Kvazistacionarni pristup za analizu mikrotalasnih vodova
Doktorand
Perić, Mirjana T.Mentor
Aleksić, SlavoljubČlanovi komisije
Raičević, NebojšaCvetković, Zlata
Dončov, Nebojša
Metapodaci
Prikaz svih podataka o disertacijiSažetak
Analysis of microwave transmission lines is the main subject of research in the
world for more than six decades. Since the day of stripline invention, back in 1949, and its
modifications that followed in the forthcoming years, an "army" of scientists was trying to
analyze it, simplify it and design new structures. These structures, due to their characteristics,
have found wide application in microwave integrated circuits, for microwave filters and
antennas design, delay lines, directional couplers, etc.
Various numerical and analytical methods such as: the variational method, the method of
moments, the boundary element method, the conformal mapping, the moving perfect electric
wall method, the equivalent electrodes method etc. can be applied with more or less accuracy
to the microwave transmission lines analysis.
The aim of this doctoral dissertation is quasi TEM analysis of microwave transmission
lines using the hybrid boundary method (HBEM). This method, developed at the D...epartment
of Theoretical Electrical Engineering in the Faculty of Electronic Engineering of Niš, is based
on the equivalent electrodes methods and the point-matching method for the potential of the
perfect electric conductor electrodes and for normal component of the electric field at the
boundary surface between any two dielectric layers. Until now, it was applied to multilayered
electromagnetic problems, grounding systems, electromagnetic field determination in the
vicinity of cable terminations as well as magnetic field and force calculations of permanent
magnets. In order to expand the field of method’s application, it is, for the first time, applied
for the microwave transmission lines analysis.
Single and coupled, shielded and open microwave transmission lines with homogeneous,
isotropic single-layer and multilayer dielectrics were analysed in the examples presented.
Structures with the ground planes of infinite width, but also the real cases – geometry with
ground planes of finite width, the finite metallization thickness and substrate width, are also
shown in this dissertation.
The hybrid boundary element method has been proved to be a very simple, powerful and
accurate procedure for microwave transmission lines analysis. The obtained system of linear
equations is always well-conditioned, as the system matrix always has the greatest elements
on the main diagonal. Quite good convergence for the desired parameters is achieved for only
700-1500 unknowns (equivalent electrodes). For the most examples, the convergence of
results, calculation time, equipotential contours and distribution of polarized charges per unit
length along boundary surfaces are shown in the tables and graphically.
In order to validate the characteristic parameters results, obtained by the hybrid boundary
element method, all the results will be compared to those obtained by software FEMM and
FlexPDE as well as the results already reported in the literature. These results were shown in
tables and graphically. The relative error for the characteristic impedance is less than 0.5 % in
regards to the results obtained using the FEMM with few thousands elements and the uniform
meshing technique. The computation time is even several times shorter than in the case of the
analysis using the FEMM and FlexPDE.
The real challenge for the author was to apply the hybrid boundary element method for
analysis of microstrip transmission lines with Tellegen material (non-reciprocal bi-isotropic
media). Unlike a wide range of literature that deals with the analysis of microwave
transmission lines with isotropic dielectric, bi-isotropic media, due to their complexity, are
not so common subject of research. The hybrid boundary element method was successfully
applied for the analysis of such structures.
Applying the hybrid boundary element method it is possible to analyze quickly, easily and
sufficiently accurate the complex configuration of microwave transmission lines with
isotropic and bi-isotropic substrate. In that way this dissertation represents a small
contribution to the history of the development of methods for the analysis of microwave lines
long more than 60 years.