Date of Award

3-1997

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Department of Electrical and Computer Engineering

First Advisor

Vittal P. Pyati, PhD

Abstract

The electromagnetic scattering from an arbitrarily shaped open cavity embedded in a perfectly conducting, infinite ground plane is examined. The cavity is filled with a linear, isotropic, homogeneous material. The fields in the cavity interior and above the ground plane are expressed in terms of the tangential fields on the cavity surface and aperture. A coupled set of three integral equations is developed governing the tangential fields on the aperture and cavity surface. The support of the unknown tangential fields is finite. A moment-method based algorithm to approximate the solution to the integral equations for axisymmetric geometries is developed. The unknown tangential fields are expanded using piecewise-linear functions in the elevation plane and complex exponentials in the azimuth plane. Orthogonality is exploited to reduce the size of the matrix. The algorithm yields a well-conditioned numerical solution. The solution obeys the edge condition at the aperture rim. The integral equations are uniquely solvable at frequencies where other integral equation-based techniques admit spurious solutions. Radar cross section calculations are compared to experimental measurements of full-scale physical models. Results show that an open cavity can serve as an effective radar cross section enhancement device.

AFIT Designator

AFIT-DS-ENG-96-16

DTIC Accession Number

ADA327139

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