Double Multiplicity Exploiting Orthogonal Polarizations of OAM Wave for OAM Communication with Loop Arrays

Eight-channel multiplexing Orbital Angular Momentum (OAM) communication at the 5-GHz band is demonstrated, exploiting dual OAM polarizations and four OAM modes. OAM polarizations are analytically shown to be exploited for multiplexing by controlling the port directions of loop antennas. With four kinds of fabricated 4-element loop arrays, transmissions between the transmitting and receiving arrays were measured at a distance of 3 cm, and the desired signal transmission between antennas of the same radius and the corresponding port direction is shown to be larger than that from other interfering antennas by more than 5 dB.