Frequency response of E polarized sources over a lossy earth in the presence of two-dimensional shielding structures.

Persistent Link:
http://hdl.handle.net/10150/184605
Title:
Frequency response of E polarized sources over a lossy earth in the presence of two-dimensional shielding structures.
Author:
Baertlein, Brian Allen.
Issue Date:
1988
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Electromagnetic shielding by thin, perfectly conducting, two dimensional cylindrical shells over a lossy earth is investigated. The temporal frequency response of the exterior field due to a line source within the shell is computed for a shell described by a three sided, rectilinear structure whose opening faces the earth. The formulation allows shells of arbitrary cross-sectional shape to be analyzed. The earth is modeled as a homogeneous half-space with a planar boundary and frequency dependent electromagnetic properties. Two solution techniques are presented. In the first, the induced current is obtained through a numerical solution of the electric field integral equation (EFIE) at many discrete frequencies. It is found that the applicability of this formulation is limited since in the case of effective shielding, fields calculated from the EFIE are very sensitive to numerical errors. In the second technique the EFIE is again solved for the currents induced on the shell. The induced currents are used to calculate the electric field in the aperture which is used to solve a combined-source integral equation (CSIE) for the external fields. It is found that the CSIE does not suffer from the numerical ill-conditioning that plagues the EFIE, and is well behaved at all frequencies. Numerical results are presented which indicate that the shell-earth combination is very effective in shielding the internal source. Interior modes are weakly transmitted to the interior for the case of a purely dielectric earth. For a lossy half-space the resonances of the closed shell are enhanced. The related topic of scattering by perfectly conducting objects over a lossy earth is addressed. Numerical formulations for the solution of the integral equations are presented which deal with several troublesome aspects of the problem, including the incorporation of the correct edge singularities.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Shielding (Electricity); Antennas (Electronics)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Electrical and Computer Engineering; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleFrequency response of E polarized sources over a lossy earth in the presence of two-dimensional shielding structures.en_US
dc.creatorBaertlein, Brian Allen.en_US
dc.contributor.authorBaertlein, Brian Allen.en_US
dc.date.issued1988en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractElectromagnetic shielding by thin, perfectly conducting, two dimensional cylindrical shells over a lossy earth is investigated. The temporal frequency response of the exterior field due to a line source within the shell is computed for a shell described by a three sided, rectilinear structure whose opening faces the earth. The formulation allows shells of arbitrary cross-sectional shape to be analyzed. The earth is modeled as a homogeneous half-space with a planar boundary and frequency dependent electromagnetic properties. Two solution techniques are presented. In the first, the induced current is obtained through a numerical solution of the electric field integral equation (EFIE) at many discrete frequencies. It is found that the applicability of this formulation is limited since in the case of effective shielding, fields calculated from the EFIE are very sensitive to numerical errors. In the second technique the EFIE is again solved for the currents induced on the shell. The induced currents are used to calculate the electric field in the aperture which is used to solve a combined-source integral equation (CSIE) for the external fields. It is found that the CSIE does not suffer from the numerical ill-conditioning that plagues the EFIE, and is well behaved at all frequencies. Numerical results are presented which indicate that the shell-earth combination is very effective in shielding the internal source. Interior modes are weakly transmitted to the interior for the case of a purely dielectric earth. For a lossy half-space the resonances of the closed shell are enhanced. The related topic of scattering by perfectly conducting objects over a lossy earth is addressed. Numerical formulations for the solution of the integral equations are presented which deal with several troublesome aspects of the problem, including the incorporation of the correct edge singularities.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectShielding (Electricity)en_US
dc.subjectAntennas (Electronics)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineElectrical and Computer Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.proquest8907950en_US
dc.identifier.oclc701908635en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.