Dual-Circularly-Polarized High-Gain Transmitarray Antennas at Ka-Band

This communication describes the performance of the dual-circularly polarized transmitarray antennas at the Ka -band with independent radiation characteristics. The proposed antenna architecture consists of a dual-linearly polarized (dual-LP) TA panel based on the interleaving technique combined with an add-on broadband polarizer to generate independent right-handed circular polarization (CP) (RHCP) and left-handed CP (LHCP) beams. This offers both dual-LP and dual-CP operation depending on the topology of the polarizer. The LP unit-cell is designed to achieve a 3 bit phase resolution, and the dual-LP TA panel is made of two interleaved single-LP subarrays with $52\times52$ and $53\times53$ elements operating in 45° and 135° single LP, respectively. The polarizer transforms the dual-LP into dual-CP while keeping the radiation independence of each polarization across the Ka -band. The experimental results obtained with three different prototypes pointing up to 50° validate the proposed concepts.