Determination of the orbital angular momentum state of a radio wave beam based on quantitative characteristics of a radio communication system

Nowadays, due to the lack of available radio frequency spectrum, there is a need for the development of technologies that would make it possible to use this spectrum more efficiently. One such technology involves the use of radio waves with orbital angular momentum (OAM). This paper proposes a new quantitative method for determining the number of single states of a beam carrying OAM based on an analysis of the S21 system parameters. This allows the receiver to be tuned to receive beams with a specific OAM state. The radio waves carrying OAM have a frequency of 80 GHz. In this work, a pyramidal horn was used as a transmitting antenna, with a spiral phase plate used to twist the emitted radio wave. An array of receiving antennas was in the form of dipoles. Limitations of this method were investigated. This work is a computer experiment.