Reconfigurable Design of a Polarization-Decoupled Dual-Circularly Polarized Reflectarray
Yulu Fan, Xian Qi Lin, Xinmi Yang, Yong Liu, Hao Liu, Y. Kang, Zhi Chen
Abstract
This communication proposes a reconfigurable reflectarray (RA) with decoupled right-/left-handed circularly polarized (RHCP/LHCP) 2-D beam steering. A simple-structured unit with mechanical reconfigurability is designed to achieve the 1 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 1-bit dual-circularly polarized (dual-CP) phase modulation, which enables the decoupled 2-D scanning of the dual-CP beams. A prototype of the designed reconfigurable dual-CP RA is tested under two working scenarios. For the RHCP beam at (45°, −30°) and the LHCP beam in (135°, from 0° to −50°), the RHCP/LHCP gain fluctuation is less than 0.9/2.9 dB. For the LHCP beam at (135°, −30°) and the RHCP beam in (45°, from 0° to −50°), the RHCP/LHCP gain fluctuation is less than 3.0/0.7 dB. For the RHCP and LHCP beams at (45°, −30°) and (135°, −30°), the axial ratio (AR) bandwidth is over 24% (AR < 2 dB), and the overlapped 1-dB gain and AR < 2-dB bandwidth is 7.5%. The prototype also exhibits ideal AR beamwidth of over 6° (AR < 2.5 dB) and maximum aperture efficiency (AE) of 20.9%. The proposed RA design simultaneously realizes independent polarization control and dual-CP 2-D beam steering for the first time, which is of great value in many fields.