FM signal detection apparatus with automatic gain control circuit connected to phase detector input terminal
US5175881A · kind A · utility
2Cited by
7References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1990 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Apr 30, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D3/244
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus for receiving broadcast FM waves using an FM (Frequency Modulated) detector is disclosed in which an output signal level of an automatic gain controller (AGC) is controllable so that when the C/N ratio is reduced and the output level of the automatic gain controller is reduced, the loop gain of a PLL type FM demodulator is accordingly reduced and response is delayed with the bandwidth being narrowed . Therefore, since delayed threshold extension is applied thereby, no signal noise, such as white points appearing on an image screen, will occur.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.