Browsing by Author "Akleman, Funda"
Now showing items 1-15 of 15
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Analytical and numerical investigations of ring resonators
Akleman, Funda; Sevgi, Levent (IEEE, 2007)Rectangular vs. cylindrical finite-difference time-domain (FDTD) electromagnetic modeling is discussed, and characteristic tests and comparisons are presented depending on the analytical and numerical analysis of ring type ... -
Comparison of rectangular and cylindrical FDTD representations on a ring resonator problem
Akleman, Funda; Sevgi, Levent (TÜBİTAK, 2008)The aim of this paper is to discuss rectangular and cylindrical representations of finite-difference time-domain (FDTD) method over characteristic tests and comparisons. A ring resonator is chosen as a canonical structure ... -
Fast integral equation solutions: Application to mixed path terrain profiles and comparisons with parabolic equation method
Tunç, Celal Alp; Akleman, Funda; Ertürk, Vakur B.; Altıntaş, Ayhan; Sevgi, Levent (Springer, 2006)The numerical modeling and simulation of multimixed path surface wave propagation is discussed. Sea land, sea-land-sea transitions are modeled via fast integral equation solutions and the results are compared against the ... -
Groundwave propagation modeling: problem-matched analytical formulations and direct numerical techniques
Sevgi, Levent; Akleman, Funda; Felsen, Leopold B. (IEEE, 2002-02)In this overview of groundwave propagation, we address a particular class of propagation scenarios in the presence of surface terrain and atmospheric refractivity. Beginning with idealized analytically solvable models over ... -
A MATLAB-based two-dimensional parabolic equation radiowave propagation package
Sevgi, Levent; Uluışık, Çağatay; Akleman, Funda (IEEE, 2005-08)This article introduces a simple MATLAB radiowave propagation package, SSPE_GUI, for the visualization of EM propagation over non-flat terrain through an inhomogeneous atmosphere, for waves radiated by a horizontally ... -
A novel MoM - and SSPE - based groundwave - propagation field - strength prediction simulator
Akleman, Funda; Sevgi, Levent (IEEE, 2007-10)Knowledge of the local groundwave-propagation characteristics is essential in wireless systems. Although Maxwell's equations establish the theoretical background, only a limited number of highly idealized groundwave-propagation ... -
Novel time domain radiowave propagators for wireless communication systems
Akleman, Funda; Özyalçın, M. Orhan; Sevgi, Levent (TÜBİTAK, 2002)In this study, novel time domain wave propagators are used in path loss calculations for macro and micro cell coverage planning in wireless communication systems. Both Transmission Line Matrix (TLM) and Finite-Difference ... -
A novel TLM-based time-domain wave propagator
Özyalçın, M. Orhan; Akleman, Funda; Sevgi, Levent (IEEE, 2003-07)In this letter, a novel time-domain wave propagator, based on the transmission line matrix (TLM) technique, is introduced. A two-dimensional (2-D) TLM algorithm is modified and the sliding window technique is applied to ... -
Realistic surface modeling for a finite-difference time-domain wave propagator
Akleman, Funda; Sevgi, Levent (IEEE, 2003-07)A new time domain wave propagator (TDWP) based on two-dimensional finite-difference time-domain (FDTD) technique (that was introduced in May 2000 issue) has been augmented in this paper so that it deals with impedance ... -
SAR simulations in wireless communication and safety discussions in the society
Özyalçın, M. Orhan; Akleman, Funda; Sevgi, Levent (TÜBİTAK, 2002)Numerical simulation in cellular phone - human tissue interaction is discussed in this paper. The powerful time domain (TD) techniques, the transmission line matrix (TLM) and the finite-difference time-domain (FDTD) methods, ... -
Validation of mom - based direct scattering analysis in circular waveguide for appropriate mesh - type decision
Aydoğan, Ahmet; Akleman, Funda (IEEE, 2012-08-28)The general formulae and algorithms for direct scattering analysis of inhomogeneous lossy dielectric objects, arbitrarily loaded inside a circular waveguide is given by means of a dyadic Green's function (DGF) concept. The ... -
Visualisations of wave dynamics in wedge-waveguides via matlab-based propagation packages
Sevgi, Levent; Akleman, Funda; Topuz, Ercan (IEEE, 2006)This presentation is intended to tutorially enhance the utility and understanding of the analytical and numerical representations for the wave propagation problem inside a wedge-waveguide with both non-penetrable and ... -
Visualizations of wave dynamics in a wedge waveguide with non-penetrable boundaries: normal - adiabatic and intrinsic - mode representations
Sevgi, Levent; Akleman, Funda; Felsen, Leopold B. (IEEE, 2007-06)Many natural or man-made guiding environments are characterized by physical parameters that render the wave equation non-separable in any of the standard coordinate systems. In particular, in the absence of transverse-longitudinal ... -
Wave propagation inside a two-dimensional perfectly conducting parallel-plate waveguide: hybrid ray-mode techniques and their visualizations
Felsen, Leopold B.; Akleman, Funda; Sevgi, Levent (IEEE, 2003-12)This article is intended as an educational aid, dealing with high-frequency (HF) electromagnetic wave propagation in guiding environments. It is aimed, at advanced senior and first-year graduate students who are familiar ... -
Yer dalgası yayılımının zaman ve frekans domeninde sayısal modellemesi
Akleman, Funda; Sevgi, Levent; Topuz, Ercan (İstanbul Teknik Üniversitesi, 2002-12)Dünya üzerinde seçilen herhangi iki nokta arasındaki yer dalgası yayılım problemi, yirminci yüzyılın başından bu yana ilgi odağı olmasına karşın, henüz sayısal olarak hesaplanabilen analitik tam çözüm ya da genel olarak ...
