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left-handed-transmission-lines
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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...
Nonlinear Josephson Transmission Lines based on High-Temperature Superconductors
, M.Sc. Thesis Sharif University of Technology ; Rejaei, Behzad (Supervisor) ; Fardmanesh, Mehdi (Co-Supervisor)
Abstract
Metamaterials are engineered sub-wavelength structures which show electromagnetic properties not found in natural materials. There is a special interest in superconductor metamaterials in microwave engineering. These metamaterials have low loss, are compact and show useful properties like tunability and parametric amplification when Josephson junctions are incorporated in them. When Josephson junctions are used, these metamaterials are called Josephson metamaterials which have attracted a good amount of research interest. Because of nonlinear nature of Josephson junction, Josephson metamaterials show nonlinear properties. One dimensional Josephson metamaterials are called Josephson...
Design and analysis of a novel tunable ferrite based left handed strip line
, Article Journal of Electromagnetic Waves and Applications ; Volume 26, Issue 7 , 2012 , Pages 914-922 ; 09205071 (ISSN) ; Komjani, N ; Rejaei, B ; Sharif University of Technology
T&F
2012
Abstract
This paper proposes, for the first time, a tunable left handed transmission line consisting of a strip line sandwiched between a ferrite superstrate and a dielectric substrate containing a metallic wire array. The left-handed behavior is realized by combining the negative permittivity of the wire array with the negative permeability of the longitudinally magnetized ferrite substrate despite them being spatially separated. Theoretical and numerical results demonstrate the tunability of the left-handed frequency band by changing the DC bias magnetic field applied to the ferrite. Compared to other tunable lefthanded structures, the fabrication requirements on this structure are not critical,...
Presentation and application of tunable reciprocal/nonreciprocal metamaterial transmission line based on edge-guided mode
, Article Electromagnetics ; Volume 33, Issue 3 , Mar , 2013 , Pages 234-248 ; 02726343 (ISSN) ; Komjani, N ; Rejaei, B ; Sharif University of Technology
2013
Abstract
This article proposes a tunable composite right-/left-handed transmission line consisting of a transversely magnetized ferrite substrate periodically loaded by microstrip inductors. The gapless transition between the left- and right-handed bands (balanced response) is the main characteristic of this structure. This composite right-/left-handed transmission line is proposed in both reciprocal and nonreciprocal versions. Based on periodic structure analysis, the dispersion relation is estimated theoretically and validated numerically by the finite-element method in the reciprocal case. Theoretical and numerical results demonstrate the tunability of the proposed structures by changing the DC...
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...