Elektrik - Elektronik Mühendisliği Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/202

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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.
Dron ve Arabalar gibi Hareketli Platformların İletişimine Yönelik Farklı Rezonanslarda Konik Radyasyon ve Konik Tarama Yapılmasına Olanak Sağlayan Çift Taraflı E Şeklindeki Düzlemsel Dizi Yama Antenlerin Tasarımı ve Geliştirilmesi
(2023) Kılıç, Veli Tayfun; Tosun, Hüseyin; Şanlıer, Şaban Duran; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Kılıç, Veli Tayfun
Bu projede dron ve arabalar gibi hareketli platformların iletişimine yönelik farklı rezonanslarda konik yayılım ve konik tarama yapılmasına olanak sağlayan çift taraflı E şeklindeki anten elemanlarından oluşan düzlemsel dizi yama antenlerin tasarımı, analizleri, üretimi ve testleri gerçekleştirilmiştir. Tasarlanan dizilerin elektromanyetik simülasyonlar ile rezonans davranışları ve yayılım örüntüleri hesaplanmıştır. Modellenen dizilerin üretimleri tarafımızca gerçekleştirilmiş ve ölçümleri yapılmıştır. Ölçüm ve simülasyon sonuçları birbirleriyle uyumlu bulunmuştur. Sonuçlar tasarlanan dizilerin öngörüldüğü üzere 2.4 GHz ve 4.8 GHz?de ilk ve ikinci rezonanslarının oluştuğunu ve bu rezonanslarda konik yayılım ve konik taramanın gerçekleştiğini göstermektedir. Daha sonra, dizideki elemanların beslenmesine yönelik 1?e 8?lik güç bölücü tasarımları yapılmıştır. Tasarlanan güç bölücü simülasyonlar ile modellenmiş ve iletim ve yansıma kaybı parametreleri hesaplanmıştır. Modellenen güç bölücülerin üretim ve testleri de yine tarafımızca gerçekleştirilmiştir. Ölçüm ve simülasyon sonuçları birbirini desteklemektedir. Sonuçlar tasarlanan güç bölücünün 2.4 GHz frekansında giriş portunda düşük yansıma kaybı ve çıkış portlarında eşit sinyal seviyelerini gerçekleştirdiğini göstermektedir. Son adım olarak dizi antenin dronun altına yerleştirildiği uzak alan yayılım örüntü ölçümünü gerçekleştirdiğimiz bir deneysel kurulum meydana getirilmiştir. Gerçekleştirdiğimiz ölçümlerde dizi antenin simülasyonlarda olduğu gibi belirli düşey eksen açılarında en yüksek yayılımı sağladığı gözlemlenmiştir.
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.
Strand wire winding method in a solenoidal coil with limited geometry for good impedance matching
(Polska Akademia Nauk, 2023) Kılıc, Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Kılıc, Veli Tayfun
This paper reports a new strand wire winding method in a solenoidal coil with limited geometry that enables good impedance matching. In the proposed method strand wires are wound layer-by-layer on top of each other allowing one to set equivalent inductance and resistance of the coil to desired values while obtaining dense magnetic flux and high current carrying capacity. As a proof-of-concept demonstration, simple model setups were constructed with solenoidal coils composed of copper wire strands wound according to the proposed method, and a plastic pipe. The measurements were repeated with a metal shell placed inside the coil to model a complete heating system. System inductance and resistance were measured at two different frequencies. The results show that with the new winding method it is possible to increase a coil’s turn number and the number of strand layers composed by the coil. Also, adding and removing strand layers in the proposed coil architectures enable inductance and resistance values to decrease and increase, respectively, in a controlled way. To understand changes of system parameters, simulations were also performed. The calculated inductance and resistance values in the simulations agree well with the measurement results and magnetic flux distribution created in the system demonstrates the changes.
Study of helical antenna endowing short wire length and compact structure for high-frequency operations and its exclusive manufacturing process
(TÜBİTAK, 2023) Aslan, Melih; Şık, Kaan; Güzelkara, İzzet; Özdür, İbrahim Tuna; Kılıç. Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Aslan, Melih; Şık, Kaan; Güzelkara, İzzet; Kılıç, Veli Tayfun
In this paper a study of a helical antenna resonating at high-frequency (HF) band with a very compact structure is reported. The designed antenna’s S11 parameter magnitude change with frequency was calculated for different geometrical parameters. For each case, first, only a single parameter was changed. Then for a fair comparison, multiple parameters were changed simultaneously while the total wire length was set to be constant. Also, shifts in resonance frequencies and variations in –10 dB bandwidths were investigated. Our results show that resonance behaviour changes distinctively with the geometrical parameters and it allows shortening of the antenna wire length. For the designed antenna, the resonances shift to lower frequencies and –10 dB bandwidths around the resonances decrease as the winding wire thickness, number of turns, and turn radius increase. Whereas as the turn spacing increases the resonances shift to higher frequencies and –10 dB bandwidths widen, although the total wire length of the antenna increases. To verify the simulation results, the designed antenna was fabricated with an exclusive manufacturing process and characterized. The measurement results are in good agreement with the simulation results. It demonstrates the feasibility of the proposed manufacturing technique, which is new in the literature and enables accurate and rigid antenna fabrication with simple and low-cost steps.
Triple band diamond-shaped polarization insensitive plasmonic nano emitter for thermal camouflage and radiative cooling
(Springer Link, 2024) Şanlı, Atıf Kerem; Tabaru, Timuçin Emre; Kılıç, Veli Tayfun; 0000-0001-6806-9053; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Şanlı, Atıf Kerem; Kılıç, Veli Tayfun
This study proposes the design of a novel Metal-Insulator-Metal (MIM) nano-infrared emitter that uses a unique diamond-shaped grating to achieve selective infrared absorption. Diamond-shaped nano emitter (DNE) structure exhibits four narrow resonant peaks within key absorption windows such as short-wave infrared (SWIR) mid-wave infrared (MWIR), alongside with a wide absorption band in the Non-Transmissive Infrared Range (NTIR) for thermal camouflage applications compatible with radiative cooling. Moreover, the proposed DNE is polarization insensitive as it has an in-plane symmetric design. Using the 3D Finite-Difference Time-Domain (FDTD) simulations, we demonstrate the nanoantenna’s superior performance characterized by its high absorption rates and tuned effective impedance matching. As of our knowledge, the findings suggest that this is the first time that a MIM structure achieved multiple narrow resonance peaks, located in SWIR and MWIR simultaneously, with a wide absorption range in NTIR. Represented DNE stands as a significant innovation in the field of stealth technology, providing a tunable, high-efficiency solution for managing and controlling thermal emissions across diverse applications.

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