All-Dielectric Transformed Material for Microwave Broadband Orbital Angular Momentum Vortex Beam

Abstract

Vortex beams of light carrying orbital angular momentum (OAM) show promise for a wide range of microwave applications. However, classical OAM wave generators in the rf band are generally hindered by narrow operating bandwidth, complicated feed structures, or high loss. This study presents a method for OAM wave generation using the concept of spatial transformation at microwave frequencies. The all-dielectric device implementation enables broadband operation, and the technique efficiently generates vortex waves carrying OAM modes, thus illustrating the practicality of employing spatial transformations to realize innovative microwave devices.