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Electrical and Computer Engineering

Turkish Journal of Electrical Engineering and Computer Sciences

Electromagnetic scattering

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Full-Text Articles in Engineering

An Analytical Formulation With Ill-Conditioned Numerical Scheme And Its Remedy: Scattering By Two Circular Impedance Cylinders, Emrah Sever, Fati̇h Di̇kmen, Olga Alexandrovna Suvorova, Yury Alexanderovich Tuchkin Jan 2016

An Analytical Formulation With Ill-Conditioned Numerical Scheme And Its Remedy: Scattering By Two Circular Impedance Cylinders, Emrah Sever, Fati̇h Di̇kmen, Olga Alexandrovna Suvorova, Yury Alexanderovich Tuchkin

Turkish Journal of Electrical Engineering and Computer Sciences

The regularization of the well-known analytical formulation of the monochromatic electromagnetic wave scattering problem from a syvstem with two neighbor impedance circular cylinders is presented. It is the improvement and extension of the work done for scattering from two perfectly conducting circular cylinders. Numerical results show that it is numerically much safer to solve the obtained infinite algebraic system at a lower truncation number also by ensuring the reliability of the solution.


Predics: A New Go-Po-Based Ray Launching Simulator For The Calculation Of Electromagnetic Scattering And Rcs From Electrically Large And Complex Structures, Caner Özdemi̇r, Betül Yilmaz, Özkan Kirik Jan 2014

Predics: A New Go-Po-Based Ray Launching Simulator For The Calculation Of Electromagnetic Scattering And Rcs From Electrically Large And Complex Structures, Caner Özdemi̇r, Betül Yilmaz, Özkan Kirik

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a new simulator called pRediCS for the calculation of electromagnetic scattering and radar cross-section (RCS) from electrically large and complex targets. The simulator utilizes the geometric optics (GO) theory and launching of electromagnetic rays for tracing and calculating the electric field values as the electromagnetic waves bounce around the target. The physical optics (PO) theory is also exploited to calculate the final scattered electric field by calculating the far-field PO integration along the observation direction. The simulator is first tested with known objects of canonical shapes, whose analytical solutions are available in the literature. Next, …


A Neural-Based Electromagnetic Inverse Scattering Approach To The Detection Of A Conducting Cylinder Coated With A Dielectric Material, Senem Makal, Ahmet Kizilay Jan 2012

A Neural-Based Electromagnetic Inverse Scattering Approach To The Detection Of A Conducting Cylinder Coated With A Dielectric Material, Senem Makal, Ahmet Kizilay

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a radial basis function neural network approach is applied for the estimation of the localization and the radius of a conducting cylinder with a circular cross-section coated with a dielectric material. A set of features, the radar cross-section (RCS) values, are derived from scattered fields, which are calculated using the surface equivalence principle and the method of moment. RCS values are obtained using 10 different scattering angles that are fed into the network. The outputs of the network are the location (x_0, y_0) and the radius (r_p) of the conducting cylinder. This is an application of the …


Electromagnetic Scattering From Layered Strip Geometries: The Method Of Moments Study With The Sinc Basis, Taner Oğuzer, Fadil Kuyucuoğlu, İbrahi̇m Avgin Jan 2011

Electromagnetic Scattering From Layered Strip Geometries: The Method Of Moments Study With The Sinc Basis, Taner Oğuzer, Fadil Kuyucuoğlu, İbrahi̇m Avgin

Turkish Journal of Electrical Engineering and Computer Sciences

Electromagnetic scattering from strips of layers is analyzed using the method of moments (MoM) for both polarizations in spatial domain with the sinc-type orthogonal sets as basis and testing functions. We exploited the sinc function's properties of exponential convergence, the orthogonality, easy convolution and better handling of singular kernels in MoM procedure resulting in fast performance and reasonable accuracy even in ordinary MoM treatment. We transferred the integral of the Hankel function multiplied by sinc functions to Hankel function introducing a slight error with large band width. We proved that this relative error during the generation of the main matrix …


Radar Cross-Section (Rcs) Analysis Of High Frequency Surface Wave Radar Targets, Gonca Çakir, Levent Sevgi̇ Jan 2010

Radar Cross-Section (Rcs) Analysis Of High Frequency Surface Wave Radar Targets, Gonca Çakir, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Realistic high frequency surface wave radar (HFSWR) targets are investigated numerically in terms of electromagnetic wave -- target interactions. Radar cross sections (RCS) of these targets are simulated via both the finite-difference time-domain (FDTD) method and the Method of Moments (MoM). The virtual RCS prediction tool that was introduced in previous work is used for these investigations. The virtual tool automatically creates the discrete FDTD model of the target under investigation and performs the FDTD RCS analysis. It also automatically constructs a MoM wire grid model of the target; therefore, it is also possible to compare FDTD results against the …


Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu Jan 2008

Recent Advances In Perfectly Matched Layers In Finite Element Applications, Özlem Özgün, Mustafa Kuzuoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

We present a comparative evaluation of two novel and practical perfectly matched layer (PML) implementations to the problem of mesh truncation in the finite element method (FEM): locally-conformal PML, and multi-center PML techniques. The most distinguished feature of these methods is the simplicity and flexibility to design conformal PMLs over challenging geometries, especially those with curvature discontinuities, in a straightforward way without using artificial absorbers. These methods are based on specially- and locally-defined complex coordinate transformations inside the PML region. They can easily be implemented in a conventional FEM by just replacing the nodal coordinates inside the PML region by …