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1 – 10 of over 10000Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community…
Abstract
Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.
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Nour Mohammad Murad, Antonio Jaomiary, Samar Yazdani, Fayrouz Haddad, Mathieu Guerin, George Chan, Wenceslas Rahajandraibe and Sahbi Baccar
This paper aims to develop high-pass (HP) negative group delay (NGD) investigation based on three-port lumped circuit. The main particularity of the proposed three-port passive…
Abstract
Purpose
This paper aims to develop high-pass (HP) negative group delay (NGD) investigation based on three-port lumped circuit. The main particularity of the proposed three-port passive topology is the consideration of only a single circuit element represented by a capacitor.
Design/methodology/approach
The methodology of the paper is to consider the S-matrix equivalent model derived from admittance matrix approach. So, an S-matrix equivalent model of a three-port circuit topology is established from admittance matrix approach. The frequency-dependent basic expressions are explored to perform the HP-NGD analysis. Then, the existence condition of HP-NGD function type is analytically demonstrated. The specific characteristics and synthesis equations of HP-NGD circuit with respect to the desired optimal NGD value are established.
Findings
After computing the frequency expressions to perform the HP-NGD analysis, this study demonstrated the existence condition of HP-NGD function type analytically. The validity of the HP-NGD theory is verified by a prototype of three-port circuit. The proof-of-concept (POC) single capacitor three-port circuit presents an NGD response and characteristics from analytical calculation and simulation is in very good correlation.
Originality/value
An innovative theory of HP-NGD three-port circuit is studied. The proposed HP-NGD topology is constituted by only a single capacitor. After the topological description, the S-matrix model is established from the Y-matrix by means of Kirchhoff voltage law and Kirchhoff current law equations. A POC of single capacitor three-port circuit was designed and simulated with a commercial tool. Then, a prototype with a surface-mounted device component was fabricated and tested. As expected, simulation and measurement results in very good agreement with the calculated model show the feasibility of the HP-NGD behavior. This work is compared to other NGD-type function with diverse number of ports and components.
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Sébastien Lalléchére, Jamel Nebhen, Yang Liu, George Chan, Glauco Fontgalland, Wenceslas Rahajandraibe, Fayu Wan and Blaise Ravelo
The purpose of this paper is to study, a bridged-T topology with inductorless passive network used as a bandpass (BP) negative group delay (NGD) function.
Abstract
Purpose
The purpose of this paper is to study, a bridged-T topology with inductorless passive network used as a bandpass (BP) negative group delay (NGD) function.
Design/methodology/approach
The BP NGD topology under study is composed of an inductorless passive resistive capacitive network. The circuit analysis is elaborated from the equivalent impedance matrix. Then, the analytical model of the C-shunt bridged-T topology voltage transfer function is established. The BP NGD analysis of the considered topology is developed in function of the bridged-T parameters. The NGD properties and characterizations of the proposed topology are analytically expressed. Moreover, the relevance of the BP NGD theory is verified with the design and fabrication of surface mounted device components-based proof-of-concept (PoC).
Findings
From measurement results, the BP NGD network with −151 ns at the center frequency of 1 MHz over −6.6 dB attenuation is in very good agreement with the C-shunt bridged-T PoC.
Originality/value
This paper develops a mathematical modeling theory and measurement of a C-shunt bridged-T network circuit.
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Mathieu Guerin, Fayu Wan, Konstantin Gorshkov, Xiaoyu Huang, Bogdana Tishchuk, Frank Elliot Sahoa, George Chan, Sahbi Baccar, Wenceslas Rahajandraibe and Blaise Ravelo
The purpose of this paper is to provide the high-pass (HP) negative group delay (NGD) circuit based (RL) network. Synthesis and experimental investigation of HP-NGD circuit are…
Abstract
Purpose
The purpose of this paper is to provide the high-pass (HP) negative group delay (NGD) circuit based (RL) network. Synthesis and experimental investigation of HP-NGD circuit are developed.
Design/methodology/approach
The research work methodology is organized in three phases. The definition of the HP-NGD ideal specifications is introduced. The synthesis method allowing to determine the RL elements is developed. The validation results are discussed with comparison between the calculated model, simulation and measurement.
Findings
This paper shows a validation of the HP-NGD theory with responses confirming NGD optimal frequency, value and attenuation of about (9 kHz, −1.12 µs, −1.64 dB) and (21 kHz, −0.92 µs, −4.81 dB) are measured. The tested circuits have experimented NGD cut-off frequencies around 5 and 11.7 kHz.
Research limitations/implications
The validity of the HP-NGD topology depends on the coil self-inductance resonance. The HP-NGD effect is susceptible to be penalized by the parasitic elements of the self.
Practical implications
The NGD circuit is usefully exploited in the electronic and communication system to reduce the undesired delay effect context. The NGD can be used to compensate the delay in any electronic devices and system.
Social implications
Applications based on the NGD technology will be helpful in the communication, transportation and security research fields by reducing the delay inherent to any electronic circuit.
Originality/value
The originality of the paper concerns the synthesis formulations of the RL elements in function of the expected HP-NGD optimal frequency, value and attenuation. In addition, an original measurement technique of HP-NGD is also introduced.
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Hongyu Du, Rong Yang, Taochen Gu, Xiang Zhou, Samar Yazdani, Eric Sambatra, Fayu Wan, Sébastien Lallechere and Blaise Ravelo
The purpose of this paper is to introduce an innovative theoretical, numerical and experimental investigations on the HP NGD function. The identified HP NGD topology under study…
Abstract
Purpose
The purpose of this paper is to introduce an innovative theoretical, numerical and experimental investigations on the HP NGD function. The identified HP NGD topology under study is constituted by first order passive RC-network. The simulations and measurements confirm in very good agreement the HP NGD behaviors of the tested circuits. NGD responses with optimal values of about -1 ns and cut-off frequencies of about 20 MHz are obtained.
Design/methodology/approach
The identified HP NGD topology understudy is constituted by a first-order passive Resistor-capacitor RC network. An innovative approach to HP NGD analysis is developed. The analytical investigation from the voltage transfer function showing the meaning of HP properties is established.
Findings
This paper introduces innovative theoretical, numerical and experimental investigations on the HP NGD function.
Originality/value
The NGD characterization as a function of the resistance and capacitance parameters is investigated. The feasibility of the HP NGD function is verified with proofs of concept constituted of lumped surface mounted components on printed circuit boards. The simulations and measurements confirm in very good agreement the HP NGD behaviors of the tested circuits. NGD responses with optimal values of about −1 ns and cut-off frequencies of about 20 MHz are obtained.
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Taochen Gu, Fayu Wan, Jamel Nebhen, Nour Mohammad Murad, Jérôme Rossignol, Sebastien Lallechere and Blaise Ravelo
The aim of this paper is to provide the theoretical conceptualization of a bandpass (BP) negative group delay (NGD) microstrip circuit. The main objective is to provide a…
Abstract
Purpose
The aim of this paper is to provide the theoretical conceptualization of a bandpass (BP) negative group delay (NGD) microstrip circuit. The main objective is to provide a theorization of the particular geometry of the microstrip circuit with experimental validation of the NGD effect.
Design/methodology/approach
The methodology followed in this work is organized in three steps. A theoretical model is established of equivalent S-parameters model using Y-matrix analysis. The GD analysis is also presented by showing that the circuit presents a possibility to generate NGD function around certain frequencies. To validate the theoretical model, as proof-of-concept (POC), a microstrip prototype is designed, fabricated and tested.
Findings
This work clearly highlighted the modelled (analytical design model), simulated (ADS simulation tool) and measured results are in good correlation. Relying on the proposed theoretical, numerical and experimental models, the BP NGD behaviour is validated successfully with GD responses specified by the NGD centre frequency: it is observed around 2.35 GHz, with an NGD value of about −2 ns.
Research limitations/implications
It is to be noticed the proposed GD analysis requires limitations of the theoretical NGD model. It is depicted and validated through a POC demonstrating that the circuit presents a possibility to generate NGD function around certain frequencies (assuming constraints around usable frequency and bandwidth).
Practical implications
The NGD O-shape topology developed in this work could be exploited in the future in the microwave and radiofrequency context. Thus, it is expected to develop GD equalization technique for radiofrequency and microwave filters, GD compensation of oscillators, filters and communication systems, design of broadband switch-less bi-directional amplifiers, efficient enhancement of feedforward amplifiers, design method of frequency independent phase shifters with negligible delay, synthesis method of arbitrary-angle beamforming antennas. The BP NGD behavior may also be successfully used for the reduction of resonance effect for the electronic compatibility (EMC) of electronic devices.
Social implications
The non-conventional NGD O-circuit theoretical development and validation through experimental POC could be exploited by academic and industrial developers in the area of wireless communications including, but not restricted to, 5-generation communication systems. The use of the remarkable NGD effect is also useful for the mitigation of electromagnetic interferences between electronic devices and more and more complex electromagnetic environment (current development of Internet of Things[ IoT]).
Originality/value
The originality of this work relies on the new NGD design proposed in this work including the extraction of S-matrix parameters of the microstrip novel structure designed. The validation process based upon an experimental POC showed very interesting levels of NGD O-circuit (nanosecond-GD duration).
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Guenter Wollenberg and Sergey V. Kochetov
The paper aims to give the reader a consolidated state of art in the full‐wave modeling of passive interconnection systems using equivalent circuits and presents several…
Abstract
Purpose
The paper aims to give the reader a consolidated state of art in the full‐wave modeling of passive interconnection systems using equivalent circuits and presents several advantageous techniques developed by the authors.
Design/methodology/approach
The paper presents the theory of generalized partial element equivalent circuit (PEEC) modeling in the frequency domain (FD) and time domain (TD) developed by the authors. The widely spread simplified approaches are derived from this general formulation and the most important issues (e.g. stability in the TD) are considered. The theoretical part is completed by a simulation example, which shows the efficiency of studied methods.
Findings
Novel approaches for co‐simulation of passive interconnections in their circuit environment.
Practical implications
The PEEC method is widely used in the practice of computational electromagnetics, e.g. by the authors in the practical electromagnetic compatibility simulation.
Originality/value
The paper is based on the original work of authors carried through over many years.
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The paper presents two new algorithms of controlled switching the power transformer. The purpose of this paper is to obtain formulas that determine the moments of closing of the…
Abstract
Purpose
The paper presents two new algorithms of controlled switching the power transformer. The purpose of this paper is to obtain formulas that determine the moments of closing of the circuit breaker poles. The study contains projects of control systems for both algorithms.
Design/methodology/approach
Mathematical formulas for the time instants of the breaker poles closing were developed on the basis of electric circuit theory and magnetic circuit theory. The presented systems were simulated using a model created in the Alternative Transients Program/Electromagnetic Transients Program software.
Findings
Numerical simulations have proved that the shown systems properly perform the controlled switching carried out in accordance with the proposed algorithms. The times of the poles closing were correctly determined and the inrush currents were reduced to a level of the current of unloaded transformer.
Originality/value
The results achieved are better than those shown in the literature. The solutions presented in the literature provide a reduction of inrush current to a value comparable to the rated current of the transformer, which is ten times greater than the no-load current. Additional achievement of the work is the development of analytical formulas that determine the times of the breaker poles closing.
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Many important electronic systems are modelled by discrete‐time equations with nonlinearities that are discontinuous and piecewise‐linear, often arising as a result of…
Abstract
Purpose
Many important electronic systems are modelled by discrete‐time equations with nonlinearities that are discontinuous and piecewise‐linear, often arising as a result of quantization. Approximations based on linearization – the standard engineering response to nonlinearity – are often quite unhelpful in these systems, because of the form of the nonlinearity. Certain methods and results have been developed over a number of years for the analysis of discontinuous piecewise‐linear discrete‐time dynamics. The aim of this tutorial paper is to review that body of knowledge, and to show how it can be applied to representative electronic systems.
Design/methodology/approach
The paper uses an important electronic circuit – the ΣΔ modulator – as a central example, and considers the dynamical behaviour exhibited by this circuit and related circuits.
Findings
The circuits under investigation exhibit complex forms of behaviour that can be explained by the application of methods of nonlinear discrete‐time dynamics.
Originality/value
This paper is intended to provide a brief introduction to the body of research that exists into the behaviour of nonlinear discrete‐time circuits and systems with discontinuous piecewise‐linear nonlinearities.
Konstanty M. Gawrylczyk and Mateusz Kugler
This paper aims to present effective methods for computing electromagnetic field sensitivity in the time domain versus conductivity perturbations in finite elements.
Abstract
Purpose
This paper aims to present effective methods for computing electromagnetic field sensitivity in the time domain versus conductivity perturbations in finite elements.
Design/methodology/approach
Two‐dimensional cases in linear, isotropic media are considered and two effective methods for sensitivity analysis of a magnetic vector potential in the time domain are described.
Findings
The paper finds that the convergence of numerical identification algorithm depends on exact measurement of magnetic flux density. For identification of real cracks the application of data filtering and TSVD regularization of Gauss‐Newton algorithm is necessary.
Practical implications
The resultant gradient information may be used for solving inverse problems such as the identification of material conductivity distributions.
Originality/value
The algorithms described are based on known methods from established circuit theory – incremental circuit and adjoint circuit, these have been expanded to apply in electromagnetic field theory.
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