A Dual-Band Dual-Circularly Polarized Folded Transmitarray Using Dual Metasurfaces

A dual-band dual-circularly polarized double folded transmitarray antenna (FTA) is proposed consisting of a main-reflector (MR), a sub-reflector (SR) and a feeding source. The MR is a frequency-selective metasurfaces designed to achieve transmission and reflection simultaneously. In lower band, it converts y-polarized wave into left circularly polarized (LCP) beam while reflecting x-polarized wave. Similarly in higher band, x-polarized waves are converted into right circularly polarized (RCP) beam while y-polarized wave are reflected. The SR is a reflective metasurface designed to reflect linearly polarized (LP) wave and convert it into its orthogonal counterpart, simultaneously. Our proposed FTA reduces the profile by 3/4 compared to its conventional counterpart centred at 12.1 and 16.7 GHz, which is distinct from previous work. Numerical results show that the proposed antenna in two bands achieves a maximum gain of 23.1 dBic and 23.6 dBic, corresponding to an aperture efficiency of 30.8% and 20.8%. Our dual-band strategy promises promising application in satellite and radar communication systems.