Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Application of nyström method for the solution of time domain electric field integral equation
Download
index.pdf
Date
2014
Author
Selçuk, Gökhun
Metadata
Show full item record
Item Usage Stats
99
views
51
downloads
Cite This
Solution of surface scattering problems with electric field integral equation (EFIE) requires careful treatment of singularities introduced by the 3D dyadic Green’s function when source and observation points are close to each other or coincide. One may either utilize the divergence conforming basis and testing functions to reduce the order of singularity or directly deal with singularities via analytical singularity extraction methods. The latter method is a not a commonly used one although it enables use of less complicated pulse-like basis functions and no attempt is done to apply it in time domain. In this study a new time domain formulation for EFIE is obtained. Self-cell contribution is evaluated by an efficient treatment of hypersingular integrals. By using Hadamard finite part interpretation new formulas are introduced for hypersingular integrals on planar surfaces. Also same interpretation is used to obtain explicit expressions for hypersingular integrals on nonplanar surfaces and these expressions improve the accuracy significantly. Close cell contribution is evaluated by increasing the number of quadrature points and applying interpolation. Explicit marching on in time (MOT) scheme along with new formulation is applied to solve transient scattering from perfectly electric conductor (PEC) surfaces. Agreement with analytical results is obtained.
Subject Keywords
Electric fields.
,
Integral equations.
,
Hadamard matrices.
,
Transients (Electricity).
URI
http://etd.lib.metu.edu.tr/upload/12618099/index.pdf
https://hdl.handle.net/11511/23954
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Linear-linear basis functions for MLFMA solutions of magnetic-field and combined-field integral equations
Ergül, Özgür Salih (2007-04-01)
We present the linear-linear (LL) basis functions to improve the accuracy of the magnetic-field integral equation (MFIE) and the combined-field integral equation (CFIE) for three-dimensional electromagnetic scattering problems involving closed conductors. We consider the solutions of relatively large scattering problems by employing the multilevel fast multipole algorithm. Accuracy problems of MFIE and CFIE arising from their implementations with the conventional Rao-Wilton-Glisson (RWG) basis functions can...
Improving the accuracy of the surface integral equations for low-contrast dielectric scatterers
Ergül, Özgür Salih (2007-06-15)
Solutions of scattering problems involving low-contrast dielectric objects are considered by employing surface integral equations. A stabilization procedure based on extracting the non-radiating part of the induced currents is applied so that the remaining radiating currents can be modelled appropriately and the scattered fields from the low-contrast objects can be calculated with improved accuracy. Stabilization is applied to both tangential (T) and normal (N) formulations in order to use the benefits of d...
Evaluation of Hypersingular Integrals on Non-planar Surfaces
Selcuk, Gokhun; Koç, Seyit Sencer (2014-05-16)
Solving electric field integral equation (EFIE) with Nystrom method requires accurate evaluation of hypersingular surface integrals since this method does not use divergence conforming basis and testing functions. The success of the method also depends on accurate representation of non-planar characteristics of the scattering object. In this study Hadamard finite part interpretation is used to evaluate hypersingular integrals over non-planar surfaces, which are represented by their Taylor series expansions....
Implementation of the equivalence principle algorithm for potential integral equations
Farshkaran, Ali; Ergül, Özgür Salih; Department of Electrical and Electronics Engineering (2018)
In this thesis, a domain decomposition method based on the Huygens' principle for integral equations is studied. Step-by-step development of equivalence principle algorithm (EPA) is described for solving arbitrary shaped perfect electric conductor (PEC) and penetrable objects. The main advantage of EPA is its efficiency thanks to the enhanced conditioning hence accelerated iterative solutions of the matrix equations derived from discretizations. For further enhancing the efficiency, the multilevel fast mult...
Combined-field solution of composite geometries involving open and closed conducting surfaces
Ergül, Özgür Salih (2005-04-07)
Combined-field integral equation (CFIE) is modified and generalized to formulate the electromagnetic problems of composite geometries involving both open and closed conducting surfaces. These problems are customarily formulated with the electric-field integral equation (EFIE) due to the presence of the open surfaces. With the new definition and application of the CFIE, iterative solutions of these problems are now achieved with significantly improved efficiency compared to the EFIE solution, without sacrifi...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
G. Selçuk, “Application of nyström method for the solution of time domain electric field integral equation,” Ph.D. - Doctoral Program, Middle East Technical University, 2014.