Antenna configuration for low and medium earth orbit satellites
AssigneeHughes Electronics Corporation
InventorsSudhakar K. Rao, Philip H. Law
Life of this patent
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Abstract
An antenna configuration suitable for LEO/MEO satellites includes a plurality of lenses whereby each lens has a plurality of feed horns positioned with respect to the lens. The lens has a first surface and a second surface. The plurality of feed horns is disposed upon a curved surface. Each of the plurality of feed horns generates a beam that has a phase distribution. The phase distributions have a predetermined phase relationship with the first surface and preferably the second surface. This allows the lens to transmit and receive a signal with desired phase distribution across a cross-section of the beam. The beams from the plurality of lenses are inter-leaved on the ground to form a contiguous coverage with multiple overlapping spot-beams.
Claims4
An antenna configuration comprising:
- a lens having an first surface and a second surface;
- and
- a plurality of feed horns, said plurality of feed horns disposed upon a curved surface, each of said plurality of feed horns generating a beam having an amplitude and phase distribution, said distribution having a predetermined phase relationship with said lens surface, said plurality of feed horns have a center feed horn having a first diameter and an edge feed horn having a second diameter, said center feed horn has a first diameter greater than said second diameter.
An antenna configuration comprising:
- a lens having an first surface and a second surface;
- and
- a plurality of feed horns, said plurality of feed horns disposed upon a curved surface, each of said plurality of feed horns generating a beam having an amplitude and phase distribution, said distribution having a predetermined phase relationship with said lens surface, wherein a distance between a center of said second surface and a feed array is defined by:
- (F−FD)(1+cos θ)/2
- wherein F is a focal length of said second surface,
- FD is a defocusing distance,
- θ is the angular distance between a central focal line and a beam.
An antenna configuration comprising:
- a lens having an first surface and a second surface;
- and
- a plurality of feed horns, said plurality of feed horns disposed upon a curved surface, each of said plurality of feed horns generating a beam having an amplitude and phase distribution, said distribution having a predetermined phase relationship with said lens surface,
- wherein the edge beam feeds are located on a surface defined by:
- ρe=F cosn θ
- wherein the exponent n controls the beam ellipticity values;
- F is a focal length of said second surface;
- and
- θ is the angular distance between a central focal line and a beam.
Dependencies are inferred from the claim text.