A Reconfigurable Beam-Scanning Reflectarray With Switchable Polarization Using Independently Controlled Dual-Linearly Polarized Units

This letter presents a pattern- and polarization-reconfigurable reflectarray antenna (RRA). Using 1-bit independently controlled dual-linearly polarized (DLP) units, the radiation beam of the RRA can be scanned with switchable polarization. The designed unit is composed of a crossed dipole, a metallic centered patch, four PIN diodes and biasing networks. By controlling the working states of the PIN diodes, the unit possesses independently 180 degrees reflection phase shift in either of the two linear polarizations (LPs). A novel polarization manipulation method is introduced, and the 1b DLP unit can be transformed into a 2b unit with agile polarization. Based on the DLP unit, the proposed RRA can realize polarization reconfigurable among +/- 45 degrees LPs, left-hand circular polarization and right-hand circular polarization by only changing the biasing voltages applied on the RRA. A prototype including 256 units is analyzed, fabricated, and measured. The 2-D beam-scanning ability is verified for dual-linear polarization and reconfigurable polarization. Good performance, including high gain and good polarization purity, can be observed. The proposed RRA features a wide beam scanning range and agile polarization, which makes it a good candidate for the wireless communication system.