System and method for hybrid geometry feed horn

A method comprising:

• communicating through a feed horn in a plurality of separate frequency bands and a plurality of separate propagation modes, wherein the plurality of separate frequency bands comprise at least a higher frequency band and a lower frequency band;
• wherein the feed horn comprises:
• a mode conversion section having a first end and a second end;
• and
• an axial corrugation section, the axial corrugation section comprising corrugations in an axial direction, the second end of the mode conversion section connected to the axial corrugation section at a location opposite a feed horn aperture of the axial corrugation section;
• propagating first signals in the higher frequency band and second signals in the lower frequency band between the first end and the second end, and at least partially converting the first signals in the higher frequency band between a first propagation mode at the first end and a second propagation mode at the second end;
• and
• propagating the first signals in the higher frequency band and the second signals in the lower frequency band between the second end of the mode conversion section and the feed horn aperture, and at least partially converting the second signals in the lower frequency band between the first propagation mode at the second end of the mode conversion section and a third propagation mode at the feed horn aperture.

A system comprising:

• a feed horn to operate in a plurality of separate frequency bands and a plurality of separate propagation modes, wherein the plurality of separate frequency bands comprises at least a first frequency band and a second frequency band, wherein the first frequency band corresponds to a higher frequency range than the second frequency band;
• the feed horn comprising:
• a mode conversion section comprising:
• a first end and a second end opposite the first end, wherein the first end is configured to pass first signals in the first frequency band and second signals in the second frequency band;
• a plurality of sections, between the first end and the second end, each comprising a section having a length and a draft;
• and
• an axial corrugation section, coupled to the mode conversion section and located between a feed horn aperture and the second end of the mode conversion section, the axial corrugation section comprising:
• a plurality of protrusions aligned parallel to a central axis of the feed horn, wherein the plurality of protrusions further comprise a plurality of protrusion surfaces each at a predetermined depth from a reference plane, wherein the protrusion surfaces are separated by a plurality of grooves;
• wherein the thickness of each groove is predetermined and the depth of each groove is predetermined;
• and
• wherein the mode conversion section predominantly propagates two modes of the first signals in the first frequency band, and wherein the axial corrugation section predominantly propagates a hybrid mode of the second signals in the second frequency band.

A feed horn to operate in a plurality of separate frequency bands and a plurality of separate propagation modes, wherein the plurality of separate frequency bands comprises at least a first frequency band and a second frequency band, wherein the first frequency band corresponds to a higher frequency range than the second frequency band, the feed horn comprising:

• a mode conversion section of the feed horn comprising a first end and a second end opposite the first end;
• and
• an axial corrugation section, the axial corrugation section coupled to the mode conversion section and located between a feed horn aperture and the second end of the mode conversion section, the axial corrugation section further comprising a plurality of protrusions aligned parallel to a central axis of the feed horn;
• wherein the feed horn has an axial length of less than four wavelengths at 18 GHz and wherein the first frequency band and the second frequency band each have greater than or equal to 1900 MHz bandwidth;
• and
• wherein mode conversion is dominated by the mode conversion section over the first frequency band and dominated by the axial corrugation section over the second frequency band.