Accession Number:

ADA243877

Title:

Electromagnetic Scattering from Dielectric Pyramidal Tips

Descriptive Note:

Master's thesis,

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s):

Report Date:

1991-12-01

Pagination or Media Count:

122.0

Abstract:

This thesis investigated the electromagnetic scattering from conducting, lossless dielectric, and lossy dielectric absorber pyramids. The backscatter from pyramids was measured and a time gate was applied to isolate the scattering from the tips. The measured results were compared to predictions from an approximate Uniform Theory of Diffraction UTD solution for scattering by a dielectric corner. The accuracy of the corner diffraction solution was found to be dependent on the polarization of the incident electric field. The accuracy of the UTD solution was also dependent on the aspect angle to the pyramid the UTD solution gave a nominally correct answer within 25 degrees of nose-on incidence at other angles the accuracy was better or worse depending on field polarization. The accuracy of the corner diffraction solution when applied to a dielectric was primarily dependent on the tip angle of the pyramid, with more acute angles giving the least accurate results. At incidence angles near nose-on to absorber pyramids, scattering from internal inhomogeneities was the dominant scattering mechanism. At incidence angles away from nose-on, the UTD solution provided reasonably accurate results. The approximate UTD dielectric corner solution was found to be accurate for many engineering applications. Author

Subject Categories:

  • Electricity and Magnetism
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE