Generation of OAM Radio Waves Using Patch Antenna

Abstract

This paper introduces a feasible patch antenna to generate OAM-carrying radio beams. Eight identical printed dipole antennas with microstrip balun feedline are arranged in an octahedron cylindrical substrate. Every printed dipole is fed with unit amplitude but with a successive phase difference from element to element. We can change the phase difference at the steps of 0, ±45o, ±90o, and ±135o to obtain mode numbers 0, ±1, ±2, and ±3. Simulation shows that the OAM states of ±1, ±2 and-3 achieve the expected results well, while the state of +3 produce a deviation due to the radiation difference of the designed antenna element and traditional tripole antenna. Furthermore, we achieve the impedance matching of every port and increase the directivity of the antenna. Thus, the proposed antenna is a promising candidate to generate OAM in engineering.