A Dual-OAM-Mode-Based Array With Shared Feeding Network for In-Band Full-Duplex Systems

A dual-mode radial uniform circular array (UCA) is proposed for orbital angular momentum (OAM) generation and in-band full-duplex (IBFD) systems. The presented configuration is composed of an eight-element sequentially rotated patch antenna array and a partially shared feeding network (SFN). Each antenna element has a single feeding port and is fed by the corresponding output port of the SFN. A novel feeding network scheme is designed to achieve dual-OAM-mode excitation and self-interference cancellation between the transmit (Tx) and receive (Rx) ports. To validate the correctness of the proposed configuration, a prototype with 0 and −2 excitation modes is fabricated and measured. The measured results demonstrate that the proposed antenna operates from 5.68 to 6.1 GHz with an isolation of more than 40 dB over the whole band of interest.