Multi-Point OAM Communication by Beam-steering Using Loop Antenna Array Displaced from Focus of Paraboloid

The beam-steering technique for an orbital angular momentum (OAM) wave is proposed and demonstrated for multi-point OAM communication with loop antenna arrays and paraboloids. The steering angle of the radiated OAM wave using the loop antenna is analytically and numerically estimated, where beam steering is realized by displacing the array center from the focus of the paraboloid. After analytically estimating the effect of beem steering on performance, the OAM communication characteristics with beam steering are measured, based on the proper configuration determined by that analysis. The measured ratio for the signal and interference is better than 15.1 dB at 23.9GHz for a beam-steering angle of 6.5 degrees.