Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
On signal processing and electromagnetic modelling: applications in antennas and transmission lines
Responsible organisation
2007 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This doctoral thesis is comprised of five parts. The first three parts concern signal processing and electromagnetic modelling of multiport antennas. The last two parts concern signal processing and transmission line theory applied to wave splitting on transmission lines. In Part I, the spherical vector wave expansion of the electromagnetic field is used to completely characterize a multiport antenna. A general framework for modelling an antenna configuration based on measurement data and numerical computation is obtained. The generic electromagnetic model for arbitrary multiport antennas or vector sensors is applied in direction of arrival (DOA) estimation. Next, in Part II using the generic electromagnetic model (from Part I), we obtain the Cramér–Rao bound (CRB) for DOA and polarization estimation using arbitrary multiport antennas. In the Gaussian case, the CRB is given in terms of the transmission matrix, the spherical vector harmonics and its spatial derivatives. Numerical examples using an ideal Tripole antenna array and a non-ideal Tetrahedron antenna array are included. In Part III, the theory of optimal experiments is applied to a cylindrical antenna near-field measurement setup. The D-optimal (determinant) formulation using the Fisher information matrix of the multipole coefficients in the spherical wave expansion of the electrical field result in the optimal measurement positions. The estimation of the multipole coefficients and corresponding electric field using the optimal measurement points is studied using numerical examples and singular value analysis. Further, Part IV describes a Digital Directional Coupler (DDC), a device for wave splitting on a transmission line. The DDC is a frequency domain digital wave splitter based on two independent wide-band measurements of the voltage and the current. A calibration of the digital processor is included to account for the particular transmission line and the sensors that are employed. Properties of the DDC are analyzed using the CRB and an experiment where wave splitting was conducted on a coaxial–cable is accounted for. Finally, in Part V the DDC has been designed and implemented for wave splitting on a medium voltage power cable in a power distribution station using low cost wide–band sensors. Partial discharge measurements are conducted on cross–linked polyethylene insulated power cables. The directional separation capabilities of the DDC are visualized and utilized to separate multiple reflections from partial discharges based on the direction of travel.

Place, publisher, year, edition, pages
Ronneby: Blekinge Institute of Technology , 2007. , 135 p.
Series
Blekinge Institute of Technology Doctoral Dissertation Series, ISSN 1653-2090 ; 8
Keyword [en]
Vector sensors, Statistical signal processing, Antennas, Directional Coupler, Tranmission lines, Partial discharge
National Category
Signal Processing
Identifiers
URN: urn:nbn:se:bth-00363Local ID: oai:bth.se:forskinfo62A51CD9A6F3D716C12572C1003F0063ISBN: 978-91-7295-109-9 (print)OAI: oai:DiVA.org:bth-00363DiVA: diva2:837055
Available from: 2012-09-18 Created: 2007-04-18 Last updated: 2017-03-16Bibliographically approved

Open Access in DiVA

fulltext(6414 kB)171 downloads
File information
File name FULLTEXT01.pdfFile size 6414 kBChecksum SHA-512
a3516005ca2b098b9f2f93df7a9b4b8f3aad8e977d93ef359b4d002367213e71adb47e63a5f0e035d7f940b335dc79ddb98b81d94b92da1d0ad7f6182046c9ed
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Lundbäck, Jonas
Signal Processing

Search outside of DiVA

GoogleGoogle Scholar
Total: 171 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 43 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf