WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Citation - WoS: 1Citation - Scopus: 2Modified Theory of Physical Optics Approach To Diffraction by an Interface Between Pemc and Absorbing Half-Planes(Lgep-supelec, 2021) Umul, Yusuf Z.The scattering of electromagnetic plane waves by an interface, located between perfect electromagnetic conductor and absorbing half-planes, is investigated. The perfect electromagnetic conductor half-plane is divided into perfect electric conductor and perfect magnetic conductor half-screens. The same decomposition is done for the absorbing surface. Then four different geometries are defined according to this approach. The scattered fields by the four sub-problems are obtained with the aid of the modified theory of physical optics. The resultant scattering integrals are combined in a single expression by using key formulas, defined for the perfect electromagnetic conductor and absorbing surfaces. The diffracted and geometric optics fields are obtained by the asymptotic evaluation of the scattering integral for large values of the wave-number. The behaviors of the derived field expressions are analyzed numerically.Article Citation - WoS: 2Citation - Scopus: 2Diffraction of Electromagnetic Waves by a Resistive Half-Plane in Magneto-Ionic Plasma(Wiley-v C H verlag Gmbh, 2020) Umul, Yusuf ZiyaThe interaction of magnetic polarized electromagnetic wave with a resistive half-plane in magneto-ionic plasma is investigated. The method of transition boundary is used for the evaluation of the diffracted wave. The excitation of surface waves is examined in the medium and their diffracted fields are derived by using the diffraction theory for grazing incidence. The uniform field expressions are obtained with the aid of the uniform theory for evanescent waves. The behaviours of the derived scattered waves are studied numerically.Article Citation - WoS: 2Citation - Scopus: 2Scattering of Waves by a Planar Junction Between Resistive Half-Screen and Perfectly Electric Conducting Wedge(Taylor & Francis Ltd, 2018) Umul, Yusuf ZiyaThe diffraction of plane waves by a planar junction between a resistive half-plane and perfectly conducting wedge is investigated. First of all, the relation between the scattered geometrical optics waves and diffracted fields by a wedge is outlined. Then the scattered GO fields of the planar junction are obtained by subtracting the initial fields from the total geometrical optics waves. The diffracted waves by the junction is derived with the aid of the scattered GO waves' structure. The behaviour of the fields is analysed numerically.Article Citation - WoS: 11Citation - Scopus: 9Diffraction of Cylindrical Waves by a Perfectly Conducting Half-Screen: a Modified Theory of Physical Optics Solution(Wiley-blackwell, 2016) Umul, Yusuf Ziya; Ziya Umul, YusufThe scattering problem of waves, radiated by a line source, is investigated by the method of modified theory of physical optics. The solution is obtained for both of the Dirichlet and Neumann boundary conditions. Two dimensional modified theory of physical optics integral is considered, since the problem is symmetric according to one of the spatial coordinates. The scattering integral is directly evaluated and a new function is defined for the scattered fields. The mathematical properties of the function are studied. The total, geometrical optics and diffracted waves are analyzed numerically. (C) 2016 Wiley Periodicals, Inc. View this article online at wileyonlinelibrary.com.Article Citation - WoS: 7Citation - Scopus: 7Scattering Theory of Waves by a Perfectly Conducting Half-Screen Between Two Different Media(Wiley, 2015) Umul, Yusuf ZiyaThe scattering process of electromagnetic waves by a half-plane, located at the interface of two media with different dielectric constants, play an important role in the remote sensing applications and wireless technology for wave propagation over land-sea transition. In this article, the diffracted fields are obtained for such geometry with the aid of a physical optics-based method. A scattering integral is constructed for both of the media. The diffracted fields are obtained by the edge point technique and the constants, which were added to the diffraction coefficients, were evaluated from the continuity conditions across the transition of the two mediums. The uniform expressions of the diffracted waves are obtained and the results are investigated numerically. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1928-1933, 2015Article Citation - WoS: 7Citation - Scopus: 7Extension of the Maliuzhinets Solution for the Resistive Half-Plane(Wiley-blackwell, 2012) Umul, Yusuf ZiyaThe solution, put forward by Maliuzhinets for the impedance half-plane, is extended for the diffraction problem of plane waves by a resistive half-plane. With this aim, the Wiener-Hopf solution of the same problem is taken into account. The resultant diffracted field expression is compared with the Wiener-Hopf solution of the problem numerically. (C) 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:777-780, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26626