Beam scanning of orbital angular momentum electromagnetic wave using annular phased array

Recently, orbital angular momentum (OAM) electromagnetic wave is of great interest owing to their unique properties and potential applications in areas such as communication, and radar technology. Particularly it may provide a new solution of the crisis of frequency domain allocation. However there are lots of unsolved problems, especially in the design of practical system. For example, the transmitter and receiver must be aligned accurately, otherwise information cannot be efficiently transferred. Based on the electronically controlled antenna array, in this paper we propose a feasible method that scanning the OAM electromagnetic wave beam using an annular phased array. We analyze an annular array of eight Vivaldi antennas which could realize two dimensional beam scanning of OAM electromagnetic wave. Numerical simulations have been carried out to verify the performance of the antenna array.