Orthogonal Linear Polarization Dependent Bifunctional Meta-Mirror / Meta-Lens Antenna for Millimeter-Wave Applications

A high-gain wideband bifunctional metasurface (BMS) antenna operating in reflection and transmission-mode based on orthogonal components of linearly polarized electromagnetic (EM) wave is proposed for next-generation 5G enabled devices. A multi-layer meta-atom is designed which simultaneously exhibits reflection and transmission characteristics for x -ampersand y-polarized incident EM waves. An array of $25\times 25$ meta-atoms is designed having an aperture volume of $7.7\lambda_{0}\times 7.7\lambda_{0}\times 0.1\lambda_{0}$ where $\lambda_{0}$ is the wavelength at operating frequency i.e. 28GHz. Polarization of the wave is varied by changing the orientation of the Antipodal Vivaldi Antenna (AVA) placed at focus of the BMS to spatially excite it. The proposed BMS enhances the gain of feed source by 15.5 dB and 14.4 dB in backward and forward direction. The maximum measured gain of 21.2 dBi and 19.9 dBi and aperture efficiency of 76% and 71.4% is achieved when BMS functions as meta-mirror and metalens respectively.