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A dual-band feed network for series-fed antenna arrays using extended composite right/left-handed transmission lines
, Article IEEE Transactions on Antennas and Propagation ; Volume 65, Issue 1 , 2017 , Pages 178-189 ; 0018926X (ISSN) ; Nikmehr, S ; Fozi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
In this paper, extended composite right/left-handed (E-CRLH) structures are studied to design multiband microwave devices. As an example, a three-way series power divider (SPD) is designed. The overall effects of the E-CRLH structures, as the feeding networks of the antenna arrays, on the antenna arrays main-beam variations are investigated. We also design and implement two antenna arrays with N=3 elements and the same interelement distances each fed by a distinct three-way SPD. The radiation patterns of the antennas are examined. Simulation and measurement results demonstrate that the desired main-beam squinting of the antenna array could be obtained by engineering the parameters of the...
Analysis of Circular Slot Antenna on a Ferrite Substrate
, M.Sc. Thesis Sharif University of Technology ; Rajaei, Behzad (Supervisor)
Abstract
Circular polarization (CP) is one of the common polarization types used in wireless systems for frequency identification (RFID), global positioning (GPS) and wireless local area networks (WLAN), since it can provide greater flexibility in orientation angle between transmitter and receiver, and better mobility and weather penetration than the linearly polarized antennas. Magnetic permeability in ferrites can be tuned by external magnetic field ; So ferrites can be good candidates for new reconfigurable CP antenna technology. In this project, we will consider circularly polarized slot antenna with a wide axial ratio beamwidth that consists of a normally magnetized ferrite substrate mounted...
Design of dual- and quad-band E-CRLH-TLs with arbitrary phase characteristics
, Article Progress In Electromagnetics Research M ; Vol. 35, issue , 2014 , p. 141-149 ; Nikmehr, S ; Ghurt-Tappeh, M.V ; Bemani, M ; Sharif University of Technology
Abstract
In this paper, extended composite right/left-handed (E-CRLH) transmission line (TL) metamaterial structures, with two left-handed (backward) and two right-handed (forward) pass bands, are investigated. Also, design procedures in order to design dual- and quad-band E-CRLH-TLs are presented in detail and the parameters of these structures are extracted by clean formulas, while satisfying arbitrary phase shifts at the operating frequencies. Finally, the dispersion and characteristic impedances of these transmission lines are derived and plotted. The results of this paper can be applied to any type of TL-based dual- and quad-band microwave component
Tunable Stopband HTS Josephson Junction Left-Handed Transmission Line with Independently Biasable Unit Cells
, Article IEEE Transactions on Applied Superconductivity ; Volume 30, Issue 1 , 2020 ; Rejaei, B ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
A practical coplanar Josephson junction left-handed transmission line based on a step-edge junction technique is proposed in high-temperature superconductor technology and analyzed by electromagnetic simulations. The layout is designed for monolayer Yttrium Barium Copper Oxide thin film fabrication process. The propagation stopbands are tunable by controlling bias currents of Josephson junction arrays acting as parallel inductors for unit cells of the transmission line. Unlike the reported designs, each unit cell of our left-handed transmission line is independently biasable due to dc isolation of the unit cells along the transmission line. Being individually biasable is practically...
Beat pressure and comparing it with ascending aorta pressure in normal and abnormal conditions
, Article 4th European Conference of the International Federation for Medical and Biological Engineering, ECIFMBE 2008, Antwerp, 23 November 2008 through 27 November 2008 ; Volume 22 , 2008 , Pages 276-285 ; 16800737 (ISSN); 9783540892076 (ISBN) ; Mirzaee, M. R ; Firoozabadi, B ; Sajadi, B ; Zolfonoon, A ; Sharif University of Technology
2008
Abstract
Lumped method (Electrical analogy) is a quick and easy way to model human cardiovascular system. In this paper Lumped method is used for simulating a complete model. It describes a 36-vessel model and cardiac system of human body with details that could show hydrodynamic parameters of cardiovascular system. Also this paper includes modeling of pulmonary, atrium, left and right ventricles with their equivalent circuits. Exact modeling of right and left ventricles pressure with division of ascending aorta into 27 segments increases the accuracy of our simulation. In this paper we show that a calculated pressure for aorta from our complex circuit is near to measured pressure by using advanced...
Exact modeling of cardiovascular system using lumped method
, Article 2008 International Conference on Bioinformatics and Computational Biology, BIOCOMP 2008, Las Vegas, NV, 14 July 2008 through 17 July 2008 ; 2008 , Pages 408-417 ; 1601320558 (ISBN); 9781601320551 (ISBN) ; Mirzaee, M. R ; Firoozabadi, B ; Hassani, K ; Sharif University of Technology
2008
Abstract
Electrical analogy (Lumped method) is an easy way to model human cardiovascular system. In this paper Lumped method is used for simulating a complete model. It describes a 36-vessel model and cardiac system of human body with details that could show hydrodynamic parameters of cardiovascular system. Also this paper includes modeling of pulmonary, atrium, left and right ventricles with their equivalent circuits. Exact modeling of right and left ventricles pressure increases the accuracy of our simulation. In this paper we show that a calculated pressure for aorta from our complex circuit is near to measured pressure by using advanced medical instruments
A simple transformation method in skewness reduction
, Article International Journal of Engineering, Transactions A: Basics ; Volume 24, Issue 2 , June , 2011 , Pages 169-175 ; 17281431 (ISSN) ; Niaki, S. T. A ; Seyedan, S. E ; Sharif University of Technology
Materials and Energy Research Center
2011
Abstract
Statistical analysis of non-normal data is usually more complicated than that for normal distribution. In this paper, a simple root/power transformation technique developed by Niaki, et al [1] is extended to transform right and left skewed distributions to nearly normal. The value of the root/power is explored such that the skewness of the transformed data becomes almost zero with an acceptable error. The proposed method is then compared to the well-known and complicated Box, et al [2] transformation method for different left and right skewed distributions using Monte Carlo simulation. While the proposed procedure is easy to understand and to implement, the results of the simulation study...
Combination of multiple classifiers with fuzzy integral method for classifying the EEG signals in brain-computer interface
, Article ICBPE 2006 - 2006 International Conference on Biomedical and Pharmaceutical Engineering, Singapore, 11 December 2006 through 14 December 2006 ; 2006 , Pages 157-161 ; 8190426249 (ISBN); 9788190426244 (ISBN) ; Esmaeeli, M ; Shouraki, S. B ; Sharif University of Technology
2006
Abstract
In this paper we study the effectiveness of using multiple classifier combination for EEG signal classification aiming to obtain more accurate results than it possible from each of the constituent classifiers. The developed system employs two linear classifiers (SVM,LDA) fused at the abstract and measurement levels for integrating information to reach a collective decision. For making decision, the majority voting scheme has been used. While at the measurement level, two types of combination methods have been investigated: one used fixed combination rules that don't require prior training and a trainable combination method. For the second type, the fuzzy integral method was used. The...