US4074191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency measuring device for telecommunication systems
Assignee: Individual
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Filing: 1976-12-30
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Granted: 1978-02-14
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Expires: 1996-12-30
Abstract
Abstract A device capable of being operated under the control of a programmer for rapidly measuring the differences between the actual values of a plurality of transmitted signal frequencies and their assigned values. It comprises a constant frequency local oscillator, a modulator fed from said oscillator and from a signal the actual frequency of which is to be determined, a bandpass filter fed from the output of said modulator, another local oscillator producing a constant frequency, and means for measuring the frequency difference between said other oscillator and the output frequency of the filter. Arrangements are provided for displaying the measured frequency difference values in digital form.
Inventors
- 👤 Jacques M. Jules
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:29
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/10; G01R23/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
205 words
A device for measuring a positive or negative difference Δf between the actual value (f+Δf) and the nominal value f of at least one frequency carried by way of a telecommunication line, comprising: a first local oscillator controlled by a master oscillator and producing a frequency value (f+f o ), f o being a constant predetermined frequency value which may be added to or subtracted from the frequency f; a balanced modulator, one input of which is connected to the said line and the other input of which is connected to the output of the first local oscillator, the said modulator then producing, among its modulation products, the frequency term: (f+f.sub.o) - (f+Δf) = f.sub.o - Δf; a bandpass filter connected to the output of the modulator, the band limits of the said bandpass filter being determined so that the said filter transmits only the said term (f o -Δf); a second local oscillator controlled by the said master oscillator and producing a frequency of value f o , and means for measuring the algebraic difference between the frequency produced by the said second local oscillator and the frequency transmitted by the filter, the said difference being equal to the value of the difference Δf.
Claim 2
Independent Claim
205 words
A device for measuring a positive or negative difference Δf between the actual value (f+Δf) and the nominal value f of at least one frequency carried by way of a telecommunication line, comprising: a first local oscillator controlled by a master oscillator and producing a frequency value (f+f o ), f o being a constant predetermined frequency value which may be added to or subtracted from the frequency f; a balanced modulator, one input of which is connected to the said line and the other input of which is connected to the output of the first local oscillator, the said modulator then producing, among its modulation products, the frequency term: (f+f.sub.o) - (f+Δf) = f.sub.o - Δf; a bandpass filter connected to the output of the modulator, the band limits of the said bandpass filter being determined so that the said filter transmits only the said term (f o -Δf); a second local oscillator controlled by the said master oscillator and producing a frequency of value f o , and means for measuring the algebraic difference between the frequency produced by the said second local oscillator and the frequency transmitted by the filter, the said difference being equal to the value of the difference Δf.
Claim 3
Dependent Claim
82 words
A device as claimed in claim 1, wherein the second local oscillator is a digital oscillator and the means for measuring the difference comprises: a frequency multiplier the input of which is connected to the output of the filter; a frequency meter (counter-frequency meter) whose input is connected to the output of the multiplier, and a differential digital counter having one input connected to the output of the digital oscillator and its other input connected to the output of the frequency meter.
Claim 4
Dependent Claim
39 words
A device as claimed in claim 1, wherein the first local oscillator is a variable-frequency oscillator and comprises a frequency control input and wherein a programmer successively generates frequency-control signals to be applied to the said frequency control input.
Claim 5
Dependent Claim
87 words
A device as claimed in claim 2, wherein the frequency multiplier comprises a phase comparator a first input of which is connected to the output of the filter, an oscillator having a frequency control input connected to the output of the phase comparator and its output connected to the input of the frequency meter, and a frequency divider the input of which is connected to the output of the latter said oscillator and the output of which is connected to the second input of the phase comparator.
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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |