Apparatus and method for inhibiting false locking of a phase-locked loop
US4077016A · kind A · utility
109Cited by
3References
21Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1977 |
| Grant date | Feb 28, 1978 |
| Priority date | — |
| Expiry date | Feb 22, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S331/02
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Apparatus and method are provided to discriminate between true locking of a phase-locked loop on the main lobe of an information signal, and false locking on a side lobe thereof. The energy in the locked signal is sensed and compared with the signal energy at fixed frequency increments, preferably twice the bit clock rate frequency, above and below the lock frequency. A greater energy content at the increment frequencies than at the locked frequency indicates a false lock condition and is used to inhibit the loop from entering a locked mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.