Browse Prior Art Database

Low Noise Amplifier

IP.com Disclosure Number: IPCOM000073479D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

Liu, CC: AUTHOR

Abstract

This amplifier is directed to situations in which the signal source and preamplifier are positioned closely adjacent each other and are of small size. It is especially aimed at magnetic head amplifiers where the preamplifiers are positioned on or closely adjacent to the head itself.

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Low Noise Amplifier

This amplifier is directed to situations in which the signal source and preamplifier are positioned closely adjacent each other and are of small size. It is especially aimed at magnetic head amplifiers where the preamplifiers are positioned on or closely adjacent to the head itself.

The signal-to-noise (SNR) power ratio at the amplifier output is

(Image Omitted)

where Eg = rms signal amplitude; fo = signal frequency; k = Boltzmann constant,
1.38 x 10/-23/joules/ok; T = absolute temperature, degrees Kelvin; H = voltage gain function of the amplifier; Zin = input impedance of the amplifier; Zs = source impedance; and Rno = equivalent noise resistance of the amplifier. SNR is optimized by properly adjusting the amplifier operating point through adjustment of Ic, the collector current, because H, Zin, and Mno are dependent on the collector current and device parameters. SNR optimization is carried out in the frequency range of interest to produce optimization as shown in the graph.

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