Pub Date : 2018-02-23DOI: 10.5152/IUJEEE.2018.1815
M. Başak, F. Kaçar
Active elements are critical in implementing active filters, oscillators, rectifiers, and signal processing circuits. We observe that several active circuits have been proposed in the literature. In this study, we have proposed four inductance simulators that employ only one active circuit current feedback operational amplifier and three or four passive components. The first and fourth topologies are designed for series lossy inductance, whereas the second and third topologies are designed for lossless negative inductance simulators. A passive RLC filter is used to demonstrate the effectiveness of the proposed inductance simulators. The simulations performed with the LTSpice program and the results agree with the theoretical analysis.
{"title":"Lossy/Lossless Grounded Inductance Simulators Using Current Feedback Operational Amplifier (CFOA)","authors":"M. Başak, F. Kaçar","doi":"10.5152/IUJEEE.2018.1815","DOIUrl":"https://doi.org/10.5152/IUJEEE.2018.1815","url":null,"abstract":"Active elements are critical in implementing active filters, oscillators, rectifiers, and signal processing circuits. We observe that several active circuits have been proposed in the literature. In this study, we have proposed four inductance simulators that employ only one active circuit current feedback operational amplifier and three or four passive components. The first and fourth topologies are designed for series lossy inductance, whereas the second and third topologies are designed for lossless negative inductance simulators. A passive RLC filter is used to demonstrate the effectiveness of the proposed inductance simulators. The simulations performed with the LTSpice program and the results agree with the theoretical analysis.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132098441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/IUJEEE.2018.1804
H. Dogan
A wide-band tunable Low-Noise Amplifier (LNA) was designed to be used in military radios. The LNA works in the frequency range of 30–512 MHz where military walkie-talkies operate. To cover the wide range of operating frequencies, the output of amplifier is divided into four sub-bands with four separate external inductors and integrated capacitor arrays. The first part of the study analyzes the performance parameters such as the gain, tuning, matching, noise figure, and distortion. Layout of the design was completed, and post-layout simulations, including the layout parasitic effects, were run to quantify the performance. The LNA achieves a minimum of 12-dB gain across the entire operating frequency range. The minimum rejections achieved by the LNA at 10% and 20% offset from the center-tuned frequency were 7 dB and 13 dB, respectively. The LNA achieves a worst-case noise figure of 4.6 dB, and the impedance-match parameter (S11) is better than −20 dB under all the conditions. The worst cases P1dB (1-dB Compression Point) and IIP3 (3rd Order Input Intercept Point) were 9.1 dBm and 18 dBm, respectively, across frequency and process–voltage–temperature corners. The design dissipates 20 mA from a 3.3-V power supply and uses a 1.5-V power supply for capacitor array termination.
{"title":"A Highly Linear Wide-Band Tunable Lna for Military Radio Applications","authors":"H. Dogan","doi":"10.5152/IUJEEE.2018.1804","DOIUrl":"https://doi.org/10.5152/IUJEEE.2018.1804","url":null,"abstract":"A wide-band tunable Low-Noise Amplifier (LNA) was designed to be used in military radios. The LNA works in the frequency range of 30–512 MHz where military walkie-talkies operate. To cover the wide range of operating frequencies, the output of amplifier is divided into four sub-bands with four separate external inductors and integrated capacitor arrays. The first part of the study analyzes the performance parameters such as the gain, tuning, matching, noise figure, and distortion. Layout of the design was completed, and post-layout simulations, including the layout parasitic effects, were run to quantify the performance. The LNA achieves a minimum of 12-dB gain across the entire operating frequency range. The minimum rejections achieved by the LNA at 10% and 20% offset from the center-tuned frequency were 7 dB and 13 dB, respectively. The LNA achieves a worst-case noise figure of 4.6 dB, and the impedance-match parameter (S11) is better than −20 dB under all the conditions. The worst cases P1dB (1-dB Compression Point) and IIP3 (3rd Order Input Intercept Point) were 9.1 dBm and 18 dBm, respectively, across frequency and process–voltage–temperature corners. The design dissipates 20 mA from a 3.3-V power supply and uses a 1.5-V power supply for capacitor array termination.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"6 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122157714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/IUJEEE.2018.1814
Hasan Demir
Herein, using support vector machines, texture images were classified based on the histogram of oriented gradients, from which feature vectors were obtained. In addition, the success rate was examined for the feature vectors with different dimensions and the minimum length of a feature vector for performing classification was determined to be 288 elements.
{"title":"Classification of Texture Images Based on the Histogram of Oriented Gradients Using Support Vector Machines","authors":"Hasan Demir","doi":"10.5152/IUJEEE.2018.1814","DOIUrl":"https://doi.org/10.5152/IUJEEE.2018.1814","url":null,"abstract":"Herein, using support vector machines, texture images were classified based on the histogram of oriented gradients, from which feature vectors were obtained. In addition, the success rate was examined for the feature vectors with different dimensions and the minimum length of a feature vector for performing classification was determined to be 288 elements.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128230107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/iujeee.2018.1813
N. Kabaoğlu
Fifth-generation (5G) cellular communication systems aim to obtain a higher data rate, decreased latency time, higher performance even at high mobility speeds, decreased system complexity, lower transmission cost, and an increased system capacity and coverage area. Many of these goals can be achieved because of the studies devoted to the physical layer of 5G cellular networks. In this respect, solutions to the problems of beamforming (steering and precoding or precoding and combining) and channel estimation that are encountered in the physical layer of 5G cellular networks are the key points to achieve the aforementioned goals. Thus, a two-stage beamforming method is proposed in this study. The proposed method is a suboptimal method that minimizes the difference between outputs obtained when fully digital and hybrid beamforming methods are used. The analytical results, which are validated through simulations, demonstrate that the proposed method is an effective solution and, hence, the preferred beamforming approach for 5G millimeter wave band-based wireless systems.
{"title":"Suboptimal Frequency-Selective Transceiver Design for Multicarrier Millimeter Wave MIMO Systems","authors":"N. Kabaoğlu","doi":"10.5152/iujeee.2018.1813","DOIUrl":"https://doi.org/10.5152/iujeee.2018.1813","url":null,"abstract":"Fifth-generation (5G) cellular communication systems aim to obtain a higher data rate, decreased latency time, higher performance even at high mobility speeds, decreased system complexity, lower transmission cost, and an increased system capacity and coverage area. Many of these goals can be achieved because of the studies devoted to the physical layer of 5G cellular networks. In this respect, solutions to the problems of beamforming (steering and precoding or precoding and combining) and channel estimation that are encountered in the physical layer of 5G cellular networks are the key points to achieve the aforementioned goals. Thus, a two-stage beamforming method is proposed in this study. The proposed method is a suboptimal method that minimizes the difference between outputs obtained when fully digital and hybrid beamforming methods are used. The analytical results, which are validated through simulations, demonstrate that the proposed method is an effective solution and, hence, the preferred beamforming approach for 5G millimeter wave band-based wireless systems.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121530900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/IUJEEE.2018.1817
S. Kahraman, A. Erturk
This study presents the most extensive performance comparison of pansharpening methodologies by considering 17 pansharpening algorithms that are applied to the satellite images obtained from RASAT, which is the first earth observation satellite designed and manufactured in Turkey. Standard and state-of-the-art pansharpening approaches from various categories, such as component substitution (CS), modulation based (MB), multiresolution analysis (MRA), and hybrid and variational methods, are included in order to gain a better insight and perform a thorough analysis of the performance of various pansharpening methods. The experimental validation procedure was designed according to Wald's protocol, and the performance evaluations were conducted both qualitatively and quantitatively on the basis of seven quantitative evaluation criteria.
{"title":"Review and Performance Comparison of Pansharpening Algorithms for RASAT Images","authors":"S. Kahraman, A. Erturk","doi":"10.5152/IUJEEE.2018.1817","DOIUrl":"https://doi.org/10.5152/IUJEEE.2018.1817","url":null,"abstract":"This study presents the most extensive performance comparison of pansharpening methodologies by considering 17 pansharpening algorithms that are applied to the satellite images obtained from RASAT, which is the first earth observation satellite designed and manufactured in Turkey. Standard and state-of-the-art pansharpening approaches from various categories, such as component substitution (CS), modulation based (MB), multiresolution analysis (MRA), and hybrid and variational methods, are included in order to gain a better insight and perform a thorough analysis of the performance of various pansharpening methods. The experimental validation procedure was designed according to Wald's protocol, and the performance evaluations were conducted both qualitatively and quantitatively on the basis of seven quantitative evaluation criteria.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132753842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/IUJEEE.2018.1802
A. Yesil, F. Kaçar
In this work, we present a current-mode and voltage-mode quadrature oscillator circuit using a voltage differencing buffered amplifier (VDBA), two grounded capacitors, and a grounded resistor. The oscillation condition and frequency are orthogonally (or independently) controllable. The current-mode and voltage-mode quadrature signals can be simultaneously obtained from the proposed circuit. The use of only grounded capacitors and resistors makes the proposed circuits ideal for integrated circuit implementation. The quadrature oscillator is simulated with SPICE simulation program using 0.35-µm technology parameters.
{"title":"Current and Voltage Mode Quadrature Oscillator Based on Voltage Differencing Buffered Amplifier","authors":"A. Yesil, F. Kaçar","doi":"10.5152/IUJEEE.2018.1802","DOIUrl":"https://doi.org/10.5152/IUJEEE.2018.1802","url":null,"abstract":"In this work, we present a current-mode and voltage-mode quadrature oscillator circuit using a voltage differencing buffered amplifier (VDBA), two grounded capacitors, and a grounded resistor. The oscillation condition and frequency are orthogonally (or independently) controllable. The current-mode and voltage-mode quadrature signals can be simultaneously obtained from the proposed circuit. The use of only grounded capacitors and resistors makes the proposed circuits ideal for integrated circuit implementation. The quadrature oscillator is simulated with SPICE simulation program using 0.35-µm technology parameters.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126035321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-02-23DOI: 10.5152/iujeee.2018.1812
E. Önal
The corona effect in the power system has a dominant role in reducing the efficiency of the high-voltage lines. In this study, the current and voltage impulses, which are important in corona determination, have been examined in frequecy spectrogram base from test result. The frequency spectrogram graphs have been obtained from the current-time and voltage-time variation by Matlab program. With these graphs, frequency values have been found to provide an important clarification of the insulation performance of electrical equipment for reliable and accurate diagnosis. These values have been observed according to different conditions like pressure, polarity, and insulation ambient. This spectrogram analysis can be used to find the characteristic frequencies and eliminate the disturbance effect. The time between corona steps decrease when Sulphur hexafluoride (SF6) gas pressure is increased. The time of second corona is close to leader's discharge time. Corona starts early when SF6 amount is decreased in gas mixtures. The corona currents are large in the low SF6 gas mixtures, this situation is related to the high insulation of the SF6 gas. A feature which is dependent the frequency is not found.
{"title":"Corona Identification of Impulse Voltage and Current","authors":"E. Önal","doi":"10.5152/iujeee.2018.1812","DOIUrl":"https://doi.org/10.5152/iujeee.2018.1812","url":null,"abstract":"The corona effect in the power system has a dominant role in reducing the efficiency of the high-voltage lines. In this study, the current and voltage impulses, which are important in corona determination, have been examined in frequecy spectrogram base from test result. The frequency spectrogram graphs have been obtained from the current-time and voltage-time variation by Matlab program. With these graphs, frequency values have been found to provide an important clarification of the insulation performance of electrical equipment for reliable and accurate diagnosis. These values have been observed according to different conditions like pressure, polarity, and insulation ambient. This spectrogram analysis can be used to find the characteristic frequencies and eliminate the disturbance effect. The time between corona steps decrease when Sulphur hexafluoride (SF6) gas pressure is increased. The time of second corona is close to leader's discharge time. Corona starts early when SF6 amount is decreased in gas mixtures. The corona currents are large in the low SF6 gas mixtures, this situation is related to the high insulation of the SF6 gas. A feature which is dependent the frequency is not found.","PeriodicalId":256344,"journal":{"name":"Istanbul University - Journal of Electrical and Electronics Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130981208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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