Frequency demodulator with reversal phenomenon compensation
US4906942A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Dec 15, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D2200/0082
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A frequency demodulator which comprises a digital FM demodulating circuit for demodulating an inputted FM signal and outputting a digital demodulated signal, a discriminator for discriminating whether or not the value of the digital demodulated signal from the digital FM demodulating circuit deviates from an upper limit value or a lower limit value set for a normal demodulating range, and a circuit operable on the basis of a result of the discrimination performed by the discriminator for replacing the value of the demodulated signal deviating from the upper limit value or the lower limit value with a compensation value set to a value approximating the upper limit value in the case where the inputted FM signal which has been demodulated is of a type having upper and lower side-bands suppressed and emphasized, respectively, or with a compensation value set to a value approximating the lower limit value in the case where the inputted FM signal which has been demodulated is of a type having upper and lower side-bands emphasized and suppressed, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.