Apparatus and method for decoding an AM stereo broadcasting signal of an independent sideband system
US4757539A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1986 |
| Grant date | Jul 12, 1988 |
| Priority date | — |
| Expiry date | Dec 10, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/49
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an AM stereo receiving apparatus for decoding an AM stereo broadcasting signal of an ISB system, an envelope detecting circuit 6 detects an output of an intermediate frequency amplifying circuit 5 and a DC removing circuit 7 removes a DC component therefrom, so that a stereo sum signal (L+R) is obtained. A quadrature detecting circuit 9 detects quadrature of the output of the intermediate frequency amplifying circuit 5. A multiplying circuit 10 multiplies the stereo sum signal (L+R), which is amplified a times as much by a first amplifying circuit 8, and the output of the quadrature detecting circuit 9. An addition circuit 12 adds the output of the quadrature detecting circuit 9, which is amplified b times as much by a second amplifying circuit 11, and the output of the multiplying circuit 10. The output of the addition circuit 12 becomes a stereo difference signal (L-R) by appropriately setting the amplification factor a of the first amplifying circuit 8 and the amplification factor b of the second amplifying circuit 11.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.