Gain-controlled amplifier
US3950708A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 4, 1974 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Nov 4, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03G3/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The collector potential of a resistively loaded common base amplifier tends to change if its emitter current is altered to affect its emitter resistance and thereby control its gain. This tendency arises because of the change in transistor collector current, which is substantially the same value as the change in its emitter current, acting on the resistive load in accordance with Ohm's Law. A control current is applied to diode means to develop a potential thereacross, which is applied to the base emitter junction of the transistor to control its emitter current. This establishes a known proportion of control current to transistor emitter and collector currents. Changes in the transistor collector current are then compensated for by another current proportional to the control current applied at the transistor collector electrode, thereby to counteract the tendency for the transistor collector potential to change as the gain of the common-base transistor amplifier is changed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.