Beam Steering of Orbital Angular Momentum Vortex Waves With Spherical Conformal Array

In this letter, a spherical conformal antenna is designed, fabricated, and experimentally demonstrated to realize the beam steering of orbital angular momentum (OAM) vortex waves with hemisphere coverage. The theoretical formula of phase shift is deduced to design the conformal array antenna producing vortex radio waves with arbitrary beam direction. A prototype of a geodesic dome-based spherical conformal phased-array antenna is presented to validate the theoretical analysis. The experimental results verify that the hemispherical beam steering of OAM vortex waves can be effectively and flexibly generated. The proposed method can provide a reference for OAM vortex communication with full space coverage.