Yazar "Gençoğlan, Duygu Nazan" seçeneğine göre listele

Listeleniyor 1 - 11 / 11
  • [ X ]
    Öğe
    A Case Study of Nelder Mead Simplex Optimization Algorithm: Trade-Offs of Sprienski Fractal Bowtie Antenna Parameters
    (2024) Gençoğlan, Duygu Nazan
    In this study, tri-band antenna design adapted for wireless communication, Internet of Things (IoT) and RFID systems is examined. The simulation results indicate that the proposed antenna has three distinct frequency bands. Band 1 (lower band) covers the frequency range of 1.64-1.78 GHz with a resonance frequency of 1.7 GHz. Band 2 covers the range of 3.06-3.9 GHz with a resonance frequency of 3.4 GHz with a high gain of 10 dBi and a radiation efficiency of 92% for long-range communication. Band 3 radiates from 6.25 to 7.6 GHz with a resonance frequency of 6.62 GHz, which is suitable for higher-frequency applications. The antenna design is simulated and analyzed regarding S11, VSWR, gain, radiation efficiency, and bandwidth. Especially, Band 2 (mid-band) provides notable performance, with its 10 dBi gain and 92% efficiency, which makes the proposed antenna an ideal structure for high-data-rate, long-distance communication systems, and 5G (midband) applications. This study also employs the Nelder-Mead Simplex algorithm to observe the optimization of the physical parameters of the proposed antenna via multiple objective functions. The optimization results outlines that longer the arm length of the proposed antenna causes to decrease the resonance frequency of Band 3. Addition to this, the gain is higher with the lower arm length except for the arm length of 90.467 mm and flare angle of 64.77o. That’s, the trade-off condition occurs between minimum return loss and gain. At this point, it can be concluded from this optimization algorithm results that each objective function should be evaluated separately due to this trade-off condition.
  • [ X ]
    Öğe
    A Dual-Band Patch Antenna with Improved Gain and Group Delay Characteristics for C-Band and X-Band Applications
    (2021) Gençoğlan, Duygu Nazan; Çolak, Şule
    In this study, a dual-band patch antenna with improved gain and group delay characteristics is proposed for C-band and X-band applications in radar and satellite communications. In the study, conventional square patch antenna is modified by partially removing the ground plane and rounding the patch corners. The radius of the rounded patch corners is determined by parametric study to achieve the best antenna performance. According to this parametric study, the value of the radius is set to 2 mm. Antenna performance is analysed both in frequency and time domains. Return Loss, Voltage Standing Wave Ratio, gain, radiation pattern, and group delay are investigated via CST Microwave Studio program. Experimental study is also performed to verify the simulation results. The results show that the designed antenna with rounded patch corners and partial ground plane has dual band characteristic. The two resonance frequencies are 6.85 GHz and 9.1 GHz in the simulation results, and 6.56 GHz and 9.12 GHz in the measurement results. The antenna has maximum gain of 5.8 dB. Additionally, group delay variation is very small in the related frequency range. Thus, it is verified that, the proposed antenna has enhanced bandwidth, improved gain and more uniform group delay as compared to the conventional square patch antenna. The proposed dual-band antenna is a quite promising structure with its appropriate gain and uniform group delay characteristics for C-band and X-band applications in radar and satellite communications.
  • [ X ]
    Öğe
    Bibliometric analysis of reconfigurable antennas in radar applications: Trends, influential authors, and future directions
    (IGI Global, 2024) Gençoğlan, Duygu Nazan
    This study conducts a comprehensive bibliometric analysis of research articles on reconfigurable antennas in radar applications retrieved from Google Scholar databases from 1989 to 2024. A total of 980 research articles are analysed, demonstrating significant interest and commitment to the topic, as evidenced by a total of 22.073 citations. Important metrics such as citations per year (649.21), citations per article (22.52), and citations per author (9,529). It highlight the importance and impact of research in this area. Collaboration is common, with an average of 410.95 articles per author and about three authors per article. The geographical analysis highlights the contributions of institutions in the United States and Switzerland. The study identifies emerging trends and future directions and highlights the need for dynamic antenna reconfiguration techniques, integration challenges, and energyefficient solutions. The bibliometric analysis gives valuable insights into the current investigation landscape on reconfigurable antennas for radar applications. © 2024, IGI Global. All rights reserved.
  • [ X ]
    Öğe
    Design of Notched Rounded Bowtie Antenna for Ultra-Wideband Communication Systems
    (2019) Gençoğlan, Duygu Nazan; Çolak, Şule
    In this paper, a modified bowtie antenna structure is proposed for Ultra-Wideband communicationsystems. This antenna is obtained by rounding and notching the edges of antenna arms. Antennaparameters for the designed structure are examined according to the restrictions specified by FederalCommunications Commission. Thus, Return Loss (S11), Voltage Standing Wave Ratio (VSWR), gain,radiation pattern and impedance are observed in the 3.1 GHz - 10.6 GHz frequency range. Additionally,the effect of arm length and dielectric material on antenna performance are interpreted in the same range.According to obtained results, the proposed structure satisfies the bandwidth requirements for Ultra-Wideband systems. Gain and impedance variations are also in acceptable limits for Ultra-Widebandapplications. The proposed antenna is analyzed through CST Microwave Studio program.
  • [ X ]
    Öğe
    Improvement and optimization of thin dipole for UWB applications
    (Islamic Azad University, 2018) Gençoğlan, Duygu Nazan; Çolak, Şule
    In this paper, thin dipole is investigated in the 3.1-10.6 GHz Ultra-Wide Band frequency range. The study includes the design of half wave dipole antenna with different dipole radii to improve the antenna characteristics. Antenna parameters including return loss, Voltage Standing Wave Ratio, -10 dB bandwidth and radiation pattern are examined according to Federal Communication Commission regulations and Ultra-Wide Band system requirements in this frequency range. Additionally, two optimization techniques, Genetic Algorithm and Particle Swarm Optimization are applied to obtain the best dipole radius. CST Microwave Studio, an electromagnetic simulation program, is used for the design of the antenna structure and the simulation purposes. The simulation is performed in transient mode. The results show that the antenna performance can be improved by selecting the suitable antenna dimensions. Additionally, Genetic Algorithm and Particle Swarm Optimization techniques are compared in terms of time consumption to obtain the best VSWR and return loss values. The results also depict that Genetic Algorithm yields better results for the proposed structure. © 2017 Majlesi Branch, Islamic Azad University.
  • [ X ]
    Öğe
    Investigation and improvement of ultra wideband antenna characteristics
    (Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi, 2017) Gençoğlan, Duygu Nazan; Çolak, Şule
    Bu çalışmada, Ultra-Geniş Bant (UGB) iletişim sistemleri için anten tasarımı yapılmış ve UGB sistemlerde anten performansını belirlemek için anten parametreleri analiz edilmiştir. Yarım dalga dipol, kelebek ve mikro şerit antenleri gibi çeşitli Ultra Geniş Bant anten yapıları, tasarlanmış ve UGB frekans aralığının tamamında, yani 3.1 - 10.6 GHz' de incelenmiştir. UGB antenlerinin tümünün benzetimi CST Mikrodalga Stüdyo programı ile yapılmıştır. Benzetim ve tasarım işlemi sırasında Geri Dönüş Kaybı (S11), Duran Dalga Oranı ve radyasyon örüntüsü gibi önemli anten parametreleri incelenmiştir. Anten bant genişliğinin ve anten performansının UGB frekans aralığında arttırılması için bazı bant genişliği iyileştirme teknikleri uygulanmıştır. Bu teknikler kelebek anten için kol kenarlarının eğilmesi ve kesilmesi, mikroşerit anten içinse yama geometrisinin değiştirilmesi şeklinde uygulanmıştır. Daha sonra verimli anten yapılarından birkaçı,Genetik Algoritma ve Parçacık Sürüsü Optimizasyonu gibi evrimsel algoritmalar ile optimize edilmek üzere seçildi. Buna ek olarak, seçilen anten yapılarını UWB frekans aralığında daha verimli bir şekilde kullanmak için optimizasyon prosedürlerinin etkisi araştırılmıştır.
  • [ X ]
    Öğe
    INVESTIGATION OF BROADER BANDWIDTH ELLIPTICAL DIPOLE ANTENNA PERFORMANCE PARAMETERS FOR 5G, KU AND KA-BAND APPLICATIONS: DIELECTRIC CONSTANT EFFECTS
    (2024) Gençoğlan, Duygu Nazan
    This study presents an examination of the design and evaluation process of an elliptical dipole antenna operating at the design frequency of 5 GHz. Initially based on conventional dipole antenna principles, the antenna's design is iteratively refined through bandwidth enhancement techniques, resulting in the emergence of ultra-wideband characteristics. Notably, the modified antenna design features a distinctive notch band spanning from 4.21 to 10.06 GHz, positioning it as a versatile solution suitable for applications across the mid-band of 5G, as well as the full Ku and partial Ka bands, encompassing frequencies from 27 GHz to 31 GHz. Furthermore, this study investigates the impact of varying dielectric constants on antenna parameters, shedding light on a critical aspect often overlooked in conventional dipole antenna calculations. Through systematic analysis, it is revealed that a dielectric constant of 4.3, aligned with the commonly used low-cost epoxy-based FR-4 material, yields optimal performance. While higher dielectric constants broaden the antenna's characteristics, lower values are found to enhance communication efficiency, thus offering potential benefits in terms of power consumption and cost savings. The detailed examination and findings presented in this study enrich the understanding of antenna design principles and provide valuable guidance for future research and practical applications in the field of wireless communication and antenna engineering.
  • [ X ]
    Öğe
    Investigation of Origami Inspired Sub-6 GHz Accordion Monopole Antenna for 5G Applications
    (2021) Gençoğlan, Duygu Nazan; Çolak, Şule
    This study presents an origami inspired sub-6 GHz accordion monopole antenna for 5G applications. Parametric study is performed by varying monopole height, fold width and bevel angle to examine the antenna performance in the 1 GHz - 6 GHz frequency range. The proposed antenna is designed with the values that yield the best performance in accordance with the results of parametric study. Antenna behavior is then evaluated in terms of Return Loss, gain and radiation pattern. The proposed antenna operates in 1.22 GHz - 6 GHz frequency range which covers almost the entire sub-6 GHz range with an approximate impedance bandwidth of 132%. Hence, the designed antenna structure has a good performance in the sub-6 GHz and it is a promising design for 5G applications.
  • [ X ]
    Öğe
    Metamaterial-inspired antenna designs for IoT/5g applications
    (Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi, 2023) Gençoğlan, Duygu Nazan; Çolak, Şule; Palandöken, Merih
    Nesnelerin İnterneti (IoT) ve Beşinci Nesil (5G) ağlarının bir araya gelmesi, kompakt cihazlarda ve yoğun ağ ortamlarında verimli anten tasarımlarına olan ihtiyacı artırmıştır. Bu tez, özellikle 6 GHz altı uygulamalara odaklanarak frekansı yeniden yapılandırılabilir metamalzeme tabanlı antenlerin derinlemesine incelenmesini sunmaktadır. Bu çalışmada temel amaç, metamalzeme yapılarının özelliklerinden faydalanan, kompaktlık ve frekans yeniden yapılandırılabilirliği sağlayan yeni anten tasarımları geliştirmektir. Kapsamlı bir literatür taraması yoluyla tez, metamalzeme tabanlı antenlerin ve Bölünmüş Halka Rezonatörü (SRR) yapılarının IoT ve 5G bağlamlarında anten performansı üzerindeki etkilerini incelemektedir. Çalışma, frekansı yeniden yapılandırılabilir antenler için yeni tasarımlar önermekte ve incelemektedir. Tasarımlar, SRR'ler dahil olmak üzere çeşitli rezonatörleri birleştirmekte ve antenlerin elektriksel uzunluğunu değiştirmek için PIN diyotları, SPDT anahtarları ve bakır yol değişiklikleri gibi farklı anahtarlama mekanizmalarını kullanmaktadır. Geri Dönüş Kaybı, Işıma Deseni ve Işıma Verimliliği gibi önemli anten parametreleri 6 GHz altı aralıkta analiz edilmektedir. Önerilen frekansı yeniden yapılandırılabilir antenlerin prototipleri de deneysel olarak test edilmektedir. Simülasyon ve deneysel sonuçlar, önerilen tasarımların etkinliğini doğrulayarak önemli ölçüde boyut küçültme, yüksek verimlilik ve dinamik frekans uyarlanabilirliği ortaya koymaktadır. Böylece bu çalışma, frekans yeniden yapılandırması, kompaktlık ve ışıma verimliliği açısından kablosuz haberleşme sistemlerindeki önemli boşlukları gidermektedir.
  • [ X ]
    Öğe
    Offset-fed Slotted Antenna Practically Loaded with Split Ring as Water Quality Sensor for X-Band Industrial Applications
    (Advanced Electromagnetics, 2024) Varshney, Atul; Gençoğlan, Duygu Nazan
    This article describes the design, testing, and analysis of an offset-fed split ring-loaded slotted antenna for various water quality sensors. The antenna is designed to resonate at 10 GHz on a low-cost FR-4 substrate of dimensions 0.621?o×0.467?o×0.053?o, where ?o is the free space wavelength at the resonant frequency. The fabricated antenna finds excellent agreement with the measured antenna parameters. At 10 GHz, the antenna achieves a gain of 7.61 dBi, a nearly unidirectional radiation pattern, and a radiation efficiency of 76%. The research is further explored to use the antenna as a water sample sensor. The antenna is tested on various water samples by submerging it in them, and in the second scenario, contactless measurements at 10 mm away from the container's upper water level. The work examines the quality of the water by observing the shift in the resonant frequency (fr), the antenna quality factor with different total dissolved solvents (TDS) in the water samples, and changes in the reflection coefficient (S11) values. It is observed that the antenna shows less than 1.5% numerical sensitivity (NS) with fr, and high NS with the S11. The antenna's S11 and bandwidth vary and depending on the water sample. This antenna is suitable for X-band industrial and microwave laboratory applications. © 2024, Advanced Electromagnetics. All rights reserved.
  • [ X ]
    Öğe
    Radar and Non-Contact Sensing
    (Elsevier, 2022) Ebrahim, Malikeh P.; Tom, Neil; Gençoğlan, Duygu Nazan; Çolak, Şule; Yuce, Mehmet R.
    Radar systems have received attention extensively in recent years for remote detection and monitoring for healthcare and security applications. Monitoring the primary vital signs is essential to evaluate people’s physical and occasionally mental health, to assess potential symptoms of diseases and to follow up on patients’ recovery. Human activity sensing plays a vital role in intelligent home and health monitoring applications. Data observed from human activities is appropriated for improving our lifestyle. In this work, recent implementations of both contact and remote radar systems are presented. The article also discusses required antennas’ specifications for mentioned applications. © 2023 Elsevier Ltd. All rights reserved