Device for measuring small frequency differencies
US4001680A · kind A · utility
7Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1976 |
| Grant date | Jan 4, 1977 |
| Priority date | — |
| Expiry date | Jan 7, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for measuring small frequency differencies includes a phase detector followed by a differentiating circuit. In order to linearize the output from the differentiating circuit the time constant thereof is decreased during the fly back time of the saw-tooth wave delivered by the phase detector and the phase of one of the frequencies is shifted 180.degree. as soon as the saw-tooth approaches the generally non-linear end portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.