Ray based finite difference method for time domain electromagnetics

Download

index.pdf

Date

2005

Author

Çiydem, Mehmet

Metadata

Show full item record

Item Usage Stats

206
views

111
downloads

In this study, novel Ray Based finite difference method for Time Domain electromagnetics(RBTD) has been developed. Instead of solving Maxwell̕s hyperbolic partial differential equations directly, Geometrical Optics tools (wavefronts, rays) and Taylor series have been utilized. Discontinuities of electromagnetic fields lie on wavefronts and propagate along rays. They are transported in the computational domain by transport equations which are ordinary differential equations. Then time dependent field solutions at a point are constructed by using Taylor series expansion in time whose coefficients are these transported distincontinuties. RBTD utilizes grid structure conforming to wave fronts and rays and treats all electromagnetic problems, regardless of their dimensions, as one dimensional problem along the rays. Hence CFL stability condition is implemented always at one dimensional eqaulity case on the ray. Accuracy of RBTD depends on the accuracy of grid generation and numerical solution of transport equations. Simulations for isotropic medium (homogeneous/inhomogeneous) have been conducted. Basic electromagnetic phenomena such as propagation, reflection and refraction have been implemented. Simulation results prove that RBTD eliminates numerical dispersion inherent to FDTD and is promising to be a novel method for computational electromagnetics.

Subject Keywords

Electronics.

URI

http://etd.lib.metu.edu.tr/upload/12606633/index.pdf
https://hdl.handle.net/11511/15835

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

On optimal resource allocation in phased array radar systems Ircı, Ayhan; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2006) In this thesis, the problem of optimal resource allocation in real-time systems is studied. A recently proposed resource allocation approach called Q-RAM (Quality of Service based Resource Allocation Model) is investigated in detail. The goal of the Q-RAM based approaches is to minimize the execution speed in real-time systems while meeting resource constraints and maximizing total utility. Phased array radar system is an example of a system in which multiple tasks contend for multiple resources in order to...
Finite element modeling of electromagnetic radiation Özgün, Özlem; Kuzuoğlu, Mustafa; Department of Electrical and Electronics Engineering (2007) The Finite Element Method (FEM) is a powerful numerical method to solve wave propagation problems for open-region electromagnetic radiation/scattering problems involving objects with arbitrary geometry and constitutive parameters. In high-frequency applications, the FEM requires an electrically large computational domain, implying a large number of unknowns, such that the numerical solution of the problem is not feasible even on state-of-the-art computers. An appealing way to solve a large FEM problem is to...
Real time color based object tracking Özzaman, Gökhan; Erkmen, İsmet; Department of Electrical and Electronics Engineering (2005) A method for real time tracking of non-rigid arbitrary objects is proposed in this study. The approach builds on and extends work on multidimensional color histogram based target representation, which is enhanced by spatial masking with a monotonically decreasing kernel profile prior to back-projection. The masking suppresses the influence of the background pixels and induces a spatially smooth target model representation suitable for gradient-based optimization. The main idea behind this approach is that a...
Leo satellites : dynamic modelling, simulations and some nonlinear attitude control techniques Karataş, Soner; Kocaoğlan, Erol; Department of Electrical and Electronics Engineering (2006) In this thesis nonlinear control method techniques are investigated to control the attitude of Low Earth Orbit satellites. Nonlinear control methods are compared with linear control methods. Simulations are done using Matlab and Simulink software and BILSAT-1 parameters are used in the simulations. Reaction wheels are used as the actuator.
Analysis of coupled lines in microwave printed circuit elements Piroğlu, Şefika Özkal; Dural Ünver, Mevlüde Gülbin; Department of Electrical and Electronics Engineering (2007) Full wave analysis of microstrip lines at microwave frequencies is performed by using method of moments in conjunction with closed-form spatial domain Green’s functions. The Green’s functions are in general Sommerfeld-type integrals which are computationally expensive. To improve the efficiency of the technique, Green’s functions are approximated by their closed-forms. Microstrip lines are excited by arbitrarily located current sources and are terminated by complex loads at both ends. Current distributions ...

Citation Formats

M. Çiydem, “Ray based finite difference method for time domain electromagnetics,” Ph.D. - Doctoral Program, Middle East Technical University, 2005.