Şengül, Metin

Şengül, Metin

Name Variants

Şengül, Metin
M.,Şengül
M. Şengül
Metin, Şengül
Sengul, Metin
M.,Sengul
M. Sengul
Metin, Sengul
Şengül, Metin Y.
Şengül,M.

Job Title

Prof. Dr.

Email Address

Msengul@khas.edu.tr

Full item page

Scholarly Output

76

Articles

49

Citation Count

0

Supervised Theses

5 Scholarly Output Search Results

Now showing 1 - 10 of 76

Citation Count: 5
Analysis of Mixed-Element Structures Formed With Shunt Capacitors Separated by Transmission Lines
(IEEE-Inst Electrical Electronics Engineers Inc, 2019) Şengül, Metin Y.; Çakmak, Gökhan
In this brief, the analysis of mixed-element structures formed with shunt capacitors separated by commensurate transmission lines is performed first time in the literature. First, a low-pass lumped-element ladder network is considered. Then the series inductors are replaced with commensurate transmission lines. As a result, a practically important mixed-element structure is obtained. Then the description of the structure by means of two frequency variables (one for shunt capacitors and one for transmission lines) is detailed: Explicit expressions for the coefficients of the descriptive two-variable polynomials in terms of the coefficients of the single variable boundary polynomials are derived for various numbers of elements, which are obtained first time in the literature. Finally, a mixed-element broadband matching network is designed to illustrate the usage of the obtained expressions. If it is preferred not to have shunt capacitors, they can be replaced with open-ended stubs via Richard's transformation. So the resultant circuit is extremely suitable for microstrip fabrication.
Citation Count: 1
Reflectance data model with mixed lumped and distributed elements for wireless communication systems
(2005) Yarman, Binboğa Sıddık; Şengül, Metin Y.; Kılınç, Ali; Aksen, Ahmet
In this paper, a new method is presented to model the given reflectance data obtained from a "passive one-port physical device", as a lossless two port consists of lumped and distributed elements. Basis of the new method rests on the interpolation of the given data as a realizable bounded-real (BR) reflection function in two variables. The desired circuit model is then obtained as the result of the synthesis of this function in two kinds of elements; namely, distributed and lumped circuit elements. An algorithm is presented to generate the circuit model step by step and an example is also included to exhibit the utilization of the new modeling algorithm.
Citation Count: 0
Production of Electron-Positron Pairs by Nuclear Dissociation in Peripheral Heavy Ion Collisions
(Elsevier, 2007) Güçlü, Mehmet Cem; Şengül, Metin Y.
The STAR Collaboration at the Relativistic Heavy Ion Collider present data on electron-positron pair production accompanied by nuclear breakup at small impact parameters where the simultaneous excitation of the two ions mainly the giant dipole resonance GDR can occur. We calculate the electron-positron pair production cross section relevant for the STAR experimental setup and compare our results with the other calculations. © 2007 Elsevier B.V. All rights reserved.
Citation Count: 2
Real Frequency Design of Pi and T Matching Networks With Complex Terminations
(Institute of Electrical and Electronics Engineers Inc., 2018) Şengül, Metin Y.; Yeşilyurt, Gökmen
In this paper real frequency design of Pi and T matching networks with complex terminations is studied. Generally the generator and load termination impedances are given as measurement values. So they can be regarded as a resistor and a reactive element connected in series. To be able to design a Pi network this series impedance models must be transformed to parallel models. But for T network designs the assumed series models can be utilized there is no need a transformation process. Then Pi or T matching networks can be designed via Q based method which is well defined in the literature. © 2017 EMO (Turkish Chamber of Electrical Enginners).
Citation Count: 0
Broadband Microwave Amplifier Design With Lumped Elements
(Walter De Gruyter Gmbh, 2016) Şengül, Metin Y.
This study introduces a broadband microwave amplifier design that utilizes the measured scattering parameters of active devices without assuming an initial topology for the matching networks or an analytic form of the system transfer function. The algorithm can be extended to design multistage broadband microwave amplifiers. An example is given to illustrate the application of the proposed method. It was found that the proposed method provides very good initials for CAD tools to further improve amplifier performance by working on the element values.
Citation Count: 0
Genetic Algorithm Based Broadband Equalizer Design With Ripple Level Control
(IEEE, 2012) Şengül, Metin Y.; Özmen, Atilla
In this paper broadband equalizer design with ripple control via genetic algorithm has been studied. The equalizer is defined as a lossless two-port terminated by load impedance and the coefficients of its describing scattering polynomials have been optimized via genetic algorithm. During the optimization process ripple level of the transducer power gain has been controlled. An example has been given to illustrate the utilization of the proposed approach. © 2012 IEEE.
Citation Count: 22
Broadband Decoupling and Matching of a Superdirective Two-Port Antenna Array
(IEEE-INST Electrical Electronics Engineers Inc, 2008) Volmer, Christian; Şengül, Metin Y.; Weber, Joern; Stephan, Ralf; Hein, Matthias A.
Decoupling and matching networks may be used to improve the performance of compact antenna arrays where mutual radiator coupling has caused a degradation of the diversity capabilities. A popular network consists of a 180 degrees rat-race directional coupler which decouples the antenna ports followed by impedance matching networks at each port. Researchers however usually neglect the presence of losses both within the antenna array and the decoupling and matching network. For this reason we have built various narrowband and broadband matching networks and compare their performances with the help of calibrated far-field measurement data.
Citation Count: 1
Phase Shifting Properties of High-Pass and Low-Pass Mixed-Element Two-Ports
(Institute of Electrical and Electronics Engineers Inc., 2021-04) Şengül, Metin Y.; Çakmak, Gökhan; Özdemir, Rabia
n many applications, circuits containing lumped-elements are preferred because of their small sizes. But it is not possible to avoid losses caused by the connections between lumped-elements at high frequencies. However, the use of these connections as circuit elements will improve the performance of the circuit. Therefore, it becomes inevitable to use circuits with mixed (lumped and distributed) elements at high frequencies. In this brief, phase shifting properties of high-pass and low-pass mixed-element two-ports is explained. Then these two-ports are used to form the initial design of high-pass and low-pass sections of a phase shifter. Finally, the initial design performance can be improved by means of commercially available computer-aided design (CAD) tools.
Citation Count: 0
DESIGN TABLE FORMATION OF STEPPED IMPEDANCE PROTOTYPE FILTERS
(Istanbul Univ, Fac Engineering, 2010) Sengul, Metin
In literature, there exist some tables containing normalized element values, to design low-pass lumped-element prototype filters with several different responses like maximally flat or equal-ripple. In this work, an algorithm is presented, to form such tables for stepped impedance prototype filters. By using the proposed algorithm, a table for 0.5 dB equal-ripple stepped impedance prototype filter is formed. Then a design example is given, to show the utilization of the formed table.
Citation Count: 2
Shifted-modified Chebyshev filters
(TUBITAK Scientific & Technical Research Council Turkey, 2013) Şengül, Metin Y.
This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain group delay and impulse and step responses of the proposed filters are compared with those of the Butterworth and Chebyshev filters and a sixth-order filter design example is presented to illustrate the implementation of the new method.