Dielectric Metasurface for Generating Broadband Millimeter Wave Orbital Angular Momentum Beams

Abstract: Electromagnetic waves carrying orbital angular momentum (OAM) have found many applications. This work reports a broadband millimeter wave OAM generator applying a dielectric metasurface with high-refractive-index dielectric elements distributed on a low-refractive-index substrate. Proper adjustment of the dimensions of the dielectric elements can make a broadband OAM generator from 53 to 70 GHz. OAM generators with different mode numbers are designed and validated by simulation. Such structures can find potential applications in high-capacity communications and imaging.