Derivation of green’s functions for spherically stratified media using an equivalent two port network model /

Download
2015
Yeni, Burcu
Derivation of dyadic Green’s functions for a variety of geometries is a problem frequently faced in different fields of electromagnetics including the analysis and design of antennas, waveguides and resonators. In the case of spherically stratified antenna, waveguide or resonator structures, the analytical derivation process of dyadic Green’s functions is often extremely complex while numerical solutions comprise heavy workload. In this thesis, an equivalent two-port network model, which was first developed for the analysis of stratified planar structures and then extended to stratified cylindrical and spherical structures, is utilized to derive the spectral-domain Green’s functions of spherically stratified media including a spherical microstrip antenna and a human head modeled as a spherical multilayer dielectric. This equivalent circuit model approach is applicable to multiple geometries and enables the utilization of simple network analysis techniques for the derivation of Green’s functions in these geometries.

Suggestions

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 ...
Efficient computation of the Green's function for multilayer structures with periodic dielectric gratings
Adanır, Süleyman; Alatan, Lale; Department of Electrical and Electronics Engineering (2011)
Numerical analysis of periodic structures in layered media is usually accomplished by using Method of Moments which requires the formation of the impedance matrix of the structure. The construction of this impedance matrix requires the evaluation of the periodic Green’s function in layered media which is expressed as an infinite series in terms of the spectral domain Green’s function. The slow converging nature of this series make these kinds of analysis computationally expensive. Although some papers have ...
On the Attenuation of the Perfectly Matched Layer in Electromagnetic Scattering Problems with the Spectral Element Method
Mahariq, I.; Kuzuoğlu, Mustafa; Tarman, Işık Hakan (2014-09-01)
Although Spectral Element Method (SEM) has been applied in the modeling of boundary value problems of electromagnetics, its usage is not as common as the Finite Element or Finite Difference approaches in this area. It is well-known that the Perfectly Matched Layer (PML) approach is a mesh/grid truncation method in scattering or radiation applications where the spatial domain is unbounded. In this paper, the PML approach in the SEM context is investigated in two-dimensional, frequency-domain scattering probl...
Calculation of the Resonant Frequencies in the Vicinity of the Transition in Quartz
Lider, M. C.; Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 2015-07-01)
The transition (847 K) in quartz is investigated using the temperature dependence of the resonant frequency and of the lattice constant which are correlated by means of the mode Gruneisen parameter. By determining the mode Gruneisen parameter, the resonant frequencies are predicted in the vicinity of the transition in quartz. This calculation is extended to low temperatures (down to about , and the resonant frequencies are predicted at low temperatures using the lattice parameter data for quartz. Prediction...
Comparative evaluation of absorbing boundary conditions using Green's functions for layered media
Aksun, MI; Dural Ünver, Mevlüde Gülbin (1996-02-01)
Absorbing boundary conditions are comparatively studied using the Green's functions of the vector and scalar potentials for multilayer geometries and general sources. Since the absorbing boundaries are introduced as additional layers with predefined reflection coefficients into the calculation of the Green's functions, this approach provides an absolute measure of the effectiveness of different absorbing boundaries. The Green's functions are calculated using different reflection coefficients corresponding t...
Citation Formats
B. Yeni, “Derivation of green’s functions for spherically stratified media using an equivalent two port network model /,” M.S. - Master of Science, Middle East Technical University, 2015.