A Closed-Loop Cross-Dipole Antenna Array for Wideband OAM Communication

In this letter, a closed-loop cross-dipole antenna array (CLCDAA) is proposed for wideband orbital angular momentum (OAM) communication. The proposed antenna array is designed based on a closed-loop cross dipoles patch, several pillow-like parasitic patches, and a hybrid wideband feeding network. The design method of the feeding network is introduced using the analysis of the multiport network, and the good performance of this feeding network is verified. A prototype CLCDAA is fabricated and measured to validate the design concept. The OAM beams can cover a wide frequency band from 2.08 to 3.95 GHz (62.02%), and the simulation and measurement results are in good agreement. Benefiting from a compact structure, simple design procedure, and steady performance, the proposed antenna array has a significant meaning in the application of wireless communications.