Antenna with Shaped Asymmetric Main Reflector and Subreflector with Asymmetric Waveguide Feed

• US 20080094298A1
• Filed: 10/23/2006
• Published: 04/24/2008
• Est. Priority Date: 10/23/2006
• Status: Abandoned Application

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Zimmerman, Kurt, Meehan, Robert, Gothard, Griffin, Howley, Robert, Kralovec, Jay
• Application Number:
  US11/551,743
• Publication Number:
  US 20080094298A1
• Time in Patent Office: Days
• US Class Current: 343/781.0CA
• CPC Class Codes: H01Q 19/19 comprising one main concave reflecting surface associated with an auxiliary reflecting surface

Abstract

A low-profile antenna system includes a main reflector (102) formed as a shaped main reflector surface that is approximately, but not precisely, parabolic. The main reflector (102) has a main reflector edge configuration (103) that is asymmetric. A feed system (104) for the main reflector includes a subreflector (106) formed as a shaped subreflector surface that is approximately, but not precisely, elliptical. The subreflector has a subreflector edge configuration (107) that is also asymmetric. An RF feed horn (108) associated with the feed system 104 has an aperture profile which also has an asymmetric shape.

Claims

1. A low-profile ring-focus reflector antenna system comprising:

a main reflector formed as a shaped main reflector surface, and having a main reflector edge configuration that is asymmetric;

a feed system for said main reflector comprising a subreflector formed as a shaped subreflector surface, and having a subreflector edge configuration that is asymmetric;

a horn antenna extending in a direction aligned with a boresight axis, said horn antenna having an aperture that has an asymmetric shape when viewed along a boresight axis of said main reflector;

wherein at least one of said shaped main reflector surface and said shaped subreflector surface is defined by a plurality of different curves extending in a plurality of different radial directions in a 360 degree arc about said boresight axis.

2. The low-profile ring-focus reflector antenna system according to claim 1, wherein horn antenna has an asymmetric waveguide feed.

3. The low-profile ring-focus reflector antenna system according to claim 1, wherein said shaped main reflector surface is defined by a plurality of different curves extending in a plurality of different radial directions about said 360 degree arc.

4. The low-profile ring-focus reflector antenna system according to claim 1, wherein said shaped main reflector surface is defined by said plurality of different curves, each respectively swept through a respective arc about said boresight axis.

5. The low-profile ring-focus reflector antenna system according to claim 4, wherein at least one of said plurality of different curves defining said shaped main reflector surface is exclusive of a parabolic curve.

6. The low-profile ring-focus reflector antenna system according to claim 1, wherein said shaped subreflector surface is defined by said plurality of different curves, each respectively swept through a respective arc about said boresight axis.

7. The low-profile ring-focus reflector antenna system according to claim 6, wherein at least one of said plurality of different curves defining said shaped subreflector surface is exclusive of an elliptical curve.

8. The low-profile ring-focus reflector antenna system according to claim 1, wherein said main reflector edge configuration is elliptical.

9. The low-profile ring-focus reflector antenna system according to claim 1, wherein said subreflector edge configuration is elliptical.

10. The low-profile ring-focus reflector antenna system according to claim 1, wherein said main reflector edge configuration is approximately elliptical.

11. The low-profile ring-focus reflector antenna system according to claim 1, wherein said subreflector edge configuration is approximately elliptical.

12. The low-profile ring-focus reflector antenna system according to claim 1, wherein said main reflector edge configuration defines a polygon.

13. The low-profile ring-focus reflector antenna system according to claim 1, wherein said subreflector edge configuration defines a polygon.

14. The low-profile ring-focus reflector antenna system according to claim 1, wherein said horn antenna is installed at a first location separated by a gap from a vertex of said subreflector on said boresight axis of said antenna.

15. The low-profile ring-focus reflector antenna system according to claim 14, wherein said gap is less than four wavelengths at an operational frequency at which said low-profile ring-focus antenna system is designed to operate.

16. The low-profile ring-focus reflector antenna system according to claim 14, wherein said feed system defines a focal ring for illuminating said main reflector at an operational frequency at which said low-profile antenna system is designed to operate, and said focal ring is asymmetric.

17. The low-profile ring-focus reflector antenna system according to claim 14, wherein said horn antenna is coupled to said shaped subreflector surface.

18. A low-profile ring-focus reflector antenna system comprising:

a main reflector formed as a shaped main reflector surface, and having a main reflector edge configuration that is asymmetric;

a feed system for said main reflector comprising a subreflector formed as a shaped subreflector surface, and having a subreflector edge configuration that is asymmetric;

a horn antenna extending in a direction aligned with a boresight axis, said horn antenna having an aperture that has an asymmetric shape when viewed along a boresight axis of said main reflector;

wherein said shaped main reflector surface is defined by a plurality of different curves extending in a plurality of different radial directions in a 360 degree arc about said boresight axis, each of said plurality of different curves swept through a respective arc about said boresight axis.

19. The low-profile ring-focus reflector antenna system according to claim 18, wherein said horn antenna has an asymmetric waveguide feed.

20. The low-profile ring-focus reflector antenna system according to claim 18, wherein at least one of said plurality of different curves defining said shaped main reflector surface is exclusive of a parabolic curve.

21. The low-profile ring-focus reflector antenna system according to claim 18, wherein said shaped subreflector surface is defined by a second plurality of different curves extending in a plurality of different radial directions in said 360 degree arc, each of said second plurality of different curves respectively swept through a respective arc about said boresight axis.

22. The low-profile ring-focus reflector antenna system according to claim 21, wherein at least one of said second plurality of different curves defining said shaped subreflector surface is exclusive of an elliptical curve.

23. A low-profile reflector antenna system comprising:

a main reflector formed as a shaped main reflector surface;

a feed system for said main reflector comprising a subreflector formed as a shaped subreflector surface;

a horn antenna extending in a direction aligned with a boresight axis, said horn antenna having an aperture that has an asymmetric shape when viewed along a boresight axis of said main reflector;

wherein at least one of said shaped main reflector surface and said shaped subreflector surface is defined by a plurality of different curves extending in a plurality of different radial directions in a 360 degree arc about said boresight axis, each of said plurality of different curves swept through a respective arc about said boresight axis.