Control loop for reducing the time of repsonse of a tuner-AGC of a superheterodyne receiver and relative leading edge differentiating circuit used in the control loop
US5263186A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1991 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Jan 15, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/3068
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a dynamic automatic loop for control of the overall gain of an input circuit of a superheterodyne receiver, the response time of the HF-AGC circuit of the TUNER, in response to the action of the TUNER DELAY circuit activated by the IF-AGC in the case of autonomously uncontrollable abrupt increases in the level of the antenna signal from the same HF-AGC of the TUNER, is markedly reduced using an additional TUNER DELAY PLUS circuit able to absorb for a determined interval of time, a discharge current from the storage capacitor the control voltage of the HF-AGC in addition to the discharge current absorbed by the existing TUNER DELAY circuit. The relevant intensity of this additional discharge current and its duration are optimized by way of suitable circuital arrangements in the design of said TUNER DELAY PLUS circuit. The response time is reduced without modifying the time constant of the HF-AGC, which cannot be freely reduced because of inter- and cross-modulation problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.