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Free Carrier Absorption Amplifier

IP.com Disclosure Number: IPCOM000097907D
Original Publication Date: 1961-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Foglia, HR: AUTHOR

Abstract

In amplifiers or triggers, a semiconductor material is employed exhibiting a free carrier absorption phenomenon. Carrier injection is increased at a PN junction, either electrically or by radiation at the junction, to change the conductivity 0 of the semiconductor.

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Free Carrier Absorption Amplifier

In amplifiers or triggers, a semiconductor material is employed exhibiting a free carrier absorption phenomenon. Carrier injection is increased at a PN junction, either electrically or by radiation at the junction, to change the conductivity 0 of the semiconductor.

The amplifier circuit has a signal source G, serially connected to a load R, and a parallel LC tank circuit. The inductance L of the circuit is provided by a silicon core S having P and N regions. A variable voltage source EB is connected across S. With a small value of EB, the LC tank is tuned to source G, providing a small voltage across R since Qo of the circuit is high. The A. C. resistive component of the circuit is changed by changing EB. Changing EB changes the conductivity sigma of S. The eddy currents in S are directly related to the conductivity sigma of S. A higher conductivity sigma provides higher eddy currents through S. Changing EB changes the Q of the circuit to a value Q1, increasing the voltage drop across R.

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