US4240076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Starting circuit for automatic frequency control arrangement
Assignee: Raytheon Co
•
Filing: 1978-06-05
•
Granted: 1980-12-16
•
Expires: 1998-06-05
Abstract
Abstract An improved automatic frequency control arrangement for a missile-borne inverse receiver is shown to include a reference oscillator and a voltage-controlled oscillator with control means for the latter, such means including a frequency-to-voltage converter responsive to the difference frequency between the two oscillators so that the latter may produce a signal representative of the Doppler shift frequency of a target. A starting circuit is also shown to ensure that the frequency of the reference oscillator is always lower than the frequency of the voltage-controlled oscillator.
Inventors
- 👤 James Williamson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:39
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/093; G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/288
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
149 words
In an inverse receiver using a first local oscillator whose frequency is to be automatically controlled to track a Doppler-shifted echo signal, the control signal for such purpose being derived from the output signal of a voltage-controlled oscillator tunable through a frequency spectrum encompassing the range of possible Doppler shift frequencies of echo signals to be received, circuitry for initiating and maintaining operation of the voltage-controlled oscillator, such circuitry comprising: (a) means for initially setting the frequency of the voltage-controlled oscillator at a frequency higher than the highest possible Doppler shift frequencies and then decreasing the frequency of the voltage-controlled oscillator to sweep through the range of possible Doppler shift frequencies; and (b) means for then sensing when the frequency of the voltage-controlled oscillator equals the Doppler shift frequency of the Doppler-shifted echo signal and thereafter controlling the frequency of the voltage-controlled oscillator to track such Doppler shift frequency.
Claim 2
Dependent Claim
149 words
In an inverse receiver using a first local oscillator whose frequency is to be automatically controlled to track a Doppler-shifted echo signal, the control signal for such purpose being derived from the output signal of a voltage-controlled oscillator tunable through a frequency spectrum encompassing the range of possible Doppler shift frequencies of echo signals to be received, circuitry for initiating and maintaining operation of the voltage-controlled oscillator, such circuitry comprising: (a) means for initially setting the frequency of the voltage-controlled oscillator at a frequency higher than the highest possible Doppler shift frequencies and then decreasing the frequency of the voltage-controlled oscillator to sweep through the range of possible Doppler shift frequencies; and (b) means for then sensing when the frequency of the voltage-controlled oscillator equals the Doppler shift frequency of the Doppler-shifted echo signal and thereafter controlling the frequency of the voltage-controlled oscillator to track such Doppler shift frequency.
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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |