Design and Fabrication of Stripline Microwave Surface-Crack Detector for Projectiles

Abstract

A self-contained coupled-stripline crack detector was built, tested, and evaluated. This detector makes use of the capability of two coupled striplines to support two orthogonal modes. The two conductors, printed on a dielectric sheet whose other side is clad with metal, scan the metal surface at a close distance. The metal surface then becomes part of the RF ground conductor. The two striplines are excited in one mode and a crack in the metal surface couples energy into the other mode, because the crack upsets the symmetry of the coupled lines. A complete detector system was built consisting of RF source, modulator, coupled-stripline detector with even-mode exciter and odd-mode receiver, and the necessary low-frequency amplifiers and detectors. Extensive measurements were performed with a planar detector on planar plates and a curved detector on 175-mm artillery shell bodies.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1974
Accession Number
ADA001624

Entities

People

  • Lester Feinstein
  • Ulrich H. Gysel

Organizations

  • SRI International

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplifiers
  • Bandpass Filters
  • Circuit Boards
  • Closed Loop Systems
  • Correlation Techniques
  • Cross Correlation
  • Detection
  • Detectors
  • Electronic Circuits
  • High Pass Filters
  • Materials
  • Oscillators
  • Power Dividers
  • Signal Processing
  • Strip Transmission Lines
  • Symmetry
  • Transmission Lines

Fields of Study

  • Physics

Readers

  • Materials Science (Mechanical Engineering).
  • Microwave Engineering.
  • Nuclear and Radiation Engineering.