Feed forward dual channel automatic level control for dual tone multi-frequency receivers
US4604755A · kind A · utility
8Cited by
6References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 1, 1984 |
| Grant date | Aug 5, 1986 |
| Priority date | — |
| Expiry date | Jun 1, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q1/453
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A dual tone multi-frequency receiver having an improved automatic level control is described. The level control is performed after the filtering operation instead of before the filtering operation as was done in previous designs. Separate channels are derived for each of the tone groups and are handled separately for automatic level control in feed forward responsive correction circuits. Improved responsiveness to twist distortion with a fast attack tracking and holding capability results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.