Electromagnetic Scattering from Impedance Strips and Impedance-Loaded Conducting Strips

Abstract

This paper investigates the scattering from impedance strips and impedance-loaded conducting strips. The UTd diffraction coefficient for an edge in a conductor is heuristically modified for impedance edges and junctions. Essentially, this is done by scaling the UTD diffraction coefficients according to changes in the geometrical optics field. The new diffraction coefficients are then used to investigate the scattering from impedance strips and impedance- loaded conducting strips. Both uniform and tapered impedances are considered. Results are compared to moment method and physical optics predictions and to measured data. The scattering pattern of a uniform impedance strip was seen to behave as that for a conducting strip, but at a lower level. However, tapering the impedance was seen to significantly decrease the sidelobe levels relative to the main lobe. Also, applying an impedance load to a conducting strip reduced the sidelobe levels. This was most pronounced for loads of tapered impedance. the modified UTD approach accurately predicted the sidelobe levels and locations for the simple impedance strips, and worked fairly well for the impedance-loaded conducting strips. The predictions for all geometries were better near broadside incidence than near edge-on.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1990
Accession Number
ADA230526

Entities

People

  • Marck C. Heaton

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Air Force
  • Aircrafts
  • Current Density
  • Diffraction
  • Electric Fields
  • Electromagnetic Scattering
  • Equations
  • Frequency
  • Geometry
  • Integral Equations
  • Magnetic Fields
  • Materials
  • Optics
  • Plane Waves
  • Scattering
  • Specific Volume
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Microwave Engineering.
  • Phased Array Antenna Design.
  • Structural Dynamics.