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34 results on '"perfect electric conductor"'

1. Broadband absorber with dispersive metamaterials

Author

Han WonHeum and Park Q-Han

Subjects
broadband absorber, electromagnetic wave absorbers, equivalent circuit model, lorentz model, metamaterial, perfect electric conductor, Physics, QC1-999
Abstract

A broadband absorber that utilizes a dispersive metamaterial and covers the entire microwave X-band (8–12 GHz) is proposed in the present study. An ideal absorber attached to the surface of a perfect electric conductor requires the permittivity of the absorbing layer to be anomalously dispersive in the targeted broad frequency band. We show that anomalous dispersion of the permittivity for the X-band can be fitted to a two-pole Lorentz oscillator model and realized with the use of a double-layered, square-loop metamaterial. We explain the connection between the two-pole oscillator model and the double-layered, square-loop metamaterial using an equivalent circuit model and present explicit design rules for the metamaterial. We fabricate a 4-mm-thick metamaterial absorber with flexible silicon rubber, a resistor element, and conductive wire using carbon and silver conductive ink. Our metamaterial absorber achieves a reflectance of less than −20 dB over the entire X-band region.

Published
2023
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2. Tri‐band radar cross‐section reduction based on optimised multi‐element phase cancellation.

Author

Su, Jianxun, Yu, Hang, Yu, Jiayong, Guo, Qingxin, and Li, Zengrui

Abstract

This study presents a planar single‐layer metasurface, with tri‐band 10 dB radar cross‐section (RCS) reduction under normal incidence for both polarisations, by employing optimised multi‐element phase cancellation. The designed artificial magnetic conductor (AMC) unit cell is composed of an upper metal structure, a dielectric layer, and a bottom metal ground. When the dielectric constant and thickness of the substrate are fixed, regardless of any upper structure, the reflection coefficients of AMC are the same as the perfect electric conductor (PEC) at the short‐circuit frequencies. Taking into account the multiple reduction bands that avoid short‐circuit frequencies, a RCS reduction surface with a large frequency ratio is achieved. The optimised planar metasurface obtains 10 dB RCS reduction in the tri‐band frequency (3.81–7.33, 19.16–22.83, and 35.63–38.37 GHz) with bandwidths of 63, 17, and 7.4%, respectively. Moreover, the bistatic scattering patterns between the proposed surface and the equal‐sized PEC are investigated. The theoretically predicted, simulated, and measured results are in good agreement and provide a new strategy for achieving multi‐band RCS reduction. [ABSTRACT FROM AUTHOR]

Published
2020
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3. Dual‐polarised wideband tightly coupled dipole array for airborne applications.

Author

Johnson, Alexander Dale, Zhong, Jingni, Sekelsky, Stephen, Alwan, Elias A., and Volakis, John L.

Abstract

An ultra‐wideband (UWB) array is presented for UHF‐S band (0.19–2.3 GHz) communications with an emphasis on dual‐linear polarisation and wide‐angle scanning. The array achieves 12:1 impedance bandwidth for a voltage standing wave ratio (VSWR) <3 at broadside with low‐angle scanning off broadside to 0°, 45°, 60° in the E‐plane (VSWR < 3, 4, 3.1) and 0°, 45°, 60° (VSWR < 3, 3.8, 5.5) in the H‐plane. A 7 × 11 prototype was fabricated and tested for verification. In addition, finite effects with respect to mounting UWB arrays in airborne platforms are discussed. Specifically, the effect of radomes, perfect electric conductor shielding walls and resistive walls on the gain of the designed tightly coupled dipole antenna was studied, showing that losses can approach 2 dB. [ABSTRACT FROM AUTHOR]

Published
2020
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4. Resonances of Characteristic Modes for Perfectly Conducting Objects.

Author

Lappalainen, Joni, Yla-Oijala, Pasi, Tzarouchis, Dimitrios C., and Sihvola, Ari

Subjects
*EIGENVALUES, *EIGENFUNCTIONS, *CAVITY resonators, *ANTENNAS (Electronics), *ELECTRIC fields, *INTEGRAL operators
Abstract

Resonances, i.e., extrema of the eigenvalues of characteristic modes for closed perfectly conducting objects are investigated. The characteristic modal solutions based on the electric, magnetic, and combined field integral operators (EFIO, MFIO, and CFIO) are studied and compared with analytical solutions for a sphere. All these formulations are found to capture both external (radiating) and internal (cavity) resonances predicted by the analytical expressions. At the internal resonances, the eigenvalues obtained with the EFIO- and MFIO-based approaches are not correct, and the corresponding modes are nonunique. These solutions also exhibit a strong duality between the electric (TM) and magnetic (TE) type modes. A connection is found between the external and internal resonances and the condition numbers of the matrices. The modal expansion of the CFIO-based solution is correct, even though it also experiences the nonuniqueness of the EFIO- and MFIO-based solutions. [ABSTRACT FROM PUBLISHER]

Published
2017
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5. Ultra Wide Band Radar Cross Section Reduction of a Perfectly Electric Conductor Sphere by the Application of Multilayer Metamaterial Coatings.

Author

Oraizi, Homayoon, Abdolali, Ali, and Fallah, Mahmoud

Subjects
ULTRA-wideband communication, ELECTRIC waves, RADAR cross sections
Abstract

A full-wave analytical method using the addition theorems and Hertzian potential functions are used to compute the radar cross section of a sphere coated by several layers composed of common materials and metamaterials. The minimization and maximization of radar cross section of a perfectly electric conductor sphere with such coatings are realized in a frequency band-width and in a wide interval of angles. One of the novelities of this contribution is, taking into dispersion relations of physically realizable metamaterials. So that the optimization procedure for RCS reduction is applied due to the coefficients describing dispersion characteristics. The method of least square is used for the design of a class of radar absorbing materials. The minimization of the error functions are performed by the combination of genetic algorithm and conjugate gradient method. It is shown that the proposed method of computation of radar cross section and its extremization effectively leads to the design of dispersive and isotropic metamaterials for the realization of radar absorbing materials. [ABSTRACT FROM AUTHOR]

Published
2016
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7. Generalized Theory of Characteristic Modes

Author

Pasi Ylä-Oijala

Subjects
perfect electric conductor, 02 engineering and technology, dielectric body, Symmetric matrices, Operator (computer programming), generalized eigenvalue equation, 0202 electrical engineering, electronic engineering, information engineering, Symmetric matrix, lossy target, surface integral equation, Electrical and Electronic Engineering, Integral equations, Electrical conductor, Eigenvalues and eigenvectors, Physics, Eigenvalues and eigenfunctions, ta114, Mathematical analysis, 020206 networking & telecommunications, Surface waves, theory of characteristic modes, Integral equation, Weighting, Conductors, Surface wave, Composite structure, Symmetrization, Dielectrics, Antennas
Abstract

The theory of characteristic modes (TCM) is presented for arbitrarily shaped 3-D structures including perfect electric conductors (PECs) and homogeneous penetrable objects. It is shown that by properly expressing the weighting operator of the generalized eigenvalue equation in terms of the integral operators related to the radiated fields, TCM can be formulated directly for the surface integral equation formulation of the problem. This avoids symmetrization or other modifications of the equations. The eigenvalues are shown to be related to radiated, reactive, and dissipated power, and the corresponding far-field patterns are orthogonal. The previously introduced TCM formulations for PEC are special cases of this generalized TCM.

Published
2019

8. A Review of Anti- Podal Vivaldi Antenna Operating in Cellular Mobile Communications

Author

Asim Alkhaibari

Subjects
Worldwide Interoperability for- Microwave access, Physics and Astronomy (miscellaneous), lcsh:T, business.industry, Computer science, Antipodal Vivaldi antenna, Electrical engineering, Global system for mobile, Long Term Evolution Advanced Wireless-fidelity, lcsh:Technology, Ultra Wideband, Perfect Electric Conductor, Computer Simulation Technology, law.invention, law, Management of Technology and Innovation, lcsh:Q, Mobile telephony, lcsh:Science, business, Vivaldi antenna, Engineering (miscellaneous), Long term evolution, Voltage Standing Wave Ratio Return Loss
Abstract

The antenna proposed is a new geomantic structure of Ultra-Wideband (UWB) Anti- Podal Vivaldi antenna (AVA). It remarkably offers an attractive performance over the bands of cellular networks. However, its benefits are not limited only in particular applications, whereas radar imaging, mining detection, the biomedical science in the heating of brain cancer tumor and treatment, and the wireless communication are considered as the main applications suitable for utilization. Therefore, the focus on this paper is to spot the light illuminating into the cellular communications network Systems. On the other hands, several characteristics of Vivaldi antenna have been provided such as the gain, return loss, Voltage Standing Wave Ratio (VSWR), current distribution and E- fields. Finally, the results illustrate the capability and feasibility of the designed antenna.

Published
2017

9. Reconstructing Distortions on Reflector Antennas With the Iterative-Field-Matrix Method Using Near-Field Observation Data.

Author

Martinez-Lorenzo, J A, Gonzalez-Valdes, B, Rappaport, C, Gutierrez Meana, Javier, and Garcia Pino, Antonio

Subjects
*ELECTRICAL conductors, *REFLECTOR antennas, *MOMENTS method (Statistics), *PHYSICAL optics, *APERTURE antennas
Abstract

This work extends the mathematical formulation of the iterative-field-matrix method for observed data from the near-field region of a Perfect Electric Conductor. The method is used as a diagnosis tool for reflector antennas, to determine the positions and extent of distortions from their idealized shapes. The new formulation is tested on a reflector antenna with several significant bumps, and excellent results are achieved. This work also presents an example where the Method of Moments is used to generate the synthetic data and the inversion is performed using Physical Optics. Such a configuration ensures that the forward model is unbiased with respect to the inversion model, demonstrating that the new formulation is also robust for these realistic scenarios. [ABSTRACT FROM PUBLISHER]

Published
2011
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10. Analysis of Electrically Large Problems Using the Augmented EFIE With a Calderón Preconditioner.

Author

Su Yan, Jian-Ming Jin, and Zaiping Nie

Subjects
*ELECTRIC field integral equations, *ELECTROMAGNETIC devices, *RESONANCE, *WAVENUMBER, *ALGORITHMS
Abstract

Calderón preconditioned electric-field integral equation (CP-EFIE) is very efficient in analyzing electromagnetic problems with a moderate electrical size. For the analysis of electrically large problems with closed surfaces, the CP-EFIE, however, suffers from the well-known spurious internal resonance problem because both the EFIE and the Calderón preconditioner are singular at resonant frequencies. In this paper, the resonance problem of the Calderón preconditioner is removed by using a complex wavenumber, and that of the EFIE is eliminated by enforcing the boundary condition n̂ · D = ρs to the EFIE, resulting in the so-called augmented EFIE (AEFIE). It is shown that the proposed Calderón preconditioned AEFIE is a resonant-free formulation, and has a fast convergence rate for an iterative solution. Numerical examples are given to demonstrate the good accuracy and fast convergence of the proposed approach for the analysis of electrically large problems. The multilevel fast multipole algorithm (MLFMA) is employed to reduce the computational and storage complexities of the iterative solution. [ABSTRACT FROM PUBLISHER]

Published
2011
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11. Resonances of Characteristic Modes for Perfectly Conducting Objects

Author

Pasi Ylä-Oijala, Joni Lappalainen, Dimitrios C. Tzarouchis, and Ari Sihvola

Subjects
perfect electric conductor, Field (physics), 010103 numerical & computational mathematics, 02 engineering and technology, Type (model theory), 01 natural sciences, Magnetic resonance imaging, internal resonance, 0202 electrical engineering, electronic engineering, information engineering, Strong duality, 0101 mathematics, Electrical and Electronic Engineering, Electric field integral operator, Integral equations, Cavity resonators, Eigenvalues and eigenvectors, Mathematics, Resonant frequency, Eigenvalues and eigenfunctions, ta114, Mathematical analysis, magnetic field integral operator, 020206 networking & telecommunications, theory of characteristic modes, Integral equation, Connection (mathematics), Maxima and minima, Antennas, Perfect conductor, external resonance
Abstract

Resonances, i.e., extrema of the eigenvalues of characteristic modes for closed perfectly conducting objects are investigated. The characteristic modal solutions based on the electric, magnetic, and combined field integral operators (EFIO, MFIO, and CFIO) are studied and compared with analytical solutions for a sphere. All these formulations are found to capture both external (radiating) and internal (cavity) resonances predicted by the analytical expressions. At the internal resonances, the eigenvalues obtained with the EFIO- and MFIO-based approaches are not correct, and the corresponding modes are nonunique. These solutions also exhibit a strong duality between the electric (TM) and magnetic (TE) type modes. A connection is found between the external and internal resonances and the condition numbers of the matrices. The modal expansion of the CFIO-based solution is correct, even though it also experiences the nonuniqueness of the EFIO- and MFIO-based solutions.

Published
2017

12. Versatile and accurate electromagnetic analysis of piecewise homogeneous composite objects

Author

Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Sekulic, Ivan, Úbeda Farré, Eduard, Rius Casals, Juan Manuel, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Sekulic, Ivan, Úbeda Farré, Eduard, and Rius Casals, Juan Manuel

Abstract

©2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works., The discretization by the Method of Moments (MoM) of electromagnetic integral equations, namely, the Electric Field Integral Equation (EFIE) for perfect electric conductors (PECs) and the Poggio-Miller-Chan-Harrington-Wu-Tsai (PMCHWT) integral formulation for penetrable objects, is usually carried out with divergence-conforming sets of basis functions. However, in the single-surface analysis of piecewise homogeneous composite objects the implementation of divergence-conforming sets around junction-edges, where several regions intersect, becomes convoluted. Recently, the monopolar-RWG discretization, discontinuous at edges, of the EFIE and the PMCHWT formulation has been proposed. In this paper we show how this facet-based scheme becomes well suited for the single-surface analysis of piecewise homogeneous composite objects without giving special attention to junction-edges., Peer Reviewed, Postprint (published version)

Published
2018

13. Versatile and accurate electromagnetic analysis of piecewise homogeneous composite objects

Author

Eduard Ubeda, Juan M. Rius, Ivan Sekulic, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, and Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio

Subjects
Ciències de la visió::Òptica física [Àrees temàtiques de la UPC], Surface analysis, Discretization, Computer science, Integral formulations, Electric field integral equation, Method of moments, Basis function, Method of moments (statistics), Electric-field integral equation, Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica [Àrees temàtiques de la UPC], Integral Equations, Matemàtiques i estadística::Equacions diferencials i integrals [Àrees temàtiques de la UPC], Method of Moments Electric fields, Electromagnetic analysis, Electromagnetic integral equation, Moments method (Statistics), Mathematical analysis, Electromagnetisme -- Mesuraments, Physical optics, Integral equation, Equacions integrals, Composite objects, Òptica física, Electromagnetic measurements, Piecewise, Perfect electric conductor, Perfect conductor, Basis functions, Method of moments (MOM)
Abstract

©2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The discretization by the Method of Moments (MoM) of electromagnetic integral equations, namely, the Electric Field Integral Equation (EFIE) for perfect electric conductors (PECs) and the Poggio-Miller-Chan-Harrington-Wu-Tsai (PMCHWT) integral formulation for penetrable objects, is usually carried out with divergence-conforming sets of basis functions. However, in the single-surface analysis of piecewise homogeneous composite objects the implementation of divergence-conforming sets around junction-edges, where several regions intersect, becomes convoluted. Recently, the monopolar-RWG discretization, discontinuous at edges, of the EFIE and the PMCHWT formulation has been proposed. In this paper we show how this facet-based scheme becomes well suited for the single-surface analysis of piecewise homogeneous composite objects without giving special attention to junction-edges.

Published
2018
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14. Ultra Wide Band Radar Cross Section Reduction of a Perfectly Electric Conductor Sphere by the Application of Multilayer Metamaterial Coatings

Author

Mahmoud Fallah, Ali Abdolali, and Homayoon Oraizi

Subjects
Radar cross-section, Radar Cross Section, 02 engineering and technology, law.invention, Metamaterial, Optics, law, Conjugate gradient method, Dispersion relation, Multilayer, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, Radar, Electrical conductor, Physics, business.industry, Isotropy, 020206 networking & telecommunications, 021001 nanoscience & nanotechnology, Perfect Electric Conductor, lcsh:Electrical engineering. Electronics. Nuclear engineering, Perfect conductor, 0210 nano-technology, business, lcsh:TK1-9971
Abstract

A full-wave analytical method using the addition theorems and Hertzian potential functions are used to compute the radar cross section of a sphere coated by several layers composed of common materials and metamaterials. The minimization and maximization of radar cross section of a perfectly electric conductor sphere with such coatings are realized in a frequency band-width and in a wide interval of angles. One of the novelities of this contribution is, taking into dispersion relations of physically realizable metamaterials. So that the optimization procedure for RCS reduction is applied due to the coefficients describing dispersion characteristics. The method of least square is used for the design of a class of radar absorbing materials. The minimization of the error functions are performed by the combination of genetic algorithm and conjugate gradient method. It is shown that the proposed method of computation of radar cross section and its extremization effectively leads to the design of dispersive and isotropic metamaterials for the realization of radar absorbing materials.

Published
2016

15. Ultra Wide Band Radar Cross Section Reduction of a Perfectly Electric Conductor Sphere by the Application of Multilayer Metamaterial Coatings

Author

Homayoon Oraizi, Ali Abdolali, and Mahmoud Fallah

Subjects
Metamaterial, Multilayer, Perfect Electric Conductor, Radar Cross Section, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

Abstract A full-wave analytical method using the addition theorems and Hertzian potential functions are used to compute the radar cross section of a sphere coated by several layers composed of common materials and metamaterials. The minimization and maximization of radar cross section of a perfectly electric conductor sphere with such coatings are realized in a frequency band-width and in a wide interval of angles. One of the novelities of this contribution is, taking into dispersion relations of physically realizable metamaterials. So that the optimization procedure for RCS reduction is applied due to the coefficients describing dispersion characteristics. The method of least square is used for the design of a class of radar absorbing materials. The minimization of the error functions are performed by the combination of genetic algorithm and conjugate gradient method. It is shown that the proposed method of computation of radar cross section and its extremization effectively leads to the design of dispersive and isotropic metamaterials for the realization of radar absorbing materials.

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16. Numerical approach for the sensitivity of a high-frequency magnetic induction tomography system based on boundary elements and perturbation method

Author

Jianna Hao, Guang Chen, Qian Zhao, Wuliang Yin, and Kai Xu

Subjects
Mathematical optimization, Discretization, perfect electric conductor, sensitivity distribution, Applied Mathematics, Mathematical analysis, Integral equation, Finite element method, law.invention, boundary element method, magnetic induction tomography, law, Electromagnetic coil, Eddy current, Magnetic induction tomography, Perfect conductor, Instrumentation, Engineering (miscellaneous), Boundary element method, Mathematics
Abstract

Magnetic induction tomography (MIT) is an imaging technique based on the measurement of the magnetic field perturbation due to eddy currents induced in conducting objects exposed to an external magnetic excitation field. In MIT, current-carrying coils are used to induce eddy currents in the object and the induced voltages are sensed with the receiving coils. When the driving frequency is significantly high relative to the frequency range in which MIT normally operates, metallic targets with high conductivity between the coils can be treated as perfect electric conductors (PEC) with negligible errors. In this scenario, the penetration depth of the magnetic field into the target is extremely small and the traditional versions of the finite element method (FEM) are not efficient for the calculation of the sensitivity and the forward problem due to the requirement for large number of elements to reach an acceptable computational precision. Other versions of FEMs (such as Hp-FEM), which have higher discretization efficiency and more advanced elements to satisfy the requirement, are exceptions. Nevertheless, the discretization regions for all FEMs have to extend beyond the region that contains the conducting object and volumetric elements are generally required for 3D problems. In contrast, the boundary element method (BEM) based on integral formulations becomes an effective way to analyze this kind of scattering problem since meshes are only required on the surface of the object. By point collocation, the boundary integral equations can be transformed into linear equations. Numerical methods are used to solve the linear equations and the solution of the original integral equations can be obtained. In this paper, we compute four typical sensitivity maps between the coil pairs in high-frequency MIT system due to a PEC perturbation. The magnetic scalar potential is used to improve the efficiency. Five PEC objects of different shapes are used in the simulation. The results have been compared with the experimental results and that obtained from the H·H formulations. We can know that the sensitivity maps derived by BEM are in good agreement with that from the experiment and theoretical solution. Overall, BEM is an effective way to calculate the sensitivity distributions of a high-frequency MIT system. © 2013 IOP Publishing Ltd.

Published
2013

17. Application of the method of auxiliary source to the sensitivity analysis of high frequency magnetic induction tomography system

Author

Wuliang Yin, Guang Chen, Jianna Hao, Qian Zhao, and Xu Kai

Subjects
MATLAB, Integral formulations, law.invention, Scattering, Photonic crystals, law, Eddy current, Electronic engineering, Boundary element method, Sensitivity (control systems), Magnetic field perturbations, Tomography, Physics, Magnetic excitation field, Measurements, Singular integral, Method of auxiliary sources, Scattering problems, Computational physics, Electromagnetic induction, Sensitivity distributions, Magnetic induction tomography, Perfect electric conductor, Perfect conductor, Instruments, Excitation
Abstract

Magnetic induction tomography (MIT) is an imaging technique based on the measurement of the magnetic field perturbation due to eddy currents induced in conducting objects exposed to an external magnetic excitation field. In MIT, current-carrying coils are used to induce eddy currents in the object and the induced voltages are sensed with receiving coils. When the driving frequency is significantly high, metallic targets with high conductivity between the coils can be treated as perfect electric conductors (PEC) with negligible errors. Boundary Element Method (BEM) based on integral formulations becomes an effective way to analyze this kind of scattering problems since meshes are only required on the surface of the object. But how to deal with the singular integral, which is a heavy burden for the computation, is a difficult issue unlikely to avoid. The method of auxiliary source (MAS) introduces the concepts of auxiliary surface and auxiliary source which avoid the computation of singular integrals. In contrast to the BEM, the MAS is more simple and fast for solving the PEC scattering problem in high MIT system. In this paper, the formula of sensitivity distribution was obtained by MAS with high efficiency and accuracy and then simulations by MATLAB were programmed. According to the good agreement of these results obtained by different numerical methods, we can know that MAS is an effective way to analyze the sensitivity distributions of high frequency MIT system. ?? 2013 IEEE. cited By (since 1996)0; Conference of org.apache.xalan.xsltc.dom.DOMAdapter@1ce0bdd5 ; Conference Date: org.apache.xalan.xsltc.dom.DOMAdapter@66cef9c2 Through org.apache.xalan.xsltc.dom.DOMAdapter@1e6f6449; Conference Code:98450

Published
2013

18. Three-Dimensional Stable Nonorthogonal FDTD Algorithm with Adaptive Mesh Refinement for Solving Maxwell's Equations

Author

DELAWARE STATE UNIV DOVER, Liu, Jinjie, DELAWARE STATE UNIV DOVER, and Liu, Jinjie

Abstract

The main objective of our effort is the development of stable, accurate and efficient Maxwell solvers. We focus on mathematical studies of the key unresolved issues in the Finite-Difference Time-Domain (FDTD) electromagnetic simulations. We have extended the subpixel smoothing FDTD method to material interface between dielectric and dispersive media by local coordinate rotation. A novel stable anisotropic FDTD algorithm based on the overlapping cells has been developed for solving Maxwell's equations of electrodynamics in anisotropic media with material interface between anisotropic dielectrics and dispersive medium or Perfect Electric Conductor (PEC). We have extended the overlapping Yee FDTD method to locally non-orthogonal grids, with application to the optical force computation on nanoparticles. We have developed a moving window full Maxwell solver algorithm with perfectly matched absorbing layer (PML) boundary conditions in order to accurately simulate the propagation of localized waves over a very long distance (millions of wavelength) in complex media. Furthermore, we have implemented the Adaptive Mesh Refine., The original document contains color images.

Published
2013

19. Parallel plate waveguide with anisotropic graphene plates: Effect of electric and magnetic biases

Author

Malekabadi, Ali, Charlebois, Serge A., Deslandes, Dominic, Malekabadi, Ali, Charlebois, Serge A., and Deslandes, Dominic

Abstract

The performances of a parallel plate waveguide (PPWG) supported by perfect electric conductor (PEC)-graphene and graphene-graphene plates are evaluated. The graphene plate behavior is modeled as an anisotropic medium with both diagonal and Hall conductivities derived from Kubo formula. The PPWG modes supported by PEC-graphene and graphene-graphene plates are studied. Maxwell’s equations are solved for these two waveguides, while the graphene layers are biased with an electric field only and with both electric and magnetic fields. It is shown that when both electric and magnetic biases are applied to the graphene, a hybrid mode (simultaneous transverse electric (TE) and transverse magnetic (TM) modes) will propagate inside the waveguide. The intensity of each TE and TM modes can be adjusted with the applied external bias fields. Study of different waveguides demonstrates that by decreasing the plate separation (d), the wave confinement improves. However, it increases the waveguide attenuation. A dielectric layer inserted between the plates can also be used to improve the wave confinement. The presented analytical procedure is applicable to other guiding structures having walls with isotropic or anisotropic conductivities.

Published
2013

20. Development of analytical solutions for quasistationary electromagnetic fields for conducting spheroids in the proximity of current-carrying turns.

Author

Shafai, Lotfollah (Electrical and Computer Engineering) Shivakumar, Pappur (Mathematics) Petriu, Emil (School of Electrical Engineering and Computer Science, University of Ottawa), Ciric, Ioan (Electrical and Computer Engineering), Jayasekara, Nandaka, Shafai, Lotfollah (Electrical and Computer Engineering) Shivakumar, Pappur (Mathematics) Petriu, Emil (School of Electrical Engineering and Computer Science, University of Ottawa), Ciric, Ioan (Electrical and Computer Engineering), and Jayasekara, Nandaka

Abstract

Exact analytical solutions for the quasistationary electromagnetic fields in the presence of conducting objects require the field solutions both internal and external to the conductors. Such solutions are limited for certain canonically shaped objects but are useful in testing the accuracy of various approximate models and numerical methods developed to solve complex problems related to real world conducting objects and in calibrating instruments designed to measure various field quantities. Theoretical investigations of quasistationary electromagnetic fields also aid in improving the understanding of the physical phenomena of electromagnetic induction. This thesis presents rigorous analytical expressions derived as benchmark solutions for the quasistationary field quantities both inside and outside, Joule losses and the electromagnetic forces acting upon a conducting spheroid placed in the proximity of a non-uniform field produced by current-carrying turns. These expressions are used to generate numerous numerical results of specified accuracy and selected results are presented in a normalized form for extended ranges of the spheroid axial ratio, the ratio of the depth of penetration to the semi-minor axis and the position of the inducing turns relative to the spheroids. They are intended to constitute reference data to be employed for comprehensive comparisons of results from approximate numerical methods or from boundary impedance models used for real world conductors. Approximate boundary conditions such as the simpler perfect electric conductor model or the Leontovich surface impedance boundary condition model can be used to obtain approximate solutions by only analyzing the field external to the conducting object. The range of validity of these impedance boundary condition models for the analysis of axisymmetric eddy-current problems is thoroughly investigated. While the simpler PEC model can be employed only when the electromagnetic depth of penetration is mu

Published
2013

21. Scattering of an arbitrarily oriented dipole field by an infinite and a finite length PEMC circular cylinder

Author

Ahsan Illahi and Qaisar Abbas Naqvi

Subjects
Physics, perfect electric conductor, finite length cylinder, Field (physics), Scattering, business.industry, 42.25.ja, QC1-999, Mathematical analysis, 42.25.fx, 42.25.gy, General Physics and Astronomy, metamaterial, Dipole, Optics, 41.20.jb, circular cylinder, Cylinder, 42.25.-p, Electric dipole transition, Perfect conductor, business, Magnetic dipole, Excitation
Abstract

Electromagnetic scattering from an infinite and a finite length PEMC circular cylinder, illuminated by an arbitrarily oriented dipole, is investigated theoretically. An electric dipole as a source of excitation is considered first, and then a magnetic dipole as a source of excitation is treated. In contrast to the case of an axially directed dipole, it is shown that no additional terms are needed to incorporate the cross-polarized component of the field for the case of radial and circumferential dipoles. Numerical verifications are presented to verify the validity of derived results and numerical code by comparing results with the published literature.

Published
2009

22. Nízkoprofilová textilní anténa s umělým magnetickým vodičem

Author

Raida, Zbyněk, Cupal, Miroslav, Raida, Zbyněk, and Cupal, Miroslav

Abstract

Planární nositelná anténa sestává z širokopásmového planárního monopólu, koplanárního vlnovodu a umělého magnetického vodiče. Cílem této práce bylo, pomocí simulací a porovnání se vzorovou publikací, ověření správnosti jejich dílčích komponentů. V práci jsou uvedeny rozbory jednotlivých komponentů, jejich dílčí simulace a následné porovnání se vzorovou publikací. Uplatnění planární nositelné antény se nalézá ve zdravotnictví, sportu, u bezpečnostních a záchranářských složek, ve vojenské sféře a všude, kde je zapotřebí monitorování polohy a zdravotního stavu osob., Planar wereable antenna consists of planar wide-band monopole, coplanar waveguide, and artificial magnetic conductor. The goal of this thesis is to verify the legitimacy of their subcomponents by using simulations and comparsions with a paragidmatic publication. The proposed thesis presents analysis of particular components, their partial simulations and comparison with paradigmatic publication. The planar wearable antenna can be used in disciplines such as healtcare, sports, security and rescue services, the military and wherever the position and health of subjects is required to track / monitor.

23. Nízkoprofilová textilní anténa s umělým magnetickým vodičem

Author

Raida, Zbyněk, Cupal, Miroslav, Raida, Zbyněk, and Cupal, Miroslav

Abstract

Planární nositelná anténa sestává z širokopásmového planárního monopólu, koplanárního vlnovodu a umělého magnetického vodiče. Cílem této práce bylo, pomocí simulací a porovnání se vzorovou publikací, ověření správnosti jejich dílčích komponentů. V práci jsou uvedeny rozbory jednotlivých komponentů, jejich dílčí simulace a následné porovnání se vzorovou publikací. Uplatnění planární nositelné antény se nalézá ve zdravotnictví, sportu, u bezpečnostních a záchranářských složek, ve vojenské sféře a všude, kde je zapotřebí monitorování polohy a zdravotního stavu osob., Planar wereable antenna consists of planar wide-band monopole, coplanar waveguide, and artificial magnetic conductor. The goal of this thesis is to verify the legitimacy of their subcomponents by using simulations and comparsions with a paragidmatic publication. The proposed thesis presents analysis of particular components, their partial simulations and comparison with paradigmatic publication. The planar wearable antenna can be used in disciplines such as healtcare, sports, security and rescue services, the military and wherever the position and health of subjects is required to track / monitor.

24. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén v kmitočtovém pásmu 1 GHz až 10 GHz., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas in the frequency range of 1 GHz to 10 GHz.

25. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén v kmitočtovém pásmu 1 GHz až 10 GHz., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas in the frequency range of 1 GHz to 10 GHz.

26. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén v kmitočtovém pásmu 1 GHz až 10 GHz., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas in the frequency range of 1 GHz to 10 GHz.

27. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas.

28. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas.

29. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Láčík, Jaroslav, and Vašina, Petr

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas.

30. Nízkoprofilová textilní anténa s umělým magnetickým vodičem

Author

Raida, Zbyněk, Cupal, Miroslav, Raida, Zbyněk, and Cupal, Miroslav

Abstract

Planární nositelná anténa sestává z širokopásmového planárního monopólu, koplanárního vlnovodu a umělého magnetického vodiče. Cílem této práce bylo, pomocí simulací a porovnání se vzorovou publikací, ověření správnosti jejich dílčích komponentů. V práci jsou uvedeny rozbory jednotlivých komponentů, jejich dílčí simulace a následné porovnání se vzorovou publikací. Uplatnění planární nositelné antény se nalézá ve zdravotnictví, sportu, u bezpečnostních a záchranářských složek, ve vojenské sféře a všude, kde je zapotřebí monitorování polohy a zdravotního stavu osob., Planar wereable antenna consists of planar wide-band monopole, coplanar waveguide, and artificial magnetic conductor. The goal of this thesis is to verify the legitimacy of their subcomponents by using simulations and comparsions with a paragidmatic publication. The proposed thesis presents analysis of particular components, their partial simulations and comparison with paradigmatic publication. The planar wearable antenna can be used in disciplines such as healtcare, sports, security and rescue services, the military and wherever the position and health of subjects is required to track / monitor.

31. Nízkoprofilová textilní anténa s umělým magnetickým vodičem

Author

Raida, Zbyněk, Cupal, Miroslav, Zbořil, Vojtěch, Raida, Zbyněk, Cupal, Miroslav, and Zbořil, Vojtěch

Abstract

Planární nositelná anténa sestává z širokopásmového planárního monopólu, koplanárního vlnovodu a umělého magnetického vodiče. Cílem této práce bylo, pomocí simulací a porovnání se vzorovou publikací, ověření správnosti jejich dílčích komponentů. V práci jsou uvedeny rozbory jednotlivých komponentů, jejich dílčí simulace a následné porovnání se vzorovou publikací. Uplatnění planární nositelné antény se nalézá ve zdravotnictví, sportu, u bezpečnostních a záchranářských složek, ve vojenské sféře a všude, kde je zapotřebí monitorování polohy a zdravotního stavu osob., Planar wereable antenna consists of planar wide-band monopole, coplanar waveguide, and artificial magnetic conductor. The goal of this thesis is to verify the legitimacy of their subcomponents by using simulations and comparsions with a paragidmatic publication. The proposed thesis presents analysis of particular components, their partial simulations and comparison with paradigmatic publication. The planar wearable antenna can be used in disciplines such as healtcare, sports, security and rescue services, the military and wherever the position and health of subjects is required to track / monitor.

32. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Zbořil, Vojtěch, Láčík, Jaroslav, Vašina, Petr, and Zbořil, Vojtěch

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén v kmitočtovém pásmu 1 GHz až 10 GHz., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas in the frequency range of 1 GHz to 10 GHz.

33. Planární spirálová anténa

Author

Láčík, Jaroslav, Vašina, Petr, Zbořil, Vojtěch, Láčík, Jaroslav, Vašina, Petr, and Zbořil, Vojtěch

Abstract

Tato diplomová práce se zabývá návrhem planární spirálové antény. Cílem práce bylo navrhnout vhodnou planární spirálovou anténu, která bude splňovat požadavky zadaní. V práci jsou představeny dva typy těchto antén a následně je pro jeden konkrétní vytvořen návrh a model. Jsou zde diskutovány výsledky simulací modelu a následná optimalizace. V práci jsou zkoumány charakteristické parametry antény a jejich rozbor. Model je následně optimalizován a probíhá diskuse nad výsledky. Výstupem této práce by měla být navrhnutá anténa, která bude sloužit jako komponenta pro měření charakteristických parametrů reálných antén., This thesis deals with the design of a planar spiral antenna. The purpose of the work was to design a suitable planar spiral antenna that would meet the requirements of the assignment. There are two types of these antennas presented in the work, and then there is also a design and model that is created for one of them. The results of model simulations and subsequent optimization are discussed. The characteristic parameters of the antenna and their analysis are investigated. The model is followed-up optimization and the results are discussed. The output of this work should be a designed antenna, which will serve as a component for measuring the characteristic parameters of real antennas.

34. Parallel plate waveguide with anisotropic graphene plates: Effect of electric and magnetic biases

Author

Malekabadi, Ali, Charlebois, Serge A., Deslandes, Dominic, Malekabadi, Ali, Charlebois, Serge A., and Deslandes, Dominic

Abstract

The performances of a parallel plate waveguide (PPWG) supported by perfect electric conductor (PEC)-graphene and graphene-graphene plates are evaluated. The graphene plate behavior is modeled as an anisotropic medium with both diagonal and Hall conductivities derived from Kubo formula. The PPWG modes supported by PEC-graphene and graphene-graphene plates are studied. Maxwell’s equations are solved for these two waveguides, while the graphene layers are biased with an electric field only and with both electric and magnetic fields. It is shown that when both electric and magnetic biases are applied to the graphene, a hybrid mode (simultaneous transverse electric (TE) and transverse magnetic (TM) modes) will propagate inside the waveguide. The intensity of each TE and TM modes can be adjusted with the applied external bias fields. Study of different waveguides demonstrates that by decreasing the plate separation (d), the wave confinement improves. However, it increases the waveguide attenuation. A dielectric layer inserted between the plates can also be used to improve the wave confinement. The presented analytical procedure is applicable to other guiding structures having walls with isotropic or anisotropic conductivities.

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