Digital FM demodulating apparatus
US4994754A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 1989 |
| Grant date | Feb 19, 1991 |
| Priority date | — |
| Expiry date | May 23, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital FM demodulating apparatus includes a phase detector for detecting the phase of an input digital FM signal; a differentiator for time differentiating the signal from the phase detector to get an instantaneous frequency of the input FM signal; an over-modulation detector for detecting an over-modulation occurence of the input FM signal according to the instantaneous frequency to generate a detection signal, and an over-modulation corrector for obtaining a demodulated output signal which is corrected so as to have no deterioration due to the over-modulation occurrence according to the detection signal from the over-modulation detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.