A STUDY OF THE NOISE CHARACTERISTICS OF ANTENNAS DUE TO EXTERNAL THERMAL NOISE SOURCES

Abstract

A study is described of the antenna noise char-ACTERISTICS DUE TO THERMAL NOISE GENERATED BY HOT OBJECTS EXTERNAL TO THE ANTENNA AND FED INTO THE ANTENNA THROUGH THE ELECTROMAGNETIC FIELD. Information was obtained that can be used to design antennas with improved signal-to-noise ratios. Thermal noise characteristics of an antenna are not unique, but are a complex function of environment and orientation as well as pattern, and so must be investigated for each individual antenna with respect to its particular location and application. This investigation was only concerned with a parabolic reflecting antenna over flat terrain with the main beam pointed vertically upwards. Methods of decreasing received thermal noise, and hence increasing the gain-to-noise ratio, by shielding are presented. A novel type of Cassegrain feed is also discussed as a possible means of obtaining more desirable illumination of the main aperture.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1961
Accession Number
AD0271760

Entities

People

  • David F. Brown
  • H. N. Dawirs
  • R. Caldecott
  • R. Lawrie

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Angle Of Incidence
  • Antennas
  • Cassegrain Antennas
  • Command And Control
  • Electrical Engineering
  • Electromagnetic Fields
  • Electromagnetic Radiation
  • Low Noise
  • Microwave Antennas
  • Parabolic Antennas
  • Radiation
  • Reflectors
  • Shielding
  • Thermal Radiation
  • Three Dimensional
  • X Band

Fields of Study

  • Engineering

Readers

  • Phased Array Antenna Design.
  • Radar Systems Engineering.
  • Rocket Propulsion.