Beam-Scanning Orbital Angular Momentum Circular Leaky-Wave Antenna With a Half-Mode Corrugated Substrate Integrated Waveguide

This letter presents a novel circular leaky-wave antenna (CLWA) on a half-mode inter-digitated capacitor based corrugated substrate integrated waveguide (HM-IDC-CSIW) to produce a beam-scanning orbital angular momentum (OAM) wave. Longitudinal radiating slots in a conventional LWA have been translated into an arc-shaped slot for this CLWA. An array of arc-shaped slots is then used to produce OAM mode 1 from 17 to 21 GHz, while producing a beam-scanning of ± 30° in the azimuth plane. The measured results of the antenna confirm a gain of 12–14.2 dBi throughout the frequency band while maintaining an efficiency >70% and a high OAM mode purity. Such OAM-based antennas with frequency-controlled beam-scanning can be used for secure communications and to create imaging systems that can sense in different directions simultaneously.