Browsing by Author "Kilic, Veli Tayfun"

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All-Surface Induction Heating With High Efficiency and Space Invariance Enabled by Arraying Squircle Coils in Square Lattice
(IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA, 2018) Kilic, Veli Tayfun; Unal, Emre; Yilmaz, Namik; Demir, Hilmi Volkan; AGÜ, Mühendislik Fakültesi, Elektrik & Elektronik Mühendisliği Bölümü;
This paper reports an all-surface induction heating system that enables efficient heating at a constant speed all over the surface independent of the specific location on the surface. In the proposed induction system, squircle coils are placed tangentially in a two-dimensional square lattice as opposed to commonly used hexagonal packing. As a proof-of-concept demonstration, a simple model setup was constructed using a 3 x 3 coil array along with a steel plate to be inductively heated. To model surface heating, a set of six locations for the plate was designated considering symmetry points. For all of these cases, power dissipated by the system and the plate's transient heating were recorded. Independent from the specific plate position, almost equal heating speeds were measured for the similar levels of dissipated energies in the system. Using full three-dimensional electromagnetic solutions, the experimental results were also verified. The findings indicate that the proposed system is proved to enable energy efficient space-invariant heating in all-surface induction hobs.
Comb-Shaped Patch Antenna Design Study with Shifted Arms and Asymmetric Architecture Enabling Controlled Resonance Change and Radiation Pattern
(Institute of Electrical and Electronics Engineers Inc., 2022) Aslan, Melih; Baydar, Huseyin; Kilic, Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Aslan, Melih; Baydar, Huseyin; Kilic, Veli Tayfun
This paper reports comb-shaped patch antennas with asymmetrical geometries having two and three arms on the sides. The proposed geometry is evolved from regular rectangular shaped patch antenna by removing certain parts of the radiator patch and shifting the arms on one side of the antenna. Systematic simulations were obtained with the designed antennas for different arm shifting distances, and changes in resonance behavior and far-field radiation pattern were investigated. Results show that as the arm shifting increases the first and second resonance frequencies of the antennas decrease. Also, it is observed that the radiation occurs with two symmetric beams at the second resonance frequency of the designed antennas with no shift between the arms. However, as the arm shifting is applied the beam on the side of the arms closer to the feeding line gets stronger, whereas the other beam weakens. Obtained plots indicate that the directivity of the antennas have a tendency to increase with the arm shifting while the side lobe level decreases. In addition, results show that the half power beam width of the antenna increases with arm shifting. The simulations were repeated for different arm thicknesses and the same observations were held.
Crown shaped edge multiband antenna design for 5G and X-Band applications
(SPRINGER, 2023) Hakanoglu, Baris Gurcan; Kilic, Veli Tayfun; Altindis, Fatih; Turkmen, Mustafa; 0000-0001-6806-9053; 0000-0002-3891-935X; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Kilic, Veli Tayfun; Altindis, Fatih
Nowadays we are experiencing the fifth-generation (5G) technology with new frequency bands to achieve high broadband speed, minimum latency and more developed end user devices. Due to the different frequency ranges for different applications at 5G bands the antennas should support multiband operation in a compact structure. This paper proposes a new multiband microstrip patch antenna design operating at mid band 5G frequencies and in the X band. The structure of the antenna includes simply loading the top radiating edge with rhombic shaped stubs and slots. This configuration yields the antenna to have resonances at multiple frequencies based on the fact that the stubs and slots affect capacitive and inductive impedances on the lower and higher operating frequencies of the antenna. The unique design enables the antenna to have reasonably high gains at four different bands of 6.76 dBi, 6.47 dBi, 7.76 dBi and 5.51 dBi at 3.34 GHz, 4.61 GHz, 6.01 and 8.02 GHz, respectively. Also, the simulated antenna has been manufactured and measured. The measurement results are in good agreement with the simulation results. The proposed design can be used with many other frequency bands and dielectric materials as well to achieve multiband operation.
Design of a Portable DF System with Simple and Compact Structure Operating at 875 Mhz GSM Band
(Institute of Electrical and Electronics Engineers Inc., 2021) Uludag, Mert; Ozoksuzkaya, Ali; Kilic, Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Uludag, Mert; Ozoksuzkaya, Ali; Kilic, Veli Tayfun
This paper reports a portable GSM direction finding system operating at 875 MHz frequency band with simple and compact structure. In the system, array of receiver antennas are placed together with other RF components including amplifiers, power dividers, phase comparators, an analog to digital converter and a processor unit. With help of the developed algorithm phase comparison between the receiver antenna channels is obtained and angle estimation is done. The developed algorithm was first run on a constructed system test setup that involves a digital oscilloscope connected to the receiver antennas in a laboratory environment. Later, the digital oscilloscope in the test setup was replaced with the RF components mentioned above such that a portable receiver system with compact structure was obtained. Direction finding experiments were repeated with the designed portable receiver system in the laboratory and in open space. Results show that with the designed system angle of a transmitter is found very accurately such that the maximum angle error between the estimated and the exact angle values of the transmitter antenna was found to be equal to 3.5° in the open space experiments for the transmitter antenna positioned at an angle between -60° and 60° on the horizontal plane same with the receiver antennas. Also, it is observed that the difference between the estimated and the exact angle values has an increasing trend with the exact angle absolute value. The findings indicate that the designed portable direction finding system is promising to be used for applications requiring accurate angle estimation of GSM signals.
High-efficiency flow-through induction heating
(INST ENGINEERING TECHNOLOGY-IET, MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND, 2020) Kilic, Veli Tayfun; Unal, Emre; Demir, Hilmi Volkan; 0000-0003-1793-112X; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
This study reports a newly designed induction heating system for efficient, fast, and safe flow-through heating. The system has a very simple architecture, which is composed of a transmitting coil, an isolating plastic pipe, and an embedded metal shell. Wireless energy transfer from the external coil to the internal metal shell through the pipe is essential for decreasing losses. Also, a large contact surface between a fluid and the immersed shell enables rapid heat transfer. The proposed heating system was systematically investigated for different shell geometries and the results were compared with a commercially available conductive flow-through heating device. As a proof-of-concept demonstration, a prototype of the designed induction heating system was manufactured and the heating measurements were conducted with water. Power transfer efficiency of the prototyped induction heating system was measured to be 97%. The comparative study indicates that such high-efficiency induction flow-through heating system offers a great potential for replacing the conventional conductive heating device used in household applications in which the rapid and compact heating is desired.
Magnetic Field Calculation Of Square Coils Having Rounded Corners
(IEEE, 2019) Erman, Muhammed Furkan; Kilic, Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Erman, Muhammed Furkan; Kilic, Veli Tayfun
There are differently shaped coils for induction heating used in industry such as circular, and square coils. While producing square-like shaped coils, it is unavoidable to face production difficulties due to the sharp corners. At the end of the production, instead of square-like shape, edges are flat and corners are rounded shape coil which is called squircle coil is produced. This paper will discuss how these rounded corners effect the magnetic field at the center of the coil by deriving missed formulas in the literature, and prove the results by comparing with the results of generally known formulas.