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Title: LOGARITHMIC AMPLIFIER

Abstract

A logarithmic current amplifier circuit having a high sensitivity and fast response is described. The inventor discovered the time constant of the input circuit of a system utilizing a feedback amplifier, ionization chamber, and a diode, is inversely proportional to the input current, and that the amplifier becomes unstable in amplifying signals in the upper frequency range when the amplifier's forward gain time constant equals the input circuit time constant. The described device incorporates impedance networks having low frequency response characteristic at various points in the circuit to change the forward gain of the amplifler at a rate of 0.7 of the gain magnitude for every two times increased in frequency. As a result of this improvement, the time constant of the input circuit is greatly reduced at high frequencies, and the amplifier response is increased.

Inventors:
Issue Date:
OSTI Identifier:
4329417
Patent Number(s):
2818504
Assignee:
U.S. Atomic Energy Commission
Patent Classifications (CPCs):
H - ELECTRICITY H03 - BASIC ELECTRONIC CIRCUITRY H03F - AMPLIFIERS
NSA Number:
NSA-12-007036
Resource Type:
Patent
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-58
Country of Publication:
United States
Language:
English
Subject:
PATENTS; AMPLIFIERS; CURRENTS; DIODES; ELECTRON TUBES; FREQUENCY; IONIZATION CHAMBERS; PATENT; SENSITIVITY; STABILITY

Citation Formats

De Shong, Jr, J A. LOGARITHMIC AMPLIFIER. United States: N. p., 1957. Web.
De Shong, Jr, J A. LOGARITHMIC AMPLIFIER. United States.
De Shong, Jr, J A. Tue . "LOGARITHMIC AMPLIFIER". United States.
@article{osti_4329417,
title = {LOGARITHMIC AMPLIFIER},
author = {De Shong, Jr, J A},
abstractNote = {A logarithmic current amplifier circuit having a high sensitivity and fast response is described. The inventor discovered the time constant of the input circuit of a system utilizing a feedback amplifier, ionization chamber, and a diode, is inversely proportional to the input current, and that the amplifier becomes unstable in amplifying signals in the upper frequency range when the amplifier's forward gain time constant equals the input circuit time constant. The described device incorporates impedance networks having low frequency response characteristic at various points in the circuit to change the forward gain of the amplifler at a rate of 0.7 of the gain magnitude for every two times increased in frequency. As a result of this improvement, the time constant of the input circuit is greatly reduced at high frequencies, and the amplifier response is increased.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1957},
month = {12}
}