INVESTIGATION OF CONTROL TECHNIQUES FOR ELECTRO MAGNETIC INTERACTION IN LOW-LEVEL CIRCUITS.

Abstract

Various methods are preseo effectively avoid or reduce electromagnetic interference in low-level circuits. Video amplifiers are examined for interference in the form of inter modulation and cross-modulation products. We have found that: (1) Interference levels are not greatly affected by temperature in a well designed circuit, (2) The trade-off in gain by using a degenerative-emitter configuration is extremely helpful in reducing the effects of interference, and (3) In cases where there is de sign freedom, the use of two low-gain stages cas caded is far superior to a single high-gain stage, with respect to interference levels. Experimental data show these results, and theory is developed that is consistent with the observed results. Two logic blocks are examined by investigating their susceptibility to interfering signals on trigger input and power-supply leads. In par ticular, a bistable and an astable multivibrator are chosen. The results of this investigation show that single isolated circuits of this type are relatively immune to all but very large interfering signals. Experimental data and an analysis of the coupling mechanism that causes failure are presented. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1963
Accession Number
AD0419108

Tags

DTIC Thesaurus Topics

  • Amplifiers
  • Circuits
  • Couplings
  • Cross Modulation
  • Electromagnetic Interference
  • Experimental Data
  • Gain
  • High Gain
  • Modulation
  • Multivibrators
  • Power Supplies
  • Video
  • Video Amplifiers

Fields of Study

  • Engineering
  • Physics

Readers

  • Electrical Engineering
  • Electronics Engineering
  • Radio communications and signal processing.