Patent US3706931A successfully refreshed from Google Patents.
US3706931A
Expired / Lapsed
US
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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: 1972-12-19
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Expires: 1991-04-01
Abstract
Abstract First and second waves at distinct frequencies are mixed to produce a third wave at their difference frequency. The phase difference between this third wave and a wave at the same frequency from a local oscillator is then detected to produce an output which is directly related to the phaseal relationship between the first and second waves.
Inventors
- 👤 Mahadevan Subramanian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:59
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46; H04B3/462
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
166 words
A combination for detecting the phasal dispersion produced between an input terminal and an output terminal of a system, said combination comprising: a source of unmodulated waves at frequencies f1 and f2, respectively, means for applying said unmodulated waves to said system input terminal, mixing means for receiving on two input terminals waves at frequencies f1 and f2, respectively, and producing an output including a wave having a frequency equal to (f2-f1), means for connecting said system output terminal to said mixing means input terminals to provide the only inputs to said mixing means, bandpass filtering means centered at the frequency (f2-f1) and connected to receive the output of said mixing means, an oscillator for producing waves at the frequency (f2-f1), a phase detector for producing outputs indicative of the phasE difference between two input waves, and means connecting said bandpass filtering means and said oscillator to said phase detector whereby the outputs from said filtering means and said oscillator comprise said phase detector input waves.
Claim 2
Dependent Claim
166 words
A combination for detecting the phasal dispersion produced between an input terminal and an output terminal of a system, said combination comprising: a source of unmodulated waves at frequencies f1 and f2, respectively, means for applying said unmodulated waves to said system input terminal, mixing means for receiving on two input terminals waves at frequencies f1 and f2, respectively, and producing an output including a wave having a frequency equal to (f2-f1), means for connecting said system output terminal to said mixing means input terminals to provide the only inputs to said mixing means, bandpass filtering means centered at the frequency (f2-f1) and connected to receive the output of said mixing means, an oscillator for producing waves at the frequency (f2-f1), a phase detector for producing outputs indicative of the phasE difference between two input waves, and means connecting said bandpass filtering means and said oscillator to said phase detector whereby the outputs from said filtering means and said oscillator comprise said phase detector input waves.
Claim 3
Dependent Claim
35 words
The combination in accordance with claim 1 which further comprises a pair of bandpass filtering means centered at the frequencies f1 and f2, respectively, and connected in series with said mixing means input terminals, respectively.
Claim 4
Dependent Claim
204 words
A combination for detecting the phasal dispersion produced between an input terminal and an output terminal of a system, said combination comprising: a source of unmodulated waves at frequencies f1 and f2, respectively, means for applying said unmodulated waves to said system input terminal, mixing means for receiving on two input terminals waves at frequencies f1 and f2, respectively, and producing an output including a wave having a frequency equal to (f2-f1), means for connecting said system output terminal to said mixing means input terminals to provide the only inputs to said mixing means, bandpass filtering means centered at the frequency (f2-f1) and connected to receive the output of said mixing means, an oscillator for producing output waves at the frequency (f2-f1), a phase shifter connected to said oscillator for controlling the phase of said waves produced by said oscillator, a phase detector for producing outputs indicative of the phase difference between a pair of input waves applied thereto, and a lead reversing means connected between said filtering means, said phase shifter, and said phase detector to alternate the order in which the outputs from said filtering means and said phase shifter are applied to said phase detector as said phase detector input waves.
Claim 5
Dependent Claim
204 words
A combination for detecting the phasal dispersion produced between an input terminal and an output terminal of a system, said combination comprising: a source of unmodulated waves at frequencies f1 and f2, respectively, means for applying said unmodulated waves to said system input terminal, mixing means for receiving on two input terminals waves at frequencies f1 and f2, respectively, and producing an output including a wave having a frequency equal to (f2-f1), means for connecting said system output terminal to said mixing means input terminals to provide the only inputs to said mixing means, bandpass filtering means centered at the frequency (f2-f1) and connected to receive the output of said mixing means, an oscillator for producing output waves at the frequency (f2-f1), a phase shifter connected to said oscillator for controlling the phase of said waves produced by said oscillator, a phase detector for producing outputs indicative of the phase difference between a pair of input waves applied thereto, and a lead reversing means connected between said filtering means, said phase shifter, and said phase detector to alternate the order in which the outputs from said filtering means and said phase shifter are applied to said phase detector as said phase detector input waves.
Claim 6
Dependent Claim
35 words
The combination in accordance with claim 3 which further comprises a pair of bandpass filtering means centered at the frequencies f1 and f2, respectively, and connected in series with said mixing means input terminals, respectively.
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 |