Series-fed dual-mode OAM antenna at 6 GHz

Official URL: https://dx.doi.org/10.1109/AP-S/INC-USNC-URSI52054.2024.10687150

In this paper, a uniform circular array with four patches operating at 6 GHz has been designed for dual-mode orbital angular momentum (OAM) generation. The antenna elements are series-fed for a concise and simpler antenna design. The challenges in series-fed design have been overcome with a novel network that ensures equal power distribution and the required phase shift between consecutive elements. The designed antenna is capable of generating vortex beams with l=±1 mode numbers when fed from one of its two ports. The realized gain of the antenna is 4.39 dBi for l=+1 and 5.24 dBi for l=-1 mode, while the simulated bandwidth of the antenna is 400 MHz. The OAM mode purities are calculated over an observation circle with varying radius and distance and are presented in this study. The antenna is designed on Rogers 4350B, with final dimensions of 99 × 109 x 0.813 mm3