Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/411
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Browsing Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu by Author "17740"
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Article Citation Count: Şener, G. (2017). A novel method to solve 2nd order neumann type boundary value problems in electrostatics. Applied Computational Electromagnetics Society Journal, 32(4), 289-294.A novel method to solve 2nd order neumann type boundary value problems in electrostatics(Applied Computational Electromagnetics Soc., 2017) Şener, Göker; 17740In this paper, the numerical method of nonpolynomial spline approximation is used to solve 2nd order Neumann type boundary value problems (bvp's) in electrostatics. This new approach provides more accurate results than the polynomial approximations and the spectral methods. The literature contains very little on the solution of Neumann type bvp's because of the fact that a unique solution does not exist for all problems. In electrostatics, Neumann type bvp's are encountered for finding the electrostatic potential inside closed surfaces where the normal derivative of the electric potential is specified everywhere on the surface. Two examples are presented to prove the accuracy of the proposed method. In these examples, the governing differential equation is solved to find the electrostatic potential inside a region bounded by conductors that are maintained at constant voltages. The results are compared with the analytic solutions.Article Citation Count: Şener, G. (2023). "Antenna Synthesis by Levin's Method using a Novel Optimization Algorithm for Knot Placement", Applied Computational Electromagnetics Society Journal, Vol.38, No.2, pp.74-79.Antenna Synthesis by Levin's Method using a Novel Optimization Algorithm for Knot Placement(2023) Şener, Göker; 17740Antenna synthesis refers to determining the antenna current distribution by evaluating the inverse Fourier integral of its radiation pattern. Since this inte-gral is highly oscillatory, Levin's method can be used for the solution, providing high accuracy. In Levin's method, the integration domain is divided into equally spaced sub-intervals, and the integrals are solved by transfer-ring them into differential equations. This article uses a new optimization algorithm to determine the location of these interval points (knots) to improve the method's accuracy. Two different antenna design examples are pre-sented to validate the accuracy and efficiency of the pro-posed method for antenna synthesis applications.Article Citation Count: Şener, Göker (2023). "Antenna Synthesis by Levin’s Method using Reproducing Kernel Functions", Applied Computational Electromagnetics Society Journal, Vol. 38, No 7, pp. 482-488.Antenna Synthesis by Levin’s Method using Reproducing Kernel Functions(2023) Şener, Göker; 17740An antenna synthesis application is presented by solving a highly oscillatory Fourier integral using a stable and accurate Levin’s algorithm. In antenna synthesis, the current distribution is obtained by the inverse Fourier integral of the antenna radiation pattern. Since this integral is highly oscillatory, the Levin method can be used for its solution. However, when the number of nodes or the frequency increases, the Levin method becomes unstable and ineffective due to the large condition number of the interpolation matrix. Thus, an improved scheme of the method is used in an antenna synthesis application in which reproducing kernel functions are used as the basis of the approximation function. The accuracy of the new method is verified by a log-periodic antenna example. The error and stability analysis results show that the new method is more stable and accurate than other well-known kernels, especially for a large number of nodes.Article Citation Count: Şener, Göker (2020). "High-gain low-profile rectangular microstrip patch antenna with Yagi elements", Journal of Electromagnetic Waves and Applications, Vol. 34, No. 8, pp. 1039-1046.High-gain low-profile rectangular microstrip patch antenna with Yagi elements(2020) Şener, Göker; 17740This paper presents a novel high gain rectangular microstrip patch antenna (RMSA) with vertically placed Yagi elements. The antenna is fed by a coaxial probe to excite TM01 fundamental waves at 2.4GHz, which is suitable for wireless local area network (WLAN) applications. In order to increase the antenna gain, Yagi elements are placed in groups of 5, on each side of the substrate in order to serveas directors for the radiating slots as well as the ground reflections. The proposed antenna offers 1.3dB gain improvement and %3 .1 impedance bandwidth increase in comparison to the plain rectangular microstrip antenna with the same specifications. The advantage of this antenna is to provide an easy and cost effective solution to increase microstrip antenna gain, particularly in 8-10dB range, without disruptingits planar structure.Article Citation Count: Şener, Göker (2022). "Ultra Geniş Bant Uygulamaları İçin Tasarlanmış Bir Düzlemsel Eliptik Tek Kutuplu Anten", Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi, Vol.9, No.16, pp.61-68.Ultra Geniş Bant Uygulamaları İçin Tasarlanmış Bir Düzlemsel Eliptik Tek Kutuplu Anten(2022) Şener, Göker; 17740Bu makalede 1-10 GHz ultra geniş bantta ışıma yapabilen bir düzlemsel eliptik tek kutuplu anten tasarlanmıştır. Yapısal olarak düzlemsel tek kutuplu antenler mikro şerit antenlerin kalınlığının arttırılarak toprak düzleminin ortadan kaldırılması ile elde edilir. Mikro şerit antenlerin kalınlığının artması ile tüm rezonans frekanslarında oluşan dalga kiplerinin frekans bandı da artmış olur. Böylece ultra geniş bantlı ışıma meydana gelir. Bununla birlikte tek kutuplu antenler, tüm bant boyunca her yönde aynı ışıma özelliği göstermezler. Genelde arzu edilen, tüm bant boyunca tek yönlü doğrusal polarizasyonda ve dik yönde yüksek kazanç verecek bir ışıma karakteristiğidir. Bu makalede bu özelliği sağlamak için farklı boyutta iki eliptik tek kutuplu anten, yansıtıcı bir toprak düzlemi üzerine yerleştirilmiştir. Bu tasarlanan anten bütün bant boyunca tek yönlü doğrusal polarizasyon ile dik yönde 1-10 GHz frekanslarında sırasıyla 4.38-3.22 dB kazanç sağlamaktadır. Elde edilen bu değerler literatürdeki diğer eliptik tek kutuplu antenlerle karşılaştırılmış ve tasarımın bant boyunca aynı ışıma karakteristiği ile 3.22 dB’nin üzerinde kazanç sağladığı gösterilmiştir. Önerilen bu anten, 2.4-5 GHz geniş bant WLAN sistemleri ve anten ölçümleri gibi ultra geniş bant uygulamalarında kullanılmaya uygundur.
