Browsing by Author "Sertel, Kubilay"

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Open Access
Comparison of surface-modeling techniques
(IEEE, 1997-07) Sertel, Kubilay; Gürel, Levent
Solution techniques based on surface integral equations are widely used in computational electromagnetics. The accurate surface models increase the accuracy solutions by using exact and flat-triangulation models for a sphere. For a required solution accuracy, the problem size is significantly reduced by using geometry models for the scatterers. The dependence of the accuracy of the solution on the geometry modeling is investigated.
Open Access
Quantitative comparison of rooftop and RWG basis functions
(IEEE, 1997-07) Gürel, Levent; Şendur, İbrahim Kürşad; Sertel, Kubilay
The `rooftops' (RT) basis functions (BFs) are well suited for the modeling of geometries that conform to Cartesian coordinates, whereas the Rao, Wilton, and Glisson subdomains (RWG) BFs are capable of modeling flat-faceted approximations of arbitrary geometries. Both basis functions can also be used in modeling unknown functions transformed from the real space to the parametric space of a curved surface. The RT and RWG basis functions have many common features: they are defined on tow neighboring subdomains and the unknown is associated with the common edge between these two subdomains; thus they are edge functions. The two BFs also differ in the way they define the direction of the current.
Open Access
Solution of electromagnetic scattering problems involving curved surfaces
(1997) Sertel, Kubilay
The method of moments (MoM) is an efficient technique for the solution of electromagnetic scattering problems. Problems encountered in real-life applications are often three dimensional and involve electrically large scatterers with complicated geometries. When the MoM is employed for the solution of these problems, the size of the resulting matrix equation is usually large. It is possible to reduce the size of the system of equations by improving the geometry modeling technique in the MoM algorithm. Another way of improving the efficiency of the MoM is the fast multipole method (FMM). The FMM reduces the computational complexity of the convensional MoM. The FMM has also lower memory-requirement complexity than the MoM. This facilitates the solution of larger problems on a given hardware in a shorter period of time. The combination of the FMM and the higher-order geometry modeling techniques is proposed for the efficient solution of large electromagnetic scattering problems involving three-dimensional, arbitrarily shaped, conducting suriace scatterers.