A Dual-band Shared-Aperture Circular Phased Array for Generating OAM Beams

This paper presents a novel dual-band shared-aperture circular phased array for producing orbital angular momentum (OAM)beams at both C- and X-bands with the center frequency of 5.8 and 10 GHz, respectively. Two circular phased arrays are combined in the common aperture, where the X-band array is mounted in the centre of the antenna substrate and the C-band array is mounted around X-band elements. To verify the design concept, one prototype is fabricated and measured. The measured results agree well with the simulated results, showing that +1 mode OAM beams are obtained with the gain around 12 dBi at C- and X- bands. The divergence angle of the radiation patterns at 5.8 GHz and 10 GHz is 15° and 16°, respectively.