umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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
Time-Domain Sensitivity Analysis for Conductivity Distribution in Maxwell's Equations
Umeå University, Faculty of Science and Technology, Department of Computing Science.ORCID iD: 0000-0002-1318-7519
Umeå University, Faculty of Science and Technology, Department of Computing Science.
Umeå University, Faculty of Science and Technology, Department of Computing Science.ORCID iD: 0000-0003-0473-3263
2015 (English)Report (Other academic)
Abstract [en]

We present expressions for the derivatives of the outgoing signal in coaxial cables with respect to the conductivity distribution in a specific domain. The derived expressions can be used with gradient-based optimization methods to design metallic electromagnetic devices, such as antennas and waveguides. We use the adjoint-field method to derive the expressions and the derivation is based on the 3D time-domain Maxwell's equations. We present two derivative expressions; one expression is derived in the continuous case and the second is derived based on the FDTD discretization of Maxwell's equations, including the uniaxial perfectly match layer (UPML) to simulate the radiation boundary condition. The derivatives are validated through a numerical example, where derivatives computed by the adjoint-field method are compared against derivatives computed with finite differences. Up to 7 digits precision matching is obtained.

Place, publisher, year, edition, pages
Umeå: Umeå University , 2015. , 20 p.
Series
UMINF 15.06
Keyword [en]
Maxwell's equations, antennas, waveguide, finite-difference time-domain (FDTD), gradient-based optimization, adjoint-field problem, sensitivity analysis.
National Category
Computer Science
Research subject
Computer Science
Identifiers
URN: urn:nbn:se:umu:diva-79483OAI: oai:DiVA.org:umu-79483DiVA: diva2:642030
Note

Originally published in licentiate thesis "Metallic Antenna Design Based on Topology Optimization Techniques",  under the title

"Sensitivity Analysis for Conductive Material Distribution Using the Time-Domain Maxwell’s Equations"

Available from: 2013-08-20 Created: 2013-08-20 Last updated: 2017-04-11Bibliographically approved
In thesis
1. Metallic antenna design based on topology optimization techniques
Open this publication in new window or tab >>Metallic antenna design based on topology optimization techniques
2013 (English)Licentiate thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Umeå: Department of Computing Science, Umeå University, 2013. 15 p.
Series
UMINF, ISSN 0348-0542 ; 13.08
National Category
Computer and Information Science
Identifiers
urn:nbn:se:umu:diva-76691 (URN)978-91-7459-649-6 (ISBN)
Presentation
2013-05-03, Mit-huset, MC313, Umeå universitet, Umeå, 10:15
Available from: 2013-07-10 Created: 2013-07-10 Last updated: 2013-08-20Bibliographically approved
2. Topology Optimization of Antennas and Waveguide Transitions
Open this publication in new window or tab >>Topology Optimization of Antennas and Waveguide Transitions
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis introduces a topology optimization approach to design, from scratch, efficient microwave devices, such as antennas and waveguide transitions. The design of these devices is formulated as a general optimization problem that aims to build the whole layout of the device in order to extremize a chosen objective function. The objective function quantifies some required performance and is evaluated using numerical solutions to the 3D~Maxwell's equations by the finite-difference time-domain (FDTD) method. The design variables are the local conductivity at each Yee~edge in a given design domain, and a gradient-based optimization method is used to solve the optimization problem. In all design problems, objective function gradients are computed based on solutions to adjoint-field problems, which are also FDTD discretization of Maxwell's equations but solved with different source excitations. For any number of design variables, the computation of the objective function gradient requires one solution to the original field problem and one solution to the associated adjoint-field problem. The optimization problem is solved iteratively using the globally convergent Method of Moving Asymptotes (GCMMA).

By the proposed approach, various design problems, including tens of thousands of design variables, are formulated and solved in a few hundred iterations. Examples of solved design problems are the design of wideband antennas, dual-band microstrip antennas, wideband directive antennas, and wideband coaxial-to-waveguide transitions. The fact that the proposed approach allows a fine-grained control over the whole layout of such devices results in novel devices with favourable performance. The optimization results are successfully verified with a commercial software package. Moreover, some devices are fabricated and their performance is successfully validated by experiments.

Place, publisher, year, edition, pages
Umeå University: Umeå University, 2015. 29 p.
Keyword
Maxwell's equations, topology optimization, antennas, waveguide transition, finite-difference time-domain, gradient-based optimization, adjoint-field problem, microwave devices.
National Category
Computer Science
Research subject
Computing Science
Identifiers
urn:nbn:se:umu:diva-102505 (URN)978-91-7601-255-0 (ISBN)
Public defence
2015-05-26, Naturvetarhuset, N450, Umeå universitet, Umeå, 10:15 (English)
Opponent
Supervisors
Available from: 2015-05-05 Created: 2015-04-27 Last updated: 2017-04-11Bibliographically approved

Open Access in DiVA

fulltext(243 kB)151 downloads
File information
File name FULLTEXT01.pdfFile size 243 kBChecksum SHA-512
527c870c7d034eab17d222a31b97d983a8bb4d8a5cbab7911e091aaaa371142877f4c9b181ca066fb76beb8b6244b5edc3378e4dbcf692eb22f72dbbade8f98b
Type fulltextMimetype application/pdf

Authority records BETA

Hassan, EmadeldeenWadbro, EddieBerggren, Martin

Search in DiVA

By author/editor
Hassan, EmadeldeenWadbro, EddieBerggren, Martin
By organisation
Department of Computing Science
Computer Science

Search outside of DiVA

GoogleGoogle Scholar
Total: 151 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

urn-nbn

Altmetric score

urn-nbn
Total: 618 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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