US3864634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Doppler correction circuit
Assignee: United States Department of the Navy
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Filing: 1973-10-01
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Granted: 1975-02-04
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Expires: 1993-10-01
Abstract
Abstract A circuit for precompensating a transmitted signal for the Doppler shift that will occur during its propagation time. The circuit takes a signal containing positive Doppler information and mixes it in a mixer, which is a component of a phase-lock loop, with a signal containing negative Doppler information which is the reverse of the positive information, leaving a signal which has practically no Doppler content. The phase-lock loop includes the mixer, a phase detector, a loop amplifier and a voltage-controlled oscillator (VCO). The signal from the mixer is fed to the phase detector which provides a DC output signal proportional to the phase difference between the mixer output and a frequency reference signal. The DC signal is amplified by the loop amplifier and used to control the output of the VCO which contains the inverted Doppler information.
Inventors
- 👤 Philip G Dragonetti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:45
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/01
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
A circuit for correcting Doppler shift in a transmitted signal for use with a tracking receiver providing an output signal containing positive Doppler information comprising, in combination: ''phase-lock-loop means comprising phase-detector means, loop amplifier means, voltage-controlled oscillator means (VCO) and mixer means, all being connected in said loop in the order named and receiving as an input the output of the preceding means in said loop; frequency standard means the output of which is connected as an input to said phase-detector means; and oscillator means connected to supply one input signal to said mixer means, said positive Doppler signal being fed to said mixer means as a third input, the output of said mixer means being a signal having minute Doppler content corresponding to the Doppler shift in the output of the tracking receiver, the output of the mixer means being compared in phase by said phase-detector means to the output of said frequency standard means and the phase difference being detected to provide a control signal which is amplified by the loop amplifier and used to control the operation of the VCO, the output of the VCO being a sIgnal containing the positive Doppler information in inverted form.
Claim 2
Dependent Claim
199 words
A circuit for correcting Doppler shift in a transmitted signal for use with a tracking receiver providing an output signal containing positive Doppler information comprising, in combination: ''phase-lock-loop means comprising phase-detector means, loop amplifier means, voltage-controlled oscillator means (VCO) and mixer means, all being connected in said loop in the order named and receiving as an input the output of the preceding means in said loop; frequency standard means the output of which is connected as an input to said phase-detector means; and oscillator means connected to supply one input signal to said mixer means, said positive Doppler signal being fed to said mixer means as a third input, the output of said mixer means being a signal having minute Doppler content corresponding to the Doppler shift in the output of the tracking receiver, the output of the mixer means being compared in phase by said phase-detector means to the output of said frequency standard means and the phase difference being detected to provide a control signal which is amplified by the loop amplifier and used to control the operation of the VCO, the output of the VCO being a sIgnal containing the positive Doppler information in inverted form.
Claim 3
Dependent Claim
86 words
A circuit as in claim 1, wherein said mixer means includes a first, a second and a third mixer circuit, said first mixer output being fed to second mixer, said second mixer output being fed to said third mixer, and said third mixer output being fed to said phase-detector means, the output from said VCO being fed to said first mixer, the signal containing positive Doppler information being fed to said second mixer, and the oscillator circuit output being fed to said first and third mixers.
Claim 4
Dependent Claim
80 words
A circuit as in claim 2, wherein the frequency of the signal containing positive Doppler information is 5(1+d)MHZ, where d is the Doppler deviation, the output frequency of the frequency standard means is 10MHZ, the output frequency of the VCO is 5(1-d)MHZ, the frequency of the oscillator circuit is 4.4MHZ, the output frequency of the second mixer is 14.4MHZ, the output frequency of the third mixer is 10MHZ with a minute Doppler variation, and the phase-detector means operates at 10MHZ.
Claim 5
Dependent Claim
206 words
A circuit for correcting Doppler shift in a transmitted signal for use with a tracking receiver providing an output signal containing positive Doppler information comprising, in combination: phase-lock-loop comprising phase-detector means, loop amplifier means, voltage-controlled oscillator means (VCO), first mixer means, second mixer means and third mixer means, all being contected on said loop in the named order and receiving as an input the output of the preceding means in the loop; frequency standard means feeding its output to said phase-detector means as one of its inputs; and oscillator means connected to supply its output as one input signal to said first and to said third mixers, said positive Doppler signal being fed to said second mixer means, the output of said third mixer means being a signal having Doppler content corresponding to the Doppler shift in the output of the tracking receiver, the output of the third mixer means being compared in phase by said phase-detector means to the output of said frequency standard means and the phase difference being detected to provide a control signal which is amplified by the loop amplifier and used to control the operation of the VCO, the output of the VCO containing the positive Doppler information in inverted form.
Claim 6
Dependent Claim
206 words
A circuit for correcting Doppler shift in a transmitted signal for use with a tracking receiver providing an output signal containing positive Doppler information comprising, in combination: phase-lock-loop comprising phase-detector means, loop amplifier means, voltage-controlled oscillator means (VCO), first mixer means, second mixer means and third mixer means, all being contected on said loop in the named order and receiving as an input the output of the preceding means in the loop; frequency standard means feeding its output to said phase-detector means as one of its inputs; and oscillator means connected to supply its output as one input signal to said first and to said third mixers, said positive Doppler signal being fed to said second mixer means, the output of said third mixer means being a signal having Doppler content corresponding to the Doppler shift in the output of the tracking receiver, the output of the third mixer means being compared in phase by said phase-detector means to the output of said frequency standard means and the phase difference being detected to provide a control signal which is amplified by the loop amplifier and used to control the operation of the VCO, the output of the VCO containing the positive Doppler information in inverted form.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |