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1
Freeman, Larry. "PREDICTION AND MEASUREMENT OF RADIATED EMISSIONS BASED ON EMPIRICAL TIME DOMAIN CONDUCTED MEASUREMENTS." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4232.
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This thesis develops a novel method to predict radiated emissions measurements. The techniques used are based on standard Electromagnetic Compatibility (EMC) qualification test methods. The empirical data used to formulate the final results was restricted to pertinent data protocol waveforms however the entire method may be applied to any waveforms for which empirical radiated emissions have been measured. The method provides a concise means for predicting worst case radiated emissions profiles based on empirical measured data.<br>M.S.E.E.<br>School of Electrical Engineering and Computer Science<br>Engineering and Computer Science<br>Electrical Engineering
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Dawson, Linda. "New techniques for the measurement of radiated emissions in a screened room for frequencies up to 200MHz." Thesis, University of York, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238715.
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Tigga, Celine. "Modelling of Measurement Equipment for High Frequency Electromagnetic Fields." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-18894.
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The aim of this thesis was to develop a model of a receiver which could be quickly used to analyze radiated interference levels from data captured at the output of the antenna equipment used to measure radiated energy. Active circuits were mainly used in developing this model for the ease with which the design and simulations could be carried out in OrCAD. The guiding document for the thesis work has been CISPR 16-1-1 (International Special Committee on Radio Interference part 16-1-1) which specifies the characteristics and performance of equipment for the measurement of radiated interference. The testing of this receiver model was carried out as far as possible based on the test setups recommended in CISPR, and all results have been compared with the standards laid down for the model. Using the results, it will be shown that a CISPR EMI receiver can be modeled as a simple EMI receiver consisting of filtering, mixing and detecting circuits built according to specifications.
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Fu, Xubo. "Measurement of electromagnetic interferences generated from repair work and vehcles." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-7983.
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In the industrial and factory when the electronic and machinery instruments are working the huge electromagnetic interference (EMI) would be generated by them which are big deal to the main disturbance of wireless communication. So the measurement of EMI is quite useful and important for electromagnetic compatibility (EMC). The main goal of my paper is analysis in which bandwidth of EMI influences to wireless communication system in the industrial and factory generated by working arc-welding instrument and moped. The method is used the traditional and classic statistical methodology to identify the strength of electromagnetic field.
5
Azpúrua, Marco A. "Full time-domain electromagnetic interference measurements and applications." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/587194.
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This thesis presents a technology that has been called the Full Time-Domain Electromagnetic Interference measurement systems and its applications. Full TDEMI measurement systems are an implementation of an FFT-based receiver that enables the usage of oscilloscopes for EMI measurements. They follow the virtual instrumentation approach for transforming oscilloscopes into a compliant CISPR 16-1-1 receiver.
Full TDEMI measurement systems have been assessed for characterizing their performance using waveform oriented calibration procedures that bridge the gap between direct measurements in the time domain and the processed frequency domain magnitudes. As a result, the conformity of Full TDEMI receivers is attested with respect to the requirements defined in the standards.
Full TDEMI systems have advantages over the conventional swept receivers for performing challenging measurements typical of EMI assessments. Time-domain captures enable full spectrum measurements that allow analyzing transient phenomena. The number of channels available in most oscilloscopes enable synchronous measurements that allow recording the EMI using a combination of transducers. Some of the applications of the multichannel EMI measurements are the single stage evaluation of the conducted EMI of all the EUT mains lines, the instantaneous measurement of the common-mode and the differential mode voltage noise, the concurrent conducted and radiated EMI measurements, and the parallelization of multi-antenna radiated emissions testing.
Such alternative test methods, have improved the EMC testing process in a variety of industries by reducing the time and the efforts required for performing a complete EMI evaluation due to the following reasons. First, Full TDEMI measurements deliver faster results because the interferences' spectrum is simultaneously estimated for all the weighting detectors. Second, the number of measurement iterations is reduced because of the multichannel possibilities and also because of an agile identification of the worst case emissions. Thirdly, Full TDEMI measurement system are a cost-effective alternative to the real-time spectrum analysers.
Full TDEMI measurement systems have extended the state-of-the-art with the expected maximum detector and the empirical interference decomposition. The expected maximum detector is a statistical measure of the most probable level of the peak emissions that is based on a time-frequency modelling of the measured EMI using the extreme value theory. Using the variability information of the EMI level at each frequency bin, the expected maximum detector estimates the equivalent max hold value of a random EMI. The expected maximum detector also provides a model for quantifying the uncertainty of peak detector measurement of stochastic EMI.
The Empirical Interference Decomposition is a modified implementation of the Hilbert-Huang transform with time-gating capabilities that allow a heuristic determination of characteristic oscillatory patterns without neither domain transformation nor a predefined set of basis function. The EID has been used successfully for ambient noise cancellation purposes during outdoor EMI measurements, obtaining more than 20 dB of attenuation of the usual broadcasting signals. The fundamentals of the ANC by means of EID is the identification, in the time and in the frequency domain, of intrinsic modes of emissions that area attributable to the EUT while subtracting the residual modes from the measurement results.
Applications of the Full TDEMI measurement systems have been published in recognized conferences and journal.
From the reasons mentioned before, the Full TDEMI measurement technology has advantages for EMI testing, analyzing and troubleshooting. It provides a complementary approach to the typical measurements entirely focused in the frequency domain and it exhibits a level of maturity that could allow it to be standardized in forthcoming years.<br>Esta Tesis comprende un compendio de contribuciones hechas por el autor al campo de la tecnología de medición de radiofrecuencia para la compatibilidad electromagnética. En particular, esta Tesis presenta una tecnología de sistemas medición de interferencias electromagnéticas completamente basado en dominio del tiempo (Full TDEMI) y algunas de sus aplicaciones más relevantes.
Los sistemas de medición Full TDEMI son una implementación de un receptor de medida basado en FFT que permite el uso de osciloscopios para mediciones de interferencias electromagnéticas. Los sistemas de medición Full TDEMI siguen el enfoque de instrumentación virtual para transformar los osciloscopios de propósito general en un receptor de medida completamente funcional y conforme con la norma CISPR 16-1-1.
Por un lado, esto es factible debido a las técnicas específicas de procesamiento de señales aplicadas sobre las adquisiciones en el dominio del tiempo utilizando una capa de software dedicada. Por otro lado, los sistemas de medida Full TDEMI se han evaluado exhaustivamente para caracterizar su rendimiento utilizando procedimientos novedosos de calibración orientados a formas de onda que acortan la brecha entre las magnitudes medidas en el dominio del tiempo y las aquellas procesadas en el dominio de frecuencia. Como resultado, se certifica la conformidad de los sistemas completos de medición TDEMI con respecto a los requisitos definidos en los estándares internacionales paramediciones EMI.
Además, se ha demostrado que los sistemas de medición Full TDEMI ofrecen ventajas en comparación con los receptores de barrido convencionales para realizar varias medidas desafiantes típicas de las evaluaciones de emisiones electromagnéticas. Por ejemplo, las capturas de dominio de tiempo posibilitan mediciones de espectro completo que permiten un análisis adecuado de fenómenos transitorios. Del mismo modo, la cantidad de canales disponibles en la mayoría de los osciloscopios hace viables múltiples mediciones síncronas que para registrar las perturbaciones interferentes mediante una combinación de transductores.
Algunas de las aplicaciones de la medición EMI multicanal son la evaluación de etapa única de la EMI conducida de todas las líneas de alimentación de los equipos bajo prueba (EUT), la medición instantánea del voltaje del ruido en modo común y en modo diferencial, las mediciones concurrentes de la EMI conducida y radiada y la paralelización de los ensayos de emisiones radiadas con múltiples antenas. Tales métodos de prueba alternativos, han mejorado significativamente el proceso de prueba de EMC en una variedad de industrias al reducir la cantidad de tiempo y los esfuerzos necesarios para realizar una evaluación completa del sistema principalmente debido a las siguientes razones. En primer lugar, las mediciones de EMI en el dominio del tiempo arrojan resultados más rápidos porque el espectro de interferencias se estima simultáneamente para todos los detectores de ponderación estándar necesarios para determinar el cumplimiento de los límites máximos de emisiones definidos en las respectivas normas de producto.
En segundo lugar, el número de iteraciones de medición se reduce debido a las posibilidades multicanal y también debido a una identificación ágil del peor caso de las emisiones de un EUT que tiene diferentes modos de funcionamiento. En tercer lugar, el sistema Full TDEMI es una alternativa económica y versátil a los analizadores de espectro en tiempo real más avanzados en lo concerniente a mediciones EMI en el rango de pocos gigahertzios.
Desde el punto de vista teórico, los sistemas de medición Full TDEMI han extendido el estado del arte, como en el caso de un par de contribuciones denominadas el detector de máximo esperado y la descomposición empírica de interferencias.
El detector de máximo esperado es una medida estadística del nivel más probable de las emisiones pico que se basa en un modelado tiempo-frecuencia de las interferencias medidas utilizando la teoría del valor extremo. Usando la información de variabilidad del nivel de interferencia en cada componente de frecuencia, el detector de máximo esperado se puede usar para estimar el valor de retención máximo (max-hold) equivalente de una interferencia aleatoria. El detector demáximo esperado también proporciona un modelo que cuantifica la incertidumbre de lamedición del detector de picos ante interferencias estocásticas.
La descomposición de interferencia empírica (EID) es una implementación modificada de la transformada de Hilbert-Huang con capacidades de sincronización de tiempo que permiten una determinación heurística de patrones oscilatorios característicos sin requerir transformación de dominio ni un conjunto predefinido de funciones base. La descomposición de la interferencia empírica se ha utilizado con éxito para la cancelación del ruido ambiental durante prueba de concepto de mediciones de EMI de al aire libre, obteniendo más de 20 dB de atenuación de las señales habituales de radiodifusión. El fundamento de la cancelación del ruido ambiental mediante EID es la identificación, en el tiempo y en el dominio de la frecuencia, de los modos de emisión intrínsecos que son atribuibles al EUT al restar los modos residuales (ruido ambiental) de los resultados de medición. Las contribuciones mencionadas se distribuyen en cuatro artículos de revista. Los resultados de medición complementarios y las aplicaciones de los sistemas de medición Full TDEMI también se han publicado en conferencias notables en el área.
Por los motivos antes mencionados, la tecnología Full TDEMI tiene ventajas significativas para los ensayos, el análisis y la resolución de problemas de EMI. Asimismo, proporciona un enfoque complementario a las mediciones típicas completamente enfocadas en el dominio de la frecuencia y exhibe un nivel de madurez que podría permitir su estandarización en los próximos años.
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Midya, Surajit. "Conducted and Radiated Electromagnetic Interference in Modern Electrified Railways with Emphasis on Pantograph Arcing." Doctoral thesis, Stockholm : Skolan för elektro- och systemteknik, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10574.
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Ebertsohn, Nolan Wade. "Cable trays and EMC : modelling and measurement." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/50293.
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Thesis (MScEng)--University of Stellenbosch, 2005.<br>ENGLISH ABSTRACT: Common mode currents are a major source of interference in electrical and electronic
systems. A universal solution to counteract common mode interference is to introduce an
electromagnetic shield with known characteristics. Cable trays are often used to shield
cables from unwanted electromagnetic interference (EM!) and its shielding characteristics
are defined in terms of its transfer impedance. This thesis pursues the modelling and
measurement of the transfer impedance and mutual inductance of non-magnetic cable
trays. Theoretical analysis is firstly employed by means of Maxwell's equations after
which method of moments (MoM) simulations are performed in order to determine the
transfer impedance and mutual inductance within the interior region of a cable tray. The
results obtained through simulation are then validated with measurements conducted with
an automatic network analyser (ANA). The computational and measured data are in good
agreement and the developed model can be used to predict the transfer impedance in the
cross-section of non-magnetic cable trays.<br>AFRIKAANSE OPSOMMING: Gemenernodus strome is 'n bron van interferensie in elektriese en elektroniese stelsels. 'n
Universele oplossing om hierdie gemenernodus interferensie teen werk is om 'n
elektromagnetiese skerm met bekende eienskappe te implementeer. Geleier leikanale word
dikwels gebruik om kabels teen elektromagnetiese interferensie te beskerm en die
afskermings eienskappe word in terme van die kanaal se oordragsimpedansie gedefinieer.
Hierdie tesis ondersoek die modelering en meting van die wedersydse induktansie en
oordragsimpedansie van nie-magnetiese geleier leikanale. 'n Teoretiese analise word eers
uitgevoer deur middel van Maxwell se vergelykings waarna metode van momente (MvM)
simulasies uitgevoer word om die oordragsimpedansie en wedersydse induktansie in die
interne gebied van 'n leikanaal te bepaal. Die resultate verkry deur simulasie word dan
bevestig deur meting wat uitgevoer word met behulp van 'n automatiese netwerk
analiseerder (ANA). Die numeriese en gemete data stem goed ooreen en die ontwikkelde
model kan deurgaans gebruik word om die oordragsimpedansie in die deursnit area van
nie-magnetiese geleier leikanale te voorspel.
8
Khan, Zulfiqar A. "EMI/EMC analysis of electronic systems subject to near zone illuminations." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196207323.
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Slim, Hassan Hani [Verfasser]. "Methods to Increase the Bandwidth of Broad-Band Time-Domain Electromagnetic Interference Measurement Systems / Hassan Hani Slim." Aachen : Shaker, 2014. http://d-nb.info/104937990X/34.
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Váško, Ondřej. "Virtuální měřicí systém pro nestandardní bezodrazové komory." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219966.
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Master thesis examines a selected part of electromagnetic compatibility. In this work, there is theoretically discussed how electromagnetic interference appears and how is spread through free space environment. To eliminate ambient interference signals, the measurements have been performed in anechoic chamber where the undesirable interference signals were suppressed. In the thesis, there are also described parameters of EMI receivers and limits of electromagnetic interference. The description of calculations of the antenna height for finding maximum intensity of electric field strength for standard measurement distance has been made. For proposed transformed measurement distance, calculations of intensity electric field with addition of parameters measuring antenna and object under test were performed. Correction curves for conversion intensity electric field have been obtained as the result.
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Krishnamoorthy, Seshagiri. "Interference Measurements and Throughput Analysis for 2.4 GHz Wireless Devices in Hospital Environments." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/31821.
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In recent years, advancements in the field of wireless communication have led to more innovative consumer products at reduced cost. Over the next 2 to 5 years, short-range wireless devices such as Bluetooth and Wireless Local Area Networks (WLANs) are expected to become widespread throughout hospital environments for various applications. Consequently the medical community views wireless applications as ineludible and necessary. However, currently there exist regulations on the use of wireless devices in hospitals, and with the ever increasing wireless personal applications, there will be more unconscious wireless devices entering and operating in hospitals. It is feared that these wireless devices may cause electromagnetic interference that could alter the operation of medical equipment and negatively impact patient care. Additionally, unintentional electromagnetic radiation from medical equipment may have a detrimental effect on the quality of service (QoS) of these short-range wireless devices.
Unfortunately, little is known about the impact of these short-range wireless devices on medical equipment and in turn the interference caused to these wireless devices by the hospital environment. The objective of this research was to design and develop an automated software reconfigurable measurement system (PRISM) to characterize the electromagnetic environment (EME) in hospitals. The portable measurement system has the flexibility to characterize a wide range of non-contiguous frequency bands and can be monitored from a remote location via the internet. In this work electromagnetic interference (EMI) measurements in the 2.4 GHz ISM band were performed in two hospitals. These measurements are considered to be very first effort to analyze the 2.4 GHz ISM band in hospitals.
Though the recorded EMI levels were well within the immunity level recommended by the FDA, it can be expected that Bluetooth devices will undergo a throughput reduction in the presence of major interferers such as WLANs and microwave ovens. A Bluetooth throughput simulator using semi-analytic results was developed as part of this work. PRISM and the Bluetooth simulator were used to predict the throughput for six Bluetooth Asynchronous Connectionless (ACL) transmissions as a function of piconet size and interferer distance.<br>Master of Science
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Chupáč, Michal. "Skener elektromagnetických polí a jeho využití při měření elektromagnetické kompatibility." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220301.
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Master’s thesis is focused on making the acquaintance of EMC issues and ways of electromagnetic field scanner RS321 utilization for pre-compliance measurements. First part contains analysis of available equipment’s influence on measurement results on the basis of gathered specification. Next part includes an example measurement used as operational manual for scanner and its controlling program. The most important part is correction evaluation for performed EMI measurement of signal generator using its EMC certification protocol and application of gained correction curve on independent EMI measurement of device tested by EMC testing laboratory. Other possibilities of scanner utilization are mentioned in the next chapters. Last part of the thesis contains suitability evaluation of EMC scanner on the basis of findings from performed measurements.
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Stylemans, Eric. "Etude d'un système de contre-mesure électroacoustique anti sous-marin destiné à la protection des navires." Valenciennes, 1997. http://www.theses.fr/1997VALE0007.
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Pour perturber les traitements du sous-marin pendant la phase de filoguidage d'une torpille et permettre au bâtiment de surface la mise en place d'une tactique efficace de réaction, un nouveau type de contre-mesure dédiée au leurrage-brouillage spécifique des senseurs du lanceur, utilisée en complément des contre-mesures anti torpilles, est indispensable. La bande d'écoute des sous-marins et des bâtiments de surface étant en partie commune, la conception d'un leurre brouilleur dans cette bande pose un problème opérationnel car toute action visant le lanceur va également perturber le porteur dans sa détection de la menace torpille. Deux nouveaux concepts de contre-mesures ont été étudiés dans ce but: * utiliser un leurre-bouilleur omnidirectionnel déployé par une roquette depuis le bâtiment de surface dans la direction estimée d'approche de la torpille * utiliser une contre-mesure a rejection contrainte à la position du porteur larguée par-dessus bord ou détachée du porteur dans le cas où elle est remorquée.
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Nicholls, Christo. "Equivalence between in-house and conventional EM immunity test techniques." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2592.
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Thesis (MScEng (Electrical and Electronic Engineering))--Stellenbosch University, 2008.<br>Conventional immunity tests are both time consuming and costly. There is
thus a reasonable interest in relatively quick, but accurate and cost
effective, in-house pre-compliance test techniques within an engineering
design-house. This thesis provides information on the equivalence between
in-house and conventional immunity test techniques.
Three techniques were evaluated, namely: 1. E-field radiation with a log
periodic antenna (conventional test technique); 2 E-field radiation with an inhouse
designed and constructed modified TEM cell (in-house test
technique); 3. Current injection using a complete off the shelf EMCO current
probe device (in-house test technique).
After the transfer data of the EMCO probe was verified, the modified TEM
cell design, construction and equivalent measurement tests were
performed. These tests revealed that within the respective bandwidth of
interest, the devices produced results that are equivalent to each other
within 0.9dB. Hence equivalence between in-house and conventional test
techniques is possible.
15
Gavshin, Ruslan. "Elektromagnetická kompatibilita výzbrojí tramvajových vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442470.
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This diploma thesis deals with the issue of EMC of tram vehicles and traction system. The first chapter defines the issues that are then dealt with in the thesis. The next chapter lists the objectives of the work. Subsequent chapters analyze the issues described in chapter 2. In the last chapter, a flow chart is proposed, which should serve as a tool to estimate the hazards of the traction drive due to induced bearing currents.
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Ware, David A. "Effects of Intentional Electromagnetic Interference on Analog to Digital Converter Measurements of Sensor Outputs and General Purpose Input Output Pins." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6640.
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As technology becomes more prevalent, its application to safety and security in critical systems continues to increase. This leads to an increased dependence on sensors to provide an accurate view of the environment surrounding an application. These sensors can also be exploited by a malicious individual to attack a system and compromise its safety or security. These attacks change the reported value of a sensor so that it doesn't re ect the real situation. The systems in a car can be used as an example of this. Cars can have numerous sensors that measure a variety of things, including the car's distance from an object, if the tires are locking up, or if the gas is low. The use of these sensors makes cars safer and more convenient to use. Using IEMI, an attacker could compromise some of these systems by changing the reported value so that an object appears further away than it actually is or that the tires aren't locking up when they are, possibly causing the car to crash. By doing this, a malicious individual could compromise the safety or security of a car.
This work attempts to understand what would be required for a malicious individual to conduct such an attack, thereby allowing for the identification of systems that are vulnerable to such attacks. This understanding would also provide the basis for designing defenses against these attacks, thereby increasing the safety of society at large.
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Friberg, Carol Diane. "Preliminary processing and evaluation of radar measurements in satellite-path propagation research." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45722.
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Rain and other precipitation cause attenuation and depolarization of high frequency satellite signals. Some characteristics of rain can be measured by dual-polarized radar. These characteristics can then be used to predict the effects of the rain on satellite-path propagation.
This thesis describes briefly the theory of radar and satellite link measurements. Methods for calibrating the equipment and deriving actual experimental values from measured power are presented in detail. A set of computer programs to approximately predict radar and link values from measured rain rate are developed. Predicted and measured values may then be compared by a researcher to evaluate system operation and assess the importance of the event data. A discussion of the use of sampled data and these comparisons concludes the report.<br>Master of Science
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Geier, Martin. "Influência dos parâmetros envolvidos no processo de união por interferência de tubos por cravamento eletromagnético." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/96295.
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A união por conformação eletromagnética de perfis tubulares de alta condutividade elétrica é um processo inovador e limpo que pode substituir com sucesso os processos convencionais de união baseados na fixação mecânica por parafusos, rebites, soldagem e adesivos estruturais. Esta tecnologia funciona a temperatura ambiente, permite a união de materiais diferentes e oferece potencial para promover novas aplicações na montagem de estruturas leves. Neste trabalho busca-se compreender a união por interferência de tubos por cravamento eletromagnético em termos de seus principais parâmetros com o objetivo de identificar a influência na resistência global das uniões e estabelecer a faixa útil de condições operacionais do processo. Inicialmente são apresentados os fundamentos teóricos do processo de conformação eletromagnética e suas principais variantes operacionais, seguido de um resumo do estado atual do conhecimento da aplicação desta tecnologia na união de perfis tubulares no qual é verificado que os parâmetros mecânicos são a tensão residual no mandril, a área e forma da zona de união e o coeficiente de atrito entre os componentes. Entretanto, tais parâmetros estão relacionados de forma complexa com o processo de cravamento eletromagnético, a começar pela energia e a distribuição do pulso de pressão magnética gerados pela máquina e ferramenta que “disparam” o processo de conformação, a folga inicial entre componentes, o material dos componentes e, a geometria, forma e rugosidade do mandril. O estudo experimental foca a união por interferência de tubos de alumínio (AA6082-O) com mandris de aço (AISI 1045) e alumínio (AA6082 nos estados O e T6) investigando de forma gradual a influência de parâmetros do processo na resistência mecânica (à tração) deste tipo de uniões. Os resultados obtidos demonstram que a resistência mecânica da união e os modos de falha associados são diretamente relacionados com os parâmetros de processo e condições do mandril. Além disso, outras importantes contribuições são apresentadas em relação à instrumentação para medição de fluxo magnético e eficiência global do processo e para o desenvolvimento e aplicações industriais desta tecnologia.<br>Joining of tubular profiles with high electrical conductivity by electromagnetic forming (EMF) is an innovative and clean technology that can successfully replace conventional joining technologies based on mechanical fixing with fasteners, rivets, welding and structural adhesives. The technology works at room temperature, allows joining dissimilar materials and offers potential to foster new applications in the assembly of lightweight tubular frame structures. This work investigates the interference-fit joining of tubes by electromagnetic crimping in terms of its major parameters with the aim of identifying their influence on the overall strength of the joints and establishing the useful range of process operating conditions. Initially, the theoretical principles of EMF and its main operational process variants are presented, followed by a summary of the current state of the knowledge of its application in the joining of tubular profiles in which it is found that the mechanical parameters are the residual stress at the joint interface, the area and shape of the joint interface and the friction coefficient between the joining partners. However, these parameters are related in a very complex way with the electromagnetic crimping process parameters, starting with the charging energy and by the machine and tool which generates the distribution of the magnetic pressure pulse that “triggers” the forming process, the initial gap between joining partners, the mandrel properties such as material, geometry, shape and surface roughness. The experimental study focuses the interference-fit of aluminum tubes (AA6082-O) on mandrels made of different materials and metallurgical conditions (AISI 1045, AA6082-O and AA6082-T6) and, therefore, the process is analyzed by the gradual influence of other process parameters aiming to achieve high strength joints. Results show that the joint strength and the associated failure mechanisms are directly related to process parameters and mandrel conditions. In addition, other important contributions are presented regarding the instrumentation for measuring the magnetic flux and overall process efficiency and to the development and implementation of this technology in industrial processes.
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Deneš, Roman. "Měření elektromagnetického vyzařování v částečně a plně bezodrazových komorách." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221241.
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This thesis is focused on a detailed analysis of the mechanisms of electromagnetic wave propagation in anechoic chambers. The analysis takes into account the influence of the measurement distance, setup of anechoic chamber and other parameters. Furthermore, the work deals with a validation of both types of anechoic chambers and examines the impact of selected parameters on the measurement results. Based on the theoretical analysis and practical measurement, the comparation between semi and fully anechoic chamber, or a three and ten meter measuring distance was made. This thesis also contains a detailed analysis of sources of the uncertainty.
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Lorenzo, Martinez Narei. "Observation of a Higgs boson and measurement of its mass in the diphoton decay channel with the ATLAS detector at the LHC." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00924105.
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The Standard Model of the particle physics predicts the existence of a massive scalar boson, usually referred to as Higgs boson in the literature, as resulting from the Spontaneous Symmetry Breaking mechanism, needed to generate the mass of the particles. The Higgs boson whose mass is theoretically undetermined, is experimentally looked for since half a century by various experiments. This is the case of the ATLAS experiment at LHC which started taking data from high energy collisions in 2010. One of the most important decay channel in the LHC environment is the diphoton channel, because the final state can be completely reconstructed with high precision. The photon energy response is a key point in this analysis, as the signal would appear as a narrow resonance over a large background. In this thesis, a detailed study of the photon energy response, using the ATLAS electromagnetic calorimeter has been performed. This study has provided a better understanding of the photon energy resolution and scale, thus enabling an improvement of the sensitivity of the diphoton analysis as well as a precise determination of the systematic uncertainties on the peak position. The diphoton decay channel had a prominent role in the discovery of a new particle compatible with the Standard Model Higgs boson by the ATLAS and CMS experiments, that occurred in July 2012. Using this channel as well as the better understanding of the photon energy response, a measurement of the mass of this particle is proposed in this thesis, with the data collected in 2011 and 2012 at a center-of-mass energy of 7 TeV and 8 TeV. A mass of 126.8 +/- 0.2 (stat) +\- 0.7 (syst) GeV/c2 is found. The calibration of the photon energy measurement with the calorimeter is the source of the largest systematic uncertainty on this measurement. Strategies to reduce this systematic error are discussed.
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Niska, Stefan. "Measurements and analysis of electromagnetic interferences in the Swedish railway systems /." Luleå : Division of Operation and Maintenance Luleå Railway Research Center, Luleå University of Technology, 2008. http://epubl.ltu.se/1402-1544/2008/76/.
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MacLeod, Leesa Marie. "Electromagnetic interference stress testing." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq41465.pdf.
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Adamu, Tigist Atnafseged. "Electromagnetic Interference in Dwnhole Applications." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19394.
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SummaryElectromagnetic compatibility (EMC) and electromagnetic interference (EMI) are topics which have been of concern to electrical industry for many years. Excessive generation of electromagnetic noise and interference, resulting inadequate EMC, is one potential source of interaction and performance degradation which may reduce operational effectiveness of the devices. Because of this, EMC testing services and regulation imposed by governments have forced product designer to pay close attention electromagnetic interference level of their products.For improving oil and gas production recovery, from mature fields and for exploitation of deep and ultra-deep offshore reservoirs new downhole technologies are required. Electrification of downhole applications has proven to be very promising and the technologies are designed for deployment in harsh environments. This master thesis deals with the study of EMI problems for downhole drive train system especially caused by EMI phenomena. The two aspects of EMI and EMC are studied, the manner in which how EMI can generate and propagate then affect receptor or victim intentionally and unintentionally are discussed. Followed by types of EMI phenomena (voltage dip, electrostatic discharge (ESD), surge, fast transient and rapid voltage change (dv/dt)) their occurrence and adverse effects of them are studied. dv/dt, overvoltage and EMI filter types are studied and designed. Compressions are made by their performance, size, power loss and cost. To verify their performance simulation model are made for downhole drive system to filter dv/dt and overvoltage at the motor terminals.After having the theoretical base, practical pre-compliance conducted EMI measurements are made for single phase chopper and three phase inverter.The influence of EMI such as reverse recovery current of diode, stray or leakage inductance, gate drive resistance, heat sink grounding, duty cycle and switching frequency are investigated on the single phase chopper. An LfCf harmonic filter is designed and placed between the inverter and motor terminals and differential mode EMI noise is measured in the system.
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Tassoudji, Mohammad Ali. "Electromagnetic interference in electronic circuits and systems." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/35392.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.<br>Includes bibliographical references (p. 191-198).<br>by Mohammad Ali Tassoudji.<br>Ph.D.
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Maggs, John David. "Electromagnetic interference from variable speed motor drives." Thesis, Aston University, 1996. http://publications.aston.ac.uk/15347/.
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A methodology is presented which can be used to produce the level of electromagnetic interference, in the form of conducted and radiated emissions, from variable speed drives, the drive that was modelled being a Eurotherm 583 drive. The conducted emissions are predicted using an accurate circuit model of the drive and its associated equipment. The circuit model was constructed from a number of different areas, these being: the power electronics of the drive, the line impedance stabilising network used during the experimental work to measure the conducted emissions, a model of an induction motor assuming near zero load, an accurate model of the shielded cable which connected the drive to the motor, and finally the parasitic capacitances that were present in the drive modelled. The conducted emissions were predicted with an error of +/-6dB over the frequency range 150kHz to 16MHz, which compares well with the limits set in the standards which specify a frequency range of 150kHz to 30MHz. The conducted emissions model was also used to predict the current and voltage sources which were used to predict the radiated emissions from the drive. Two methods for the prediction of the radiated emissions from the drive were investigated, the first being two-dimensional finite element analysis and the second three-dimensional transmission line matrix modelling. The finite element model took account of the features of the drive that were considered to produce the majority of the radiation, these features being the switching of the IGBT's in the inverter, the shielded cable which connected the drive to the motor as well as some of the cables that were present in the drive.
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Mohajer, Iravani Baharak. "Electromagnetic interference reduction using electromagnetic bandgap structures in packages, enclosures, cavities, and antennas." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7669.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.<br>Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Radojicic, Marko L. M. "Aspects of electromagnetic interference on printed circuit boards." Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5873.
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General guidelines for the design of printed circuit boards have been developed for two important aspects of electromagnetic compatibility: cross-talk and radiated emissions. Numerical methods were used to study the cross-talk between tracks of several common printed circuit board technologies. Design recommendations are suggested that minimize the cross-talk on printed circuit boards. A simple model was developed to predict radiated emissions from complicated circuits on printed circuit boards. The concepts of ground impedance and common-mode currents were used to build a model which gives fast and accurate predictions. The technique was tested using a method of moments program.
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Ingram, Vernon D., and Stephen Jauregui. "Strategies in the topological approach to electromagnetic interference control." Thesis, Monterey, California: U.S. Naval Postgraduate School, 1987. http://hdl.handle.net/10945/22502.
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Wong, Kok Hoong. "Use of recycled carbon fibre for electromagnetic interference shielding." Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439856.
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Oakes, Benjamin Donald. "Risk Analysis of Intentional Electromagnetic Interference on Critical Infrastructures." Licentiate thesis, KTH, Systemanalys och ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-203788.
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Our modern society depends on the functioning and interplay of a wealth of infrastructures. Practicallyall of these infrastructures are in some form or another, dependent on electrical and electronicsystems. The majority of modern infrastructure is dependent on electric power and controlled bySupervisory Control and Data Acquisition (SCADA) systems. Electronic systems are sensitive toelectromagnetic interference and at the same time, sources of electromagnetic interference are becomingmore readily available on the market.This means that certain important electronic infrastructure could be exposed to the risk of intentionalelectromagnetic interference (IEMI). Therefore, and also due to the complex nature of electronicinfrastructure, a comprehensive risk assessment methodology is needed. A game-theoretic approachfor quantitative risk assessment of the recently recognised threat of intentional electromagneticinterference on critical infrastructures is presented. The thesis bridges the gap between thefields of IEMI and risk analysis and lays a foundation for further development within this multidisciplinaryfield.In paper I, the probability distribution function of the electric field strength from a continuouswave source is estimated in complex building structures. Probability distribution functions arecombined for small and large scale fluctuations.In paper II, a structured risk assessment framework is presented for identifying and quantifyingthe risk of IEMI on a distribution network infrastructure. The dimensions and components of riskare dissected and a suitable definition of risk is formulated.In paper III, an operational model is formulated to optimise the operation of a wireless networkunder the course of a coordinated jamming attack. The model captures the time dimension andillustrates how the network operator must dynamically control the network so as to reduce the totalnetwork operational cost.<br>Det moderna samhället är starkt beroende av funktionaliteten och samspelet mellan en mängd olikainfrastrukturer. Alla dessa infrastrukturer beror på ett eller annat sätt på elektriska och elektroniskasystem. Majoriteten av modern infrastruktur är beroende av elkraft och styrs av så kallade SupervisoryControl and Data Aquisition (SCADA) system. Elektronik är känslig mot elektromagnetiskastörningar och samtidigt har elektromagnetiska störsändare blivit alltmer lättillgängligt för allmänhetenpå marknaden.Således kan viss kritisk teknisk infrastruktur vara utsatt för risk av avsiktliga elektromagnetiskastörningar. Denna sårbarhet och komplexiteten hos elektronisk infrastruktur kräver en utförlig metodför riskanalys. Här presenteras en spelteoretisk metod för kvantitativ riskanalys av det relativtnyligen identifierade hotet avsiktlig elektromagnetisk störning av samhällsviktig teknisk infrastruktur.Avhandlingen knyter ihop ämnesområdena IEMI och riskanalys och lägger en grund för vidareutveckling inom samverkansområdet.I papper I beräknas sannolikhetsfördelningen hos elektriska fältstyrkan från en kontinuerlig vågkällai komplexa byggnadsstrukturer. Sannolikhetsfördelningar kombineras för små och storskaligafluktuationer.I papper II presenteras ett strukturerat ramverk för riskanalys som identifierar och kvantifierarrisken för IEMI hos en infrastruktur i form av ett distributionsnätverk. Dimensionerna och komponenternaav risk identifieras och riskbegreppet definieras specifikt för IEMI.I papper III formuleras en “operational model” som optimerar underhållningen av ett trådlöstnätverk under ett koordinerat jamming attack. Modellen tar hänsyn till tidsdimensionen och illustrerarhur nätverksoperatorn måste dynamiskt styra om nätverket så att totala underhållningskostnaden minimeras.<br><p>QC 20170317</p>
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Nicholls, Christo. "Equivalence between in-house and conventional EM immunity test techniques /." Link to the online version, 2007. http://hdl.handle.net/10019/885.
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Golestaneh, Shahram Carleton University Dissertation Engineering Electrical. "Adjacent channel interference reduction by adaptive equalizers." Ottawa, 1992.
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Ren, Fei. "Performance improvements of automobile communication protocols in electromagnetic interference environments." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.mst.edu/thesis/pdf/Ren_09007dcc80487aed.pdf.
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Thesis (M.S.)--University of Missouri--Rolla, 2007.<br>Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed March 27, 2008) Includes bibliographical references (p. 55-56).
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Theodore, Susan Mack 1958. "Reduction of electromagnetic interference in multiple switched mode power supplies." Thesis, The University of Arizona, 1995. http://hdl.handle.net/10150/278520.
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A method to reduce Electromagnetic Interference (EMI) of multiple switching waveforms by harmonic cancellation is presented. The waveforms considered are input currents generated by 'n' Discontinuous Mode (DCM) Flyback Switched Mode Power Supplies (SMPS) that share a common source. The waveforms are modeled as ideal triangular waveforms and a Fourier analysis is performed to determine the phase relationship, θ, that minimizes the EMI. The combined EMI is minimum when θ=360°/n and maximum when θ=0°. A system of two DCM Flyback SMPS is designed in such a way that both 0° and 180° phase shifts between input current waveforms are possible. In both cases EMI filters are designed to meet EMI standard MIL-STD-461. The system is simulated and constructed and the experimental results are presented. These results demonstrate the accuracy of the modeled waveform and the reduction of conducted EMI when optimal phasing is achieved.
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Adams, Peter. "Fault demarcation and electromagnetic interference identification for broadband DSL access." Thesis, Queen Mary, University of London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538377.
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Grodek, Thomas Leopold. "Practical considerations of the topological approach to electromagnetic interference control." Thesis, Monterey, California: U.S. Naval Postgraduate School, 1986. http://hdl.handle.net/10945/22039.
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Li, Hong. "Reducing electromagnetic interference in DC-DC converters with chaos control." Düsseldorf VDI-Verl, 2009. http://d-nb.info/998470414/04.
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Chang, I.-Jen, and 張怡仁. "Time-Domain Electromagnetic Interference Measurement for Radiated Emission." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/77703316286096348407.
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碩士<br>輔仁大學<br>電子工程學系<br>97<br>This article discussed and used a digital oscilloscope to do the measuring technology in the time domain while matching the auxiliary operation of the computer mainly. The measured frequency is from 30 MHz to 250 MHz. The antenna received the electromagnetic interference noise in radiated emission from EUT so the signals from the antenna are sampled. The amplifier amplified the signals, and the low pass filter filtered the signals in frequency range. Then the digital oscilloscope converted the analog signals to digital ones, and transmitted the signals to the computer. The computer controlled LabVIEW program to converter the measured signals from time-domain to frequency-domain with the fast Fourier transform (FFT). The system can simulate all kinds of measured modes in spectrum such as peak value and average value measurement modes so that it can measure the electromagnetic interference noise in radiated emission. Lastly using the spectrum analyzer carried out the measured result verification. Compared the difference between the time domain and the frequency domain measurements in order to check the system can replace a spectrum analyzer. Due to the system allows the parallel processing for the amplitude and the phase of whole spectrum range, it can reduce the measured time.
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Willcock, Peter Richard. "Conducted electromagnetic interference in boost converters." Thesis, 2012. http://hdl.handle.net/10210/6460.
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M.Ing.<br>The use of electronically controlled electrical power equipment, specifically power converters, has rapidly increased in recent years. It has subsequently been found that different electrical equipment, placed or working in close proximity, can negatively influences each other's performance. The degradation in performance could be attributed to mutual electromagnetic interference (EMI). Traditional methods of testing conducted EMI usually follow a black box approach with additional filter elements being added to the converter input to bring it within specification. This study focuses on the conducted electromagnetic interference of a specially built experimental boost converter that would typically be used as a preregulator to improve the power factor. The converter circuit was constructed in a number of functional circuit sections in order to assess an individual section's contribution to the emission and propagation of conducted EMI throughout the converter. The operational behaviour of the converter can thus be systematically studied and improved before additional filter components are added. The measurement standards require that conducted EMI measurements are made at the power source input of the equipment under test. These measurement techniques do not allow a systematic tracing of the propagation of conducted EMI throughout a converter circuit. Since no frequency spectrum measurement is available at any other measurement point in the converter. Part of this thesis was thus devoted to the development of an enhancement to current measurement techniques that enables EMI frequency measurements throughout a converter. A special EMI probe was developed for this purpose. Using this EMI probe conducted EMI propagation can be traced from its source throughout a converter to the power input. An analytical analysis of the boost converter's behaviour, with emphasis placed on its switching transients, was initially undertaken. This was continued with PSPICE® circuit simulation. Various aspects of the converters operational behaviour were considered. The simulation results suggested modifications to the converter switch circuit, which would improve the boost converter's conducted EMI characteristics. These were then evaluated with corresponding practical measurements carried out on the boost converter. The practical results confirm that the converters switching behaviour can be directly related to the parasitic and other components. Improvement of the converter switching behaviour lead to an improvement of the conducted EMI emissions of the boost converter.
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Wang, Yao-hsien, and 王耀賢. "Measurement and Countermeasure of Electromagnetic Interference for Electronic Ballast." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/62540190088628736057.
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碩士<br>逢甲大學<br>資訊電機工程碩士在職專班<br>94<br>The lighting is a basic human necessity, influencing economic development and consequent goals for the promotion of an increased quality of life. However in striving for our goals we have a problem of fulfilling increasing output lighting demand in a frugal power consumption world. To resolve this dilemma we have to ‘do more with less’ creating innovative energy systems and product designs of higher efficiencies that not only save energy but more importantly the environment itself for future generations.
With electromagnetic interference (EMI) being recognized for decades as the single prime factor affecting component life cycles of equipment and systems, we have focused upon 3 kinds of electronic ballasts those being: Conducted Emission, Radiated Magnetic Field and Harmonics testing. In this paper, we theorize the factors influencing the success of electronic ballast strategies used in lighting to counter (EMI) output emissions through controlled comparative measurement studies.
Alternatively addressing EMI currents problems at the source of lighting design, we analyze non-compliant compact fluorescent lamp design under set regulatory limits. Additionally this paper puts forward remedial measures to take such an appliance to be within compliance regarding EMI emissions under the Commission of the European Community CE mark.
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Lin, Hui-Ching, and 林惠卿. "Electromagnetic Interference Emission Automatic Measurement and Filter Design System." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/18801199309091931738.
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碩士<br>淡江大學<br>資訊工程學系<br>90<br>With the fast development of power electronic techniques, the switch-mode power supplies have been widely employed in the electrical products for industrial and commercial applications. These high-frequency switching power supplies are inherently noise sources and can affect the operation of the other equipments. Therefore, it is very important to investigate and study the electromagnetic interference problems.
In this thesis, a PC-based automatic measurement and filter design system for the electromagnetic interference emission is developed. The effort of solving the conductive EMI is greatly reduced by the fast computing speed and the friendly man-machine interface of the PC. The noise measurement and suppression procedure established can accomplish the reduction of the developing period and cost. Not only the production is speeded up, but also the acceptability of the product to the publicans can increase.
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Chang, Hong Yang, and 張宏揚. "Measurement and Analysis of Electromagnetic Interference on High Frequency Circuits." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/32522521356993008860.
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碩士<br>義守大學<br>電子工程學系<br>88<br>The rise time of signals in PCB (printed circuit board) circuits become shorter and shorter. High speed transmission and high density packaging have become the trend of PCB development. Therefore, when designing a PCB circuit, the electrical characteristics under high frequency circumstance and noise-control can not be ignored. One of the most common noise sources in digital systems is the crosstalk noise, and the crosstalk noise is very significant within high frequency PCB circuits.
Thus, in this thesis, a PCB circuit is simulated by a corresponding coupling multiconductor transmission line model. The unit length parameters of the transmission line can be determined by analytical calculations or numerical simulations. However, analytical solutions are satisfied only under simple circuit and homogeneous medium conditions. If the geometry of PCB circuit are complex and the medium is nonhomogeneous, then these parameters are found through numerical methods. However, numerical simulations usually talk a lot of time. Thus, in this thesis, these unit length parameters are determined by measurement methods. A distributed SPICE model is proposed, and the measured parameters are used to simulate the crosstalk, The SPICE model are verified by comparison with experimental and analytical results in frequency and time domains.
At last, the effects influence crosstalk noise on PCB circuits and the shielding methods are investigated.
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Chang, Yin-Cheng, and 章殷誠. "Wideband Conducted Electromagnetic Interference and Susceptibility Measurement Techniques for ICs." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/zc2ubt.
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博士<br>國立清華大學<br>電子工程研究所<br>107<br>This work focuses on the wideband measurement technique development of the conducted electromagnetic compatibility (EMC) for IC, and presents the chip level design strategies. For the electromagnetic interference (EMI) test, a 1-Ω probe is presented to comply with the IEC61967-4 standard. The insertion loss specification of 34±2 dB is achieved within 1 GHz bandwidth. To meet the demand of high speed/high frequency testing, the on-chip test setup is proposed. By implementing the 1-Ω current probe and 150-Ω voltage probe in the integrated passive device (IPD) technology, the bandwidth could reach up to 15 GHz. With the flip-chip technology, the chip level EMI test is performed. Furthermore, an active 1-Ω probe is proposed to overcome the high loss property of the conventional passive probe. By integrating the precise 1-Ω resistor design and a wide band amplifier, the insertion loss is reduced form 34 dB to 18 dB with the operating bandwidth of 3 GHz. A MCU chip is tested to demonstrate that the active probe shows a better ability of detecting interference than the conventional passive probe. For the electromagnetic susceptibility (EMS) test, the bandwidth of the IEC62132-4 standard, the direct power injection (DPI) method, is extended from 1 GHz to 18 GHz. A linear low dropout regulator (LDO) IC is tested to demonstrate that the IC would still malfunction when it encounters with the interference at the frequency higher than its operating frequency. Finally, two chip level EMC solutions are proposed. The slew rate controller could change the rising/falling rate of a signal. It reduces the high frequency contents of the signal and results in the improved EMI issue. Besides, a decoupling capacitor (decap) which stacks MOM and MOS capacitors is proposed. It provides extra 17% capacitance compared with the MOS capacitor. By embedding the proposed decaps into a LDO, the immunity can be improved with a maximum value of 11.6 dB.
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jong-mou, fang, and 方仲謀. "The Experiments and Analysis for Measurement Uncertainty of a Radiated Electromagnetic Interference." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/89797082866791093499.
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碩士<br>元智大學<br>電機工程研究所<br>89<br>This thesis analyzes the uncertainty of a radiated electromagnetic interference test based on the ISO Guide. The major sources of uncertainty in the radiated electromagnetic interference test which include EMI receiver, measurement cable, load impedance mismatch and antenna factor, are measured at 27 sampled frequencies in range of 30MHz to 1000 MHz, According to the regulation of ANSI-C63.4. The mean and variance of measured data are used to calibrate the loss of a radiated electromagnetic interference test and to calculate uncertainty. Finally, the relation between the expanded uncertainty for a confidence level of 95% and EMC compliance is investigated and the cost effective of the uncertainty test is evaluated.
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Engelbrecht, Jacobus Johannes. "Methods to measure and limit electromagnetic interference, with reference to power systems and satellite earth stations." Thesis, 2009. http://hdl.handle.net/10210/2163.
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M.Ing.<br>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.
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Yu, Ku Jen, and 顧仁裕. "The Study of Measurement Theorem and Prevention over Electromagnetic Interference Environment and RF Noise." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/03977085969863272777.
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碩士<br>大葉大學<br>電信工程學系碩士在職專班<br>93<br>In this thesis, the theory of EMI/REI and the propagation methods are investigated and introduced at the beginning. Moreover, the solution for internal and external interference sources with the difference conditions of a communication system include the location, the environments and the equipments of a communication system are discussed. Besides, the thesis not only study the processes and the device for measuring the interference of a communication system, the choose of the location of a communication system is also analyzed by some physical measured data.
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MING-HUNG, SUN, and 孫銘宏. "Electromagnetic Interference Emission Automatic Measurement and Filter Design for Switch-mode Rectifier Power Supply." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/75909083617749637320.
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碩士<br>義守大學<br>電子工程學系<br>91<br>In this thesis, a PC-based automatic measurement and filter design system for the electromagnetic interference emission of SMR is developed. The man-machine interface is written in LabVIEW graphical programming language. The effort of solving the conductive EMI is greatly reduced by the fast computing speed and the friendly man-machine interface of the PC. The emission measurement and suppression procedure established can accomplish the reduction of the developing period and cost. Not only the production is speeded up, but also the acceptability of the SMR manufacturers can increase. Finally, in order to verify the feasibility of the developed system, a 3kW SMR is taken as the equipment under test (EUT). The resulted EMI can be successfully solved and make SMR meet VDE Class B limit.
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陳嘉珮. "The Measurement and Rectification of Electromagnetic Interference for Electric Massage - Neck and Shoulder Massage." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/44460337100438660566.
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碩士<br>國立彰化師範大學<br>機電工程學系<br>99<br>Busy is a common phenomenon for the people in modern industrialized society. Due to working stress and bad gesture, most people usually have the problem of body pain, for example, sore and stiff neck and shoulder. In order to relief the pain, electric massagers have been used widely. Shoulder and neck massager is the one that has to be contacted on human skin during working; the electromagnetic problem then becomes an essential issue that has to be measured and tested. Therefore, the objective of this study is dealing with the electromagnetic interference which is generated by “shoulder and neck massager”. Based on standardized measuring processes, the conducted emissions and radiated emissions are tested and determined. The electromagnetic interference level and frequency are analyzed. If required, systematic approach of correction action to reduce the magnitude level of electromagnetic interference is conducted. The result will then be tested and verified.
Key words: Electromagnetic interference; conducted emissions; radiated emissions.
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Chiu, Shih-ting, and 邱士庭. "Statistical model building and inference about the normalized site attenuation (NSA) measurements for electromagnetic interference (EMI)." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/92145950830616450567.
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碩士<br>國立中山大學<br>應用數學系研究所<br>92<br>Open site measurement on the electromagnetic interference is the most direct and universally accepted standard approach for measuring radiated emissions from an equipment
or the radiation susceptibility of a component or equipment. A site is qualified for testing
EMI or not is decided by the antenna measurements. In this work, we use data from setups with di erent factors to find relations of measurement and the situation of antenna. A one change point model has been used to fit observed measurements and compare the di erences
with two kinds of antenna (broadband antenna and dipole antenna). However, with only one change point model it may not give a suitable fit for all data sets in this work.
Therefore, we have tried other models and applied them to the data. Furthermore, we try to set up another standard more strict than ±4dB based on statistical inference results in deciding whether a site is a better one with more precision in measuring EMI values.
Finally, a program by Matlab with a complete analysis based on the procedure performed here is provided, so that it may be used as a standard tool for evaluating whether a site is with good measurement quality in practice.
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Cheng, Chiung-Ping, and 鄭竣平. "A Study on the Statistical Models of Normalized Site Attenuation(NSA) Measurements for Electromagnetic Interference(EMI)." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/02709755224267764104.
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碩士<br>國立中山大學<br>應用數學系研究所<br>91<br>In this work, we discuss the accuracy of measurements for
electromagnetic. The two kinds of antenna we use are Dipole
antenna and Broadband antenna. In general, if the antenna
measurements we recorded at different frequencies do not exceed
the ideal value $pm 4$dB, we would regard this site as a
normalized site, otherwise it is not a normalized site(just a
measurement exceeds the range). Traditionally, all we use is
Dipole antenna, but due to difficulty of operation and inaccuracy
of Dipole antenna, we investigate by statistical methods if we may
use the Broadband antenna to replace the traditional Dipole
antenna to measure. First of all, we introduce the data and
procedure in the experiments, and fit a statistical regression
model to predict the measurements at different frequencies in
different test setups. Then, according to the data we collected,
use the change point models to modify the statistical models. Our
goal is to find a suitable statistical model for the
measurements. Finally, we compare the measurements of Broadband
antenna
with Dipole antenna in the other experimental conditions keep the same.