A Wideband 3-D Printed Reflectarray Antenna With Mechanically Reconfigurable Polarization

This letter describes a wideband and polarization-reconfigurable reflectarray (RA) antenna using 3-D printing technology for 5G millimeter-wave applications. An air-perforated dielectric stub is proposed as a unit cell (UC) to provide simultaneous polarization-rotation and phase-shifting capabilities. By optimizing the dimensions of the UC, four UCs are found to offer a 90° out-of-phase for transverse electric and transverse magnetic incidence waves and a 2 bit reflection phase of {-π, -π/2, 0, π/2}, which are employed to implement the reflective panel. By rotating the reflective panel mechanically, the proposed RA antenna can achieve linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP) modes. The measured results are highly consistent with the simulated counterparts, indicating that the proposed RA antenna can reach a 3 dB axial ratio bandwidth of 43.2% and 37.5% for RHCP and LHCP modes, respectively. Besides, a 3 dB gain bandwidth of 37.5%, 34.4%, and 37.5% is experimentally obtained for RHCP, LHCP, and LP modes of the proposed RA antenna, respectively.