Multifunctional Orbital Angular Momentum Generator With High-Gain Low-Profile Broadband and Programmable Characteristics

Abstract

Transmissive and reflective metasurfaces have been extensively studied for generating an orbital angular momentum (OAM)-carrying beam. However, the existing OAM generators suffer from feed blockage, large profile, OAM mode nonreconfigurable, and narrowband. An OAM generator that integrates multiple functions into a single module is in high demand in OAM-based applications. In this study, we proposed an OAM generator based on a folded reflectarray with high-gain low-profile broadband and programmable characteristics. The proposed multifunctional OAM generator, comprising half the volume of the normal OAM metasurfaces, can generate a high-gain <inline-formula> <tex-math notation="LaTeX">$l=0$ </tex-math></inline-formula>, <inline-formula> <tex-math notation="LaTeX">$l=+1$ </tex-math></inline-formula>, and <inline-formula> <tex-math notation="LaTeX">$l=+2$ </tex-math></inline-formula> OAM-mode-reconfigurable beams with high mode purity over the frequency range of 9.5&#x2013;10.5 GHz. The proposed OAM generator-integrated multiple functions have potential applications in OAM-based wireless communications and radar detection.