Patent US1791254A successfully refreshed from Google Patents.
US3594638A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asuring apparatus
Assignee: United States Department of the Navy
•
Filing: 1954-03-25
•
Granted: 1971-07-20
•
Expires: 1974-03-25
Abstract
Abstract A two-channel phase difference determination system in which the signal component in one channel is mixed with a local oscillator signal and the same signal component appearing in the second channel is mixed with the output of the first mixer. The resultant is filtered to phase only the local oscillator frequency, which now contains the phase difference information, and is compared with the phase of the local oscillator signal on the screen of a cathode-ray tube.
Inventors
- 👤 Robert H Quint
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:32
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/14; G01S3/46; G01S3/48; G01R; G01R25/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
234 words
An apparatus for measuring phase difference between two input signals of the same frequency with an unknown phase relation therebetween comprising first and second frequency selective input channels each operative to receive input signals of a selected first frequency; said first input channel comprising an oscillator operative to provide an output signal of a reference frequency and phase and first signal mixing means operative to combine the input signal to said first channel means and the output signal of said oscillator; second signal mixing means; means connecting the output of said second input channel to said second signal mixing means; first band-pass means connecting the output of said first signal mixing means in said first input channel means to said second signal mixing means, said first band-pass means being operative to pass a narrow band of frequencies having a center frequency separated from said first frequency by said reference frequency, a cathode ray tube type display means having an intensity grid and beam deflection means; amplitude sensitive pulse generating means connected to said intensity grid of said display means; second band-pass means connecting the output of said second mixing means to said pulse generating means and operative to control the output of said pulse generating means and sweep generating means connected to said deflection means and to said oscillator and operative to produce a sweep in synchronism with the output signal of said oscillator.
Claim 2
Independent Claim
234 words
An apparatus for measuring phase difference between two input signals of the same frequency with an unknown phase relation therebetween comprising first and second frequency selective input channels each operative to receive input signals of a selected first frequency; said first input channel comprising an oscillator operative to provide an output signal of a reference frequency and phase and first signal mixing means operative to combine the input signal to said first channel means and the output signal of said oscillator; second signal mixing means; means connecting the output of said second input channel to said second signal mixing means; first band-pass means connecting the output of said first signal mixing means in said first input channel means to said second signal mixing means, said first band-pass means being operative to pass a narrow band of frequencies having a center frequency separated from said first frequency by said reference frequency, a cathode ray tube type display means having an intensity grid and beam deflection means; amplitude sensitive pulse generating means connected to said intensity grid of said display means; second band-pass means connecting the output of said second mixing means to said pulse generating means and operative to control the output of said pulse generating means and sweep generating means connected to said deflection means and to said oscillator and operative to produce a sweep in synchronism with the output signal of said oscillator.
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) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |