Multibeam dual-circularly polarized reflectarray for connected and autonomous vehicles

This paper presents a multibeam dual-circularly polarized (CP) reflectarray for the connected and autonomous vehicles. The developed reflectarray uses one aperture to realize dual-band and multibeam operation. At each frequency band, there are two simultaneously shaped beams with different circular polarizations. Totally four beams are obtained with a single feed and each of the beams can be independently controlled. A simple but effective polarization suppression technique is introduced to suppress the cross polarizations at large scan angles so the CP beam of the reflectarray can be configured to point at large scan angles. Thus, the present reflectarray is suitable to be applied to the vehicles for reliable high data-rate satellite communications. To validate the design concept, an X-band prototype was designed, fabricated and measured. The design concept is flexible and can be applied to the design of dual-band, dual-CP reflectarray with different frequencies ratios. Moreover, the presented design can also be extended to a continuous beam-steering design by incorporating the phase shifters.