Quad-polarization multi-beam folded transmitarray in Ku-band

We propose a quad-polarization multi-beam folded transmitarray (QPMBFTA) by integrating dual-linearly polarized transmission metasurface (DLPTM) and polarization conversion metasurface (PCM) in Ku-band. The DLPTM is a multi-layer structure alternately stacked by square metal patches and annular metal slots, which has the ability to realize transmission and conversion of different polarized waves. The PCM is employed to provide proper phase distributions for reducing the profile height of the QPMBFTA. By integrating PCM and DLPTM, the QPMBFTA is capable of realizing quad-polarization multi-beam radiation with uniform energy distribution by independently manipulating the phase distribution of DLPTM in the x-direction and y-direction based on phase weighting method and aperture field superposition method. Finally, the QPMBFTA is fabricated and measured experimentally, and the tested results show the peak gains of XP, YP, LHCP and RHCP are 17.5dBi at 13.8GHz, 16.9 dBi at 13.9 GHz, 17.5 dBic at 13.9GHz, and 17.0 dBic at 14.0GHz, and the 3dB axial ratio bandwidths are 12.9-14.5 GHz for LHCP and 13.0-14.3 GHz for RHCP. Our proposed design that possesses quad-polarization multi-beams radiation performance should pave the way for multichannel wireless communication system to improve the channel capacity.