Search

A circularly-polarized (CP) traveling-wave endfire antenna featuring low profile, high gain, and simple feeding structure is presented in this communication. Offset parallel strips with proper dielectric loading are employed in a low-profile substrate to achieve two orthogonal electric field components with equal magnitude and 90° phase difference for circularly polarized endfire radiation. Meanwhile periodic phase-loading technique is used to achieve a proper phase constant for high endfire gain. A prototype is designed and fabricated to verify the proposed method. Experimental results demonstrate CP endfire radiation within a frequency band of 9.78-10.09 GHz. The average endfire gain is 10.3 dBic with an average efficiency of 62.5%.

A circularly-polarized (CP) traveling-wave endfire antenna featuring low profile, high gain, and simple feeding structure is presented in this communication. Offset parallel strips with proper dielectric loading are employed in a low-profile substrate to achieve two orthogonal electric field components with equal magnitude and 90° phase difference for circularly polarized endfire radiation. Meanwhile periodic phase-loading technique is used to achieve a proper phase constant for high endfire gain. A prototype is designed and fabricated to verify the proposed method. Experimental results demonstrate CP endfire radiation within a frequency band of 9.78-10.09 GHz. The average endfire gain is 10.3 dBic with an average efficiency of 62.5%.

This paper presents the results of an analysis of the necessary propagation conditions in a step-index optical fiber with a Kerr nonlinearity of two modes, LP01 and LP11, during the transmission of high-power optical pulses. All results were obtained by solving a system of two nonlinear equations for these modes, obtained by the Gauss approximation method, and the subsequent use of a procedure for refining estimates using the mixed finite elements method. The necessary conditions are determined, estimates of the boundaries for the range of normalised frequencies for which they are fulfilled are obtained, and an approximate formula is proposed for estimating the upper limit of this range.

[EN] Optical fibers featuring multi-layer refractive index profiles have been widely investigated and developed in a variety of scenarios, including space-division multiplexing transmission, fiber sensing, loss and dispersion management, as well as high-power amplifiers and lasers. For the first time to our knowledge, we present in this paper a general model deriving the universal characteristic equation for multi-layer optical fibers that comprise a set of concentric layers with arbitrary radial dimensions and refractive index values, considering both stepped (as step-index) or continuous (as graded-index) profiles. Expressions for the main fiber propagation parameters are also derived. We validate the model by comparing our results to the ones provided by numerical software tools with excellent matching for a series of particular optical fibers comprising step-index trench-assisted, ring-core, triangular-index and four-cladding profiles. This compact universal characteristic equation serves as a useful tool for optical fiber designers, where one can get valuable physical insights without the need to resort to numerical software tools, and even evaluate the effect of a single layer in isolation without the need to evaluate the whole refractive index structure.

[EN] Optical fibers featuring multi-layer refractive index profiles have been widely investigated and developed in a variety of scenarios, including space-division multiplexing transmission, fiber sensing, loss and dispersion management, as well as high-power amplifiers and lasers. For the first time to our knowledge, we present in this paper a general model deriving the universal characteristic equation for multi-layer optical fibers that comprise a set of concentric layers with arbitrary radial dimensions and refractive index values, considering both stepped (as step-index) or continuous (as graded-index) profiles. Expressions for the main fiber propagation parameters are also derived. We validate the model by comparing our results to the ones provided by numerical software tools with excellent matching for a series of particular optical fibers comprising step-index trench-assisted, ring-core, triangular-index and four-cladding profiles. This compact universal characteristic equation serves as a useful tool for optical fiber designers, where one can get valuable physical insights without the need to resort to numerical software tools, and even evaluate the effect of a single layer in isolation without the need to evaluate the whole refractive index structure.

[EN] Optical fibers featuring multi-layer refractive index profiles have been widely investigated and developed in a variety of scenarios, including space-division multiplexing transmission, fiber sensing, loss and dispersion management, as well as high-power amplifiers and lasers. For the first time to our knowledge, we present in this paper a general model deriving the universal characteristic equation for multi-layer optical fibers that comprise a set of concentric layers with arbitrary radial dimensions and refractive index values, considering both stepped (as step-index) or continuous (as graded-index) profiles. Expressions for the main fiber propagation parameters are also derived. We validate the model by comparing our results to the ones provided by numerical software tools with excellent matching for a series of particular optical fibers comprising step-index trench-assisted, ring-core, triangular-index and four-cladding profiles. This compact universal characteristic equation serves as a useful tool for optical fiber designers, where one can get valuable physical insights without the need to resort to numerical software tools, and even evaluate the effect of a single layer in isolation without the need to evaluate the whole refractive index structure.

We consider propagation of surface TM waves in a circular metal-dielectric waveguide filled with nonlinear (Kerr nonlinearity) metamaterial medium. Analysis is reduced to solving a nonlinear transmission eigenvalue problem for an ordinary differential equation; eigenvalues of the problem correspond to propagation constants of the surface waves. For the numerical solution, a method is proposed based on solving an auxiliary Cauchy problem (a version of the shooting method). As a result of comprehensive numerical modeling, new propagation regimes are discovered., We gratefully acknowledge the support of the University of Gavle and the Swedish Institute within the frames of the project Largescale. The research of Eugene Smolkin and Maxim Snegur is supported by the Ministry of Education and Science of the Russian Federation, Project No. 1.894.2017/4.6.

This paper describes an algorithm for numerical simulation of the propagation relativistic effects arising in noninertial reference systems and, in particular, in rotating media. The author proposes a fast segmentation method based on obtaining the electromagnetic refraction parameters of the medium (permittivity and permeability), due to spatial harmonics in the expansion of fields, and the subsequent derivation of the propagation constant in the coordinate dependence. The geometry of the scatterer may be arbitrary axisymmetric, but with a circular cross-section along the direction of propagation. The accuracy of the modeling is estimated in comparison with analytics. The results of the simulation prove the effectiveness of the method., В данной статье описывается алгоритм численного моделирования релятивистских эффектов распространения электромагнитных волн, возникающих в неинерциальных системах отсчета, а именно во вращающейся среде. Автор предлагает быстрый метод сегментирования геометрии диэлектрика, основанный на уточненных параметрах электромагнитной рефракции в среде (диэлектрическая и магнитная проницаемости), получаемых за счет пространственных гармоник в разложениях полей, с последующим выводом координатной зависимости постоянной распространения. Геометрия рассеивателя может быть произвольно осесимметричной, но с круговым поперечным сечением вдоль направления распространения электромагнитных волн. Точность моделирования оценивается в сравнении со строгими решениями, полученными ранее.

In this letter, we demonstrate that the dispersion properties of printed double-sided parallel-strip lines can be controlled by using glide symmetry. Glide symmetry is introduced in with corrugations in both strips of a double-sided line. We demonstrate that glide symmetry eliminates the stopband between first and second propagating modes and yields to a higher propagation constant, preserving its linearity, and the broadband nature of the underlying guiding technology. Thus, the glide-symmetric double-sided line can be designed to possess a high equivalent refractive index in an ultrawide range of frequencies. These exceptional properties have been numerically and experimentally validated. Finally, we demonstrate the possibilities of this technology with a specific design, a glide-symmetric double-sided parallel-strip line with filtering properties. Potential applications are low-dispersive leaky-wave antennas and electromechanical tunable phase shifters and filters., Export Date: 22 October 2018; Article; CODEN: IMWCB; Correspondence Address: Padilla, P.; Department of Signal Theory, Telematics and Communications, Universidad de GranadaSpain; email: pablopadilla@ugr.es; Funding details: PRX17/00100; Funding details: PRX17/00630; Funding text: Manuscript received April 30, 2018; revised July 5, 2018; accepted July 17, 2018. Date of publication August 10, 2018; date of current version September 4, 2018. This work was supported in part by the Spanish Program of Research, Development, and Innovation under Grant TIN2016-75097-P and GrantUNGR15-CE-3311 and in part by the Salvador de Madariaga Program under Grant PRX17/00100 and Grant PRX17/00630. (Corresponding author: P. Padilla.) P. Padilla and J. F. Valenzuela-Valdés are with the Department of Signal Theory, Telematics and Communications, Universidad de Granada, 18071 Granada, Spain (e-mail: pablopadilla@ugr.es). QC 20181023

This paper deals with the propagation of electromagnetic waves in cylindrical waveguides with irregularly deformed cross-sections. The general theory of electromagnetic waves is of high interest because of its practical use as a transmission medium. But only in a few special cases, an analytic solution of Maxwell's equations and the appropriate boundary conditions can be found (Spencer 1951). The coupled-mode theory, also known as Schelkunoff's method, is a semi-numerical method for computing electromagnetic waves in hollow and cylindrical waveguides bounded by perfect electric walls (Saad 1985). It allows to calculate the transverse field pattern and the propagation constant. The aim of this paper is to derive the so-called generalized telegraphist's equations for irregular deformed waveguides. Subsequently, the method's application will be used on a circular waveguide as an illustrating example.

We consider normal waves in multi-layered dielectric rod and Goubau line that are basic types of open metal-dielectric waveguides. The dispersion equations are analyzed using the notion of generalized cylindrical polynomials and methods of calculating determinants of block-diagonal matrices. Sufficient conditions of the existence of symmetric waves are established.

The propagation of monochromatic nonlinear symmetric hybrid waves in a cylindrical nonlinear dielectric waveguide is considered. The physical problem is reduced to solving a transmission eigenvalue problem for a system of ordinary differential equations. Spectral parameters of the problem are propagation constants of the waveguide. Numerical results are found with the modification of the shooting method. The method allows us to determine approximate eigenvalues with any prescribed accuracy. The comparison with known exact solutions (for particular values of parameters) are made. The approach described in this paper can be applied to other problems, e.g., to multilayered inhomogeneous waveguides., Project Largescale

The propagation of monochromatic electromagnetic waves in a cylindrical anisotropic metal-dielectric waveguide is considered. The physical problem is reduced to solving a transmission eigenvalue problem for a system of ordinary differential equations. Spectral parameters of the problem are propagation constants of the waveguide. Numerical results are found with a projection method., Project Largescale

When a perfectly electrically conducting (PEC) waveguide is perturbed by the insertion of a PEC structure aligned with its axis, its propagation constants are perturbed. Two complementary approaches to the determination of change induced by the insert are described. The first provides an analytic estimate when the insert is a small flat strip. The second approach converts the underlying boundary value problem to a homogeneous Fredholm matrix equation in which the propagation constants are found from the roots of the determinant of the matrix and stable numerical processes may be employed to find the propagation constants. The second approach is not constrained by the size or shape of the inserts, and thus provides an independent estimate of the accuracy of the analytic estimate of perturbation to the propagation constants of the empty waveguide; it also determines the empty waveguide parameters themselves.

The propagation of monochromatic electromagnetic waves in a cylindrical anisotropic inhomogeneous waveguide with longitudinal magnetization is considered. The physical problem is reduced to solving a transmission eigenvalue problem for a system of ordinary differential equations. Spectral parameters of the problem are propagation constants of the waveguide. Numerical results are obtained using a modification of the projecting methods. The comparison with known exact solutions (for particular values of parameters) are made. © 2018 Electromagnetics Academy. All rights reserved., Export Date: 4 June 2018; Conference Paper, Project Largescale

Настоящая статья посвящена разработке математической модели и построению алгоритма для расчета постоянной распространения круглого волновода с металлическими стенками с поперечно неоднородным диэлектрическим заполнением. В основе математической модели лежат аппарат функций Грина и математический аппарат теории длинных линий для анализа многослойных структур. В статье описаны решения, использованные для создания алгоритмов, позволяющих применить описанную математическую модель для получения частотных зависимостей постоянной распространения., This article is dedicated to the development of mathematical model and building of an algorithm for calculation of propagation constant of circular metal waveguide with multilayer dielectric filling. Mathematical model is based on Green’s function methods and methods of circuits theory for analysis of multilayered structures. Ideas and solutions, which were used for algorithms created for applying of described mathematical model for obtaining of frequency dependences of propagation constant are described.

We consider a homogeneous Goubau line (GL) with a lossy cover. We analyze the dispersion equation for symmetric waves with respect to the problem parameters, find radially symmetric complex waves, and examine their behavior. We show that longitudinal wavenumbers of complex waves are regular perturbations of the propagation constants of eigenwaves of lossless GL, weakly depend om the imaginary part of permittivity of the cover, and that attenuation in GL is low at higher losses.

We consider propagation of surface TE waves in a circular dielectric waveguide filled with nonlinear (Kerr non-linearity) multilayered inhomogeneous medium. Each layer is characterized by a specific value of the nonlinearity coefficient α. Analysis is reduced to solving a nonlinear transmission eigenvalue problem for an ordinary differential equation; eigenvalues of the problem correspond to propagation constants of the waveguide. For the numerical solution, a method is proposed based on solving an auxiliary Cauchy problem (a version of the shooting method). As a result of comprehensive numerical modeling, new propagation regimes are discovered.

The propagation of monochromatic electromagnetic TE waves in the Goubau line (conducting cylinder covered by a concentric dielectric layer) filled with nonlinear inhomogeneous medium is considered. Two types of nonlinearity are studied. A physical problem is reduced to solving a nonlinear transmission eigenvalue problem for an ordinary differential equation. Eigenvalues of the problem correspond to propagation constants of the waveguide. A method is proposed for finding approximate eigenvalues of the nonlinear problem based on solving an auxiliary Cauchy problem (by the shooting method). The existence of eigenvalues that correspond to a new propagation regime is predicted. A comparison with the linear case is given.

The propagation of monochromatic electromagnetic TM waves in the Goubau line (conducting cylinder covered by a concentric dielectric layer) filled with nonlinear inhomogeneous medium is considered. Two types of nonlinearity are studied. A physical problem is reduced to solving a nonlinear transmission eigenvalue problem for a system of ordinary differential equations. Eigenvalues of the problem correspond to propagation constants of the waveguide. A method is proposed for finding approximate eigenvalues of the nonlinear problem based on solving an auxiliary Cauchy problem (by the shooting method). The existence of eigenvalues that correspond to a new propagation regime is predicted. A comparison with the linear case is given., Article number: 7297390

Представлена методика проектування світловодів з профілем показника заломлення одномодового неоднорідного оптичного волокна, оптимізованого для одержання збільшеної ефективної площі поперечного перерізу поля основної моди. В основу покладено метод розв’язку зворотної задачі теорії розсіяння, який полягає у відновленні диференційного оператора за спектральною функцією. Для перевірки результатів виконано модельний експеримент, який полягає у розв’язку прямої задачі для одержаних світловодів. Одержані параметри волокна відповідають вимогам до сучасних телекомунікаційних ліній зв’язку із спектральним ущільненням.

The technique of engineering of lightguides with refraction index of singlemode inhomogeneous fibre optimized for inlarge effective area of mode field cross section is presented/ The method of solving of return scattering problem consisting in restoration of differential pperator from its spectral function is based in this technique. For verification of results the model experiment with solving of direct problem for obtaining waveguides is executed. Parameters of singlemode optical fibre that satisfy to the requirements for up to date telecommunication optical lines with spectral multiplexing are obtained., Представлена методика проектирования световодов с профилем показателя преломления одномодового неоднородного оптичесокго волокна, оптимизированным для получения увеличенной эффективной площади поперечного сечения поля основной моды. В основу положен метод решения обратной задачи теории рассеяния, заключающийся в восстановлении дифференциального оператора по спектральной функции. Для проверки результатов выполнен модельный эксперимент, состоящий в решении прямой задачи для полученных световодов. Полученные параметры волокна соответствуют требованиям к современным телекоммуникационным линиям связи со спектральным уплотнением., Представлена методика проектування світловодів з профілем показника заломлення одномодового неоднорідного оптичного волокна, оптимізованого для одержання збільшеної ефективної площі поперечного перерізу поля основної моди. В основу покладено метод розв’язку зворотної задачі теорії розсіяння, який полягає у відновленні диференційного оператора за спектральною функцією. Для перевірки результатів виконано модельний експеримент, який полягає у розв’язку прямої задачі для одержаних світловодів. Одержані параметри волокна відповідають вимогам до сучасних телекомунікаційних ліній зв’язку із спектральним ущільненням.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications.The electromagnetic model is focused on frequencies between 0 and 100 kHz since higher frequencies essentially will be attenuated. An exact dispersion relation is formulated and the propagation constant is computed numerically. The dominating mode is the first Transversal Magnetic (TM) mode of order zero, denoted TM01, which is also referred to as the quasi-TEM mode. A comparison is made with the second propagating TM mode of order zero denoted TM02. The electromagnetic model is verified against real time data from Time Domain Reflection (TDR) measurements on a HVDC power cable. A mismatch calibration procedure is performed due to matching difficulties between the TDR measurement equipment and the power cable regarding the single-mode transmission line model.An example of power cable length measurements is addressed, which reveals that with a “perfect” model the length of an 80 km long power cable could be estimated to an accuracy of a few centimeters. With the present model the accuracy can be estimated to approximately 100 m.In order to understand the low-frequency wave propagation characteristics, an exact asymptotic analysis is performed. It is shown that the behavior of the propagation constant is governed by a square root of the complex frequency in the lowfrequency domain. This thesis also focuses on an analysis regarding the sensitivity of the propagation constant with respect to some of the electric parameters in the model. Variables of interest when performing the parameter sensitivity study are the real relative permittivityand the conductivity.

We present a simple analytical solution for a one dimensionalgrooved structure which, when placed concentricallyaround or flanking a small aperture, has been shown to enhancemicrowave radiation from it.We will show that the transcendentalequation which describes the grooved structure reduces to a transverseresonance condition at the slot openings. For some parameters,the solution to the problem manifests as a complex wave. Wedemonstrate that this complex wave indeed well approximates thefield distribution when a single aperture is excited for frequencieswhere the enhancement ismost significant. In addition, we proposea simple and intuitive design procedure for the grooved structure

The characteristics of the slot- and perturbed TE10 modes in a slitted waveguide are studied for the purpose of suppressing the undesired slot-mode. The use of the finite difference time domain (FDTD) with periodic boundary conditions allows the extraction of the individual complex waven umbers of the two modes, and thus the tracking of the modes as modifications are made to the structure. Two structures are presented, the first suppressing the propagation of the slot-mode, and the second suppressing the radiation of the slot-mode. Experimental validation is presented supporting the numerical results. It will be shown that a wide band suppression of the slot-mode propagation is achievable. However, there is a significant impact on the propagation characteristics of the desired perturbed TE10 modes. Conversely, the suppression of the slot-mode radiation is achievable with minimal impact on the perturbed TE10 mode.

By the point matching method, taking into account only the even electric longitudinal field components, is considered the eigenvalue problem – constant propagation in inhomogeneous dielectric waveguide. The following model is accepted: a dielectric waveguide of round cross-section with single circular heterogeneity. A result of numerical studies of the dependence of the propagation constant for different types of waves, depending on the parameters and the location of the in homogeneity, are introduced. The results of the study can be extended to the study of waveguides with a cross section of different shapes and/or contain multiple heterogeneous domains with different parameters, Методом точечного согласования, с учетом только четных продольных составляющих электрического поля, решается задача на собственные значения – постоянные распространения волн в неоднородном волновод круглого поперечного сечения с одной неоднородностью круглой формы. Приведены результаты численных исследований зависимости постоянной распространения для разных типов волн в зависимости от параметров и месторасположения неоднородности. Результаты данной работы можно расширить для исследования волноводов, имеющих сечение другой формы и/или содержащих несколько неоднородных областей с разными параметрами., Методом точкового узгодження, з врахуванням лише парних поздовжніх складових електричного поля, розв’язується задача на власні значення – сталі поширення хвиль в неоднорідному діелектричному хвилеводі. Розглядається наступна модель: діелектричний хвилевід кругового поперечного перетину з однією неоднорідністю кругової форми. Наведені результати чисельних досліджень залежності сталої поширення для різних типів хвиль в залежності від параметрів та місцеположення неоднорідності. Результати даної роботи можуть бути поширені для дослідження хвилеводів, які мають перетин іншої форми та/або містятьдекілька неоднорідних областей з різними параметрами

Методом точкового узгодження, з врахуванням лише парних поздовжніх складових електричного поля, розв’язується задача на власні значення – сталі поширення хвиль в неоднорідному діелектричному хвилеводі. Розглядається наступна модель: діелектричний хвилевід кругового поперечного перетину з однією неоднорідністю кругової форми. Наведені результати чисельних досліджень залежності сталої поширення для різних типів хвиль в залежності від параметрів та місцеположення неоднорідності. Результати даної роботи можуть бути поширені для дослідження хвилеводів, які мають перетин іншої форми та/або містятьдекілька неоднорідних областей з різними параметрами

In this paper, the wave propagation characteristics of single-phase medium voltage (MV) cross-linked polyethylene (XLPE) power cable are determined using time domain reflectometry (TDR) measurement technique. TDR delivers the complex propagation constant (attenuation and phase constant) of lossy cable transmission line as a function of frequency. The frequency-dependent propagation velocity is also determined from the TDR measurements through the parameters extraction procedure. The calibration of the measuring system (MS) is carried-out to avoid the effect of multiple reflections on the accuracy of measurements. The results obtained from the measurements can be used to localize the discontinuities as well as the design of communication through distribution power cables., Conference: 6th International Conference on Electrical and Electronics Engineering. Bursa, TURKEY. NOV 05-08, 2009

“© © 20xx 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.”, In this letter, a method for the improved consideration of propagation losses in metallic waveguide structures is presented. The method relies on the perturbation of the boundary conditions on the metallic walls of the waveguides. Following this advanced technique, we are able to compute a complex modal propagation constant, thus avoiding the drawbacks of the classical power-loss method where losses associated to evanescent modes were not taken into account. A Computer Aided Design (CAD) software package based on such a modal analysis tool has been applied to predict the propagation loss effects in a Ka-Band rectangular waveguide filter. © 2011 IEEE.

This article presents an analysis of electrical distribution theory for 60Hz-lines operating at low voltage, particularly underground lines and residential indoor installations. Such distribution lines' behaviour is observed as a function of frequency to consider any advantages regarding the potential use of power transmission lines (PTL) for transmitting telecommunication signals. A method for computing the secondary parameters is proposed which has been based on the primary parameters, namely inductance, capacitance, conductance and resistance. The secondary parameters so obtained were characteristic impedance, propagation constant (together with its real value) and the attenuation constant. Conductor configurations, insulation materials and gauges commonly used in Colombia were verified for such low-voltage lines. A mathematical model is proposed as a theoretical tool for analysing and predicting characteristic impedance pattern and the attenuations which occur at high frequencies, thereby complementing our group's previous work. Conclusions are drawn, together with a perspective regarding future work and applications., En este documento se presenta un análisis de la teoría de las líneas eléctricas de 60 Hz para baja tensión, en particular las líneas subterráneas y las de instalaciones internas residenciales y su comportamiento con la variación de la frecuencia, para considerar su aprovechamiento como medio de transmisión de señales de telecomunicaciones PLT. A partir de los parámetros primarios: inductancia, capacitancia, conductancia y resistencia se propone un método para el cálculo de los parámetros secundarios: impedancia característica y constante de propagación junto con su componente real, la constante de atenuación. Se verifican las configuraciones, aislamientos y calibres de conductor más usados en Colombia para estas líneas de baja tensión y se propone un modelo matemático como herramienta teórica a los fines de analizar y predecir el comportamiento de la impedancia característica y la atenuación en altas frecuencias, complementando trabajos previos. Las conclusiones se muestran al final junto con la perspectiva de aplicación y trabajos posteriores.

This article presents an analysis of electrical distribution theory for 60Hz-lines operating at low voltage, particularly underground lines and residential indoor installations. Such distribution lines’ behaviour is observed as a function of frequency to consider any advantages regarding the potential use of power transmission lines (PTL) for transmitting telecommunication signals. A method for computing the secondary parameters is proposed which has been based on the primary parameters, namely inductance, capacitance, conductance and resistance. The secondary parameters so obtained were characteristic impedance, propagation constant (together with its real value) and the attenuation constant. Conductor configurations, insulation materials and gauges commonly used in Colombia were verified for such low-voltage lines. A mathematical model is proposed as a theoretical tool for analysing and predicting characteristic impedance pattern and the attenuations which occur at high frequencies, thereby complementing our group’s previous work. Conclusions are drawn, together with a perspective regarding future work and applications., En este documento se presenta un análisis de la teoría de las líneas eléctricas de 60 Hz para baja tensión, en particular las líneas subterráneas y las de instalaciones internas residenciales y su comportamiento con la variación de la frecuencia, para considerar su aprovechamiento como medio de transmisión de señales de telecomunicaciones PLT. A partir de los parámetros primarios: inductancia, capacitancia, conductancia y resistencia se propone un método para el cálculo de los parámetros secundarios: impedancia característica y constante de propagación junto con su componente real, la constante de atenuación. Se verifican las configuraciones, aislamientos y calibres de conductor más usados en Colombia para estas líneas de baja tensión y se propone un modelo matemático como herramienta teórica a los fines de analizar y predecir el comportamiento de la impedancia característica y la atenuación en altas frecuencias, complementando trabajos previos. Las conclusiones se muestran al final junto con la perspectiva de aplicación y trabajos posteriores.

This article presents an analysis of electrical distribution theory for 60Hz-lines operating at low voltage, particularly underground lines and residential indoor installations. Such distribution lines’ behaviour is observed as a function of frequency to consider any advantages regarding the potential use of power transmission lines (PTL) for transmitting telecommunication signals. A method for computing the secondary parameters is proposed which has been based on the primary parameters, namely inductance, capacitance, conductance and resistance. The secondary parameters so obtained were characteristic impedance, propagation constant (together with its real value) and the attenuation constant. Conductor configurations, insulation materials and gauges commonly used in Colombia were verified for such low-voltage lines. A mathematical model is proposed as a theoretical tool for analysing and predicting characteristic impedance pattern and the attenuations which occur at high frequencies, thereby complementing our group’s previous work. Conclusions are drawn, together with a perspective regarding future work and applications., En este documento se presenta un análisis de la teoría de las líneas eléctricas de 60 Hz para baja tensión, en particular las líneas subterráneas y las de instalaciones internas residenciales y su comportamiento con la variación de la frecuencia, para considerar su aprovechamiento como medio de transmisión de señales de telecomunicaciones PLT. A partir de los parámetros primarios: inductancia, capacitancia, conductancia y resistencia se propone un método para el cálculo de los parámetros secundarios: impedancia característica y constante de propagación junto con su componente real, la constante de atenuación. Se verifican las configuraciones, aislamientos y calibres de conductor más usados en Colombia para estas líneas de baja tensión y se propone un modelo matemático como herramienta teórica a los fines de analizar y predecir el comportamiento de la impedancia característica y la atenuación en altas frecuencias, complementando trabajos previos. Las conclusiones se muestran al final junto con la perspectiva de aplicación y trabajos posteriores.

This article presents an analysis of electrical distribution theory for 60Hz-lines operating at low voltage, particularly underground lines and residential indoor installations. Such distribution lines’ behaviour is observed as a function of frequency to consider any advantages regarding the potential use of power transmission lines (PTL) for transmitting telecommunication signals. A method for computing the secondary parameters is proposed which has been based on the primary parameters, namely inductance, capacitance, conductance and resistance. The secondary parameters so obtained were characteristic impedance, propagation constant (together with its real value) and the attenuation constant. Conductor configurations, insulation materials and gauges commonly used in Colombia were verified for such low-voltage lines. A mathematical model is proposed as a theoretical tool for analysing and predicting characteristic impedance pattern and the attenuations which occur at high frequencies, thereby complementing our group’s previous work. Conclusions are drawn, together with a perspective regarding future work and applications., En este documento se presenta un análisis de la teoría de las líneas eléctricas de 60 Hz para baja tensión, en particular las líneas subterráneas y las de instalaciones internas residenciales y su comportamiento con la variación de la frecuencia, para considerar su aprovechamiento como medio de transmisión de señales de telecomunicaciones PLT. A partir de los parámetros primarios: inductancia, capacitancia, conductancia y resistencia se propone un método para el cálculo de los parámetros secundarios: impedancia característica y constante de propagación junto con su componente real, la constante de atenuación. Se verifican las configuraciones, aislamientos y calibres de conductor más usados en Colombia para estas líneas de baja tensión y se propone un modelo matemático como herramienta teórica a los fines de analizar y predecir el comportamiento de la impedancia característica y la atenuación en altas frecuencias, complementando trabajos previos. Las conclusiones se muestran al final junto con la perspectiva de aplicación y trabajos posteriores.

This article presents an analysis of electrical distribution theory for 60Hz-lines operating at low voltage, particularly underground lines and residential indoor installations. Such distribution lines’ behaviour is observed as a function of frequency to consider any advantages regarding the potential use of power transmission lines (PTL) for transmitting telecommunication signals. A method for computing the secondary parameters is proposed which has been based on the primary parameters, namely inductance, capacitance, conductance and resistance. The secondary parameters so obtained were characteristic impedance, propagation constant (together with its real value) and the attenuation constant. Conductor configurations, insulation materials and gauges commonly used in Colombia were verified for such low-voltage lines. A mathematical model is proposed as a theoretical tool for analysing and predicting characteristic impedance pattern and the attenuations which occur at high frequencies, thereby complementing our group’s previous work. Conclusions are drawn, together with a perspective regarding future work and applications., En este documento se presenta un análisis de la teoría de las líneas eléctricas de 60 Hz para baja tensión, en particular las líneas subterráneas y las de instalaciones internas residenciales y su comportamiento con la variación de la frecuencia, para considerar su aprovechamiento como medio de transmisión de señales de telecomunicaciones PLT. A partir de los parámetros primarios: inductancia, capacitancia, conductancia y resistencia se propone un método para el cálculo de los parámetros secundarios: impedancia característica y constante de propagación junto con su componente real, la constante de atenuación. Se verifican las configuraciones, aislamientos y calibres de conductor más usados en Colombia para estas líneas de baja tensión y se propone un modelo matemático como herramienta teórica a los fines de analizar y predecir el comportamiento de la impedancia característica y la atenuación en altas frecuencias, complementando trabajos previos. Las conclusiones se muestran al final junto con la perspectiva de aplicación y trabajos posteriores.

Vehicle-to-vehicle (V2V) communications have received increasingattention lately, but there is a lack of reported results regarding important quantities such as path loss. This paper presents parameterized path loss models for V2V communications based on extensive sets of measurement data collected mainly under line-of-sight conditions in four different propagation environments: highway, rural, urban, and suburban. The results show that the path loss exponent is low for V2V communications, i.e., path loss slowly increases with increasing distance. We compare our results to those previously reported and find that, while they confirm some of the earlier work, there are also differences that motivate the need for further studies.

Engineering of refraction index profile for planar metal-dielectric waveguide is performed., Проведено моделирование профиля показателя преломления в планарных металлодиэлектрических волноводах., Проведено моделювання профілю показника заломлення у планарних металодіелектричних хвилеводах для одержання оптимальних параметрів.

Проведено моделювання профілю показника заломлення у планарних металодіелектричних хвилеводах для одержання оптимальних параметрів.

A three-dimensional (3D) finite-element mode-propagation analysis is presented to give an accurate and efficient simulation for silicon-nanowire- based multimode interference (MMI) couplers. For the presented numerical method, a finite-element method mode solver is used to calculate the mode profiles and the propagation constants in a multimode section. The comparison between the presented method and some other numerical methods [e.g., finite-difference time-domain (FDTD) method, beam propagation methods, etc.] is also shown. It is shown that the presented numerical method gives simulation results very close to those from the 3D FDTD (with a deviation less than 1%). Therefore, it is very convenient for the design of Si-nanowire-based MMI couplers., QC 20211116

We present an accurate approach to compute the attenuation of waves, propagating in circular waveguides with lossy and superconducting walls. A set of transcendental equation is developed by matching the fields at the surface of the wall with the electrical properties of the wall material. The propagation constant kz is found by numerically solving for the root of the equation. The complex conductivity of the superconductor is obtained from the Mattis-Bardeen equations. We have compared the loss of TE11 mode computed using our technique with that using the perturbation and Stratton’s methods. The results from the three methods agree very well at a reasonable range of frequencies above the cutoff. The curves, however, deviate below cutoff and at millimeter wave frequencies. We attribute the discrepancies to the dispersive effect and the presence of the longitudinal fields in a lossy waveguide. At frequencies below the gap, the superconducting waveguide exhibits lossless transmission behavior. Above the gap frequency, Cooper-pair breaking becomes dominant and the loss increases significantly.

We present an accurate approach to compute the attenuation of waves, propagating in circular waveguides with lossy and superconducting walls. A set of transcendental equation is developed by matching the fields at the surface of the wall with the electrical properties of the wall material. The propagation constant kz is found by numerically solving for the root of the equation. The complex conductivity of the superconductor is obtained from the Mattis-Bardeen equations. We have compared the loss of TE11 mode computed using our technique with that using the perturbation and Stratton’s methods. The results from the three methods agree very well at a reasonable range of frequencies above the cutoff. The curves, however, deviate below cutoff and at millimeter wave frequencies. We attribute the discrepancies to the dispersive effect and the presence of the longitudinal fields in a lossy waveguide. At frequencies below the gap, the superconducting waveguide exhibits lossless transmission behavior. Above the gap frequency, Cooper-pair breaking becomes dominant and the loss increases significantly.

We present an accurate approach to compute the attenuation of waves, propagating in circular waveguides with lossy and superconducting walls. A set of transcendental equation is developed by matching the fields at the surface of the wall with the electrical properties of the wall material. The propagation constant kz is found by numerically solving for the root of the equation. The complex conductivity of the superconductor is obtained from the Mattis-Bardeen equations. We have compared the loss of TE11 mode computed using our technique with that using the perturbation and Stratton’s methods. The results from the three methods agree very well at a reasonable range of frequencies above the cutoff. The curves, however, deviate below cutoff and at millimeter wave frequencies. We attribute the discrepancies to the dispersive effect and the presence of the longitudinal fields in a lossy waveguide. At frequencies below the gap, the superconducting waveguide exhibits lossless transmission behavior. Above the gap frequency, Cooper-pair breaking becomes dominant and the loss increases significantly.

We present an accurate approach to compute the attenuation of waves, propagating in circular waveguides with lossy and superconducting walls. A set of transcendental equation is developed by matching the fields at the surface of the wall with the electrical properties of the wall material. The propagation constant kz is found by numerically solving for the root of the equation. The complex conductivity of the superconductor is obtained from the Mattis-Bardeen equations. We have compared the loss of TE11 mode computed using our technique with that using the perturbation and Stratton’s methods. The results from the three methods agree very well at a reasonable range of frequencies above the cutoff. The curves, however, deviate below cutoff and at millimeter wave frequencies. We attribute the discrepancies to the dispersive effect and the presence of the longitudinal fields in a lossy waveguide. At frequencies below the gap, the superconducting waveguide exhibits lossless transmission behavior. Above the gap frequency, Cooper-pair breaking becomes dominant and the loss increases significantly.

We present an accurate approach to compute the attenuation of waves, propagating in circular waveguides with lossy and superconducting walls. A set of transcendental equation is developed by matching the fields at the surface of the wall with the electrical properties of the wall material. The propagation constant kz is found by numerically solving for the root of the equation. The complex conductivity of the superconductor is obtained from the Mattis-Bardeen equations. We have compared the loss of TE11 mode computed using our technique with that using the perturbation and Stratton’s methods. The results from the three methods agree very well at a reasonable range of frequencies above the cutoff. The curves, however, deviate below cutoff and at millimeter wave frequencies. We attribute the discrepancies to the dispersive effect and the presence of the longitudinal fields in a lossy waveguide. At frequencies below the gap, the superconducting waveguide exhibits lossless transmission behavior. Above the gap frequency, Cooper-pair breaking becomes dominant and the loss increases significantly.

Engineering method for circular cross-section waveguide refraction index profile is proposed. Mathematical apparatus of Gel’fund-Levitan-Martchenko for solving of inverse scattering problem of nonrelativistic quantum mechanic been used., Предложен метод проектирования профиля показателя преломления в волноводе круглого поперечного сечения с использованием математического аппарата Гельфанда-Левитана-Марченко решения обратной задачи рассеяния нерелятивистской квантовой механики., Запропоновано метод проектування профілю показника заломлення у хвилеводі круглого поперечного перерізу з використанням математичного апарату Гельфанда-Левітана-Марченко розв’язку зворотної задачі розсіяння нерелятивістської квантової механіки.

Запропоновано метод проектування профілю показника заломлення у хвилеводі круглого поперечного перерізу з використанням математичного апарату Гельфанда-Левітана-Марченко розв’язку зворотної задачі розсіяння нерелятивістської квантової механіки.