Browse Prior Art Database

Negative Resistance Generator

IP.com Disclosure Number: IPCOM000076997D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Bigbie, SE: AUTHOR

Abstract

A current source, attached to input terminal 1 provides base current for transistor 2. Resistor 3 functions as a feedback resistor by determining the amount of current fed back to the base of transistor 2. Because transistors 4 and 5 are a matched pair and the bases are connected in common, their collector currents will be nearly equal.

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Negative Resistance Generator

A current source, attached to input terminal 1 provides base current for transistor 2. Resistor 3 functions as a feedback resistor by determining the amount of current fed back to the base of transistor 2. Because transistors 4 and 5 are a matched pair and the bases are connected in common, their collector currents will be nearly equal.

As base current supplied to input terminal 1 is increased, the voltage drop across load impedance 6 also increases, lowering the potential at the collector of transistor 2. This lowered potential has the effect of decreasing the collector current through transistors 4 and 5. The reduced collector current through transistor 5 represents an increased impedance at input terminal 1. A decrease in the current supplied to input terminal 1 has the opposite effect, since the collector current of transistor 5 is reduced.

The circuit will operate as a self-starting oscillator, if a current source is connected to input terminal 1 and load impedance 6 is an L-C resonant circuit. The circuit is well suited for integrated circuit fabrication techniques and is useful for oscillator stabilization, switching networks or the like.

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