Dissertation
APPLICATIONS OF, AND ENHANCEMENTS TO, FINITE-DIFFERENCE-BASED SOLUTIONS TO PROBLEMS IN ELECTROMAGNETICS
Doctor of Philosophy (PhD), Washington State University
01/2013
Handle:
https://hdl.handle.net/2376/5057
Abstract
We describe how the analytic field propagation (AFP) technique can be coupled with a total-field/scattered-field (TFSF) boundary to obtain a novel implementation of a "gen- eralized" total-field/scattered-field (G-TFSF) boundary. Using a G-TFSF boundary, one can directly model "infinite" objects, such as wedges, corners, and edges. Example applications of the AFP-based G-TFSF technique are shown that model not just scatter- ing from wedges, but also scattering from 3D "defects" in wedges or edges. As described in the thesis, the AFP-based G-TFSF method described in this thesis possesses various advantages over the original G-TFSF method presented by Anantha and Taflove [IEEE Trans. Antennas and Propagat., 50(10):1337-1349, 2002]. We revisit the long-standing debate surrounding whether or not "enhanced total internal reflection" (ETIR) is possible. ETIR implies that the magnitude of the reflection coefficient is greater than unity and is conjectured to be possible when a field is incident from a lossless material to a gainy material beyond the critical angle. We examine this problem using FDTD modeling where the Poynting vector is used to examine the flow of energy. The two-dimensional simulations employ a Gaussian incident beam and make no a priori assumptions about the reflection coefficient. We consider illumination of gainy, lossless, and lossy materials. For gainy material, the magnitude of the reflection coefficient is found to be greater than unity, but there is a delay between when energy enters the gainy material and when the "excess" energy is reflected from the interface. Corona onset conditions in periodic micro- and nano-materials are analyzed via a dis- cretization of Gauss's Law. A numerical model is developed to examine the mechanism by which nano-materials may provide superior performance relative to micro-materials. Starting from a single-cell layered structure, the electrical field distribution is computed using the finite difference method (FDM) and a sparse matrix solver.
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Details
- Title
- APPLICATIONS OF, AND ENHANCEMENTS TO, FINITE-DIFFERENCE-BASED SOLUTIONS TO PROBLEMS IN ELECTROMAGNETICS
- Creators
- Zhen Chen
- Contributors
- John B. Schneider (Advisor)Robert G. Olsen (Committee Member)Shira L. Broschat (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 94
- Identifiers
- 99900581738801842
- Language
- English
- Resource Type
- Dissertation