A Low-Profile Dual-Band Dual-Circularly Polarized Folded Transmitarray Antenna With Independent Beam Control

This communication presents a low-profile, compact, high gain dual-band and dual-circularly polarized (CP) folded transmitarray antenna (FTA) with independent beam control at Ku-band. The element with independent phase control capability in two bands is designed to achieve the functionality of linear polarization to different circular polarization conversion. To reduce the profile of the whole FTA, a dual-band and dual-linearly polarized patch antenna is adopted as the feed source. By controlling the phase distribution and circular polarization of the transmitarray (TA) according to the phase compensation principle, the proposed antenna can radiate left-hand CP (LCP) waves and right-hand CP (RCP) waves at 12 and 15 GHz, respectively. On the basis, three typical FTA prototypes with different beam directions are simulated to validate the capability of independent beam control. Two of the prototypes are fabricated and measured, and the results are shown in reasonable agreement with the simulation. The proposed antenna not only reduces the profile by 2/3 compared to the traditional TA antenna, but also has the advantages of compact planar structure, low cost, high gain, and easy integration, which presents great application potential in two-way satellite communication systems with limited volume and space.