Design of Single Layer Quad-Beam CP Reflectarray Metasurface Using Compact Unit Cell

Single-feed microstrip reflectarray (MSRA) that can generate pencil-shaped quad beams when illuminated by a CP horn antenna is presented for 12 – 22 GHz band. The generation of focused quad-beams is based on the combination of the parabolic focusing phase with a coding sequence 10101010. Here the coding state “1” and “0” represents the 180° and 0° phases, respectively. The proposed MSRA composed by 32×32 Pancharatnam-Berry (PB) meta-atoms periodically distributes in the xy-plane. The meta-atom periodicity was optimized to be 5 mm and proposed RA has square dimensions of 170 × 170 × 2 mm³, and illuminated by a CP horn antenna. The proposed MSRA contains 1024 elements which are etched on a single-layer dielectric substrate. The proposed RA contains A phase correction was introduced at each PB unit cell by rotating the metallic resonator on the upper side of the unit cell according to PB phase theory. The quad-beams generation of the proposed MSRA was studied and investigated by means of full-wave simulations. It has been shown that, the proposed MSRA can successfully generate pencil-shaped quad-beams with acceptable gain and side-lobe level. Currently, a prototype of the proposed MSRA is being fabricated and will be measured in an anechoic chamber and the measured results will be presented during the conference session.