Dual frequency band radar detector
First Claim
1. Apparatus for detecting the presence of radar signals occurring within either of a first or a second range of frequencies comprising:
- antenna means for receiving radar signals including radar signals occurring within said first and second range of frequencies;
signal generating means for producing at least one pilot signal at a predetermined non-varying audio frequency;
means for frequency modulating said received radar signals with said at least one pilot signal;
means for isolating ones of the modulated signals produced in response to received signals in said first range of frequencies or in said second range of frequencies;
frequency demodulating means coupled with said isolating means for detecting said at least one pilot signal; and
control means responsive to said detected pilot signal for producing a control output signal;
whereby the presence of said control output signal indicates the reception of said radar signals occurring within at least one of said first and second range of frequencies;
wherein said control means comprises;
band-pass filter means coupled to said demodulating for passing signals in a predetermined frequency band including the predetermined frequency of said at least one pilot signal; and
phase comparator means coupled to said band-pass filter means and to said pilot signal producing means for producing said control output signal when the detected pilot signal is substantially the same frequency as and substantially in phase with at least one produced pilot signal.
1 Assignment
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Accused Products
Abstract
A dual frequency band radar detector responds to radar signals occurring within either of a first or a second range of frequencies. The detector comprises one or more antennas for receiving radar signals including radar signals occurring within the first and second ranges of frequencies. At least one pilot signal at a predetermined frequency is produced for modulating the received radar signals. The modulated signals produced in response to received signals in either of said first range of frequencies or said second range of frequencies are isolated. A detector is coupled in circuit for detecting the one pilot signal in these isolated and modulated signals and a control output signal is produced responsive to the detected pilot signal. Accordingly, the presence of a control output signal indicates the reception of radar signals occurring within at least one of the first and second ranges of frequencies.
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Citations
18 Claims
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1. Apparatus for detecting the presence of radar signals occurring within either of a first or a second range of frequencies comprising:
- antenna means for receiving radar signals including radar signals occurring within said first and second range of frequencies;
signal generating means for producing at least one pilot signal at a predetermined non-varying audio frequency;
means for frequency modulating said received radar signals with said at least one pilot signal;
means for isolating ones of the modulated signals produced in response to received signals in said first range of frequencies or in said second range of frequencies;
frequency demodulating means coupled with said isolating means for detecting said at least one pilot signal; and
control means responsive to said detected pilot signal for producing a control output signal;
whereby the presence of said control output signal indicates the reception of said radar signals occurring within at least one of said first and second range of frequencies;
wherein said control means comprises;
band-pass filter means coupled to said demodulating for passing signals in a predetermined frequency band including the predetermined frequency of said at least one pilot signal; and
phase comparator means coupled to said band-pass filter means and to said pilot signal producing means for producing said control output signal when the detected pilot signal is substantially the same frequency as and substantially in phase with at least one produced pilot signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
- antenna means for receiving radar signals including radar signals occurring within said first and second range of frequencies;
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12. Apparatus for detecting the presence of radar signals occurring within either of a first or a second range of frequencies comprising:
- antenna means for receiving radar signals including radar signals occurring within said first and second ranges of frequencies;
a first local oscillator for producing a first frequency oscillator signal;
a second local oscillator for producing a second frequency oscillator signal;
means for producing a pilot signal at a predetermined frequency;
means for frequency modulating both said first frequency oscillator signal and said second frequency oscillator signal with said pilot signal;
a first mixer coupled to said antenna means and to said first local oscillator for mixing the received signals in said first range of frequencies with said modulated first frequency oscillator signal;
a second mixer coupled to said antenna means and to said second local oscillator for mixing the received signals in said second range of frequencies with said modulated second frequency oscillator signals;
frequency demodulating means coupled to said first and second mixers for detecting said pilot signal; and
control means responsive to said detected pilot signal for producing a control output signal;
whereby the presence of said control output signal is indicative of the reception of radar signals occurring within at least one of said first and second ranges of frequencies;
wherein said control means comprises phase comparator means coupled to receive the detected pilot signal and the initially produced pilot signal for producing said control output signal in response to a detected pilot signal and the produced pilot signal occurring at substantially the same frequency and phase, and wherein said phase comparator means and said pilot signal producing means are coupled together in a phase-locked loop for substantially locking in the produced pilot signal with the detected pilot signal. - View Dependent Claims (13, 14, 15, 16, 17)
- antenna means for receiving radar signals including radar signals occurring within said first and second ranges of frequencies;
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18. Apparatus for detecting the presence of radar signals occurring within a predetermined range of frequencies comprising:
- antenna means for receiving radar signals including radar signals occurring within said predetermined range of frequencies;
a first local oscillator for producing a first frequency oscillator signal;
means for producing a pilot signal at a predetermined frequency;
means for frequency modulating said first frequency oscillator signal with said pilot signal;
a first mixer coupled to said antenna means and to said first local oscillator for mixing the received signals with said modulated first frequency oscillator signal;
frequency demodulating means coupled to said first mixer for detecting said pilot signal; and
control means responsive to said detected pilot signal for producing a control output signal;
whereby the presence of said control output signal is indicative of the reception of radar signals occurring within said predetermined ranges of frequencies;
wherein said control means comprises comparator means coupled to receive the detected pilot signal and the initially produced pilot signal for producing said control output signal in response to a detected pilot signal and the produced pilot signal occurring at substantially the same frequency and phase, and wherein said comparator means and said pilot signal producing means are coupled together in a phase-locked loop for substantially locking in the produced pilot signal with the detected pilot signal.
- antenna means for receiving radar signals including radar signals occurring within said predetermined range of frequencies;
Specification