Accession Number:

AD0921140

Title:

Evaluation of Sensors for SPACETRACK Augmentation (ESSA). Volume IV. Low-Noise Detector Preamplifier Design.

Descriptive Note:

Final technical rept. 6 Jun 73-1 May 74,

Corporate Author:

NORTHROP CORP PALOS VERDES PENINSULA CA ELECTRONICS DIV

Personal Author(s):

Report Date:

1974-06-01

Pagination or Media Count:

106.0

Abstract:

This volume discusses the types and sources of noise that limit the performance of low-level amplifiers. The concepts of signal-to-noise, noise figures and equivalent input noise are reviewed. Because of the relative ease of obtaining measurement data, the equivalent input noise method of analyzing circuits is discussed. The sensor signal-to-noise ratio is shown to be very dependent on loading. The excess noise in a resistor and the concept of a noise index are discussed and the usable ranges of various types of resistor are tabulated. The noise mechanisms and noise models for both the bipolar and the JFET transistors are derived and it is shown that the noise and bandwidth in a bipolar transistor increase with increased base and collector current. It is shown why the FET is potentially superior to the bipolar transistor, especially for high input impedance amplifiers. Six basic input configurations are discussed and some conclusions drawn as to why the Common Emitter or Common Source configurations are theoretically better. Six preamp examples taken from working designs are given. Data on some transistor types are given and a type E311 is selected for evaluation. Recommendations are provided for the continuation of the low-noise video preamp design, including the expansion and refinement of the computer noise program, and fabrication and testing of a low-noise preamplifier circuit.

Subject Categories:

  • Military Intelligence
  • Optical Detection and Detectors
  • Solid State Physics
  • Unmanned Spacecraft
  • Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE