Browsing by Author "Bilgin, Gülsima"

Now showing 1 - 8 of 8

Citation Count: 6
Comparative assessment of electromagnetic simulation tools for use in microstrip antenna design: Experimental demonstrations
(Wiley, 2019) Bilgin, Gulsima; Yilmaz, Vadi Su; Kara, Ali; Aydin, Elif; Electrical-Electronics Engineering; Department of Electrical & Electronics Engineering
This paper presents a better understanding of the use of finite integration techniques (FIT) and finite element method (FEM) in different types of microstrip antennas in order to determine which numerical method gives relatively more accurate results. Although the theoretical formulation based on Maxwell's equations of both FEM and FIT are approached from different aspects in the literature, there is still a lack of comparison of the same antenna type using different numerical methods employing FEM and FIT. Therefore, in this study, FEM and FIT were applied to two different types of microstrip antennas, and their simulation and experimental results was compared. For the first antenna demonstration, a multilayer structure was chosen to achieve one of the significant parameters. Then, a microstrip antenna with a compact structure was used in the second demonstration. Using these two antennas, the accuracy of FEM and FIT in different structures were compared and all simulated return loss and gain results were verified by the measured results. The experimental demonstrations show that FEM performs better for both types of microstrip antennas while FIT provides an adequate result for two-layer microstrip antennas.
Citation Count: 0
Design considerations for near to the ground communication system and associated Sub-GHz low profile antenna
(Institute of Electrical and Electronics Engineers Inc., 2017) Yilmaz,V.S.; Bilgin,G.; Aydin,E.; Kara,A.; Department of Electrical & Electronics Engineering; Electrical-Electronics Engineering
This paper presents propagation aspects of a peer-to peer communication link where antennas are placed near to the ground (low height). First, some of the propagation models are evaluated for understanding of propagation mechanisms. In this regard, as the height of the antennas are very low and the distance is large enough, reflecting angle becomes very small that makes use of two ray model. On the other hand, in the horizontal plane, the positions of the scattering objects, as a source of lateral waves, might vary largely due to the terrain undulations along with variety of objects around the link. This makes propagation mechanisms a little bit complicated. In order to design low profile, high gain sub-GHz antenna for such propagation environment, microstrip antenna with vertical ground was designed and fabricated. The antenna is required to be protected from natural and man-made effects. Therefore, the antenna with associated sensors are embedded into a metal box with a dielectric cover. All these are discussed and some of the findings are presented. © 2017 IEEE.
Citation Count: 0
Design Considerations for Near to the Ground Communication System and Associated Sub-GHz Low Profile Antenna
(Ieee, 2017) Yilmaz, Vadi Su; Bilgin, Gulsima; Aydin, Elif; Kara, Ali; Department of Electrical & Electronics Engineering; Electrical-Electronics Engineering
This paper presents propagation aspects of a peer-to peer communication link where antennas are placed near to the ground ( low height). First, some of the propagation models are evaluated for understanding of propagation mechanisms. In this regard, as the height of the antennas are very low and the distance is large enough, reflecting angle becomes very small that makes use of two ray model. On the other hand, in the horizontal plane, the positions of the scattering objects, as a source of lateral waves, might vary largely due to the terrain undulations along with variety of objects around the link. This makes propagation mechanisms a little bit complicated. In order to design low profile, high gain sub-GHz antenna for such propagation environment, microstrip antenna with vertical ground was designed and fabricated. The antenna is required to be protected from natural and man-made effects. Therefore, the antenna with associated sensors are embedded into a metal box with a dielectric cover. All these are discussed and some of the findings are presented.
Citation Count: 2
Design Considerations For Sub-GHz Multilayer Microstrip Antenna For Near Ground Communication Links In Rural Areas
(Ieee, 2017) Bilgin, Gulsima; Yilmaz, Vadi Su; Aydin, Elif; Kara, Ali; Department of Electrical & Electronics Engineering; Electrical-Electronics Engineering
This paper presents some preliminary results of design and development of sub-GHz multilayer microstip antenna for use in near ground communication applications. In design stage of the antenna, iterative approach was applied. Firstly, a two layer microstrip antenna design process is presented. Next, the corners of the patch were cut, and a vertical wall on all sides of the antenna were introduced. In this way, both the size and resonant freqeuncy can be tuned. Moreover, as an application specific requirement, it is intended to embed this antenna into a metal box in order to protect it from man-made and natural environmental effects. This was also studied, and effects of the embedding ground on the antenna characteristics were examined. It is shown that the designed antenna provides -27dB resturn loss, and 7.3dB peak gain at 915MHz with the dimension of 150x200x13mm. Some preliminary measurements have proven the simulations.
Citation Count: 3
Design considerations for sub-GHz multilayer microstrip antenna for near ground communication links in rural areas
(Institute of Electrical and Electronics Engineers Inc., 2017) Bilgin,G.; Yilmaz,V.S.; Aydin,E.; Kara,A.; Department of Electrical & Electronics Engineering; Electrical-Electronics Engineering
This paper presents some preliminary results of design and development of sub-GHz multilayer microstip antenna for use in near ground communication applications. In design stage of the antenna, iterative approach was applied. Firstly, a two layer microstrip antenna design process is presented. Next, the corners of the patch were cut, and a vertical wall on all sides of the antenna were introduced. In this way, both the size and resonant freqeuncy can be tuned. Moreover, as an application specific requirement, it is intended to embed this antenna into a metal box in order to protect it from man-made and natural environmental effects. This was also studied, and effects of the embedding ground on the antenna characteristics were examined. It is shown that the designed antenna provides -27dB resturn loss, and 7.3dB peak gain at 915MHz with the dimension of 150×200×13mm. Some preliminary measurements have proven the simulations. © 2017 EMO (Turkish Chamber of Electrical Enginners).
GHZ altı bantlarda çalışan yüksek kazançlı mikroşeritanten tasarımı ve üretimi
(2019) Bilgin, Gülsima; Aydın, Elif; Kara, Ali; Department of Electrical & Electronics Engineering
Bu tezde, GHz altı bantlarda çalışan çok katmanlı mikroşerit anten tasarımı, üretimi ve çevreyle etkileşimi sunulmaktadır. GHz altı bantlarda antenin kazancını artırmak için, boyutu mümkün olduğu kadar küçük tutan çok katmanlı anten yapısı en uygun yöntem olarak öngörülmektedir. İlk önce, mikroşerit antenle ilgili genel temel bilgiler sunulmuş ve daha sonra çok katmanlı mikroşerit anten teorisi ayrıntılı olarak ele alınmıştır. Farklı tiplerde çok katmanlı anten tasarımları gerçekleştirilmiş olup içlerinden bir tanesi üretilmiş ve ölçümleri gerçekleştirilmiştir. Ek olarak anteni sert çevresel koşullardan korumak için anten, metal bir kutuya yerleştirilmiş ve sert bir yalıtkan malzeme ile kaplanmıştır. Kutu ve yalıtkan malzemenin anten parametreleri üzerindeki etkisi incelenmiştir. Bu tez aynı zamanda elektromanyetik sayısal yöntemleri hem teorik hem de deneysel olarak açıklamaktadır. FEM ve FIT kullanan iki ticari araç yardımı ile aynı anten yapısı tasarlanmış ve önemli parametreleri karşılaştırılmıştır.
Citation Count: 4
Miniaturised antenna at a sub-GHZ band for industrial remote controllers
(inst Engineering Technology-iet, 2019) Yilmaz, Vadi Su; Bilgin, Gulsima; Aydin, Elif; Kara, Ali; Electrical-Electronics Engineering; Department of Electrical & Electronics Engineering
This study presents the design and the fabrication of a miniaturised sub-GHz antenna for remote control applications. Miniaturisation techniques were examined to identify the most appropriate topology for sub-GHz band requirements. First, the design parameters of the antenna were determined, and then, a commercial electromagnetic simulation tool was used for the design and optimisation phases. Then, measurements of the fabricated antenna were undertaken. Parametric studies with several iterations were performed to achieve the best possible results. Second, the effects of the box in which the antenna could be placed were examined as most of such antennas are enclosed by plastic boxes. For this purpose, material properties of a typical industrial box available in the market were studied initially, and the most appropriate material of the box was used in simulations. Finally, a polyamide box with appropriate size was fabricated, and the designed antenna was placed inside the box and the measurements were conducted. The measurement results show that the designed antenna provides resonance at the targeted license-free band with adequate size for industrial remote controllers.
Citation Count: 0
A Miniaturized Multi-layer Microstrip Antenna for Linear Wireless Sensor Network Monitoring Systems
(Gazi Univ, 2022) Benzaghta, Mohamed; Er, Burak; Bilgin, Gulsima; Aydin, Elif; Kara, Ali; Department of Electrical & Electronics Engineering
This article presents a sub-GHz ISM band microstrip patch antenna based on the use of multilayer compact structure, which overcomes the shortcomings of typical microstrip antennas such as low gain and high resonant frequency. The antenna was simulated using an electromagnetic simulator, ANSYS HFSS, and fabricated on two different substrates: RT Duroid 5880 and FR4 epoxy with a compact size of 100 x 100 x 8 mm3 (0.29 lambda x 0.29 lambda x 0.02 lambda). The simulated results of the antenna were then compared with the measured ones, and the two were observed to have a reasonable agreement. The proposed antenna operates in the sub-GHz license-free ISM band (862-875 MHz), with a gain value of 2.92 dB. Two prototypes of the proposed antenna were fabricated and used in a Linear Wireless Sensor Networks (LWSNs) monitoring system. Results show that the proposed antenna is a good candidate for those types of LWSNs systems.