Oscillator control circuit with phase detection feedback
US5654674A · kind A · utility
5Cited by
2References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 4, 1996 |
| Grant date | Aug 5, 1997 |
| Priority date | — |
| Expiry date | Jan 4, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J7/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A controllable crystal oscillator of a receiver having a mixer producing an IF signal is controlled by a feedback loop that includes a phase detector. The IF signal is delayed by an odd multiple of .pi./2 and fed to one input of an exclusive-OR circuit, with the other input receiving the IF signal directly. The phase detection signal from the exclusive-OR circuit can be counted and converted to an analog voltage when the oscillator is a voltage controlled oscillator or it can be counted and used as a digital control signal when the oscillator is a data controlled oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.