Rigorous study of propagation in metallic circular waveguide filled with anisotropic metamaterial

2017 ◽  
Vol 9 (4) ◽  
pp. 805-813 ◽  
Author(s):  
Hedi Sakli ◽  
Mohamed Yahia ◽  
Wyssem Fathallah ◽  
Jun Wu Tao ◽  
Taoufik Aguili
Keyword(s):  
Computation Time ◽  
Circular Waveguide ◽  
Transverse Magnetic ◽  
Higher Order Modes ◽  
Anisotropic Metamaterials ◽  
Matching Technique ◽  
Theoretical Predictions ◽  
Rigorous Study ◽  
Circular Waveguides ◽  
Anisotropic Metamaterial

This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes in the case of metallic circular waveguides filled with anisotropic metamaterials. The determined higher-order modes have been analyzed and exploited to the design of filters. Among the particularities of anisotropic material, the backward waves can propagate below the cut-off frequency. The numerical results for TE and TM modes have been compared with theoretical predictions. Good agreements were obtained. We analyzed a periodic structure containing waveguides filled with anisotropic metamaterial using the mode-matching technique. By using modal analysis, our approach reduced considerably the computation time compared to HFSS.

scholarly journals Cylindrical Waveguide on Ferrite Substrate Controlled by Externally Applied Magnetic Field

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 474
Author(s):  
Hedi Sakli
Keyword(s):  
Magnetic Field ◽  
Transverse Electric ◽  
Computation Time ◽  
Transverse Magnetic ◽  
Industrial Applications ◽  
Mode Matching ◽  
Higher Order Modes ◽  
Cylindrical Waveguides ◽  
Ferrite Substrate ◽  
Te And Tm Modes

This paper presents an extension of the formulation of wave propagation in transverse electric (TE) and transverse magnetic (TM) modes for the case of metallic cylindrical waveguides filled with longitudinally magnetized ferrite. The higher order modes were exploited. We externally controlled the cut-off frequency through the application of DC magnetic fields. The numerical results of dispersion diagrams for TE and TM modes were obtained and analyzed. We analyzed a waveguide antenna filled with partially magnetized ferrite using the mode matching (MM) technique based on the TE and TM modes. By using modal analysis, our approach considerably reduced the computation time compared to HFSS. Ferrites are important for various industrial applications, such as circulators, isolators, antennas and filters.

scholarly journals Electromagnetic Properties of Neutrinos

2012 ◽  
Vol 2012 ◽  
pp. 1-47 ◽  
Author(s):  
C. Broggini ◽  
C. Giunti ◽  
A. Studenikin
Keyword(s):  
Radiative Decay ◽  
Dipole Moments ◽  
Form Factors ◽  
Transverse Magnetic ◽  
Electromagnetic Properties ◽  
Electromagnetic Form Factors ◽  
General Description ◽  
Electric Dipole Moments ◽  
Theoretical Predictions ◽  
Majorana Neutrinos

In this paper, we discuss the main theoretical aspects and experimental effects of neutrino electromagnetic properties. We start with a general description of the electromagnetic form factors of Dirac and Majorana neutrinos. Then, we discuss the theory and phenomenology of the magnetic and electric dipole moments, summarizing the experimental results and the theoretical predictions. We discuss also the phenomenology of a neutrino charge radius and radiative decay. Finally, we describe the theory of neutrino spin and spin-flavor precession in a transverse magnetic field and we summarize its phenomenological applications.

A Feature Fast Matching Technique Using Improved Self-Organizing Map for Stereo Vision

2014 ◽  
Vol 602-605 ◽  
pp. 1299-1302
Author(s):  
Xiang Ping Meng ◽  
Lei Wang ◽  
Quan De Yuan ◽  
Xiu Ji
Keyword(s):  
Binocular Vision ◽  
Feature Matching ◽  
Computation Time ◽  
Visual Navigation ◽  
Self Organizing Map ◽  
Match Method ◽  
Learning Methods ◽  
Matching Technique ◽  
Feature Match ◽  
Self Organizing

Landmark feature match method of robot visual navigation has been studied, An unsupervised learning methods based on binocular vision has been proposed to match Landmark feature fast. Firstly, environmental Information images are obtained by binocular vision, Then SIFT feature vectors are abstracted from binocular vision images, Lastly, Self-Organizing Map is pulled in to match multidimensional feature point fast by using competitive learning methods. Experiments showed that the proposed methods on feature matching with better computation time and effect than the traditional SIFT and SURF of feature matching methods. And it can satisfied the requirement of real-time.

Mode matching technique-based modeling of coaxial and circular waveguide discontinuities for material characterization purposes

2011 ◽  
Vol 3 (6) ◽  
pp. 679-690 ◽  
Author(s):  
Emmanuel Decrossas ◽  
Mahmoud A. EL Sabbagh ◽  
Victor Fouad Hanna ◽  
Samir M. El-Ghazaly
Keyword(s):  
Complex Permittivity ◽  
Dielectric Material ◽  
Circular Waveguide ◽  
Mesh Size ◽  
Mode Matching ◽  
Full Wave ◽  
Matching Technique ◽  
Operational Frequency ◽  
Computational Resources ◽  
Mode Matching Technique

In this paper, it is proposed to use a cylindrical cell for the characterization of dielectric material. The extraction of complex permittivity is based on inverse gradient approach where the full-wave simulation results are mapped to experimental data to extract the complex permittivity. As the operational frequency of radio frequency (RF)/microwave devices is increased, it becomes difficult to accurately model waveguide transitions using traditional methods based on meshing such as finite-element method (FEM) where mesh size is determined according to the wavelength. Moreover, these techniques usually require extensive computational resources. Mode matching technique (MMT) is the full-wave tool implemented in this current work. It is used to compute the generalized scattering matrices (GSMs) of the different discontinuities of test setup. These GSMs model precisely discontinuities as they include the effects of all higher-order modes propagating and evanescent. Simulation and experimental results are included to validate the proposed approach for the rigorous modeling of those discontinuities and hence the extraction of complex permittivity.

scholarly journals Attenuation in Superconducting Circular Waveguides

2016 ◽  
Vol 5 (2) ◽  
pp. 34 ◽  
Author(s):  
K. H. Yeap ◽  
S. S. Ong ◽  
H. Nisar ◽  
K. C. Lai ◽  
C. A. Ng
Keyword(s):  
Electrical Properties ◽  
Lattice Structure ◽  
Propagation Constant ◽  
Circular Waveguide ◽  
Wall Material ◽  
Complex Conductivity ◽  
Cooper Pairs ◽  
Sharp Rise ◽  
Circular Waveguides ◽  
Transcendental Equations

We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity) of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency) is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.

Cutoff manipulation of anisotropic reactance lining in circular waveguides

2018 ◽  
Vol 11 (4) ◽  
pp. 334-340
Author(s):  
Zhangjie Luo ◽  
Tie Jun Cui ◽  
Hui Feng Ma
Keyword(s):  
Transverse Electric ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Bandwidth Extension ◽  
Impedance Boundary ◽  
Cutoff Frequencies ◽  
Circular Waveguides ◽  
First Time ◽  
Theoretical Results ◽  
Made In

AbstractThe control of cutoffs is of great interest in designs of circular waveguides. In this paper, this topic is investigated for pure transverse-electric (TE) and transverse-magnetic (TM) modes by taking advantage of anisotropic reactance lining loadings. It is found that the cutoffs of TE and TM modes are determined by the reactance in the azimuthal and axial directions, respectively. When the reactance values are positive, the cutoff frequencies are lower than those of a normal conducting waveguide with the same cross-section. However, in contrast to the claim made in the previous literature that the negative reactance values caused the same reducing effect on the cutoffs as the positive values did, the cutoffs are found to be increased by the negative reactances. The theoretical results are validated by the simulations using commercial software, where a delicate model with an approximate curved anisotropic impedance boundary is proposed for the first time. By lowering the TE cutoffs and raising the TM ones, some intriguing applications, such as single-mode bandwidth extension and degenerate mode avoidance, are predicted, which would pave a way for designs of novel waveguide devices.

scholarly journals THE HIGHER ORDER MODES IN THE OPEN RESONATOR WITH THE SEGMENT OF THE CIRCULAR WAVEGUIDE

2019 ◽  
Vol 24 (3) ◽  
pp. 218-226
Author(s):  
M. E. Ilchenko ◽  
◽  
I. K. Kuzmichev ◽  
T. N. Narytnik ◽  
S. V. Denbnovetsky ◽  
...  
Keyword(s):  
Open Resonator ◽  
Circular Waveguide ◽  
Higher Order ◽  
Higher Order Modes
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