US3706932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplitude independent, automatic frequency control/discriminator
Assignee: United States Department of the Navy
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Filing: 1971-01-07
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Granted: 1972-12-19
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Expires: 1991-01-07
Abstract
Abstract A system for deriving a constant intermediate frequency output over a band of input frequencies comprising a mixer, a power splitter for splitting the output of the mixer into two segments of equal power, two band pass filters connected to the power splitter and a servo loop incorporating a variable frequency local oscillator whose output is connected to the mixer such that the output of the local oscillator is controlled to maintain the output of the mixer at an essentially constant frequency.
Inventors
- 👤 Richard Smith Hughes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:12
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/02; H03J; H03J7/00; H03J7/02; H03J7/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
243 words
A system for deriving a constant intermediate frequency output signal comprising; input means adapted to receive an input signal of a particular frequency which may vary over a range; a servo loop operatively connected between the output of said filter means and said mixer means for maintaining said signal having a different frequency at a predetermined essentially constant frequency, including means coupled to said first filter means for detecting the amplitude of the output of said first filter, means coupled to said second filter means for detecting the amplitude of the output of said second filter, means for logarithmIcally amplifying the output of said first filter outputs amplitude detecting means, means for logarithmically amplifying the output of said second filter output amplitude detecting means, and means for combining the logarithmically amplified outputs. mixer means coupled to said input means adapted to receive said input signal and output a signal having a different frequency; power splitter means operatively coupled to the output of said mixer means and adapted to divide said difference frequency signal thereby providing at least two output signals; filter means receiving one of said at least two output signals and having a predetermined pass band; another filter means receiving the other of said at least two output signals and having a predetermined pass band different from said first mentioned filter means; said combination of filter means providing output signals the amplitude of at least one of which varies with frequency; and
Claim 2
Independent Claim
243 words
A system for deriving a constant intermediate frequency output signal comprising; input means adapted to receive an input signal of a particular frequency which may vary over a range; a servo loop operatively connected between the output of said filter means and said mixer means for maintaining said signal having a different frequency at a predetermined essentially constant frequency, including means coupled to said first filter means for detecting the amplitude of the output of said first filter, means coupled to said second filter means for detecting the amplitude of the output of said second filter, means for logarithmIcally amplifying the output of said first filter outputs amplitude detecting means, means for logarithmically amplifying the output of said second filter output amplitude detecting means, and means for combining the logarithmically amplified outputs. mixer means coupled to said input means adapted to receive said input signal and output a signal having a different frequency; power splitter means operatively coupled to the output of said mixer means and adapted to divide said difference frequency signal thereby providing at least two output signals; filter means receiving one of said at least two output signals and having a predetermined pass band; another filter means receiving the other of said at least two output signals and having a predetermined pass band different from said first mentioned filter means; said combination of filter means providing output signals the amplitude of at least one of which varies with frequency; and
Claim 3
Dependent Claim
59 words
A system for deriving a constant intermediate frequency output signal as set forth in claim 1 wherein; the output signals from said filter means and another filter means are essentially equal amplitude; and wherein the cutoff point of one pass band of one of said filter means lies within the pass band of the other of sad filter means.
Claim 4
Dependent Claim
32 words
A system as set forth in claim 1 and further including; a variable frequency oscillator included in said servo loop for producing an output frequency which is dependent upon an input voltage.
Claim 5
Dependent Claim
61 words
A system as set forth in claim 3 and further including; differencing circuit means operatively coupled to the output of said at least two filter means for receiving the detected and log amplified outputs thereof and providing a difference signal therefrom; said differencing circuit means being said combining means and said difference signal being operatively coupled to said variable frequency oscillator.
Claim 6
Dependent Claim
37 words
A system as set forth in claim 4 and further including; pulse integrator means operatively coupled to the output of said differencing circuit means for providing an output voltage which is coupled to the variable frequency oscillator.
Claim 7
Dependent Claim
99 words
A system as set forth in claim 2 and further including; differencing circuit means operatively coupled to the output of said at least two filter means for receiving the detected and logarithmically amplified outputs thereof and providing a difference signal corresponding to an output voltage therefrom, wherein said differencing circuit means is said combining means; and a variable frequency oscillator included in said servo loop for producing an output frequency which is dependent upon an input voltage; said output voltage to said oscillator; and the output frequency of said oscillator being coupled as another input to said mixer means.
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) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |