Analysis of Composite Structures Involving Near-Zero-Index Materials

Date

2019-01-01

Author

Koyaz, Yesim
İbili, Hande
Karaosmanoglu, Bariscan
Ergül, Özgür Salih

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

236
views

0
downloads

We consider numerical solutions of electromagnetic problems involving near-zero-index materials with permittivity and/or permeability values close to zero. These types of problems are inherently multiscale due to the large variety of the wavelength from very large values to ordinary values in the same problem. In addition to developing a stable formulation for extreme values of the intrinsic impedance, we employ a broadband multilevel fast multipole algorithm based on approximate diagonalization for efficient solutions. Examples involving nearzero -index materials inside ordinary waveguides are presented to demonstrate interesting electromagnetic responses of these exotic materials, as well as the effectiveness of the developed solver.

Subject Keywords

Composite materials, Computational electromagnetics, Electromagnetic wave scattering, Matrix algebra, Optical metamaterials, Permeability, Permittivity

URI

https://hdl.handle.net/11511/34579

DOI

https://doi.org/10.1109/comcas44984.2019.8958126

Collections

Department of Electrical and Electronics Engineering, Conference / Seminar

Suggestions

OpenMETU
Core

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...
Investigation of rough surface scattering of electromagnetic waves using finite element method Aşırım, Özüm Emre; Kuzuoğlu, Mustafa; Özgün, Özlem; Department of Electrical and Electronics Engineering (2013) This thesis analyzes the problem of electromagnetic wave scattering from rough surfaces using finite element method. Concepts like mesh generation and random rough surface generation will be discussed firstly. Then the fundamental concepts of the finite element method which are the functional form of a given partial differential equation, implementation of the element coefficient matrices, and the assemblage of elements will be discussed in detail. The rough surface and the overall mesh geometry will be imp...
Solutions of electromagnetics problems involving hundreds of millions of unknowns with parallel multilevel fast multipole algorithmt Ergül, Özgür Salih (2009-06-05) We present the solution of extremely large electromagnetics problems formulated with surface integral equations (SIEs) and discretized with hundreds of millions of unknowns. Scattering and radiation problems involving three-dimensional closed metallic objects are formulated rigorously by using the combined-field integral equation (CFIE). Surfaces are discretized with small triangles, on which the Rao-Wilton-Glisson (RWG) functions are defined to expand the induced electric current and to test the boundary c...
Accurate analysis of metamaterials involving finite arrays of split-ring resonators and thin wires Gurel, Levent; Ergül, Özgür Salih; Unal, Alper (2007-03-30) In order to gain physical insight into how some metamaterial structures behave, we report our results obtained by accurate numerical solutions of electromagnetic problems related to various constructions of split-ring-resonators (SRRs) and thin wires (TWs). Single and multiple layers of arrays of SRRs and TWs are investigated in detail using the electric-field integral equation. Without utilizing any homogenization techniques, we accurately model large numbers of unit cells that translate into very large co...
Efficient solution of the electric and magnetic current combined-field integral equation with the multilevel fast multipole algorithm and block-diagonal preconditioning Ergül, Özgür Salih (2009-11-04) We consider the efficient solution of electromagnetics problems involving dielectric and composite dielectric-metallic structures, formulated with the electric and magnetic current combined-field integral equation (JMCFIE). Dense matrix equations obtained from the discretization of JMCFIE with Rao-Wilton-Glisson functions are solved iteratively, where the matrix-vector multiplications are performed efficiently with the multilevel fast multipole algorithm. JMCFIE usually provides well conditioned matrix equa...

Citation Formats

Y. Koyaz, H. İbili, B. Karaosmanoglu, and Ö. S. Ergül, “Analysis of Composite Structures Involving Near-Zero-Index Materials,” 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34579.