Mode-Tunable OAM Antenna System with Polarization Selectivity Characteristic

This paper presents a new Orbital Angular Momentum (OAM) antenna system with an innovative reconfigurable feeding network and dual-polarized antennas. The 2x4 feeding network generates phase gradients of 0°, 90°, and -90° at its outputs, enabling OAM modes 0, -1, and +1. By integrating a 2x2 uniform circular array with dual-polarized antennas and two copies of the proposed feeding network, the system supports six reconfigurable propagation types, ideal for smart OAM communications. Operating at 2.4 GHz, it achieves phase gradients with a maximum 4° imbalance, and input port reflection coefficients below -15 dB. All in all, the novel configuration of the feeding network, concept of combination of polarization and OAM modes, and ability to generate additional orthogonal reconfigurable beams can be highlighted as the novel parts of this paper.