Distributed conformal adaptive antenna array for SATCOM using decision direction

• US 7,606,528 B2
• Filed: 11/10/2006
• Issued: 10/20/2009
• Est. Priority Date: 11/10/2006
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Mesecher, David Keith
• Primary Examiner(s): FERGUSON, KEITH
• Application Number:
  US11/595,577
• Publication Number:
  US 20090023383A1
• Time in Patent Office: 1,075 Days
• Field of Search: 455/3.01, 455/3.02, 455/3.03, 455/3.04, 455/3.05, 455/3.06, 455456-457, 455/431, 455/500, 455/502, 455/517, 455/550.1, 455/553.1, 455/422.1, 455/403, 455/39, 455/42, 455/526, 343/705, 343/702, 343/777, 343/763, 342/357.08, 342/359
• US Class Current: 455/3.02
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/30 varying the relative phase between the radiating elements of an array H01Q3/2605, H01Q3/2658, H01Q3/2682, H01Q3/44 take precedence
• CPC Class Codes: H04H 20/51 specially adapted for satellite broadcast systems

Abstract

An apparatus comprises a distributed array of antenna elements for receiving a radio frequency signal on a satellite communications link, wherein the radio frequency signal includes a known preamble; a plurality of mixers for translating the radio frequency signal to a plurality of baseband signals having in-phase and quadrature components; a processor for applying weights to the baseband signals, wherein the weights are found adaptively in response to the preamble in combination with decision-directed feedback when the preamble is not present; and a receiver for processing the weighted baseband signals. A pre-processor can be used to create sub-arrays of the antenna elements using maximal-ratio weighting. A method performed by the apparatus is also provided.

Claims

1. An apparatus comprising:

a distributed array of antenna elements for receiving a radio frequency signal on a satellite communications link, wherein the radio frequency signal includes a known preamble;

a plurality of mixers for translating the radio frequency signal to a plurality of baseband signals having in-phase and quadrature components;

a processor for applying weights to the baseband signals, wherein the weights are found adaptively in response to the preamble in combination with decision-directed feedback when the preamble is not present; and

a receiver for processing the weighted baseband signals.

2. The apparatus of claim 1, wherein the distributed array of antenna elements is a conformal array.

3. The apparatus of claim 1, wherein the weights maximize signal-to-noise ratio in the baseband signals.

4. The apparatus of claim 1, further comprising:

a pre-processor for creating a sub-array of the antenna elements using maximal-ratio weighting.

5. A method comprising the steps of:

receiving a radio frequency signal using a distributed array of antenna elements, wherein the radio frequency signal includes a known preamble;

translating the radio frequency signal to a plurality of baseband signals having in-phase and quadrature components;

applying weights to the baseband signals, wherein the weights are found adaptively in response to the preamble in combination with decision-directed feedback when the preamble is not present; and

processing the weighted baseband signals.

6. The method of claim 5, further comprising the step of:

creating sub-arrays of the antenna elements using maximal-ratio weighting.

7. The method of claim 6, further comprising the step of:

using default patterns of the sub-arrays of the antenna elements to select an active sub-array.

8. The method of claim 7, further comprising the step of:

using separate adaptive signal processing on signals received by each sub-array.

9. The method of claim 5, wherein the distributed array of antenna elements is a conformal array.

10. The method of claim 5, wherein the weights maximize signal-to-noise ratio in the baseband signals.