Systems and methods for generating and steering orbital angular momentum electromagnetic beams

A method of generating and steering an orbital angular momentum (OAM) electromagnetic beam, comprising:

• generating a plurality of beamforming signals by modulating a plurality of input signals in accordance with beamforming phase shifts related to a mode content of the OAM electromagnetic beam;
• generating a plurality of beamsteering signals by modulating the plurality of beamforming signals in accordance with beamsteering phase shifts related to steering conditions for the OAM electromagnetic beam;
• and
• emitting the OAM electromagnetic beam according to the steering conditions by feeding the plurality of beamsteering signals to an antenna structure comprising a first radial waveguide, the first radial waveguide comprising a first base plate and a first slot plate defining a first waveguide cavity therebetween, the first slot plate having a plurality of first radiating slots formed therethrough, the first radial waveguide being partitioned into a plurality of first waveguide sectors by a plurality of azimuthally spaced first partition walls, wherein each first partition wall of the plurality of azimuthally spaced first partition walls extends radially over less than a radial extent of the first waveguide cavity, wherein emitting the OAM electromagnetic beam comprises introducing a corresponding one of the plurality of beamsteering signals into each first waveguide sector to cause the corresponding beamsteering signal to radiate through a number of radiating slots of the plurality of first radiating slots corresponding to the first waveguide sector.

A system for generating and steering an orbital angular momentum (OAM) electromagnetic beam, comprising:

• a beamforming device configured to receive a plurality of input signals and output a plurality of beamforming signals by modulating the plurality of input signals in accordance with beamforming phase shifts related to a mode content of the OAM electromagnetic beam;
• a beamsteering device configured to receive the plurality of beamforming signals and output a plurality of beamsteering signals by modulating the plurality of beamforming signals in accordance with beamsteering phase shifts related to steering conditions for the OAM electromagnetic beam;
• and
• an antenna structure comprising:
• a first radial waveguide comprising a first base plate and a first slot plate defining a first waveguide cavity therebetween, the first slot plate having a plurality of first radiating slots formed therethrough, the first radial waveguide being partitioned into a plurality of first waveguide sectors by a plurality of azimuthally spaced, radially extending first partition walls, each first waveguide sector comprising a first feed probe connected to the beamsteering device and configured to introduce a corresponding one of a first subset of the plurality of beamsteering signals into the first waveguide sector and cause the corresponding beamsteering signal to radiate through a number of radiating slots of the first radiating slots corresponding to the first waveguide sector, thereby generating a first beam component of the OAM electromagnetic beam;
• and
• a second radial waveguide azimuthally enclosing the first radial waveguide, the second radial waveguide comprising a second base plate and a second slot plate defining a second waveguide cavity therebetween, the second slot plate having a plurality of second radiating slots formed therethrough, the second radial waveguide being partitioned into a plurality of second waveguide sectors by a plurality of azimuthally spaced, radially extending second partition walls, each second waveguide sector comprising a second feed probe connected to the beamsteering device and configured to introduce a corresponding one of a second subset of the plurality of beamsteering signals into the second waveguide sector and cause the corresponding beamsteering signal to radiate through a number of radiating slots of the second radiating slots corresponding to the second waveguide sector, thereby generating a second beam component of the OAM electromagnetic beam,
• wherein the first slot plate defines a first radiating surface, the second slot plate defines a second radiating surface, and the first radiating surface and the second radiating surface are substantially coplanar with each other.