Multi-mode orbital angular momentum antenna

The invention discloses a microstrip array antenna capable of generating a plurality of orbital angular momentum modes, and mainly solves the problem that the conventional orbital angular momentum antenna has few modes. The antenna comprises 12 unit patch antennas, a dielectric substrate, a metal floor, 12 feed binding posts and the like. According to the array, the 12 hexagonal patch units with the same structure are arranged at equal intervals along the same circumference, and three-dimensional electromagnetic field simulation software is utilized for optimization, so that the optimal structure of the antenna is determined. The result shows that the return loss of the antenna at the center frequency of 10.15 GHz reaches -14.81 dB. When excitation with equal amplitude and equal phase difference is fed to each antenna feed port, parameters such as an electric field radiation pattern and a directional diagram of the antenna show that the antenna can generate vortex electromagnetic waves carrying 11 effective d