Beamforming for spatial sidelobe cancellation and AMR direction finding

• US 20080068266A1
• Filed: 11/23/2005
• Published: 03/20/2008
• Est. Priority Date: 11/23/2005
• Status: Abandoned Application

• Current Assignee: Northrop Grumman Corporation
• Original Assignee: Northrop Grumman Corporation
• Inventors: DeAgro, William C.
• Application Number:
  US11/287,544
• Publication Number:
  US 20080068266A1
• Time in Patent Office: Days
• US Class Current: 342/424
• CPC Class Codes: G01S 7/2813 Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00
• CPC Class Codes: H01Q 21/293 one unit or more being an array of identical aerial elements adaptive arrays H01Q3/2605
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence

Abstract

An apparatus comprising an array of antenna elements, a beamformer for adjusting signals to and from the elements to form a first beam pattern and a second beam pattern, and wherein the first beam pattern is a sum pattern and the second beam pattern is a null pattern. A method of beamforming for sidelobe cancellation is also provided.

Claims

1. An apparatus comprising:

an array of antenna elements including a center element and a plurality of other elements symmetrically positioned with respect to the center element;

a beamformer for adjusting signals to and from the plurality of other elements to form a first beam pattern;

a sum element for adding signals from the beamformer and the center element to form a sum pattern; and

a difference element for subtracting signals from the beamformer and the center element to form a null pattern including a null aligned with a boresight of the array of antenna elements, and an omni-like pattern on opposite sides of the boresight.

6. The apparatus of claim 1, further comprising:

a level compensator for adjusting a level of the signal from the center element.

7. The apparatus of claim 1, further comprising:

a transceiver for receiving signals from, and for transmitting signals to, the sum element and the difference element.

8. The apparatus of claim 7, wherein:

during transmission, the sum element splits a transmission signal between the beamformer and the center element.

9. The apparatus of claim 8, wherein:

the beamformer splits and scales the transmission signal.

2. (canceled)

3. (Canceled)

4. (Canceled)

5. (Canceled)

10. (canceled)

11. A method of beamforming for sidelobe cancellation, the method comprising:

providing an array of antenna elements including a center element and a plurality of other elements symmetrically positioned with respect to the center element;

using a beamformer to adjust signals to and from the plurality of other elements to form a first beam pattern;

adding signals from the beamformer and the center element to form a sum pattern; and

subtracting signals from the beamformer and the center element to form a null pattern including a null aligned with a boresight of the array of antenna elements, and an orrni-like pattern on opposite sides of the boresight.

15. The method of claim 11, further comprising

adjusting a level of the signal from the center element.

17. The method of claim 11, comprising:

splitting a transmission signal between the plurality of other elements and the center element.

12. (canceled)

13. (canceled)

14. (canceled)

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18. (canceled)

19. (canceled)

20. (canceled)