Composite limiting sum and difference circuitry for extending the reception area of a frequency modulated stereo radio transmitter
US4301331A · kind A · utility
1Cited by
7References
8Claims
0Family size
Inventor
Key dates
| Filing date | Nov 15, 1979 |
| Grant date | Nov 17, 1981 |
| Priority date | — |
| Expiry date | Nov 15, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/48
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A frequency modulated stereo transmitter in the preferred embodiment has a stereo generator which receives audio sterero signals directly. The stereo generator includes gain control circuitry which acts directly on the sum and difference signals generated in the stereo generator. The stereo generator then directly modulates a modulation protion of an RF transmitter unit thereby maintaining a very high index of modulation. Audio gain control and audio limiting are thus eliminated. In alternative embodiments the stereo generator unit gain control circuitry is adapted to existing FM stereo transmitters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.