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

This work 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° reflection phase shift in either of the two linear polarizations (LPs). A novel polarization manipulation method is introduced, and the 1-bit DLP unit can be transformed into a 2-bit unit with agile polarization. Based on the DLP unit, the proposed RRA can realize polarization reconfigurable among ±45° LPs, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) 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.