A Scalable Densely Packed Configuration for Continuous OAM Beam Steering With Uniform Circular Self-Filtering Antenna Array

This paper presents an advanced densely packed configuration of a Uniform Circular Self-Filtering Antenna (UCSFA) array, featuring an innovative two-layer architecture that seamlessly integrates Reflection-Type Phase Shifters (RTPS), an edge-fed eight-way radial power divider, and self-filtering antennas. The RTPS are designed to provide continuous 360-degree phase shifts with minimal insertion loss variation across different phase states. These phase shifters can be independently tuned using voltage controllers, enabling precise generation and direction of the Orbital Angular Momentum (OAM) beam. Moreover, we proposed a self-filtering antenna that operates without the need for supplementary circuitry, showcasing a band-pass filter response across its operational frequency range by adjusting the dominant mode’s electric field distribution. This antenna offers a broader bandwidth and achieves a significant 15 dB reduction in cross-polarization compared to conventional rectangular patch antennas (RPAs). The filtering capabilities effectively mitigate unwanted harmonics, noise figure (NF), and losses within wireless communication systems. Finally, a prototype of the proposed configuration has been fabricated, demonstrating commendable alignment between simulation results and experimental measurements, thereby enhancing the efficiency of the OAM-based wireless communication link.