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Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications

Persson, Kristin LU (2010)
Abstract
The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. The body of revolution enables usage of a Fourier transform to reduce the dimensions of the problem. A singular value decomposition is utilized to suppress singular values in the inversion process. A nose-cone radome is diagnosed by recreating the equivalent surface currents on its surface from measured near fields.

It is shown how the radome interacts with the field, creating beam deflection, pattern distortion, etc. The phase shift of the field due to the... (More)
The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. The body of revolution enables usage of a Fourier transform to reduce the dimensions of the problem. A singular value decomposition is utilized to suppress singular values in the inversion process. A nose-cone radome is diagnosed by recreating the equivalent surface currents on its surface from measured near fields.

It is shown how the radome interacts with the field, creating beam deflection, pattern distortion, etc. The phase shift of the field due to the transmission through the radome, i.e., the insertion phase delay, is visualized. Disturbances due to defects, not detectable in the measured near field, are correctly localized by the equivalent surface currents. The alteration of side and flash lobes, together with the introduction of scattering due to the defects, are also visualized. Verification is made by comparison between the calculated and measured far field. (Less)
Please use this url to cite or link to this publication:
author
supervisor
organization
publishing date
type
Thesis
publication status
published
subject
keywords
extinction theorem, inverse source problem, integral representation, radome diagnosis, near-field transformation
pages
123 pages
publisher
Department of Electrical and Information Technology, Lund University
project
Teorel: Radomes and frequency selective surfaces (FMV)
language
English
LU publication?
yes
id
1eeb2710-7966-4e41-be63-c51aff2f0486 (old id 1544626)
date added to LUP
2010-02-16 10:21:15
date last changed
2018-05-29 11:53:10
@misc{1eeb2710-7966-4e41-be63-c51aff2f0486,
  abstract     = {The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. The body of revolution enables usage of a Fourier transform to reduce the dimensions of the problem. A singular value decomposition is utilized to suppress singular values in the inversion process. A nose-cone radome is diagnosed by recreating the equivalent surface currents on its surface from measured near fields. <br/><br>
It is shown how the radome interacts with the field, creating beam deflection, pattern distortion, etc. The phase shift of the field due to the transmission through the radome, i.e., the insertion phase delay, is visualized. Disturbances due to defects, not detectable in the measured near field, are correctly localized by the equivalent surface currents. The alteration of side and flash lobes, together with the introduction of scattering due to the defects, are also visualized. Verification is made by comparison between the calculated and measured far field.},
  author       = {Persson, Kristin},
  keyword      = {extinction theorem,inverse source problem,integral representation,radome diagnosis,near-field transformation},
  language     = {eng},
  note         = {Licentiate Thesis},
  pages        = {123},
  publisher    = {Department of Electrical and Information Technology, Lund University},
  title        = {Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications},
  year         = {2010},
}