An Antenna Array Design for Generating OAM Waves

In this paper, a wideband circularly polarized antenna array for generating OAM (orbital angular momentum) radio waves is proposed. The wideband circularly polarized microstrip slot antenna fed by coplanar waveguide is applied as the array element, which is equidistant along the circumference and designed with phase delay. The OAM radio waves are generated by the antenna array operating in X-band (8 GHz - 12 GHz). By constructing a testing system for experimental verification, the antenna array can generate first-order OAM waves. The antenna array is easy to integrate and the feed network is simple, which demonstrates that the design provides a way to obtain OAM waves.