Abstract
This paper proposes a novel method to enable mode and polarization OAM multiplexing at four different frequencies (30, 70, 90, and 110 GHz) through a reflectarray (RA) antenna. The suggested RA delivers almost matched electromagnetic (EM) responses for x- and y-polarized incident waves for both reflected OAM modes of l=2 . The designed antenna can considerably improve channel capacity and spectrum efficiency.