Feed spoiler for microwave antenna

• US 5,905,474 A
• Filed: 05/22/1997
• Issued: 05/18/1999
• Est. Priority Date: 06/28/1996
• Status: Expired due to Fees

• Current Assignee: Tripoint Global Microwave Inc.
• Original Assignee: Gabriel Electronics, Inc. (General Dynamics Corporation)
• Inventors: Ngai, Eugene, Whiting, Robert
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): NGUYEN, HOANG V
• Application Number:
  US08/861,486
• Time in Patent Office: 726 Days
• Field of Search: 343/840, 343/772, 343/779, 343/786, 343/765, 343/777, 333/248, 333/237
• US Class Current: 343/840
• CPC Class Codes: H01Q 19/023 for reducing the scattering of mounting structures, e.g. of the struts
• CPC Class Codes: H01Q 19/028 for reducing the cross polarisation
• CPC Class Codes: H01Q 19/13 the primary radiating source being a single radiating element, e.g. a dipole, a slot, a waveguide termination H01Q19/15 takes precedence

Abstract

A microwave antenna feed spoiler for reducing side lobes of a microwave antenna with a feed support. The microwave antenna feed spoiler provides one or more segments of electrically conducting surface forming a roof which is coupled to and hides beneath it at least a portion up to the whole length of the feed support.

Claims

1. A feed spoiler for reducing side lobes of a microwave antenna having a concave reflector, a beam axis, and a feed support projecting out from the concave reflector to support a feed horn, the feed spoiler comprising at least one segment of electrically conductive surface forming a roof structure having a first and second face, each face having a first edge and a second edge, the first edges of the first and second faces being separated by at least the width of the feed support, and the second edges of the first and second faces being joined to form at least one ridge in such a manner as to substantially cover at least one segment of the feed support.

2. A feed spoiler according to claim 1, wherein the at least one ridge parallels at least one segment of the feed support.

3. A feed spoiler according to claim 1, wherein the first edges of the first and second face are electrically coupled to the feed support.

4. A feed spoiler according to claim 1, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to hide a portion of said feed support facing the feed horn.

5. A feed spoiler according to claim 1, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to hide a portion of said feed support perpendicular to said beam axis and facing said concave reflector.

6. A feed spoiler according to claim 1, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to hide a portion of said feed support perpendicular to said beam axis and facing away from said concave reflector.

7. A microwave antenna comprising:

a. a concave reflector having a beam axis;

b. a feed support projecting out from the concave reflector;

c. a feed horn supported by an end of the feed support distal to the concave reflector; and

d. at least one segment of electrically conductive surface forming a roof structure having a first and second face, each face having a first edge and a second edge, the first edges of the first and second faces being separated by at least the width of the feed support, and the second edges of the first and second faces being joined to form at least one ridge in such a manner as to hide at least one segment of the feed support.

8. A microwave antenna according to claim 7, wherein the at least one ridge parallels a segment of the feed support.

9. A microwave antenna according to claim 7, wherein the first edges of the first and second face are electrically coupled to the feed support.

10. A microwave antenna according to claim 7, further comprising a segment of electrically conductive surface forming a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially cover a portion of said feed support facing said feed horn.

11. A microwave antenna according to claim 7, further comprising a segment of electrically conductive surface forming a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially cover a portion of said feed support perpendicular to said beam axis and facing said concave reflector.

12. A microwave antenna according to claim 7, further comprising a segment of electrically conductive surface forming a roof having two faces each having an edge coupled to a portion of said feed support such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially cover a portion of said feed support perpendicular to said beam axis and facing away from said concave reflector.

13. A feed spoiler for reducing side lobes of a microwave antenna for transmitting and receiving electromagnetic radiation having a characteristic wavelength, the microwave antenna having a concave reflector, a beam axis, and a waveguide feed having a rectangular cross-section with height and width cross-sectional dimensions, comprising at least one segment of electrically conductive surface forming a roof structure having a first and second face, each face having a first edge and a second edge, the first edges of the first and second faces being separated by at least the width of the waveguide feed, and the second edges of the first and second faces being joined to form at least one ridge in such a manner as to substantially electromagnetically hide at least one segment of the waveguide feed.

14. A feed spoiler according to claim 13, wherein each ridge parallels a segment of the waveguide feed.

15. A feed spoiler according to claim 13, wherein the first edges of the first and second face are electrically coupled to the waveguide feed.

16. A feed spoiler according to claim 13, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said waveguide feed such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially electromagnetically hide a portion of said waveguide feed facing the feed horn.

17. A feed spoiler according to claim 13, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said waveguide feed such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially electromagnetically hide a portion of said waveguide feed perpendicular to said beam axis and facing said concave reflector.

18. A feed spoiler according to claim 13, wherein the at least one segment of electrically conductive surface forms a roof having two faces each having an edge coupled to a portion of said waveguide feed such that the opposite edges of the faces of the roof are joined to form a ridge in such a manner as to substantially electromagnetically hide a portion of said waveguide feed perpendicular to said beam axis and facing away from said concave reflector.

19. A feed spoiler according to claim 13, wherein said feed spoiler comprises a segment of electrically conductive surface forming a roof having two faces each having an edge coupled to opposite edges of the height of a portion of said waveguide perpendicular to said beam axis and facing said concave reflector such that the opposite edges of the faces of the roof are joined to form a ridge parallel to said portion of said waveguide.

20. A feed spoiler according to claim 13, wherein the ridge of said roof is disposed at a distance on the order of one and a half times the characteristic wavelength of the electromagnetic radiation from the center of the cross-section of the rectangular waveguide feed.

21. A feed spoiler for reducing side lobes of a microwave antenna having a concave reflector, a beam axis, and a feed support projecting out from the concave reflector and to support a feed horn, comprising at least one segment of electrically conductive surface forming two roofs, each roof having two faces, each face having an edge coupled to at least a portion of the feed support up to the whole length thereof, such that the opposite edges of the faces of each roof are joined to form ridges disposed on opposite sides of said feed support.