LOGARITHMIC AMPLIFIER

Patent · Tue Dec 31 00:00:00 EST 1957

OSTI ID:4329417

De Shong, Jr, J A

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.

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-12-007036
• Assignee: U.S. Atomic Energy Commission
• Patent Number(s): US 2818504
• OSTI ID: 4329417
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-58
• Country of Publication: United States
• Language: English

Related Subjects

PATENTS
AMPLIFIERS
CURRENTS
DIODES
ELECTRON TUBES
FREQUENCY
IONIZATION CHAMBERS
PATENT
SENSITIVITY
STABILITY