Directivity and Axial Ratio Distribution of Orbital Angular Momentum Vortex Waves based on Circular Planar Yagi Antenna Array and Sequential Phase Shift

This paper presents the far-field characteristics of vortex wave of orbital angular momentum (OAM) with circular array antenna. Planar quasi yagi-uda antenna of 8 elements are arranged in circular array and folded into a hollow cylinder. The OAM radio beam can be generated by changing the sequential phase shift of antenna element inputs for each OAM mode number. A full-wave electromagnetic simulator is used to design circular array antenna and to observe distribution of directivity and axial ratio. The depicted results provide insight for the vortex wave radiation.