Horn antennas for generating radio waves bearing orbital angular momentum by using spiral phase plate

International audience; The design of two new horn antennas for the generation of radio waves bearing orbital angular momentum (OAM) is presented. The OAM mode = 1 or -1 is generated by combining the guided modes of a circular waveguide with a spiral phase plate. The authors present here two structures to generate OAM wave based on TE11 and TM01 modes. The resulting magnitude and phase patterns of the electrical field and the radiation patterns evidence the presence of waves carrying OAM.