Phase-locked loop frequency modulation circuit for input modulation signals having low-frequency content
US5412353A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1993 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | Nov 12, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/093
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A phase-locked loop frequency modulation circuit that compensates for the inability of a phase-locked loop to pass low-frequency content of an input modulation signal, and that may be utilized with existing communication apparatus, such as a cellular telephone voice radio, for accurate data transmission without having to modify such apparatus, includes a compensation circuit for processing an input modulation signal to provide a compensation signal that is added to a loop filter output signal by processing the input modulation signal to provide the same effect as adding the input modulation signal to an integrated input modulation signal that is filtered by a filter having the same transfer function as the loop filter to provide the compensation signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.