Design of High-Gain Vortex Electromagnetic Wave Based on Radial Line Slot Antenna

The method based on spiral array radial line slot antennas (SA-RLSA) is proposed to generate four modes of orbital angular momentum(OAM) in this paper. The phase of the radiation field is adjusted by changing the length of each loop gap, and eight coaxial probes at the parallel plate waveguide (PPW) are excited with a constant amplitude and progressive difference to generate four radial modes. SA-RLSA can realize four modes of OAM ranging from 30 to 32GHz. SA-RLSA can not only maintains low-profile and compact construction but also achieves the simulated maximum gain of 24 dBic. It uses the concentric slot arrangement to generate OAM and has the potential to be used in future 6G OAM multiplexing.