US3675136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for use in measuring phase dispersion produced by apparatus or a system
Assignee: AT&T Inc
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Filing: 1971-04-01
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Granted: 1972-07-04
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Expires: 1991-04-01
Abstract
Abstract First and second waves at distinct frequencies are mixed with a 3rd wave to produce fourth and fifth waves having a common frequency. The phase difference between the fourth and fifth waves is then detected to produce an output which is directly related to the phaseal relationship between the first and second waves.
Inventors
- 👤 Kevin Christopher O'brien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:45
CPC Classifications
G; G01; G01R; G01R25/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
156 words
In combination, first mixing means for receiving on two input terminals waves at frequencies f1 and (f1 - f2)/2, respectively, to produce an output having a wave at the frequency (f1 + f2)/2, second mixing means for receiving on two input terminals waves at frequencies f2 and (f1 - f2)/2, respectively, to produce an output having a wave at the frequency (f1 + f2)2, an oscillator connected to one of said first mixing means input terminals and one of said second mixing means input terminals to apply thereto waves at the frequency (f1 - f2)/2, first and second bandpass filtering means centered at the frequency (f1 + f2)/2 and connected to receive the outputs of said first and second mixing means, respectively, and a phase detector connected to receive the outputs of said first and second filtering means to produce outputs indicative of the phase difference between the outputs of said first and second filtering means.
Claim 2
Dependent Claim
156 words
In combination, first mixing means for receiving on two input terminals waves at frequencies f1 and (f1 - f2)/2, respectively, to produce an output having a wave at the frequency (f1 + f2)/2, second mixing means for receiving on two input terminals waves at frequencies f2 and (f1 - f2)/2, respectively, to produce an output having a wave at the frequency (f1 + f2)2, an oscillator connected to one of said first mixing means input terminals and one of said second mixing means input terminals to apply thereto waves at the frequency (f1 - f2)/2, first and second bandpass filtering means centered at the frequency (f1 + f2)/2 and connected to receive the outputs of said first and second mixing means, respectively, and a phase detector connected to receive the outputs of said first and second filtering means to produce outputs indicative of the phase difference between the outputs of said first and second filtering means.
Claim 3
Dependent Claim
39 words
A combination in accordance with claim 1 which further comprises third and fourth bandpass filtering means centered at the frequencies f1 and f2, respectively, and connected to the other of said first and second mixing means input terminals, respectively.
References Cited (Backward Citations)
US3562646A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |