Systems and Methods for Protecting a Receiving Antenna from Interference by a Transmitting Antenna

• US 20110260920A1
• Filed: 04/22/2010
• Published: 10/27/2011
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Aerospace Corporation
• Original Assignee: Aerospace Corporation
• Inventors: SooHoo, Keith M., Dybdal, Robert B., Curry, Samuel J.
• Granted Patent: US 8,614,644 B2
• Time in Patent Office: Days
• US Class Current: 342/379
• 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: H04B 7/0825 with main and with auxiliary or diversity antennas
• CPC Class Codes: H04B 7/0842 Weighted combining

Abstract

Embodiments of the invention provide systems and methods for systems and methods for adaptively canceling interfering signals generated by a transmission antenna. Under one aspect, a system includes: an auxiliary antenna co-located with the main antenna, the auxiliary antenna configured to transmit an auxiliary signal to the victim antenna; a sensing antenna located on a line-of-sight path between the transmission antenna and the victim antenna, the sensing antenna configured to receive a composite of the interference and the auxiliary signal, and to output a first signal based on the received composite; a controller comprising an input coupled to the sensing antenna and configured to receive the first signal, the controller being configured to adjust at least one of an amplitude, a phase, a polarization, and a frequency characteristic of the auxiliary signal based on the first signal so as to reduce the composite of the interference and the auxiliary signal received by the sensing antenna.

Claims

1. A system for reducing interference at a receiving antenna caused by a transmission from a main antenna, the system comprising:

an auxiliary antenna co-located with the main antenna, the auxiliary antenna configured to transmit an auxiliary signal;

a sensing antenna located on a line-of-sight path between the main antenna and the victim receiving antenna, the sensing antenna configured to receive a composite of the interference and the auxiliary signal, and to output a first signal based on the received composite;

a controller comprising an input coupled to the sensing antenna and configured to receive the first signal,

the controller being configured to adjust at least one of an amplitude, a phase, a polarization, and a frequency characteristic of the auxiliary signal based on the first signal so as to reduce the composite of the interference and the auxiliary signal received by the sensing antenna.

2. The system of claim 1, wherein the main antenna generates a main signal and is configured to output a second signal based on the main signal, and wherein the controller is further configured to receive the second signal.

3. The system of claim 2, wherein the controller comprises a correlator configured to cross-correlate the first signal and the second signal and to output third and fourth signals based on the cross-correlation.

4. The system of claim 3, wherein the controller comprises a processor configured to receive the third and fourth signals and compute an error value based on the third and fourth signals.

5. The system of claim 4, wherein the processor is further configured to obtain a weighting coefficient that reduces the computed error value.

6. The system of claim 5, wherein the controller further comprises an output coupled to the auxiliary antenna, the processor providing the weighting coefficient to the auxiliary antenna via the output, the provided weighting coefficient adjusting an amplitude, phase, and polarization of the auxiliary signal.

7. The system of claim 3, wherein the controller further comprises a storage medium configured to store the third and fourth signals and the error value.

8. The system of claim 1, comprising a plurality of auxiliary antennas.

9. The system of claim 8, wherein at least one auxiliary antenna of the plurality is a different type of antenna than at least one other auxiliary antenna of the plurality.

10. The system of claim 9, wherein at least one auxiliary antenna of the plurality comprises a reflector antenna positioned behind the main antenna, and at least one other auxiliary antenna of the plurality comprises a horn antenna.

11. The system of claim 8, wherein the plurality of auxiliary antennas are mounted to a frame to which the main antenna is mounted.

12. A method for reducing interference at a receiving antenna caused by a transmission from a main antenna, the method comprising:

co-locating an auxiliary antenna with the main antenna;

locating a sensing antenna on a line-of-sight path between the main antenna and the victim receiving antenna;

transmitting an auxiliary signal from the auxiliary antenna to the sensing antenna;

receiving with the sensing antenna a composite of the interference and the auxiliary signal; and

based on a sample of the received composite, adjusting at least one of an amplitude, a phase, a polarization, and a frequency characteristic of the auxiliary signal so as to reduce the composite of the interference and the auxiliary signal received by the sensing antenna.

13. The method of claim 12, wherein the main antenna generates a main signal, and wherein said adjusting is further based on a sample of the main signal.

14. The method of claim 13, further comprising cross-correlating the sample of the received composite and the sample of the main signal.

15. The method of claim 13, further comprising computing an error value based on the cross-correlation.

16. The method of claim 15, further comprising storing the cross-correlation and the error value.

17. The method of claim 15, further comprising obtaining a weighting coefficient that reduces the computed error value.

18. The method of claim 17, further comprising providing the weighting coefficient to the auxiliary antenna so as to adjust the amplitude of the auxiliary signal.

19. The method of claim 12, comprising co-locating a plurality of auxiliary antennas.

20. The method of claim 19, wherein at least one auxiliary antenna of the plurality is a different type of antenna than at least one other auxiliary antenna of the plurality.

21. The method of claim 20, wherein at least one auxiliary antenna of the plurality comprises a reflector antenna positioned behind the main antenna, and at least one other auxiliary antenna of the plurality comprises a horn antenna.

22. The method of claim 19, wherein said co-locating comprises mounting the plurality of auxiliary antennas to a frame to which the main antenna is mounted.