International Advanced Researches and Engineering Journal
In this paper, a new broadband patch antenna design for fifth-generation (5G) sub-6 GHz mobile sy... more In this paper, a new broadband patch antenna design for fifth-generation (5G) sub-6 GHz mobile systems is presented. The proposed 5G antenna has a very compact size with an overall dimension of 10.7 × 22.5 mm2. The 5G antenna consists of a log-periodic patch in the form of an equilateral triangle with a 50 Ω microstrip line feed and a ground plane of rectangular shape. The prototype of the proposed 5G antenna was made by etching on an FR4 substrate with a 1.6mm thickness, 4.3 dielectric constant and 0.02 tangent loss. The 5G antenna is designed and simulated for the frequency band range of 3.4-4.2 GHz. According to the measurement results, the 5G antenna impedance band range is determined as 3.1-3.9 GHz. Besides, the proposed 5G antenna has also near-omnidirectional radiation patterns both simulation and measurement at the resonance frequencies of 3.8 GHz and 3.5 GHz, respectively. According to these results, the proposed antenna is showed similar radiation characteristics in both m...
International Journal of Intelligent Systems and Applications in Engineering, 2019
Today, mobile devices are required to be portable in size and have long-lasting power supplies. F... more Today, mobile devices are required to be portable in size and have long-lasting power supplies. For this reason, it is desirable that the components used in the devices have low power consumption, in particular the size of the antennas and that they meet the need for high band. In order to meet these needs, especially the intense increase in array antenna studies has been observed frequently in recent years. In this study, an array of 1x4 microstrip antenna elements was designed and produced. For this purpose, the study focused on the possible smallest width of the feed line considering the high antenna performance. Electrical parameters such as return loss, gain, directivity and radiation efficiency of the antenna array designed for KU Band region at 16 GHz resonance frequency were obtained and its performance was evaluated. In addition, the return loss, frequency and bandwidth of the antenna were calculated with Artificial Neural Networks (ANN). The ANN structure, which is trained with Multilayer Perceptron (MLP) network structure, is a 4-input, 3output structure. Levenberg-Marquardt was used as the training algorithm in the calculation with ANN and tested for 8 measured values.
Studies on the examination of pathological tissue samples with antennas have begun to be develope... more Studies on the examination of pathological tissue samples with antennas have begun to be developed. In this study, normalization studies performed using a microstrip antenna structure with increased gain are presented. FR-4 substrate with a dielectric constant of 4.4 is preferred in the antenna structure used in the normalization studies. In pathological tissue samples, samples of normal and cancerous skin tissue are modeled in HFSS and simulated. The differences in the normalized S-parameters as a result of the simulations are shown in the tables. While the normal skin tissue normalization value at S11 is 13.4, the value for the tumor skin tissue sample is 18.0. For other S-parameters, different values are obtained for normal and cancerous skin tissue. The differences in the values reveal the success of the proposed antenna structure.
2017 25th Signal Processing and Communications Applications Conference (SIU), 2017
According to researches, the most common diseases of unexpected death causes are related to heart... more According to researches, the most common diseases of unexpected death causes are related to heart. The one of basic reasons of heart diseases is congestion of heart vessel. To detect these failures, various solutions are produced and these solutions are continued. With the proposed study, the congestion of heart vessel related to heart disease is modelled on rectangular microstrip patch antenna and evaluations of electromagnetic field values are tried in situations while there is congestion and not congestion. In modelling, permittivity values of heart vessel and fat tissues are used, by selecting 2.45 GHz as operating frequency and FR-4 as substrate, simulations are realized in High Frequency Structural Simulator(HFSS). From obtained results, it has been shown that the congestion of heart vessel can be detected with electromagnetic data.
2020 4th International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT), 2020
In this study, it is aimed to detect occlusion in the cardiac vessels with two different microstr... more In this study, it is aimed to detect occlusion in the cardiac vessels with two different microstrip antennas. Occlusions located in different locations and sizes in the vessel are simulated using ANSYS HFSS and detected by evaluating the Scattering parameters and Electric field values. Antennas in Circular and Seljuk star geometries are designed on Jean (Denim) substrate that allow usage in wearable applications. This study is a preliminary study of a research project and it is predicted that cardiovascular occlusions can be detected by using microstrip antennas in non-ionizing frequency band. Again, by evaluating the values taken, the location and percentage of the occlusion can be determined.
Cancer diseases significantly affect lives of many people for last years. The diagnosis and treat... more Cancer diseases significantly affect lives of many people for last years. The diagnosis and treatment process is quite difficult and painful. It is especially important to reach the result of pathological tissue samples in which the structure of the cancerous tissue is determined and helps to shape the treatment in a short time. Today, it may take days or even months to obtain these results. In this study, microstrip antenna structures that are frequently used due to many advantages in biomedical applications are studied. Electromagnetic field and scattering parameter data of two antennas operating in the 2.45 GHz and 5.8 GHz operating frequency in ISM (Industrial, Scientific and Medical) band region are analyzed and compared. Pathological sample transformed form of tumor and normal skin tissue is simulated and compared in Ansys' HFSS program. Both the electric field values and the S-parameter values were compared by obtaining the values of both antennas at 2.45 GHz and 5.8 GHz ...
Kanser hastaliklari gunumuzde bircok insanin hayatini onemli olcude etkilemektedir. Teshis ve ted... more Kanser hastaliklari gunumuzde bircok insanin hayatini onemli olcude etkilemektedir. Teshis ve tedavi sureci ise oldukca zor ve agrilidir. Ozellikle kanserli dokunun yapisinin belirlendigi ve tedavinin sekillenmesine yardimci olan patolojik doku orneklerinin sonucuna kisa surede ulasmak onemlidir. Gunumuzde bu sonuclara ulasmak gunler hatta aylar surebilmektedir. Bu calismada biyomedikal uygulamalarda bircok avantaji sebebi ile sikca kullanilan mikroserit anten yapilari calisilmaktadir. ISM band bolgesinde bulunan 2.45 GHz ve 5.8 GHz isima bolgelerinde calisan iki adet antenin elektromanyetik alan ve sacilma parametre verileri incelenmekte ve kiyaslanmaktadir. Tumorlu ve normal deri dokusunun patolojik numune donusturulmus hali Ansys’in HFSS programinda simule edilerek kiyaslanmaktadir. Her iki antenin hem 2.45 GHz’deki hem de 5.8 GHz’deki degerleri simulasyonlardan elde edilerek hem elektrik alan degerleri hem de S-parametre degerleri kiyaslanmistir. Elde edilen sonuclara bakildigin...
International Journal of Applied Mathematics, Electronics and Computers, 2016
In this study, a new microstrip patch geometry, called Seljuk star, is proposed. The performance ... more In this study, a new microstrip patch geometry, called Seljuk star, is proposed. The performance of the designed antenna is compared with the performances of square and circular microstrip antennas, which are two other popular patch geometries in literature. The design procedure consists of two phases: First, the patch dimensions of circular and square antennas are taken as the same with Seljuk star dimension. Then the patch surface areas of antennas are fixed to the area of Seljuk star patch and patch dimensions are calculated for the new designs. The effect of different patch types on bandwidth are investigated. Rogers Duroid 6010 ( h = 3.175 mm, ɛ r =10.2) is chosen as the substrate of the antennas which are expected to have a bandwidth center at 5800 MHz. All antenna designs are simulated in HFSS. Each individual antenna is intended to be working at a single frequency, but during the simulations multiple resonance are obtained in many designs. Therefore, the bandwidth and frequ...
In this study, efiects of etching U-slot on circular patches on their bandwidths are investigated... more In this study, efiects of etching U-slot on circular patches on their bandwidths are investigated. The study is carried out by etching U-slots on the present microstrip patches in the literature by simulating them with HFSS. Simulation results are used for training and testing of an Artiflcial Neural Network model for difierent microstrip patches' bandwidth predictions. The obtained simulation results are compared with Artiflcial Neural Network results. In comparison of the simulation and Artiflcial Neural Network results, accuracy rates of training and testing were found as 93.28% and 94.19%, respectively. It is obtained that by etching U-slot, the band- widths can be enhanced for the present circular microstrip patches. It is shown that possible the bandwidth behavior of U-slot circular microstrip disc antenna with this Artiflcial Neural Network model is powerfully estimated.
Bu calismada, gunumuz teknolojisi olan LTE ya da 4.5G ile gelecek nesil olarak da bilinen besinci... more Bu calismada, gunumuz teknolojisi olan LTE ya da 4.5G ile gelecek nesil olarak da bilinen besinci nesil (5G) mobil iletisimde kullanilan mobil terminaller icin dort elemanli coklu giris coklu cikis (MIMO) mimarisinde yeni bir yama anten dizisi sunulmustur. Onerilen anten dizisinde yer alan her bir eleman log-periyodik yama seklinde tasarlanmis ve karsilikli gelen MIMO elamanlari birbirinin ozdesi olacak sekilde yerlestirilmistir. Bilindigi gibi, gunumuzde yer alan mobil cihazlar oldukca kompakt yapiya sahiptirler. Bu cihazlarda yer alan anten sistemlerinin de bu boyutlara uygun olmalari gerektiginden, onerilen antenin toplam boyutu 80×150mm2 ile standart bir akilli cihazla esdegerdir. Onerilen antenin tasarimindan sonra, 4.3 nispi gecirgenlige ve 1.6 mm kalinliga sahip FR4 substrat uzerine baski devre (PCB) teknolojisi kullanilarak prototip uretimi de gerceklestirilmistir. Onerilen antenin olcum ve simulasyon degerleri arasinda buyuk oranda bir benzerlik elde edilmistir. Onerilen do...
Pathological reports play an important role in the diagnosis and especially in the treatment of d... more Pathological reports play an important role in the diagnosis and especially in the treatment of diseases. For this reason, it is important to be able to access the reports of pathological tissue samples in a short time. Today, depending on the pathologist and the number of samples, the report delivery time can take months. For this reason, microstrip antenna structures, which are frequently used in the biomedical field, are investigated to evaluate pathological tissue samples. In this study, the variation of the gain values of antenna structures depending on the simulation results is examined. FR-4 substrate material, which has a dielectric constant of 4.4, is used in the microstrip antenna structure. The diameters of four circles added to the antenna patch structure with an operating frequency of 2.45 GHz are changed parametrically. The highest gain value of the antenna structure is investigated. The gain value has been increased from 1.89 dB to about 3.5 dB.
Studies on the examination of pathological tissue samples with antennas have begun to be develope... more Studies on the examination of pathological tissue samples with antennas have begun to be developed. In this study, normalization studies performed using a microstrip antenna structure with increased gain are presented. FR-4 substrate with a dielectric constant of 4.4 is preferred in the antenna structure used in the normalization studies. In pathological tissue samples, samples of normal and cancerous skin tissue are modeled in HFSS and simulated. The differences in the normalized S-parameters as a result of the simulations are shown in the tables. While the normal skin tissue normalization value at S11 is 13.4, the value for the tumor skin tissue sample is 18.0. For other S-parameters, different values are obtained for normal and cancerous skin tissue. The differences in the values reveal the success of the proposed antenna structure.
2021 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2021
In the study, an antenna array is designed that has two circular patch elements. Elliptic slots a... more In the study, an antenna array is designed that has two circular patch elements. Elliptic slots are etched on circular patches than a rectangular piece is added in the center of the slots. The array has a directional radiation pattern with a gain of 11.95 dB. It is resonated at 5.8 GHz ISM band with a return loss value of over -10dB. It is fed by a microstrip line matched to 50 Ω. The array is simulated by ANSYS Electromagnetics Suite, HFSS and parametric optimizations are completed. After determining the optimum parameters, it is manufactured on FR-4 substrate that a thickness of 1.6 mm and a dielectric constant value of 4.4 and a tangent loss of 0.002 by handmade in our laboratory. FR-4 is chosen because of it’ s easy to find and cheap. It is studied in a Bachelor degree final thesis by Ayse Ozge Cinar and her supervisor Seyfettin Sinan Gultekin, and planned to use in an international competition. The 2x1 array is manufactured by using chemical process method that uses hydrochloric acid and hydrogen peroxide solution with a ratio of 3:1. The measurements of S 11 and impedance are obtained with Rohde Schwarz ZVL-13 Vector Network Analyzer in normal room conditions. The array is designed and manufactured as two, for a usage with Unmanned Aerial Vehicle (UAV) communication system on the both receiver and transmitter modules. So, the main aim is obtaining a high gain value over 10dB, and a resonant frequency of near 5.8 GHz. An applicable dimension of the whole array and being light are other necessities. In addition, a long communication distance about 1.5-2 km is needed. The study is started with designing a single circular patch, using formulas from literature. In the second step, with an inspiration of [3] , an elliptic slot is etched on it. Patch and slot parameters are tried with different values in simulations to aim a higher gain. The third step is adding a rectangular piece in the center of the slot with a parametric sweep. For the optimum parameters, the single antenna is also manufactured and measured. After the performance evaluation of this single patch design, the array is created for two antenna elements. The suitable proximity between antenna elements that blocked interference and impedance matching arrangement of the microstrip feedline are completed in simulation media. From comparison of simulation and measurement results, they are compatible with each other and showed that the array design can be used by successfully on communication of unmanned aerial vehicles.
Bu calismada, 0.5-3.5 GHz araligindaki frekans degerleri icin hibrit Yapay Sinir Agi modeline day... more Bu calismada, 0.5-3.5 GHz araligindaki frekans degerleri icin hibrit Yapay Sinir Agi modeline dayali Selcuklu Yildizi mikroserit anten (SSMA) tasarimi gerceklestirilmistir. Bu calismada, bir geri yayilma (BP) ve bir meta-sezgisel algoritmayi birlestirerek sinir agi egitimi icin yeni bir algoritma gelistirilmistir. Geri yayilmanin cozum bulmadaki en buyuk dezavantaji, kuresel minimumdan ziyade yerel minimuma sikismasidir. Bu yeni hibrit egitim algoritmasinda, yerel ve global arama es zamanli olarak yapilmistir. Baslangicta, uzun atlama sayesinde yerel minimuma yakalanma olasiliginin dusuk olmasi nedeniyle sinir aglarinin agirliklarini elde etmek icin Ates Bocegi Algoritmasi (FA) kullanildi. Daha sonra, bu algoritma, Firefly Algoritmasinin gelismis kuresel arama yeteneginin ve BP algoritmasinin yerel arama yeteneginin noral ag egitiminde kullanilmasi icin geri yayilma (BP) ile birlestirilmistir. Yapay Sinir Aginin egitim asamasinda Levenberg-Marquardt geri yayilma algoritmasi kullanilmistir. Bu calismada Selcuklu Yildizi mikroserit anteni, cift yuzlu 1.55mm dielektrik ve 35um iletken kalinliginda, 4.37 elektrik iletkenligine ve 0.002 kayip tanjantina sahip DE104 uzerine tasarlanmistir. 272 mikroserit anten tasarimi icin HFSS anten simulasyon programi kullanilmistir. Veri setinin %90'i egitim, %10'u test verisi olarak kullanilmistir. Ates Bocegi Algoritmasi ile YSA sonuclari simulasyon sonuclariyla daha uyumludur.
Substrate material used in microstrip antenna structures fully impact the performance of antenna ... more Substrate material used in microstrip antenna structures fully impact the performance of antenna and applications of it. In this work, simulations are carried out for microstrip antenna structure used in biomedical applications. Heart vessel structure used for determining heart diseases is modelled in Ansoft HFSS program. Simulations are implemented with and without occlusion in heart vein. Antenna structure is simulated with different substrate materials and different thicknesses of them. After simulations, various electromagnetic field data are obtained and evaluated for dissimilar substrate materials and thickness of them.
Due to the many advantages of microstrip patch antennas, nowadays, microstrip patch antennas are ... more Due to the many advantages of microstrip patch antennas, nowadays, microstrip patch antennas are mostly preferred in biomedical areas. This study aims two antenna structures, as both transceiver and receiver, have same dimensions are designed to produce solution of the difficulties in pathology. For antennas with an operating frequency of 2.45 GHz, FR-4 substrate material with a value of 4.4 dielectrics is used. A model has been prepared to detect the presence of skin cancer with the designed antennas. The model is a method of determining E-field and scattering parameters differences between two antennas of cancerous and normal tissue specimens placed on the glass slides. The same antennas and experimental setup were prepared with the normal and cancerous structure of the skin tissue prepared by pathologists. Thus, scattering parameters are measured and their differences are determined. It has been shown that cancerous tissue can be determined with different values obtained as a res...
In this study, a wideband low profile microstrip antenna design for C-band applications is presen... more In this study, a wideband low profile microstrip antenna design for C-band applications is presented. The proposed antenna consists of a monopol log periodic patch in the equilateral triangular dimensions with the microstrip line fed and a rectangular ground plane. The antenna has 9×19.8 mm2 overall size, thickness of 1.6 mm and 4.3 dielectric constant. According to the simulation results, the proposed antenna has a very wide bandwidth while operating in the frequency band of 4.25-7.95 GHz and 5 GHz resonance frequency. The proposed antenna was also prototyped on FR4 substrate with the 0.02 tangent loss and the measurement results were quite similar by the simulated results.
International Advanced Researches and Engineering Journal
In this paper, a new broadband patch antenna design for fifth-generation (5G) sub-6 GHz mobile sy... more In this paper, a new broadband patch antenna design for fifth-generation (5G) sub-6 GHz mobile systems is presented. The proposed 5G antenna has a very compact size with an overall dimension of 10.7 × 22.5 mm2. The 5G antenna consists of a log-periodic patch in the form of an equilateral triangle with a 50 Ω microstrip line feed and a ground plane of rectangular shape. The prototype of the proposed 5G antenna was made by etching on an FR4 substrate with a 1.6mm thickness, 4.3 dielectric constant and 0.02 tangent loss. The 5G antenna is designed and simulated for the frequency band range of 3.4-4.2 GHz. According to the measurement results, the 5G antenna impedance band range is determined as 3.1-3.9 GHz. Besides, the proposed 5G antenna has also near-omnidirectional radiation patterns both simulation and measurement at the resonance frequencies of 3.8 GHz and 3.5 GHz, respectively. According to these results, the proposed antenna is showed similar radiation characteristics in both m...
International Journal of Intelligent Systems and Applications in Engineering, 2019
Today, mobile devices are required to be portable in size and have long-lasting power supplies. F... more Today, mobile devices are required to be portable in size and have long-lasting power supplies. For this reason, it is desirable that the components used in the devices have low power consumption, in particular the size of the antennas and that they meet the need for high band. In order to meet these needs, especially the intense increase in array antenna studies has been observed frequently in recent years. In this study, an array of 1x4 microstrip antenna elements was designed and produced. For this purpose, the study focused on the possible smallest width of the feed line considering the high antenna performance. Electrical parameters such as return loss, gain, directivity and radiation efficiency of the antenna array designed for KU Band region at 16 GHz resonance frequency were obtained and its performance was evaluated. In addition, the return loss, frequency and bandwidth of the antenna were calculated with Artificial Neural Networks (ANN). The ANN structure, which is trained with Multilayer Perceptron (MLP) network structure, is a 4-input, 3output structure. Levenberg-Marquardt was used as the training algorithm in the calculation with ANN and tested for 8 measured values.
Studies on the examination of pathological tissue samples with antennas have begun to be develope... more Studies on the examination of pathological tissue samples with antennas have begun to be developed. In this study, normalization studies performed using a microstrip antenna structure with increased gain are presented. FR-4 substrate with a dielectric constant of 4.4 is preferred in the antenna structure used in the normalization studies. In pathological tissue samples, samples of normal and cancerous skin tissue are modeled in HFSS and simulated. The differences in the normalized S-parameters as a result of the simulations are shown in the tables. While the normal skin tissue normalization value at S11 is 13.4, the value for the tumor skin tissue sample is 18.0. For other S-parameters, different values are obtained for normal and cancerous skin tissue. The differences in the values reveal the success of the proposed antenna structure.
2017 25th Signal Processing and Communications Applications Conference (SIU), 2017
According to researches, the most common diseases of unexpected death causes are related to heart... more According to researches, the most common diseases of unexpected death causes are related to heart. The one of basic reasons of heart diseases is congestion of heart vessel. To detect these failures, various solutions are produced and these solutions are continued. With the proposed study, the congestion of heart vessel related to heart disease is modelled on rectangular microstrip patch antenna and evaluations of electromagnetic field values are tried in situations while there is congestion and not congestion. In modelling, permittivity values of heart vessel and fat tissues are used, by selecting 2.45 GHz as operating frequency and FR-4 as substrate, simulations are realized in High Frequency Structural Simulator(HFSS). From obtained results, it has been shown that the congestion of heart vessel can be detected with electromagnetic data.
2020 4th International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT), 2020
In this study, it is aimed to detect occlusion in the cardiac vessels with two different microstr... more In this study, it is aimed to detect occlusion in the cardiac vessels with two different microstrip antennas. Occlusions located in different locations and sizes in the vessel are simulated using ANSYS HFSS and detected by evaluating the Scattering parameters and Electric field values. Antennas in Circular and Seljuk star geometries are designed on Jean (Denim) substrate that allow usage in wearable applications. This study is a preliminary study of a research project and it is predicted that cardiovascular occlusions can be detected by using microstrip antennas in non-ionizing frequency band. Again, by evaluating the values taken, the location and percentage of the occlusion can be determined.
Cancer diseases significantly affect lives of many people for last years. The diagnosis and treat... more Cancer diseases significantly affect lives of many people for last years. The diagnosis and treatment process is quite difficult and painful. It is especially important to reach the result of pathological tissue samples in which the structure of the cancerous tissue is determined and helps to shape the treatment in a short time. Today, it may take days or even months to obtain these results. In this study, microstrip antenna structures that are frequently used due to many advantages in biomedical applications are studied. Electromagnetic field and scattering parameter data of two antennas operating in the 2.45 GHz and 5.8 GHz operating frequency in ISM (Industrial, Scientific and Medical) band region are analyzed and compared. Pathological sample transformed form of tumor and normal skin tissue is simulated and compared in Ansys' HFSS program. Both the electric field values and the S-parameter values were compared by obtaining the values of both antennas at 2.45 GHz and 5.8 GHz ...
Kanser hastaliklari gunumuzde bircok insanin hayatini onemli olcude etkilemektedir. Teshis ve ted... more Kanser hastaliklari gunumuzde bircok insanin hayatini onemli olcude etkilemektedir. Teshis ve tedavi sureci ise oldukca zor ve agrilidir. Ozellikle kanserli dokunun yapisinin belirlendigi ve tedavinin sekillenmesine yardimci olan patolojik doku orneklerinin sonucuna kisa surede ulasmak onemlidir. Gunumuzde bu sonuclara ulasmak gunler hatta aylar surebilmektedir. Bu calismada biyomedikal uygulamalarda bircok avantaji sebebi ile sikca kullanilan mikroserit anten yapilari calisilmaktadir. ISM band bolgesinde bulunan 2.45 GHz ve 5.8 GHz isima bolgelerinde calisan iki adet antenin elektromanyetik alan ve sacilma parametre verileri incelenmekte ve kiyaslanmaktadir. Tumorlu ve normal deri dokusunun patolojik numune donusturulmus hali Ansys’in HFSS programinda simule edilerek kiyaslanmaktadir. Her iki antenin hem 2.45 GHz’deki hem de 5.8 GHz’deki degerleri simulasyonlardan elde edilerek hem elektrik alan degerleri hem de S-parametre degerleri kiyaslanmistir. Elde edilen sonuclara bakildigin...
International Journal of Applied Mathematics, Electronics and Computers, 2016
In this study, a new microstrip patch geometry, called Seljuk star, is proposed. The performance ... more In this study, a new microstrip patch geometry, called Seljuk star, is proposed. The performance of the designed antenna is compared with the performances of square and circular microstrip antennas, which are two other popular patch geometries in literature. The design procedure consists of two phases: First, the patch dimensions of circular and square antennas are taken as the same with Seljuk star dimension. Then the patch surface areas of antennas are fixed to the area of Seljuk star patch and patch dimensions are calculated for the new designs. The effect of different patch types on bandwidth are investigated. Rogers Duroid 6010 ( h = 3.175 mm, ɛ r =10.2) is chosen as the substrate of the antennas which are expected to have a bandwidth center at 5800 MHz. All antenna designs are simulated in HFSS. Each individual antenna is intended to be working at a single frequency, but during the simulations multiple resonance are obtained in many designs. Therefore, the bandwidth and frequ...
In this study, efiects of etching U-slot on circular patches on their bandwidths are investigated... more In this study, efiects of etching U-slot on circular patches on their bandwidths are investigated. The study is carried out by etching U-slots on the present microstrip patches in the literature by simulating them with HFSS. Simulation results are used for training and testing of an Artiflcial Neural Network model for difierent microstrip patches' bandwidth predictions. The obtained simulation results are compared with Artiflcial Neural Network results. In comparison of the simulation and Artiflcial Neural Network results, accuracy rates of training and testing were found as 93.28% and 94.19%, respectively. It is obtained that by etching U-slot, the band- widths can be enhanced for the present circular microstrip patches. It is shown that possible the bandwidth behavior of U-slot circular microstrip disc antenna with this Artiflcial Neural Network model is powerfully estimated.
Bu calismada, gunumuz teknolojisi olan LTE ya da 4.5G ile gelecek nesil olarak da bilinen besinci... more Bu calismada, gunumuz teknolojisi olan LTE ya da 4.5G ile gelecek nesil olarak da bilinen besinci nesil (5G) mobil iletisimde kullanilan mobil terminaller icin dort elemanli coklu giris coklu cikis (MIMO) mimarisinde yeni bir yama anten dizisi sunulmustur. Onerilen anten dizisinde yer alan her bir eleman log-periyodik yama seklinde tasarlanmis ve karsilikli gelen MIMO elamanlari birbirinin ozdesi olacak sekilde yerlestirilmistir. Bilindigi gibi, gunumuzde yer alan mobil cihazlar oldukca kompakt yapiya sahiptirler. Bu cihazlarda yer alan anten sistemlerinin de bu boyutlara uygun olmalari gerektiginden, onerilen antenin toplam boyutu 80×150mm2 ile standart bir akilli cihazla esdegerdir. Onerilen antenin tasarimindan sonra, 4.3 nispi gecirgenlige ve 1.6 mm kalinliga sahip FR4 substrat uzerine baski devre (PCB) teknolojisi kullanilarak prototip uretimi de gerceklestirilmistir. Onerilen antenin olcum ve simulasyon degerleri arasinda buyuk oranda bir benzerlik elde edilmistir. Onerilen do...
Pathological reports play an important role in the diagnosis and especially in the treatment of d... more Pathological reports play an important role in the diagnosis and especially in the treatment of diseases. For this reason, it is important to be able to access the reports of pathological tissue samples in a short time. Today, depending on the pathologist and the number of samples, the report delivery time can take months. For this reason, microstrip antenna structures, which are frequently used in the biomedical field, are investigated to evaluate pathological tissue samples. In this study, the variation of the gain values of antenna structures depending on the simulation results is examined. FR-4 substrate material, which has a dielectric constant of 4.4, is used in the microstrip antenna structure. The diameters of four circles added to the antenna patch structure with an operating frequency of 2.45 GHz are changed parametrically. The highest gain value of the antenna structure is investigated. The gain value has been increased from 1.89 dB to about 3.5 dB.
Studies on the examination of pathological tissue samples with antennas have begun to be develope... more Studies on the examination of pathological tissue samples with antennas have begun to be developed. In this study, normalization studies performed using a microstrip antenna structure with increased gain are presented. FR-4 substrate with a dielectric constant of 4.4 is preferred in the antenna structure used in the normalization studies. In pathological tissue samples, samples of normal and cancerous skin tissue are modeled in HFSS and simulated. The differences in the normalized S-parameters as a result of the simulations are shown in the tables. While the normal skin tissue normalization value at S11 is 13.4, the value for the tumor skin tissue sample is 18.0. For other S-parameters, different values are obtained for normal and cancerous skin tissue. The differences in the values reveal the success of the proposed antenna structure.
2021 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2021
In the study, an antenna array is designed that has two circular patch elements. Elliptic slots a... more In the study, an antenna array is designed that has two circular patch elements. Elliptic slots are etched on circular patches than a rectangular piece is added in the center of the slots. The array has a directional radiation pattern with a gain of 11.95 dB. It is resonated at 5.8 GHz ISM band with a return loss value of over -10dB. It is fed by a microstrip line matched to 50 Ω. The array is simulated by ANSYS Electromagnetics Suite, HFSS and parametric optimizations are completed. After determining the optimum parameters, it is manufactured on FR-4 substrate that a thickness of 1.6 mm and a dielectric constant value of 4.4 and a tangent loss of 0.002 by handmade in our laboratory. FR-4 is chosen because of it’ s easy to find and cheap. It is studied in a Bachelor degree final thesis by Ayse Ozge Cinar and her supervisor Seyfettin Sinan Gultekin, and planned to use in an international competition. The 2x1 array is manufactured by using chemical process method that uses hydrochloric acid and hydrogen peroxide solution with a ratio of 3:1. The measurements of S 11 and impedance are obtained with Rohde Schwarz ZVL-13 Vector Network Analyzer in normal room conditions. The array is designed and manufactured as two, for a usage with Unmanned Aerial Vehicle (UAV) communication system on the both receiver and transmitter modules. So, the main aim is obtaining a high gain value over 10dB, and a resonant frequency of near 5.8 GHz. An applicable dimension of the whole array and being light are other necessities. In addition, a long communication distance about 1.5-2 km is needed. The study is started with designing a single circular patch, using formulas from literature. In the second step, with an inspiration of [3] , an elliptic slot is etched on it. Patch and slot parameters are tried with different values in simulations to aim a higher gain. The third step is adding a rectangular piece in the center of the slot with a parametric sweep. For the optimum parameters, the single antenna is also manufactured and measured. After the performance evaluation of this single patch design, the array is created for two antenna elements. The suitable proximity between antenna elements that blocked interference and impedance matching arrangement of the microstrip feedline are completed in simulation media. From comparison of simulation and measurement results, they are compatible with each other and showed that the array design can be used by successfully on communication of unmanned aerial vehicles.
Bu calismada, 0.5-3.5 GHz araligindaki frekans degerleri icin hibrit Yapay Sinir Agi modeline day... more Bu calismada, 0.5-3.5 GHz araligindaki frekans degerleri icin hibrit Yapay Sinir Agi modeline dayali Selcuklu Yildizi mikroserit anten (SSMA) tasarimi gerceklestirilmistir. Bu calismada, bir geri yayilma (BP) ve bir meta-sezgisel algoritmayi birlestirerek sinir agi egitimi icin yeni bir algoritma gelistirilmistir. Geri yayilmanin cozum bulmadaki en buyuk dezavantaji, kuresel minimumdan ziyade yerel minimuma sikismasidir. Bu yeni hibrit egitim algoritmasinda, yerel ve global arama es zamanli olarak yapilmistir. Baslangicta, uzun atlama sayesinde yerel minimuma yakalanma olasiliginin dusuk olmasi nedeniyle sinir aglarinin agirliklarini elde etmek icin Ates Bocegi Algoritmasi (FA) kullanildi. Daha sonra, bu algoritma, Firefly Algoritmasinin gelismis kuresel arama yeteneginin ve BP algoritmasinin yerel arama yeteneginin noral ag egitiminde kullanilmasi icin geri yayilma (BP) ile birlestirilmistir. Yapay Sinir Aginin egitim asamasinda Levenberg-Marquardt geri yayilma algoritmasi kullanilmistir. Bu calismada Selcuklu Yildizi mikroserit anteni, cift yuzlu 1.55mm dielektrik ve 35um iletken kalinliginda, 4.37 elektrik iletkenligine ve 0.002 kayip tanjantina sahip DE104 uzerine tasarlanmistir. 272 mikroserit anten tasarimi icin HFSS anten simulasyon programi kullanilmistir. Veri setinin %90'i egitim, %10'u test verisi olarak kullanilmistir. Ates Bocegi Algoritmasi ile YSA sonuclari simulasyon sonuclariyla daha uyumludur.
Substrate material used in microstrip antenna structures fully impact the performance of antenna ... more Substrate material used in microstrip antenna structures fully impact the performance of antenna and applications of it. In this work, simulations are carried out for microstrip antenna structure used in biomedical applications. Heart vessel structure used for determining heart diseases is modelled in Ansoft HFSS program. Simulations are implemented with and without occlusion in heart vein. Antenna structure is simulated with different substrate materials and different thicknesses of them. After simulations, various electromagnetic field data are obtained and evaluated for dissimilar substrate materials and thickness of them.
Due to the many advantages of microstrip patch antennas, nowadays, microstrip patch antennas are ... more Due to the many advantages of microstrip patch antennas, nowadays, microstrip patch antennas are mostly preferred in biomedical areas. This study aims two antenna structures, as both transceiver and receiver, have same dimensions are designed to produce solution of the difficulties in pathology. For antennas with an operating frequency of 2.45 GHz, FR-4 substrate material with a value of 4.4 dielectrics is used. A model has been prepared to detect the presence of skin cancer with the designed antennas. The model is a method of determining E-field and scattering parameters differences between two antennas of cancerous and normal tissue specimens placed on the glass slides. The same antennas and experimental setup were prepared with the normal and cancerous structure of the skin tissue prepared by pathologists. Thus, scattering parameters are measured and their differences are determined. It has been shown that cancerous tissue can be determined with different values obtained as a res...
In this study, a wideband low profile microstrip antenna design for C-band applications is presen... more In this study, a wideband low profile microstrip antenna design for C-band applications is presented. The proposed antenna consists of a monopol log periodic patch in the equilateral triangular dimensions with the microstrip line fed and a rectangular ground plane. The antenna has 9×19.8 mm2 overall size, thickness of 1.6 mm and 4.3 dielectric constant. According to the simulation results, the proposed antenna has a very wide bandwidth while operating in the frequency band of 4.25-7.95 GHz and 5 GHz resonance frequency. The proposed antenna was also prototyped on FR4 substrate with the 0.02 tangent loss and the measurement results were quite similar by the simulated results.
Uploads
Papers by Dilek Kocer