-wavelength. It is observed that the 1-bit coded near-field corrected metasurface when excited with dipole-fed antenna placed at a height of quarter-wavelength, generates a beam in the direction of 16 degrees with directivity of 9.55 dBi and a half-power beamwidth (HPBW) of 37 degrees. In the other two cases, the incident field splits into multiple directions. Such coded metasurface based antennas useful for beam steering in future 6 G wireless communication and Radar applications.