Realization of various OAM divergence angles based on fabry-perot antenna design

In this paper, Fabry-Perot (FP) OAM antenna, consisting of a metal reflect surface, an OAM element and a partially reflecting surface(PRS), is applied to realize the variation of OAM wave's divergence angles by changing FP's height. And then, the principle of changing OAM wave's divergence angle is described and validated by the simulation. This method of changing divergence angle may provide more options to utilize OAM wave in communication system.