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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

EMI/EMC analysis of electronic systems subject to near zone illuminations

Khan, Zulfiqar A., January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 83-90).
32

EMI studies in motor drives /

Hellany, Ali. January 1900 (has links)
Thesis (M.Eng)(Hons)--University of Western Sydney, Nepean, 1997. / Includes appendices. Includes bibliography.
33

System and IC level analysis of electrostatic discharge (ESD) and electrical fast transient (EFT) immunity and associated coupling mechanisms

Koo, Ja Yong, January 2008 (has links) (PDF)
Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 21, 2008) Includes bibliographical references.
34

Investigating cable transfer impedance and layout for microsatellite applications

Doyi, Silulami J. (Silulami Julius) 12 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The co-existence of electronic devices and their attached transmission cables requires a careful planning regarding the energy leakage across cable shields. This leakage poses potential serious problems and impedes system functioning. This thesis pursues an investigation into the EMC cabling protocols for microsatellite systems. Network analysis techniques are applied in calibrating current probes and to recover the cable transfer impedance, Zr. The calibration approach provides accurate results for frequencies up to 600MHz. The methods used to determine Zr are based on injecting a disturbance current onto the outside of the cable-under-test (CUT) and measuring the corresponding voltage induced on the centre conductor. Useful results are obtained up to 80MHz with the use of a O.5m length of cable. It is thus proposed that Zr is a practical concept for shielding performance evaluation and for the testing of cable philosophy. The results are usable in classifying cables for verification and signal usage. Further research involves a prediction tool called an EMC ITS that simulates the hardware of a microsatellite system to allow studies on design trade-offs, transmission cable criteria and placement of devices. / AFRIKAANSE OPSOMMING: Die gelyktydige bestaan van elektroniese toestelle en hul aangehegte transmissielynkabels benodig deeglike beplanning met betrekking tot die lek van energie deur die kabels se afskerming. Hierdie lekkassie kan ernstige probleme tot gevolg hê en die stelsel se funksionering belemmer. Hierdie tesis loods 'n ondersoek na die EMV bekabelingprotokolle vir mikrosatellietstelsels. Netwerk analise tegnieke word gebruik in die kalibrasie van stroom-probes en die verkryging van die kabel se oordragsimpedansie, Zr. Die benadering wat gevolg is in die kalibrasie verskaf akkurate resultate tot en met frekwensies van 600MHz. Die metode wat gebruik word om Zr te bepaal is gebaseer op die injeksie van 'n versteuringstroom op die buitekant van die toetskabel en die meting van die ooreenstemmende spanning wat opgewek word op die binne-geleier. Bruikbare resultate is tot en met 80MHz verkry met die gebruik van 'n kabel met 'n lengte van O.Sm. Daar word dus voorgestel dat Zr 'n praktiese wyse is om afskermingsprestasie mee te evalueer, asook vir die toetsing van kabel-filosofie. Die resultate is bruikbaar in die klassifikasie van kabels vir verifikasie en seingebruik. Verdere navorsing sluit in 'n voorspellingswyse wat 'n EMV GTS genoem word, wat die hardewaarde van 'n mikrosatellietstelsel simuleer om studie aangaande ontwerpkompromieë, transmissielyn kriteria en die plasing van toestelle binne die gebruiksomgewing moontlik te maak.
35

An EMC framework for South Africa

Venter, Francois A 04 1900 (has links)
Thesis (MScEng)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: This thesis pursues the establishment of a new Electromagnetic Compatibility (EMC) framework for South Africa. The aim of this framework is to ensure that the user is protected from sub-standard products as well as to ensure that products such as medical devices operate safely within the electromagnetic environment. The thesis presents a basic introduction into EMC and then overviews current worldwide legislation. After this information is studied a new framework is proposed for South Africa. This framework covers all areas of industry and the standards with which one has to comply as well as the procedure for demonstrating the compliance of the product. In order to establish the basis whereby smaller manufacturers can show compliance by means of in-house testing, a method for establishing measurement accuracy is also presented. In conclusion some standard measurements and an overview of some alternative measurement techniques are presented. / AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek en stel 'n nuwe Elektromagnetiese Versoenbaarheids (EMV) raamwerk voor vir Suid Africa. Die doel van die raamwerk is om 'n eenvormige stelsel daar te stel waarteen produkte getoets kan word om die publiek teen onder standaard produkte te beskerm. In sekere gevalle help die raamwerk ook om te verseker dat produkte soos mediese toerusting veilig werk in die Elektromagnetiese omgewing. Die tesis lê 'n basiese inleiding oor EMV voor en gee 'n opsomming van huidige wêreldwye wetgewing as inleiding tot 'n raamwerk vir Suid Afrika. Nadat die inligting bestudeer is, word 'n nuwe raamwerk vir Suid Afrika voorgestel. Die raamwerk dek die hele elektroniese industrie, spesifiseer die toepaslike standaarde en voorsien die metodes hoe voldoenning aan die vereistes bewys moet word. Die tesis verskaf ook riglyne hoe kleiner vervaardigers kan bewys dat hulle voldoen aan die vereistes, deur in-huis toetsing. Tesame met 'n oorsig oor basiese meet tegnieke en alternatiewe tegnieke word 'n metode daar gestel vir sulke vervaardigers om hul metings se akuraatheid te bewys.
36

Análise de interferência eletromagnética entre condutores com a utilização do simulador Spice. / Analysis of crosstalk among conductors using software Spice.

William Gerlach Dietz 04 May 2007 (has links)
O fenômeno \"crosstalk\" constitui-se de acoplamentos eletromagnéticos não intencionais entre condutores. Motivado pela importância deste fenômeno para a área de Compatibilidade Eletromagnética, este trabalho apresenta uma metodologia de análise do fenômeno através do aplicativo SPICE considerando-se configurações compostas por condutores múltiplos. A proposta de desenvolvimento de uma ferramenta computacional de simulação do fenômeno utilizando uma versão estudantil, com livre acesso, possibilita, entre outras coisas, a disseminação de um modelo alternativo, simples e eficaz, e a inclusão do estudo do \"crosstalk\" no conteúdo programático de cursos de Graduação ou Pós-graduação. Para este fim, adotou-se um modelo de simulação de acoplamento eletromagnético com base em modelos de linha de transmissão. Tal modelo é complementado com geradores vinculados controlados por tensão e corrente, que representam fontes de interferência eletromagnética. Em face de limitações dos blocos funcionais que representam essas fontes no aplicativo, foi utilizado em um primeiro instante um método de representação do modelo através de arquivos-texto, ao invés da utilização da interface gráfica existente no software. Posteriormente, novos blocos foram desenvolvidos e acrescentados à biblioteca, tornando possível à aplicação dessa interface diretamente nas simulações. A validação do modelo foi feita, inicialmente, comparando-se os resultados simulados àqueles disponíveis na literatura internacional. Além disto, foi desenvolvida uma bancada experimental para comprovação dos resultados e validação do modelo implementado no aplicativo SPICE através de casos simples do fenômeno. Esses resultados mostram a viabilidade da utilização dos componentes desenvolvidos para o aplicativo, tornando possível e confiável o uso dessa ferramenta na simulação do fenômeno \"crosstalk\". Passou-se então a aplicação da ferramenta desenvolvida a sistemas mais complexos com um número superior de condutores. / This work presents an approach, in which the well-known SPICE simulator is used as a tool to simulate the phenomenon crosstalk. Basically, it is based on transmission line model, where the electromagnetic interferences are simulated by controlled voltage and current sources. Due to the limitations of the available Spice models concerning multiconductors configurations, additional models were developed and implemented as part of the SPICE library. Theoretical and experimental results were obtained. They were used as part of the validation process of the proposed methodology. The developing of specific models allowed the use of this modeling in SPICE student versions. This turns possible the introduction of crosstalk simulations in undergraduate and graduate courses. Besides, the methodology was applied to complex systems in order to present its versatility.
37

Projeto e implementação de câmara GTEM - giga hertz transverse electromagnetic para testes de compatibilidade eletromagnética de circuitos e sistemas eletrônicos / Design and implementation of a GTEM chamber for electromagnetic compatibility tests of electronic circuits and systems

Araujo, Humberto Xavier de 19 August 2018 (has links)
Orientador: Luiz Carlos Kretly / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-19T12:48:04Z (GMT). No. of bitstreams: 1 Araujo_HumbertoXavierde_D.pdf: 7050651 bytes, checksum: 1d22c38822d1b7ff3ee74974b2d874b9 (MD5) Previous issue date: 2012 / Resumo: Este trabalho apresenta a análise detalhada, simulações numéricas completas e os procedimentos para o projeto e a implementação de uma câmara GTEM -GigaHertz Transverse Electromagnetic- para análise de pré-conformidade em circuitos e sistemas eletrônicos. O sistema construído é capaz de realizar testes de EMC - Electromagnetic Compatibility, tanto de interferência - EMI quanto de susceptibilidade - EMS, na faixa de freqüência de 500 MHz - 18 GHz. O projeto apresenta uma inovação ao introduzir estruturas metamateriais na câmara tornando-a mais flexível na determinação da freqüência e níveis de RF e Microondas de teste. Os detalhes do projeto, simulações, a tecnologia de fabricação e medidas de validação da GTEM são descritos neste trabalho / Abstract: In this work it is shown a detailed analysis, complete numerical simulations and the guidelines for the design and fabrication of a GTEM - GigaHertz Transverse Electromagnetic chamber, for pre-compliance tests of integrated circuits and electronic boards. With the built structure electromagnetic tests - EMC, including electromagnetic interference - EMI and immunity becomes feasible, on 500 MHz - 18 GHz frequency range. Besides that, an innovative concept is shown with the use of metamaterial technology applied to the GTEM chamber in order to make it more flexible in terms of frequency range. The design, simulation and fabrication strategy are clearly described along throughout this work / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica
38

Uitleg elektromagnetiese effekte in drywingselektroniese omsetters

Van Wyk, Jacobus Daniel 12 September 2012 (has links)
M.Ing. / Electromagnetic Compatibility (EMC) of electronic equipment is currently an important design parameter. Layout play a significant role in the EMC of power electronic converters. This thesis describes an investigation undertaken into the electromagnetic effects of converter layout. Typical detrimental effects identified during experimental work are presented. Possible causes for these effects are discussed. The experimental work is based on a systematic approach, which starts with a basic single switch chopper and ends in a split supply half-bridge converter. Interconnection modelling and SPICE simulations of layout affects are investigated next. The focus falls on analytical equations for extraction and simplified simulation circuits to make the process generally accessible. Typical resonant frequencies present in some of the experimental circuits are investigated with the help of analytically extracted parameters. The possibility of minimizing detrimental layout effects through impedance matching of interconnections and their terminations, is investigated next, since the previous section quantified layout parameters. Distributed vs. lumped element modelling of interconnections, and the boudary in between, are discussed. Simulation and experimental results are presented. Since maximum fuctionality and power, and minimum cost, per volume drives product development, all elements of a circuit should be investigated for the possibility of realizing secondary or even tertiary functions contributing to normal circuit operation. This is the focus of the last part of this thesis. Employing interconnections as low-pass or surge filters are investigated. Several waveforms are used to test experimental interconnection structures. Lumped and distributed modelling of these strucutres are discussed. The thesis concludes with a theoretical investigation into the possibility of dissipation of surge-energy instead of reflection utilizing interconnection-structures. One of these structures utilizes the skin- and proximity effect to realize low-pass behaviour.
39

Methods to measure and limit electromagnetic interference, with reference to power systems and satellite earth stations

Engelbrecht, Jacobus Johannes 26 February 2009 (has links)
M.Ing. / This thesis investigates why electromagnetic interference (EMI) and electromagnetic compatibility (EMC) problems exist and how EMI is generated, measured and limited. This investigation is done with reference to power systems and satellite earth stations. To understand the full extend of EMI generation from power systems on satellite earth stations, it was necessary to do a study of EMI, in order to understand EMI in its simplest form. This study consists of the following work: •A background study investigates the components of EMI, how EMI are generated and manifest in electric systems, methods to limit conducted EMI, a theoretical model on how to estimate conducted EMI quantities and EMI measurement techniques. •A conducted EMI model with which the parasitic impedances could be controlled was developed. With this model it could then be determined how conducted EMI would manifest in 3-wire circuit designs and how conducted EMI could be reduced in such circuits. •It was investigated how inductive coupling and capacitive coupling can be reduced. Time and frequency domain measurements were used to investigate the effects of these couplings. It was also of great importance to understand how EMI from measurement set-ups could influence measurements to give inaccurate results. This work investigated how high frequency measurements can be done effectively, how high frequency circuit designs can be improved and how parasitic impedances can be limited in high frequency equipment. •The expected EMI problem at the Klipheuwel wind farm was analysed. Simulations of expected EMI levels, worst case scenarios and measurements taken there showed that no significant EMI are generated from the wind generators and that power systems don’t hold a threat to satellite earth stations, if the necessary precautions are taken.
40

Modélisation l’immunité électromagnétique des composants en vue de la gestion de l’obsolescence des systèmes et modules électroniques. / Electromagnetic immunity modeling of components for the obsolescence management of systems and electronic modules

Amellal, Mohammed 14 December 2015 (has links)
Dos nos jours, l'évolution croissante des domaines d'application des circuits intégrés impose aux industriels de nouvelles contraintes de conception. Afin de réaliser des circuits électroniques plus denses et plus performants, ils cherchent à faire cohabiter plusieurs types de composants sur des surfaces plus petites et de surcroît, fonctionnant à des fréquences de plus en plus élevées. Cependant, cette cohabitation pourrait générer des problèmes de CEM (compatibilité électromagnétique). Les travaux présentés dans ce mémoire rentrent dans le cadre du projet de recherche SEISME (Simulation de l'Emission et de l'Immunité des Systèmes et Modules Electroniques). Ils décrivent des méthodologies de mesure et de modélisation de’immunité conduite des circuits intégrés complexes comme les mémoires non volatiles ou bien les microcontrôleurs. L'objectif est d'étudier l'influence des changements de composants et de cartes sur le comportement électromagnétique d'un système électronique. Dans cette perspective, afin de valider son utilisation dans le cas des circuits intégrés complexes, une étude détaillée du standard de mesure DPI (Direct Power injection) est d'abord proposée. Basé sur cette dernière, un nouveau prototype de chemin de couplage est réalisé. Ce multiplexeur permet de superposer un signal agresseur à un signal fonctionnel, avec un chevauchement de leurs bandes de fréquences. Ainsi, il est possible d'agresser une broche fonctionnelle (horloge par exemple) d'un circuit intégré pendant son fonctionnement. Ensuite, une procédure de mesure globale d'immunité conduite est présentée. Elle permet de caractériser la susceptibilité conduite des circuits complexes en tenant compte des différents modes de fonctionnement et avec la possibilité d’utiliser un critère d’immunité fonctionnel ou électrique. Grâce à l'application de cette procédure à deux mémoires non volatiles compatibles broche à broche (mêmes caractéristiques mais de deux différents fournisseurs), il est possible de constater l’influence des technologies de fabrication sur l’immunité conduite de ce type de circuits. Par conséquent, l’effet du changement de composant sur le comportement électromagnétique d’un système électronique devient prédictible. Enfin pour la modélisation, deux méthodologies sont proposées. Une au niveau composant et l'autre au niveau carte. La démarche de modélisation au niveau composant repose sur le standard ICIM-CI (Integrated Circuit Immunity Model-Conducted Immunity) et vise à générer un modèle d’immunité simulable et prédictif. Grâce à l'application de cette démarche dans le contexte des mémoires non volatiles, il est possible de prédire leur immunité dans le cas de modification de l’impédance d'entrée par rajout d'éléments de filtrage par exemple. En ce qui concerne la modélisation au niveau carte, une procédure basée sur la proposition de modèle EBIM-CI (Electronic Board Immunity Model-Conducted Immunity) est développée. Elle consiste à générer un modèle d’immunité d’une carte électronique en utilisant les modèles des différents composants qui la constituent. Un cas d’étude a été défini. Le modèle issu de cette approche permet de simuler l’immunité conduite globale du démonstrateur ainsi que de prédire le comportement électromagnétique de ce dernier lors du changement d’un ou plusieurs composants. / Nowadays, the growing evolution of application fields for integrated circuits sets new constraints for designers and manufacturers. Due to continuous technological advances in integrated circuits, those have become smaller, denser and operational at higher frequencies. The miniaturization of integrated circuits has led to the reduction of power consumption and, thus, noise margins. Mixing digital and analog functions inside the same chip also makes electromagnetic interferences (EMis) more likely to spread and cause disturbances. As a result, complex ICs with coexisting different functions represent a challenge from an EMC point of view, as interferences can cause critical functional failures. The work presented in this manuscript falls within the SEISME project which aims, among others, to perform the simulation of both the emission and the immunity of electronic systems and modules at different levels (JC, PCB, equipment, system). More precisely, this work deals with the development of measurement and modeling methodologies for the characterization of the conducted immunity of complex ICs, such as microcontrollers and non-volatile memories. The main goal is to study the effect of component and/or board replacement on the electromagnetic behavior of a complete electronic system. In this context, a thorough study of the Direct Power Injection (DPI) technique is presented, thus validating its use for complex integrated circuits. Based on this study, a new prototype for the disturbance coupling path is proposed. It consists of a multiplexer that enables the superposition of a disturbance signal and a functional one with overlapping frequency bands. Therefore, it is possible to disturb an IC functional pin (a clock for instance) during its operation. Moreover, measurement procedure for conducted immunity is introduced. Its advantage is to make it possible to characterize the immunity of complex ICs by taking into account different operation modes as well as flexible immunity criteria (electrical / functional). Thanks to the application of this methodology for two different, non-volatile, pin-to-pin-compatible memories (having the same characteristics but different manufacturers), the influence of fabrication technology on the conducted immunity of such ICs is better identified and understood. As a consequence, the effect of changing components on the electromagnetic behavior of an electronic system has become predictable. As far as modeling aspects are concerned, two methodologies are presented in this manuscript. The first one deals with the immunity at the component level whereas the other involves board level immunity. At the IC level, the modeling approach is rather based on the ICIM-CI (lntegrated Circuit Immunity Model-Conducted Immunity) draft standard which makes it possible to extract simulation models that can be incorporated within IC design flows. Once applied to the context of non-volatile memories, this approach allows predicting their immunity in the case of modified input impedance, for example. As far as immunity modeling at the board level is concerned, the idea is to make use of ICIM-CI models corresponding to different ICs on the PCB in order to construct an Electronic Board Immunity Model for Conducted Immunity (EBIM-CI). A case study has been defined and the extracted model makes it possible to simulate the demonstrator's global conducted immunity as well as to predict its electromagnetic behavior following the replacement of one or more components.

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