A Novel Circularly Polarized Radial-Line Slot Array Antenna with Beam-Steering Solution

A novel all-metal circularly polarized radial-line slot array antenna (CP-RLSA) is presented in this paper. The RLSA is based on new CP unit radiators and is designed to be a standing wave antenna. A high circular polarization quality was achieved by utilizing these new CP unit radiators. A 14.25 GHz antenna prototype was simulated, fabricated and tested. Experimental results report a peak gain of 32.4 dBi. The antenna has excellent cross-polar rejection, with a measured cross-polar level of −30 dB in the main lobe direction. A beam-steering solution using the proposed RLSA is also presented in this paper, which is implemented through a pair of Pancharatnam–Berry metasurfaces (PBMs). These two PBMs are placed above the RLSA in the near-field region. For demonstration, four different steering cases are presented as examples. The measured results agree well with the simulated counterparts. The measured results of the antenna system demonstrate that the system can steer the beam to a maximum elevation angle of 45.8° with a maximum gain of 38.01dBi, corresponding to an aperture efficiency of 78.8%.