Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

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End date: 2009Institution Author: search.filters.institutionAuthor.Kuştepeli, Alp

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Now showing 1 - 7 of 7
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Novel Square Spiral Antennas for Broadband Applications
    (Walter de Gruyter GmbH, 2009) Saynak, Uğur; Kuştepeli, Alp
    An investigation of novel square spiral antennas is presented. The antennas are designed by considering the special arrangements of spiral arms. The new designs perform much better in terms of the frequency independency of the fundamental antenna parameters, when compared with the well known and widely used Archimedean spiral antenna, which makes the antennas very suitable for broadband wireless applications. Experimental results are also presented and there is a good agreement between the measured and numerical data.
  • Conference Object
    Citation - WoS: 1
    Citation - Scopus: 1
    High Frequency Diffraction of Cylindrical Waves by Perfectly Conducting Successive Step Discontinuities
    (Institute of Electrical and Electronics Engineers Inc., 2006) Türetken, B.; Alkumru, Ali; Büyükaksoy, A.; Kuştepeli, Alp
    The diffraction of high frequency cylindrical electromagnetic waves by step discontinuities is investigated rigorously by using the Fourier transform technique in conjunction with the mode matching method. The hybrid method of formulation gives rise to a scalar Wiener-Hopf equation of the third kind, the solution of which contains infinitely many constants satisfying infinite systems of linear algebraic equations.
  • Conference Object
    Citation - Scopus: 1
    Three-Dimensional Electromagnetic Scattering From Flat Plates by Using Sinc-Type Basis Functions in Method of Moments
    (Institute of Electrical and Electronics Engineers Inc., 2009) Özbakış, Başak; Oğuzer, Taner; Kuştepeli, Alp
    Sinc functions are used in the basis and testing procedures in the conventional method of moments (MoM) formulation. But unlike conventional MoM, simple pointwise meshing is enough and no integral computation is required due to the mathematical properties of the sinc function. The simulation results of surface current densities and radar cross section for a few wavelength square flat plate are obtained by using our own codes. The results are compared with those of the rooftop basis functions. The CPU-time decreases by half of the time of the conventional method. The error that occurs from the approximated integral of the sinc function in the computation of main matrix elements is very small and decreases while the bandwidth of the sinc function increases.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 16
    The Resonant Behavior of the Fibonacci Fractal Tree Antennas
    (John Wiley and Sons Inc., 2008) Özbakış, Başak; Kuştepeli, Alp
    An investigation of a novel fractal tree antenna with the application to two different geometries is presented. The antenna is designed by using the special Fibonacci number sequence which leads to nonuniform branch length ratios to form the fractal tree. This new approach gives better performance, especially in the miniaturization of the antenna, when compared with the conventional designs. The results obtained from the experiments are also compared with the computed ones and there is a very good agreement between the numerical and measured data.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 1
    Design of Coupling Structures for Groove Guide Resonators
    (John Wiley and Sons Inc., 2008) Bechteler, Thomas F.; Kuştepeli, Alp; Aydınlık Bechteler, Ayşe Sevinç
    Three different coupling structures for a groove guide resonator operating at 10 GHz are investigated. First, propagatable modes are determined analytically. Then, the efficiency of the coupling structures is investigated by means of the method of moments and measurements. Finally, a groove guide resonator is designed and the resonance spectrum for each coupling structure is computed numerically, applying the finite-difference time-domain method. Numerical results are compared with experimental measurements. There is good agreement between the measured and simulated data.
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 2
    A novel square-spiral strip antenna
    (Institute of Electrical and Electronics Engineers Inc., 2007) Saynak, Uğur; Kuştepeli, Alp
    A square-spiral strip antenna is designed considering the procedure used to obtain log-periodic antennas. Simulation results of the new design are compared with those of the well known and widely used Archimedean spiral antenna in terms of the frequency dependency. The effect of dielectric substrate used to support the antennas is also investigated.
  • Article
    Citation - WoS: 52
    Citation - Scopus: 67
    On the Splitting Parameter in the Ewald Method
    (Institute of Electrical and Electronics Engineers Inc., 2000) Kuştepeli, Alp; Martin, Anthony Q.
    An investigation of the Ewald method is presented. The method involves a splitting parameter that is theoretically an arbitrary number. An analysis is presented to show why the splitting parameter cannot always be treated as arbitrary in calculations and how this parameter should be chosen for all. periodic spacing of a structure.