Systems and methods for discriminating signals in a multi-band detector

• US 7,579,976 B1
• Filed: 11/10/2008
• Issued: 08/25/2009
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: Valentine Research, Inc.
• Original Assignee: Valentine Research, Inc.
• Inventors: Valentine, Michael D., Carrelli, Gary E.
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US12/268,060
• Time in Patent Office: 288 Days
• Field of Search: 342/20, 342/91, 342/98, 342/99, 342/159, 342/162, 342/195
• US Class Current: 342/20
• CPC Class Codes: G01S 7/022 Road traffic radar detectors
• CPC Class Codes: H03D 7/1408 with diodes

Abstract

A radar detector is operated to suppress nuisance radar alerts by identifying a first signal in radar band of interest, e.g., having a frequency that is a harmonic of a first nuisance local oscillator frequency leaked from a nearby radar detector and identifying a second signal having a frequency that is a harmonic of a second nuisance local oscillator frequency leaked from the radar detector where the first and second local oscillators are companion signals. A detector is also provided that suppresses nuisance radar alerts by detecting a first signal in a radar band, providing a first alert designating the detection of the first signal, determining that the first signal is a nuisance signal, providing a second alert designating that the first signal is a false alarm, and turning off the second alert after a predetermined period.

Claims

1. A method of operating a radar detector to suppress nuisance radar alerts due to signals received in a radar band which are not radar signals of interest, said method comprising:

detecting a first signal in a radar band of interest;

providing a first alert designating the detection of said first signal;

determining whether said first signal is a nuisance signal that should be suppressed;

providing a second alert designating that said first signal is a false alarm if it is determined that said first signal is a nuisance signal; and

turning off said second alert after a predetermined period.

2. The method according to claim 1 wherein determining whether said first signal is a nuisance signal that should be suppressed comprises:

identifying whether said first signal has a frequency that is a harmonic of a first nuisance local oscillator frequency;

identifying whether a second signal has a frequency that is a harmonic of a second nuisance local oscillator frequency; and

identifying said second signal as a companion signal of said first signal if a fundamental frequency of said second nuisance local oscillator frequency is different from and not harmonically related to a fundamental frequency of said first nuisance local oscillator frequency.

3. The method according to claim 2 further comprising:

tracking said first signal;

determining whether said first signal is being suppressed as a nuisance signal; and

continuing to track said first signal as suppressed until a predetermined time after said first signal is no longer detected regardless of whether said second signal continues to be detected.

4. The method according to claim 2 wherein said first and second alerts are generated in response to detecting local oscillator signals leaked from an other radar detector and identifying said second signal as being a companion signal of said first signal comprises identifying a pattern that associates said first signal with said second signal by determining that said first signal is being leaked by said other radar detector while sweeping a first frequency range and said second signal is being leaked by said other radar detector while sweeping a second frequency range different from said first frequency range, said frequency of said second signal being different from and not harmonically related to said frequency of said first signal.

5. The method according to claim 4 wherein said first and second signals are judged to be companion signals if said pattern comprises detecting said first and second signals as being alternatively switched on and off.

6. The method according to claim 2 wherein said first signal is detected in the Ka band and said second signal is detected outside of the Ka band.

7. The method according to claim 2 wherein:

said first signal is in the range of 33.4 to 34 gigahertz; and

said second signal is outside of the Ka band in the range of 32 to 33 gigahertz.

8. The method according to claim 2 wherein said first and second signals are not both always simultaneously on.

9. The method according to claim 2 wherein said first and second signals are detected such that said first signal is suppressed before said first alert is issued.

10. A radar detector capable of suppressing nuisance radar alerts due to signals received in a radar band which are not radar signals of interest, comprising:

a first processing stage that receives and filters incoming electromagnetic signals;

a second processing stage coupled to said first processing stage that shifts the frequency of filtered electromagnetic signals received by the first processing stage;

control circuitry that controls said first processing stage and said second processing stage, said control circuitry having a processor and memory having code embodied therein, the code comprising;

code executable by said processor to detect a first signal in a radar band of interest;

code executable by said processor to provide a first alert designating the detection of said first signal;

code executable by said processor to determine whether said first signal is a nuisance signal that should be suppressed;

code executable by said processor to provide a second alert designating that said first signal is a false alarm if it is determined that said first signal is a nuisance signal; and

code executable by said processor to turn off said second alert after a predetermined period.

11. The radar detector according to claim 10 wherein said code executable by said processor to determine whether said first signal is a nuisance signal that should be suppressed comprises:

code executable by said processor to identify whether said first signal has a frequency that is a harmonic of a first nuisance local oscillator frequency;

code executable by said processor to identify whether a second signal is detected as having a frequency that is a harmonic of a second nuisance local oscillator frequency; and

code executable by said processor to identify said second signal as a companion signal to said first signal if a fundamental frequency of said first nuisance local oscillator frequency is different from and not harmonically related to a fundamental frequency of said second nuisance local oscillator frequency.

12. The radar detector according to claim 11 wherein said memory further comprises:

code executable by said processor to track said first signal;

code executable by said processor to determine whether said first signal is being suppressed as a nuisance signal; and

code executable by said processor to continue to track said first signal as suppressed until a predetermined time after said first signal is no longer detected regardless of whether said second signal continues to be detected.

13. The radar detector according to claim 11 wherein said first and second alerts are generated in response to detecting local oscillator signals leaked from an other radar detector and said code executable by said processor to identify said second signal as a companion signal to said first signal comprises code executable by said processor to identify a pattern that associates said first signal with said second signal by determining that said first signal is being leaked by said other radar detector while sweeping a first frequency range and said second signal is being leaked by said other radar detector while sweeping a second frequency range different from said first frequency range, said frequency of said second signal being different from and not harmonically related to said frequency of said first signal.

14. The radar detector according to claim 13 wherein said code executable by said processor to identify said second signal as a companion signal to said first signal comprises code executable by said processor to detect said first and second signals as being alternatively switched on and off.

15. The radar detector according to claim 11 wherein said code executable by said processor to detect a first signal in a radar band of interest comprises code executable by said processor to detect said first signal in the Ka band and said second signal outside of the Ka band.

16. The radar detector according to claim 11 wherein:

said code executable by said processor to detect a first signal in a radar band of interest comprises code executable by said processor to detect a first signal in the range of 33.4 to 34 gigahertz; and

said second signal is outside of the Ka band in the range of 32 to 33 gigahertz.

17. The radar detector according to claim 11 further comprising code executable by said processor to detect said first and second signals such that said first signal is suppressed before said first alert is issued.

18. The radar detector according to claim 10, further comprising an alarm coupled to said control circuitry, said alarm configured to provide at least one of a visual or audible indication of said first and second alarm signals.

19. The radar detector according to claim 10, further comprising a table configured in said memory to track detected in-band signals for each sweep cycle.