Elektronik ve Haberleşme Mühendisliği Bölümü

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/179

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Citation Count: ÜNAL, G. (2009). 500MHz-2GHz broadband power amplifier design by non-linear modeling methods. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
500MHz-2GHz broadband power amplifier design by non-linear modeling methods
(2009-09-01) Ünal, Gökalp; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
This thesis presents the design methods of 500MHz-2GHz broadband RF power amplifier. First of all, RF power transistor technologies are searched and the most suitable one is chosen according to its operation of frequency band, maximum output power, efficiency and cost features. The amplifier is designed as it has two stages, and in both stages LDMOS transistor technology is used as RF power transistors. Large signal models for the LDMOS devices are used in simulation, and according to the measurement results, the circuitry in simulation is tried to model at nonlinear conditions. A broadband RF-Choke structure with a new technique is developed to obtain high DC isolation and low RF loss over the desired bandwidth. Input and output matching networks and shunt feedback topology are introduced to fulfill the bandwidth requirements. Typical values of 20dB power gain, 37dBm output power, have been achieved at the most part of the frequency band of 500MHz-2GHz.
Citation Count: CORAN, A.N.N. (2014). A new narrow band microstrip patch filter for modern wireless applications. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
A new narrow band microstrip patch filter for modern wireless applications
(2014-06) Coran, Ali Najdet Nasret; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
A narrowband, compact, and flexible fabricated microstrip bandpass filter design is introduced in this thesis as a candidate for use in modern wireless systems. The proposed filter design is based on the use of dual-mode (two pole) patch microstrip resonator with uniform geometrical slot. This filter has the advantages of possessing much narrower and sharper performance responses as compared to single mode resonator and other conventional square patch filters. The performance of filter structures, based on dual-mode resonators, has been evaluated using Microwave office electromagnetic software package. Dual slotted patch microstrip filters have been designed at resonant frequencies 4.16 and 2.04 GHz using a substrate with a dielectric constant of 10.8 and thickness of 1.27mm.Performance simulation results show that these filter structures offer very good frequency responses in addition to narrow bands gained, compactness properties and 2nd harmonic isolation in out of band region.
Citation Count: DEMİREL, M. (2008). Analysis and observation on quality of service for data networks of turkish telecommunication infrastructure. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Analysis and observation on quality of service for data networks of turkish telecommunication infrastructure
(2008-06-20) Demirel, Mustafa; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, Jitter, Delay and Packet Loss values are measured for different points on TT IP/MPLS Backbone and compared with acceptable values. Measurements are made by using TT’s Alcatel 7750-SR12 devices which run in Ankara, Konya, Kahramanmaraş and Van. During measurements the device running in Ankara is always used as resource.Each of the other points are used as targets.The transmission distances between the devices measurements are as Ankara-Dikmen distance 10 Km and Ankara-Konya 300 Km, Ankara-Kahramanmaraş 602 Km and finally Ankara-Van 1248 Km. In this way, the connection between Jitter, Packet Loss and Delay Values and transmission distance is determined During tests every measurement is performed using 1500 and 4000 Bytes divided packets.The measurement values are taken using ping command on a software called SMART which can reach all devices on TT IP/MPLS Backbone. Measurements made are calculated in a day time zone. The connection of the software by which we perform measurements to the backbone is 100 Mbps. In the measurements taken, increase in Jitter and Delay value is observed when there is an increase in packet size. At the same time, increase in Jitter and Delay value is observed when there is an increase in transmisson distance. The packet loss value is evaluated as %0 in all of the tests made on TT IP/MPLS Backbone.
Citation Count: DURUKAN, S. (2012). Analysis of electromagnetic interference between antennas. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Analysis of electromagnetic interference between antennas
(2012-07) Durukan, Sami; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In an electromagnetic interference (EMI) phenomenon, there is at least a transmitter antenna, and a receiver antenna which is also called as a victim system. To be able to understand this phenomenon analytically, power radiation from the transmitter and power received by the victim antenna should be evaluated. Electric fields of the antennas are used for power intensity calculations. Pattern function with respect to the spherical coordinates is a very important factor in the evaluation of an antenna’s electric field. In this thesis, two fundamental cases for EMI analysis are studied. First, a dipole antenna is considered as a transmitter and a microstrip patch antenna is considered as a victim receiver. Secondly, a circular loop antenna and a microstrip patch antenna are taken into consideration as a transmitter and a receiver, respectively. For both cases, their interference mechanisms are shown analytically. The results of the calculations are shown graphically in the MATLAB simulations.
Citation Count: KİR, K. (2010). Analysis on link-16 tactical digital information link (tadil) system networks. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Analysis on link-16 tactical digital information link (tadil) system networks
(2010-12-01) Kir, Kaan; Çankaya Üniversitesi,Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
Link-16 Joint Tactical Information Distribution System (JTIDS) allows a tactical information exchange between air, ground and naval units near real time in the presence of adversary units. Link-16 employs the Time Division Multiple Access (TDMA) technique for data communication, and at the same time by using frequency hopping capability and encryption properties interconnects various units simultaneously in synchronized nets concurrently near real time in accordance with the mission requirements. In this study, a network design and management tool is developed that designs, programs and manages the Link-16 Network. This tool’s objective is to effectively and reliably distribute the time slots among the tactical participants based on the mission requirements and scenario.
Citation Count: ŞEKER, R. (2014). Application and development of control center and freelog tracking for 24s4 logistics management model. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Application and development of control center and freelog tracking for 24s4 logistics management model
(2014-03) Şeker, Reşat; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, Freelog Logistic, Freelog Tracking and Control Center Development and Application one of the subsystems of San-tez project has been run on the vehicle tracking system. In this context, data types that global positioning system provides has been examined and then studies on tracking and navigation components, performance test of the system and evaluation of the test results have been carried out, test procedures have been conducted in the test conditions similar to real conditions by using hardware used in the system, data have been collected with developed software, also the accuracy of the test procedure has been confirmed with the obtained results by examining the factors that affect the performance of the system.
Citation Count: MAHMOOD, S.N. (2014). Applications of fault-tolerant supervisory control for discrete event systems. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Applications of fault-tolerant supervisory control for discrete event systems
(2014-06) Mahmood, Sarmad Nozad; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
Failure-recovery supervisory control for discrete event systems (DES) is concerned with the recovery from faults that impair the desired system behaviors. Hereby, it is required to detect the occurrence of faults using fault diagnosis and then adapt the system operation such that the system can continue its operation with a potentially degraded performance. In addition, it is generally desired to resume the original system operation after a faulty component is repaired. As the first contribution of this thesis, a new fault diagnosis method is implemented and evaluated. Different from existing approaches, this method allows detecting the repeated occurrence of faults and is particularly useful when considering systems where faults can repeatedly occur after repair. As the second contribution of the thesis, a new method for the fault-recovery supervisory control is developed. Similar to existing approaches, this method assumes that the system follows its nominal behavior as long as the system is non-faulty. If a fault occurs, the system should atleast obey a degraded specification until the desired behavior under fault is achieved in a bounded number of steps. As an extension, the proposed method also allows returning to the nominal behavior after system repair. In addition, our approach is based on the idea of modular supervisory control and hence scalable to large-scale systems. To the best of our knowledge, there is no other modular approach for the fault-recovery supervisory control. The applicability of the developed method is demonstrated by a medium-size laboratory model of a manufacturing system.
Citation Count: AL-HASHİMİ, H. (2014). Channel estimation using per-survivor processing. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Channel estimation using per-survivor processing
(2014-08) Al-Hashimi, Hayder; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis per-survivor processing has been used for estimating the coefficients of a frequency selective channel. Two well-known methods, least mean square and recursive least mean square, along with per-survivor processing have been used during channel estimation. To increase the accuracy of the estimated channel coefficients an improved per-survivor processing channel estimation technique has been proposed and from the simulation results it is seen that the proposed technique results in better estimated channel coefficients than the channel coefficients obtained using classical per-survivor approach.
Citation Count: ÇATMAKAŞ, Ö.K. (2014). Comparison of beam profiles from analytic solution and computational models. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Comparison of beam profiles from analytic solution and computational models
(2014-01) Çatmakaş, Ömer Kemal; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, we have compared the receiver plane beam profiles by computing the Huygens-Fresnel integral as convolution integral and Fourier integral operator and the results obtained from analytic derivation. The comparisons made on different beam types such as Gaussian, Annular-Gaussian, Sine-Gaussian, Sinh-Gaussian, Cos- Gaussian, Cosh-Gaussian beams. To make computations and comparisons we have developed a Matlab code, this code formulates the field expression for beam types on source plane, computes the receiver plane intensity distribution for three approaches of Huygens-Fresnel diffraction integral, and compares the results. Using this code, for the mentioned beam types, receiver beam profiles are computed and compared against different propagation distances and different beam parameters in free space.
Citation Count: ELMABRUK, K.K. (2012). Design of a jammer for spread spectrum signal using matlab simulation. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Design of a jammer for spread spectrum signal using matlab simulation
(2012-08-29) Elmabruk, Kholoud Khaled; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
The term spread spectrum is today one of the most popular terms in the radio engineering and communication community. Since, code division multiple access “CDMA” is a form of spread spectrum, a family of digital communication techniques that have been used in military applications for many years. Originally there were two motivations: either to resist enemy efforts to jam the communications “anti-jam, or AJ”, or to hide the fact that communication was even taking place, sometimes called low probability of intercept “LPI”. It has a history that goes back to the early days of World War II. In the late 1940's the proposed theoretically use of CDMA for civilian mobile radio applications is novel, but the practical application in the civilian marketplace did not take place until 40 years later. Nowadays, because of the dramatic growth of using the communication devices in every day’s life, and since this usage is sometimes has to be disturbed for some reasons, so to achieve this jammers are used. In practice, many types of jammers such as partial band noise jammer, pulsed noise jammer, and single-tone jammer are used. While this thesis studies the jammer design differently, by using the same spreading codes which spreads the message signals. This thesis addresses a study of designing a jammer for spread spectrum signal by analyzing the performance of the system using the MATLAB simulation. To achieve this, after a brief introduction the principles of the spread spectrum systems are explained in details, then the techniques of the detection which are used to retrieve the message signal are presented. Finally, the implementation of the design based on using the same spreading codes, which are used by the jammed system itself. Each of Gold, PN, and Kasami codes is used not only to spread the message signals but also to jam them. The channel is assumed to be an Additive White Gaussian Noise “AWGN”, and the suboptimum detector is used to retrieve the messages. According to the simulation results the designed jammer perform close to the theoretical jammer at a low signal to noise ration “SNR”, and increasing the code length diverge the designed jammer from the theoretical, in contrast the effect of increasing the number of users is opposite.
Citation Count: KAHYA, A.H.M.A. (2012). Development of a dc-motor control laboratory experiment. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Development of a dc-motor control laboratory experiment
(2012-11-08) Kahya, Ardm H.Mohammed Ali; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
Control laboratory experiments are usually expensive and do not allow much flexibility regarding controller designs and controller implementation. Because of this reason, the subject of this thesis is the development of a low-cost DC motor speed control experiment that can be used for various controller designs and different controller implementations. The thesis both describes the hardware components of the experiment and performs controller designs using the pole placement method, root locus method, symmetrical optimum and magnitude optimum method. In addition it is shown that control architectures such as disturbance forward can be used for the DC motor speed control. All controller designs are evaluated by simulations in Matlab/Simulink and are applied to the hardware experiment in the form of discrete-time control algorithms.
Citation Count: ILĞIN, R. (2011). Development of air data computation function of a combined air data and aoa computera. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Development of air data computation function of a combined air data and aoa computera
(2011-09-16) Ilğın, Rafet; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, Air Data Computer part of a Combined Air Data System (CADS) and the simulator environment to test the developed CADS are developed on standard personal computers. Normally, a CADS system on an aircraft is composed of two separate equipments, the Air Data Computer (ADC) and the Angle of Attack (AOA) system. Therefore the developed CADS system combines both functionalities in an integral manner on a card. This approach not only reduces the volume but the total cost of the CADS system as well.
Citation Count: KARABULUT, M.M. (2011). Development of angle of attack (aoa) / stall warning computer function sofa combine dair data andaoa computer. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Development of angle of attack (AOA)/stall warning computer functions of a combined air data and angle of attack computer
(2011-09-16) Karabulut, Mehmet Mustafa; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, the Angle of Attack (AOA part) of a combined air data system (CADS), and the CADS software are developed on a standard PC and without real interface. In its current form, a CADS system on an aircraft is composed of two different equipments, one is the ADC and the other is the AOA system. Therefore the developed CADS system combines both functionalities in an integral manner on a card. This way the volume and cost of the CADS system are reduced.
Citation Count: ANWAR, A.M.O. (2012). Development of laboratory experiments for control and power systems :the water ‐tank experiment. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Development of laboratory experiments for control and power systems :the water ‐tank experiment
(2012-09-21) Anwar, Abas M. O.; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
Control system design is needed in many application areas such as manufacturing, automotive systems or power systems. Hence, a thorough education including practical experience is very beneficial for engineering students. In view of this, the thesis develops a water level control experiment for control laboratories. The system is designed to allow system modeling, set-point linearization and the application of various controller design algorithms both in continuous time and in discrete time. The thesis consists of two main parts. In the practical part, guidelines for the choice of system components such as pressure sensor, amplifiers, motor driver and water pump for the water tank system are given and supported by hardware experiment. In the theoretical part of the thesis, different variants of the water level control system are studied, and control methods such as pole placement, root locus, symmetrical optimum, Youlaparametrization and disturbance feedforward are applied. All these experiments are validated by simulations in Matlab/Simulink.
Citation Count: COŞKUN, G.Ç. (2008). Diffraction of electromagnetic waves by impedance slits and strips. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Diffraction of electromagnetic waves by impedance slits and strips
(2008-06-11) Coşkun, Galip Çağlar; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, diffraction process of electromagnetic waves by strips and slits will be examined by using the methods of the physical optics (PO) and modified theory of physical optics (MTPO) that have impedance boundary conditions on them. The integral will be evaluated by using the methods of stationary phase and edge point. The obtained solutions will be compared plotted numerically by using MATLAB.
Citation Count: TATGİN, D. (2008). Effects of beam types in the performance of free space optics systems. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Effects of beam types in the performance of free space optics systems
(2008-09-19) Tatgin, Deniz; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, a general light source beam formula is developed which combines many beam types. Using different parameter sets in the general source beam formula, we obtained different beam’s source equations. Using Matlab, intensity distributions at the source plane for various beam types are plotted. Received average intensity in atmospheric turbulence is calculated for the general source beam and numerical evaluations are made and the received average intensities are plotted for certain specific beams such as Dark Hollow, Flat-topped, Bottle, Lorentz and Super Gaussian beams.
Citation Count: ALİ AL-ISAWİ, A.S. (2014). Effects of channel estimation on turbo equalizer performance. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Effects of channel estimation on turbo equalizer performance
(2014-09) Ali Al-Isawi, Ahmed Sami; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
Equalizer design is an important concept for the wireless communication systems suffering from multipath effects such as ISI. Turbo equalizers are one of the most powerful equalizers introduced several decades ago. For the equalizers to be efficient in removing ISI reliable channel estimation is essential. In this thesis the performance of turbo equalizers for blind and non-blind channel estimators is inspected. For blind channel estimation per-survivor processing with least mean square method is employed. For non-blind channel estimation training sequences are used for channel estimation. An improved channel estimation approach for non-blind technique was suggested and via simulation results, it was seen that the proposed method shows better performance in turbo equalizer than the classical blind and nonblind channel estimation methods do.
Citation Count: KADHİM, O.R. (2014). Effects of degree distribution in rateless coding. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Effects of degree distribution in rateless coding
(2014-09) Kadhim, Omar Raad; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis rateless codes which are adopted by a variety of applications such as, wireless transmission, 3GPP, data storage, multicasting, video streaming are inspected in details. The performance of two important types of rateless codes which are Luby Transform and Raptor codes are measured via computer simulations. Both hard decision and soft decision methods are used while measuring the performance of these codes. For the soft decision decoding Belief Propagation algorithm was used in an iterative manner. Degree distribution is an important criteria for the performance of Luby Transform codes. A new degree distribution called random degree (or exponential random) distribution is proposed for Luby Transform codes. And simulation results support that the proposed distribution shows better performance than the classical degree distributions such as all-at-once, ideal soliton, robust soliton, and sparse.
Citation Count: HAS, A.C. (2010). Field measurement of 3g base station. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Field measurement of 3g base station
(2010-01-18) Has, Ahmet Can; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
3G mobile communication systems launched after some hardware and software changes on existing systems. After these changes operators have new services for subscribers. In this thesis, our target is to find problems, which faced by subscribers, with field measurements. Along these field measurements there were drop, congestion, and low data rate problems. After analyzing these problems we did some hardware and software changes. In this thesis you will find information about these hardware and software changes and the result graphs, which contains comparison for before and after these changes. These results verified by verification tests, if needed the problems re-analyzed and tried to optimize the system.
Citation Count: ONURSAL, Z. (2012). Gigabit passive optical networks (gpon) and the network analysis in the fiber to the home (ftth) project applications in Ankara. Yayımlanmamış yüksek lisans tezi. Ankara: Çankaya Üniversitesi Fen Bilimleri Enstitüsü.
Gigabit passive optical networks (gpon) and the network analysis in the fiber to the home (ftth) project applications in Ankara
(2012-10) Onursal, Zafer; Çankaya Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik ve Haberleşme Mühendisliği Bölümü
In this thesis, the FTTH architectures, which are used by the telecom operators steadily in recent years to provide the increasing subscribers’ expectations, and the application of Gigabit Passive Optical Networks (GPON), which has increasing popularity amongst the FTTH architectures in Ankara are examined. The advantages and disadvantages of GPON architecture over traditional copper networks are presented with bit rate and cost comparison of a target site which has both GPON and copper networks. Cost comparisons between the networks are also made.

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