Noise suppression apparatus for FM receiver
US5036543A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1990 |
| Grant date | Jul 30, 1991 |
| Priority date | — |
| Expiry date | Jun 26, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/344
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A noise component is extracted either from FM-detected output or from the so-called signal meter in the intermediate frequency amplifier. The noise component is amplified and rectified to provide a d-c signal indicative of the noise level. The rectified noise is then shaped to produce a control signal having a predetermined level and a width. The control signal is supplied to the gate circuit to control the opening and closing of the gate through which the FM detected output passes. The gate is closed during a period when the pulse noise is superimposed on the FM detected output, and is opened during a period when the pulse noise is not superimposed to the FM detected output. In the mean time, the rectified d-c signal is smoothed out to be used as a control signal for controlling the stereo separation, the attenuation of high frequency component of the MPX-demodulated audio outputs, and the overall signal level of the audio outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.