Steerable Collimated Vortex Wave Beam Generation by a Planar Radiating Aperture as a Phased Array Excited by Multi-Parameter Virtual Antenna Systems

A multi-parameter virtual antenna (VA) creates collimated electromagnetic vortex wave beams with orbital angular momentum (OAM). The VA comprises a collimating paraboloidal reflector fed by a point source feed. The near field (NF) of VA illuminates a tilted real reference aperture., called a radiating aperture (RAP) or an active phased array (P A). The square planar RAP is divided into square sub-apertures (SAP)., replaced by linearly polarized rectangular micro-strip patch antennas excited by the NF of VAs. This method is used for RAPs with 60–68 wavelength sides and steering (tilt) angles of 0 to 60 degrees. The OAM mode number., topological charge., ranges from 1 to 25. The chosen dimensions of the SAP., 0.81-0.9 wavelengths., cause grating lobes., which are suppressed by intra- SAP sub-arrays. The numerical simulations provided verify the effectiveness of this method.