Dual-UWB Dielectric Resonator Antenna for OAM Communication

designed a dielectric resonator antenna (DRA) that carries orbital angular momentum and has dual-band ultra-wideband characteristics based on the advantage of minor rain decay in L-band and C-band of microwave bands. The cavity of the antenna adopts an inner and outer nested spiral structure, and the material of resonant cavity shell is photosensitive resin. The internal medium is distilled water with a dielectric constant of 81, and the outer filling is saline with a concentration of 0.035 g/ml at room temperature for the dielectric constant. At the bottom of the cavity, we applied 2 feeds with phase difference of 90 degrees to produce a circularly polarized beam in the DRA. Adjusting the size of the DRA and the height of the helical step surface to excite the OAM waves in higher order modes. The designed DRA generates resonance in 0.82-1.63 GHz and 3.35-7.27 GHz, and achieves ultra-wideband in both operating bands; furthermore, the antenna can generate OAM waves in l = & PLUSMN;1 and l = & PLUSMN;3 modes when operating at 1.51 GHz and 5.28 GHz, respectively. The simulation results match the measured results. The results show that the vortex wave generated by our designed antenna also has advantages such as high mode purity. Therefore, it can be effective in near-field communication and also provides a new solution for OAM near-field communication in 6G which is of great importance, and also for satellite communication and downlink signal transmission of communication satellites.