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1
Ekman, Jonas. "Electromagnetic modeling using the partial element equivalent circuit method." Doctoral thesis, Luleå, 2003. http://epubl.luth.se/1402-1544/2003/27.
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Lau, Mark C. "Small Signal Equivalent Circuit Extraction From A Gallium Arsenide MESFET Device." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36952.
Full textAbstract:
The development of microwave Gallium Arsenide Metal Semiconductor Field
Effect Transistor (MESFET) devices has enabled the miniaturization of pagers, cellular
phones, and other electronic devices. With these MESFET devices comes the need to
model them. This thesis extracts a small signal equivalent circuit model from a Gallium
Arsenide MESFET device. The approach taken in this thesis is to use measured S-
parameters to extract a small signal equivalent circuit model by optimization. Small signal
models and S-parameters are explained. The Simplex Method is used to optimize the
small signal equivalent circuit model. A thorough analysis of the strengths and
weaknesses of the Simplex method is performed.<br>Master of Science
3
Ekman, Jonas. "The partial element equivalent circuit method : modeling and experimental verification of PCB structures." Licentiate thesis, Luleå tekniska universitet, EISLAB, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18244.
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To help products comply with international Electromagnetic Compatibility (EMC)regulations or as a help in a design process numerical simulation of electromagnetic (EM) characteristics are a valuable tool. With the development of high-speed computers the complexity of EM simulation programs and the systems they can simulate has increased considerable. But still, problems must be partitioned due to computer resource and/or EM simulation technique limitations. In this thesis, four different EM simulation techniques are described and the nature of these are discussed. The focus is on the partial element equivalent circuit (PEEC) method for which the following improvements and investigations have been proposed in the enclosed papers. First, a recent proposed formulation for the direct simulation of the radiated electric field from a device is compared against traditional post-processing equations and measurements. The results show that the proposed direct method, the electric field sensor, is unreliable for arbitrarily implementations since the length of the sensor strongly affects the results. Second, a technique to obtain simplified PEEC models are presented. The first step is to use a discretisation procedure where partial elements with small effect on the complete PEEC model are excluded. Then, instead of using numerical integration, closed-form equations are used to calculate the partial elements. The obtained simplified PEEC models are shown to comply well against measurements. Third, an introductory paper to the PEEC method is presented. The international interest for the method has been gaining rapidly for the past years resulting in considerable progress for the technique. But, in the Nordic countries the research effort has been low. The paper presents the technique using simple antenna examples, both printed and free space, and illustrations. For verification, simulations have been compared against analytical solutions and measurements.<br>Godkänd; 2001; 20070314 (ysko)
4
Leinonen, M. (Mikko). "Finite element method and equivalent circuit based design of piezoelectric actuators and energy harvester dynamics." Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526208374.
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Abstract The main objective of this thesis was to use and combine Finite Element Method (FEM) and small signal equivalent circuit models in actuator and energy harvesting design and to study the dynamics of the said designs. The work is divided into four different sections. In the first section, the small signal parameters are derived for a pre-stressed piezoelectric actuator using a series of measurements. In addition, the tunability of the resonance frequency using mass and series capacitors is investigated. In the second section, a piezoelectric Fabry Perot Interferometer actuator is simulated using FEM and the small signal parameters are derived using FEM simulations. The modelled results are compared with the actual measurements and the resonance frequency is found to differ by only 0.8 percent from the measured values when the mirror is attached to the actuator. In the third section a piezoelectric wide band energy harvester is developed with multiple beam topology. Two different designs are compared, one produced using the conventional PZT-steel structure and one with a PZT-LTCC structure. The final section presents an FEM model for a shoe mounted energy harvester and concentrates on the modelling of walking dynamics in FEM. The simulation results are compared to actual measurements and the simulated power values are found to differ by only 7% when the cymbal stroke is below 1.3 mm. The generated model is also expandable to other types of energy harvesters and the methods developed can be used in a variety of different energy harvesting simulations and harvester development. The results show that the equivalent circuit approach together with FEM modelling is a powerful tool in the dynamics design of piezoelectric actuators and energy harvesters<br>Tiivistelmä Väitöstyön päätavoitteena oli yhdistää elementtimenetelmät (FEM) ja piensignaalimallit aktuaattorien ja energiankorjuukomponenttien suunnittelussa ja tutkia niiden dynamiikkaa. Työ on jaettu neljään eri osaan. Ensimmäisessä osassa piensignaalimallit johdettiin pietsosähköisestä aktuaattorista mittausten avulla. Lisäksi resonanssitaajuuden muuttamista tutkitaan massan ja sarjaan kytketyn kapasitanssin avulla. Toisessa osassa simuloidaan pietsosähköistä Fabry Perot interferometria käyttäen elementtimenetelmää. Lisäksi komponentin piensignaalimalli luodaan käyttäen simulointimallia. Lopuksi piensignaalimallin ja prototyypin mittaustuloksia verrataan. Mallin resonanssitaajuus poikkeaa mitatusta vain 0.8 %, kun aktuaattoriin on kiinnitetty peili. Kolmannessa osassa kehitetään ja verrataan toisiinsa kahta erilaista laajakaistaista monipalkkista pietsosähköistä energian korjuukomponenttia. Toinen komponenteista on toteutettu perinteisellä PZT-teräs rakenteella ja toinen yhteissintratulla PZT-LTCC rakenteella. Viimeisessä osassa luodaan simulaatio malli kenkään asennetulle cymbal tyyppiselle pietsosähköiselle energian korjuukomponentille ja kävelyn dynamiikkaa tutkitaan. Luotua mallia verrataan prototyypin mittaustuloksiin ja simuloitu energian tuotto poikkeaa vain 7 % alle 1.3 mm puristusliikkeellä. Tulokset osoittivat, että piensignaalimallin ja elementtimenetelmän yhdistäminen on tehokas apu pietsosähköisten aktuaattorien ja energiankorjuukomponenttien dynamiikan suunnittelussa
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Sugden, Frank Daniel. "A NOVEL DUAL MODELING METHOD FOR CHARACTERIZING HUMAN NERVE FIBER ACTIVATION." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1318.
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Presented in this work is the investigation and successful illustration of a coupled model of the human nerve fiber. SPICE netlist code was utilized to describe the electrical properties of the human nervous membrane in tandem with COMSOL Multiphysics, a finite element analysis software tool. The initial research concentrated on the utilization of the Hodgkin-Huxley electrical circuit representation of the nerve fiber membrane. Further development of the project identified the need for a linear circuit model that more closely resembled the McNeal linearization model augmented by the work of Szlavik which better facilitated the coupling of both SPICE and COMSOL programs. Related literature was investigated and applied to validate the model. This combination of analysis tools allowed for the presentation of a consistent model and revealed that a coupled model produced not only a qualitatively comparable, but also a quantitatively comparable result to studies presented in the literature. All potential profiles produced during the simulation were compared against the literature in order to meet the purpose of presenting an advanced computational model of human neural recruitment and excitation. It was demonstrated through this process that the correct usage of neuron models within a two dimensional conductive space did allow for the approximate modeling of human neural electrical characteristics.
6
Boussetta, Chokri. "Modélisation électromagnétique des interconnexions en micro-onde et en logique rapide." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0153.
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La modelisation electromagnetique est un outil tres important dans l'amelioration des performances des circuits logiques rapides. La haute densite d'integration et la diminution du temps de montee necessite l'utilisation des cao de plus en plus performants. Ces outils doivent integrer une caracterisation precise des interconnexions, et plus particulierement des discontinuites. Parmi les differents methodes de caracterisation et de modelisation en hyperfrequence qui ont ete developpes, nous avons choisi la methode tlm. Nous avons mis au point un logiciel d'extraction des elements des schemas equivalents des discontinuites facilement integrables dans les logiciels de cao (spice, mds,). Nous avons applique notre methodologie a la modelisation de quelques discontinuites (coude, via, croissement,) sur une bande de 20 ghz. Nous avons confronte nos resultats a des resultats publies dans la litterature, ainsi qu'a des resultats de mesures. Ces comparaisons nous ont ainsi permis de valider le principe de modelisation que nous avons developpe
7
Martinho, Lucas Blattner. "Numerical modeling of electromagnetic coupling phenomena in the vicinities of overhead power transmission lines." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-28062016-152807/.
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Les phénomènes de couplage électromagnétique entre les lignes aé- riennes de transmission d\'énergie et des structures voisines sont inévitables, surtout dans les zones densément peuplées. Les effets indésirables découlants de cette proximité sont variés, allant de l\'établissement des tensions dangereuses à l\'apparition de phénomènes de corrosion dus au courant alternatif. L\'étude de cette classe de problèmes est nécessaire pour assurer la sécurité dans les alentours de la zone d\'interaction et aussi pour préserver l\'intégrité des équipements et des dispositifs présents. Cependant, la modélisation compl ète de ce type d\'application implique la représentation tridimensionnelle de la région d\'intérêt et nécessite des méthodes numériques de calcul de champs spécifiques. Dans ces travaux, des problèmes liés à la circulation de courants électriques dans le sol (ou de couplage dit conductif) seront abordés avec la méthode des éléments finis. D\'autres problèmes résultants de la variation temporelle des champs électromagnétiques (ou de couplage dit inductif) seront aussi considérés et traités avec la méthode PEEC (Partial Element Equivalent Circuit) généralisée. Plus précisément, une condition limite particulière sur le potentiel électrique est proposée pour tronquer le domaine de calcul dans l\'analyse par éléments finis des problèmes de couplage conductif et une formulation PEEC complète pour la modélisation de problèmes de couplage inductif est présentée. Des con gurations tests de complexités croissantes sont considérées pour valider les approches précédentes. Ces travaux visent ainsi à apporter une contribution à la modélisation de cette classe de problèmes, qui tendent à devenir communs avec l\'expansion des réseaux électriques.<br>Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of the equipment and of the devices there present. However, the complete modeling of this type of application requires the three- -dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids.
8
Sahraoui, Omar. "Calcul des paramètres du schéma équivalent de la machine asynchrone par la méthode des éléments finis." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0056.
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Depuis son invention par Tesla, au siècle dernier, la machine asynchrone s'est imposée dans l'industrie grâce à sa robustesse, sa fiabilité et son coût faible. Avec le développement de l'électronique de puissance et de la commande vectorielle ces dernières années, elle est devenue compétitive dans le domaine de la vitesse variable. Il existe principalement deux approches différentes pour l'étude de la machine asynchrone : le schéma équivalent et la méthode des éléments finis. Les méthodes classiques de détermination des paramètres des éléments finis (f. E. M. ) est plus précise car elle permet de prendre en compte des phénomènes complexes tels que la saturation et l'effet de peau dans la machine, mais exige généralement des moyens et des temps de calcul importants. Pour combiner les deux approches ci-dessus, nous avons abordé, au cours de notre travail, le problème de la détermination des paramètres du schéma équivalent de la machine asynchrone par la méthode des éléments finis. Ainsi nous obtenons un schéma équivalent précis et facile à mettre en leurre. Pour ceci, nous avons développé plusieurs méthodes parmi lesquelles on peut citer : - La méthode du diagramme vectoriel qui se base sur les équations classiques de la machine en régime permanent. Cette méthode permet de mettre en évidence la variation des paramètres du schéma équivalent avec les conditions de fonctionnement de la machine. - La méthode de l'essai fréquentiel à l'arrêt (Standstill Frequency Response, SSFR) qui permet de modéliser finement l'effet de peau dans la machine, et de déterminer les constantes de temps électriques, très importantes dans l'étude du comportement dynamique de la machine. La validation de ces méthodes a été faite sur une machine asynchrone à structure inversée (cage au stator). Les résultats de calcul sont en bon accord avec les mesures
9
Martinson, Christiaan Adolph. "Characterisation of a PEM electrolyser using the current interrupt method / Christiaan Adolph Martinson." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8741.
Full textAbstract:
The need to characterise a PEM electrolyser is motivated by a South African hydrogen
company. One of two electrochemical characterisation methods, namely the current
interrupt method or electrochemical impedance spectroscopy, is investigated to
characterise the PEM electrolyser. Various literature sources can be found on the
electrochemical characterisation methods.
In this study the current interrupt method is used for the electrochemical characterisation
of a PEM electrolyser. The current interrupt method is an electrical test method
that will be used to obtain an equivalent electric circuit model of the PEM electrolyser.
The equivalent electric circuit model relates to various electrochemical characteristics
such as the activation losses, the ohmic losses and the concentration losses.
Two variants of the current interrupt method, namely the natural voltage response
method and the current switching method, are presented. These methods are used to
obtain two different equivalent electric circuit models of the PEM electrolyser. The
parameters of the first equivalent electric circuit, namely the Randles cell, will be
estimated with the natural voltage response method. The parameters of the second
equivalent electric circuit, namely the Randles-Warburg cell, will be estimated with
the current switching method.
Simulation models of the equivalent electric circuits are developed and tested. The
simulation models are used to verify and validate the natural voltage response method
and the current switching method. The parameters of the Randles cell simulation
model is accurately calculated with the natural voltage response method. The
parameters of the Randles-Warburg cell simulation model is accurately calculated with
the current switching method.
The natural voltage response method and the current switching method are also
practically implemented. The results is used to indicate the various electrochemical
characteristics of the PEM electrolyser. A Nafion 117 type membrane was tested with the current interrupt method. The membrane resistance parameters of Randles cell
were estimated with the natural voltage response method. These values are validated
with conductivity measurements found in literature. The results of the Randles-
Warburg cell is validated with a system identification validation model.<br>Thesis (MIng (Computer and Electronic Engineering))--North-West University, Potchefstroom Campus, 2013
10
Martinho, Lucas Blattner. "Modélisation numérique des phénomènes de couplage électromagnétique dans les alentours des lignes aériennes de transmission d'énergie." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT030/document.
Full textAbstract:
Les phénomènes de couplage électromagnétique entre les lignes aériennes de transmission d'énergie et des structures voisines sont inévitables, surtout dans les zones densément peuplées. Les effets indésirables découlants de cette proximité sont variés, allant de l'établissement des tensions dangereuses à l'apparition de phénomènes de corrosion dus au courant alternatif. L'étude de cette classe de problèmes est nécessaire pour assurer la sécurité dans les alentours de la zone d'interaction et aussi pour préserver l'intégrité des équipements et des dispositifs présents. Cependant, la modélisation complète de ce type d'application implique la représentation tridimensionnelle de la région d'intérêt et nécessite des méthodes numériques de calcul de champs spécifiques. Dans ces travaux, des problèmes liés à la circulation de courants électriques dans le sol (ou de couplage dit conductif) seront abordés avec la méthode des éléments finis. D'autres problèmes résultants de la variation temporelle des champs électromagnétiques (ou de couplage dit inductif) seront aussi considérés et traités avec la méthode PEEC (Partial Element Equivalent Circuit) généralisée. Plus précisément, une condition limite particulière sur le potentiel électrique est proposée pour tronquer le domaine de calcul dans l'analyse par éléments finis des problèmes de couplage conductif et une formulation PEEC complète pour la modélisation de problèmes de couplage inductif est présentée. Des configurations tests de complexités croissantes sont considérées pour valider les approches précédentes. Ces travaux visent ainsi à apporter une contribution à la modélisation de cette classe de problèmes, qui tendent à devenir communs avec l'expansion des réseaux électriques<br>Electromagnetic coupling phenomena between overhead power transmission lines and other nearby structures are inevitable, especially in densely populated areas. The undesired effects resulting from this proximity are manifold and range from the establishment of hazardous potentials to the outbreak of alternate current corrosion phenomena. The study of this class of problems is necessary for ensuring security in the vicinities of the interaction zone and also to preserve the integrity of equipment and devices there present. However, the complete modeling of this type of application requires the three-dimensional representation of the region of interest and needs specific numerical methods for field computation. In this work, the modeling of problems arising from the flow of electrical currents in the ground (the so-called conductive coupling) will be addressed with the finite element method. Those resulting from the time variation of the electromagnetic fields (the so-called inductive coupling) will be considered as well, and they will be treated with the generalized PEEC (Partial Element Equivalent Circuit) method. More specifically, a special boundary condition on the electric potential is proposed for truncating the computational domain in the finite element analysis of conductive coupling problems, and a complete PEEC formulation for modeling inductive coupling problems is presented. Test configurations of increasing complexities are considered for validating the foregoing approaches. These works aim to provide a contribution to the modeling of this class of problems, which tend to become common with the expansion of power grids<br>Fenômenos de acoplamento eletromagnético entre linhas aéreas de transmissão de energia e outras estruturas vizinhas são inevitáveis, sobretudo emáreas densamente povoadas. Os efeitos indesejados decorrentes desta proximidadesão variados, indo desde o estabelecimento de potenciais perigosos até o surgimento de processos de corrosão por corrente alternada. O estudo desta classe de problemas é necessária para a garantia da segurança nas imediações da zona de interação e também para se preservar a integridade de equipamentos e dispositivos ali presentes. Entretanto, a modelagem completa deste tipo de aplicação requer a representação tridimensional da região de interesse e necessita de métodos numéricos de cálculo de campos específicos. Neste trabalho, serão abordadas as modelagens de problemas decorrentes da circulação de correntes elétricas no solo (ditos de acoplamentocondutivo) com o método dos elementos finitos. Também serão considerados problemas produzidos pela variação temporal dos campos eletromagnéticos (ditos de acoplamento indutivo), que serão tratados com o método PEEC(Partial Element Equivalent Circuit) generalizado. Mais especificamente, uma condição de contorno particular sobre o potencial elétrico é proposta para o truncamento do domínio de cálculo na análise de problemas de acoplamento condutivo com o método dos elementos finitos, e uma formulação completa tipo PEEC para a modelagem de problemas de acoplamento indutivo é apresentada. Problemas teste de complexidades crescentes são considerados para a validação das abordagens precedentes. Estes trabalhos visam fornecer desta forma uma contribuição à modelagem desta classe de problemas, que tendem a se tornar comuns com a expansão das redes elétricas
11
Walpole, Mark Edward. "Intrinsically Safe (IS) Active Power Supplies." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15896/1/Mark_Walpole_Thesis.pdf.
Full textAbstract:
Intrinsically safe (IS) active power supplies subjected to certain transient load conditions can deliver power to a circuit at significantly higher levels than indicated on their nameplate ratings. During a transient load such as an intermittent short-circuit, energy is transferred from the power supply to the short-circuit and an electrical arc may form when the short-circuit is applied or removed. This poses a spark ignition risk as energy is transferred from the arc to the surrounding atmosphere.
Currently various International and Australian Standards define the performance requirements for IS electrical apparatus. A duly accredited laboratory is required to establish the intrinsic safety compliance of an apparatus with the Standards. It involves an assessment of the apparatus and may include testing. The assessment of the apparatus determines adequate segregation, separation, construction, and selection of components. The tests performed on the apparatus include a temperature rise test and in some cases, the sparking potential of the circuit is tested using the spark test apparatus (STA). Testing the sparking potential of active power supplies to establish compliance adds significantly to the time and costs involved in establishing compliance.
A new alternative assessment method is proposed in this report to augment or replace the testing phase of the compliance certification process for active power supplies. The proposed alternative assessment method (PAAM) is derived from a determination of the steady-state and transient output characteristics of the active power supply under consideration. Parameters such as peak output current, time constant of peak current decay, and the output voltages at these times are measured from the circuit's output characteristics. These measurements can subsequently be used to derive the topology and component values of an equivalent circuit. The resulting equivalent circuit is then considered like a linear power supply and the sparking potential can be determined using existing assessment methods.
This thesis investigates in detail the equivalent circuit of a number of direct current (DC) active power supplies whose transient output characteristics exhibit predominantly capacitive behaviour. The results of the PAAM using the equivalent circuit are then compared with results achieved using the current testing procedure with a STA.
A small sample of active power supplies is used to generate data from which a relationship between the current testing procedure and the PAAM can be established.
The PAAM developed in this research project can be used as a pre-compliance check by designers, manufacturers, or IS testing stations. A failure of this test would indicate that the active power supply's sparking energy is not low enough to be regarded as intrinsically safe. The PAAM requires fewer resources to establish a result than the STA. The benefits of a simplified spark ignition test would flow on from designers and manufacturers to end users.
12
Walpole, Mark Edward. "Intrinsically Safe (IS) Active Power Supplies." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15896/.
Full textAbstract:
Intrinsically safe (IS) active power supplies subjected to certain transient load conditions can deliver power to a circuit at significantly higher levels than indicated on their nameplate ratings. During a transient load such as an intermittent short-circuit, energy is transferred from the power supply to the short-circuit and an electrical arc may form when the short-circuit is applied or removed. This poses a spark ignition risk as energy is transferred from the arc to the surrounding atmosphere. Currently various International and Australian Standards define the performance requirements for IS electrical apparatus. A duly accredited laboratory is required to establish the intrinsic safety compliance of an apparatus with the Standards. It involves an assessment of the apparatus and may include testing. The assessment of the apparatus determines adequate segregation, separation, construction, and selection of components. The tests performed on the apparatus include a temperature rise test and in some cases, the sparking potential of the circuit is tested using the spark test apparatus (STA). Testing the sparking potential of active power supplies to establish compliance adds significantly to the time and costs involved in establishing compliance. A new alternative assessment method is proposed in this report to augment or replace the testing phase of the compliance certification process for active power supplies. The proposed alternative assessment method (PAAM) is derived from a determination of the steady-state and transient output characteristics of the active power supply under consideration. Parameters such as peak output current, time constant of peak current decay, and the output voltages at these times are measured from the circuit's output characteristics. These measurements can subsequently be used to derive the topology and component values of an equivalent circuit. The resulting equivalent circuit is then considered like a linear power supply and the sparking potential can be determined using existing assessment methods. This thesis investigates in detail the equivalent circuit of a number of direct current (DC) active power supplies whose transient output characteristics exhibit predominantly capacitive behaviour. The results of the PAAM using the equivalent circuit are then compared with results achieved using the current testing procedure with a STA. A small sample of active power supplies is used to generate data from which a relationship between the current testing procedure and the PAAM can be established. The PAAM developed in this research project can be used as a pre-compliance check by designers, manufacturers, or IS testing stations. A failure of this test would indicate that the active power supply's sparking energy is not low enough to be regarded as intrinsically safe. The PAAM requires fewer resources to establish a result than the STA. The benefits of a simplified spark ignition test would flow on from designers and manufacturers to end users.
13
Torchio, Riccardo. "Extending the Unstructured PEEC Method to Magnetic, Transient, and Stochastic Electromagnetic Problems." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422324.
Full textAbstract:
The main focus of this thesis is to extend and improve the applicability and the accuracy of the Unstructured Partial Element Equivalent Circuit (PEEC) method. The interest on this subject is spurred by the growing need of fast and efficient numerical methods, which may help engineers during the design and other stages of the production of new generation electric components.
First, the PEEC method in its unstructured form is extended to magnetic media. In this regard, two formulations are developed and compared: the first one, based on the Amperian interpretation of the magnetization phenomena, is derived from the existing literature concerning the standard (structured) version of PEEC; the second one, based on the Coulombian interpretation of the magnetization phenomena, is proposed by the author with the aim of collocating PEEC in the context of Volume Integral Equation methods.
Then, the application of low-rank compression techniques to PEEC is investigated. Two different methods are applied: the first is based on hierarchical matrices (H and H2 matrices) whereas the second is based on hierarchical-semi-separable (HSS) matrices. The two methods are compared and the main numerical issues which emerge by applying low-rank techniques to PEEC are analyzed.
Finally, the developed unstructured PEEC method is combined with the Marching On-in Time scheme for the study of fast transient phenomena with wide range of harmonics. Moreover, two different stochastic PEEC methods are developed for uncertainty quantification analysis. The first is based on the Polynomial Chaos expansion while the second is based on the Parametric Model Order Reduction technique coupled with spectral expansion.<br>L'obiettivo principale di questa tesi è di estendere e migliorare l'applicabilità e l'accuratezza del metodo Partial Element Equivalent Circuit (PEEC) non strutturato (Unstructured PEEC). L'interesse riguardo tale argomento è stimolato dalla crescente necessità di metodi numerici rapidi ed efficienti, che possono aiutare gli ingegneri durante la progettazione e altre fasi della produzione di componenti elettrici ed elettronici di nuova generazione.
Durante la prima fase della tesi, il metodo PEEC (nella sua forma non strutturata) è esteso ai mezzi magnetici. A questo proposito, vengono sviluppate e confrontate due formulazioni: la prima, basata sull'interpretazione amperiana dei fenomeni di magnetizzazione, deriva dalla letteratura esistente relativa alla versione standard (strutturata) del metodo PEEC; il secondo, basato sull'interpretazione coulombiana dei fenomeni di magnetizzazione, è proposto dall'autore con l'obiettivo di collocare il metodo PEEC nel contesto dei metodi di integrali di volume (Volume Integral Equation).
Successivamente, la ricerca si focalizza sull’utilizzo di tecniche di compressione a basso rango al fine di risolvere problemi PEEC in maniera computazionalmente efficiente, salvaguardando tempo e memoria di calcolo. A tal proposito, vengono applicati due metodi diversi: il primo si basa su matrici gerarchiche (matrici H e H2 mentre il secondo si basa su matrici gerarchiche-semi-separabili (HSS). I due metodi vengono confrontati e vengono analizzati i principali problemi numerici che emergono applicando tali tecniche di compressione a basso rango al metodo PEEC.
In seguito, il metodo PEEC non strutturato viene combinato con l’approccio Marching On-In Time (MOT) per lo studio di fenomeni transitori rapidi con un ricco contenuto armonico.
Infine, sono stati sviluppati due diversi metodi PEEC stocastici per la quantificazione dell'incertezza. Il primo si basa sull'espansione Polynomial Chaos, mentre il secondo si basa sulla tecnica di riduzione d'ordine parametrica (Parametric Model Order Reduction) unita all'espansione spettrale.
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Sifi, Nedjem-Eddine. "Caractérisation de dispositifs microondes dans le domaine temporel par identification à des modèles électriques équivalents." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0092.
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Dans le domaine des telecommunications, nous constatons que non seulement la recherche et le developpement mais aussi la fabrication et le controle des systemes sont grandement conditionnes par les moyens de mesure et d'experimentation disponibles. Ce constat est encore plus net dans le domaine des microondes. En effet, bien que l'evolution rapide de la conception assistee par:ordinateur (cao) limite maintenant les etapes intermediaires, il n'est pas realiste d'envisager des systemes ou composants concus et realises sans experimentation preliminaire, intermediaire ou finale. Tenir compte des phenomenes physiques qui se manifestent dans et autour d'un systeme donne dans une configuration operationnelle est donc une condition imperative pour la simulation, le controle de conception ou bien la verification du fonctionnement sous des conditions non realisables sur le vrai systeme. Il apparait donc que la formulation d'un modele et l'estimation de ses parametres est une etape essentielle dans la comprehension d'un phenomene ; nous sommes donc confrontes a un probleme d'identification. Actuellement, l'identification phenomenologique des systemes a des modeles equivalents joue un role de plus en plus important dans la resolution de divers problemes en hyperfrequences et notamment dans le domaine des circuits et composants. Cette evolution puise son origine d'une part dans la formidable evolution des calculeurs numeriques et le developpement de simulateurs electriques tres puissants et d'autre part dans la disponibilite d'appareils de mesures hyperfrequences tres performants notamment les appareils de mesure par reflectometrie temporelle
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Vyčítal, Václav. "Ustálený chod a zkratové poměry v síti 110 kV E.ON napájené z transformovny Sokolnice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221345.
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This thesis can be divided into five main parts. The first part deals with theoretical analysis of power flow calculation in power network during steady state condition. Load flow calculation is presented here as a linear and nonlinear problem. Newton iteration method is proposed for solving power flow as nonlinear problem. The second part of this thesis deals with the analysis of short-circuit calculation in accordance with valid International Standard IEC 60909. The equivalent voltage source method is adopted in case of the short-circuit calculation. For the calculation of unbalanced short-circuit currents, the symmetrical components method is also presented. The last three parts of this paper are focused on calculations of power flow and short-circuit conditions in power grid Sokolnice. So in the third part is the description of nodal area Sokolnice with its substations and the calculation of load flow and short-circuit conditions for two different power supply options. For each supply option is also considered an abnormal (fault) grid condition. (overall there are solved four different options) The fourth part of this thesis deals with the result analysis and also the results of different power supply options are compared. In the last part there are presented necessary technical improvements for fault-free operation of power grid Sokolnice based on the result of power flow and short-circuit conditions in that grid.
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Susetyo, Budi. "Modélisation de l'impédance harmonique de charges agrégées." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0027.
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Les applications de l’électronique de puissance contribuent à la pollution harmonique des réseaux électriques. Pour estimer le niveau de distorsion de tension, les différents composants du réseau doivent être modélisés en régime harmonique, en particulier les charges consommatrices, industrielles, commerciales et domestiques. L’étude concerne la modélisation de l’impédance harmonique des charges qui peuvent être séparées en deux grandes catégories: les charges passives et les charges dites actives qui réalisent une conversion d’énergie électromécanique. Les modèles disponibles pour les charges élémentaires sont récapitules en termes de complexité et de précision. Puis une méthode d’agrégation est développée, permettant d'obtenir un circuit équivalent d'ordre minimal et de structure compatible avec celle du réseau. La méthode d'identification des paramètres de ce circuit est basée sur une représentation fréquentielle de l’impédance harmonique, afin d'obtenir une réponse qui coïncide avec celle du réseau réel. Ce modèle agrège est utilise pour étudier la sensibilité de l’impédance harmonique aux variations aléatoires des paramètres caractéristiques du réseau et des charges.
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Tabaga, Saleh. "Modélisation du comportement fréquentiel du transformateur : détermination des paramètres du schéma équivalent par la méthode des éléments finis en géométries 2D et 3D." Grenoble INPG, 1995. http://www.theses.fr/1995INPG0081.
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La connaissance et la maîtrise des régimes transitoires qui apparaissent et se propagent sur les réseaux et dans le matériel électrique (transformateurs, parafoudres,. . . ) est un problème d'actualité. Relié au réseau électrique, un transformateur peut subir différents types de surtensions dont la connaissance permet d'évaluer les contraintes auxquelles sont soumises les isolations internes. La modélisation du comportement à haute fréquence d'un transformateur industriel de type cuirassé, nous a conduit à élaborer un schéma électrique équivalent à constantes localisées et à paramètres constants, qui sont déterminés d'une manière précise en tenant compte de la géométrie réelle du transformateur. La méthode des éléments finis bi et tri-dimensionnel: en électromagnétique, nous a semblé intéressante à utiliser puisqu'elle est basée sur la détermination du champ électromagnétique régissant tout le comportement du transformateur. Cette méthode a été utilisée pour calculer les paramètres capacitifs, inductifs et résistifs du schéma équivalent, respectivement en électrostatique, magnétostatique et magnétodynamique. Différents éléments spéciaux en 3D ont été utilisés pour évaluer les courants de Foucault dans les régions minces du transformateur (la cuve, le circuit magnétique et les écrans électrostatiques). On a pu montrer que ces courants affectent les valeurs des paramètres relatifs aux parties du bobinage qui leur sont géométriquement proches. Une fois les éléments du schéma équivalent calculés, nous avons effectué un calcul temporel et fréquentiel afin de déterminer les fréquences propres du transformateur. Nous avons pu valider notre modèle dans une gamme de fréquences allant de 40 kHz à 600 kHz. Les fréquences de résonances calculées, sont en bon accord avec celles mesurées
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Zheng, Yexin. "Circuit Design Methods with Emerging Nanotechnologies." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/30000.
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As complementary metal-oxide semiconductor (CMOS) technology faces more and more severe physical barriers down the path of continuously feature size scaling, innovative nano-scale devices and other post-CMOS technologies have been developed to enhance future circuit design and computation. These nanotechnologies have shown promising potentials to achieve magnitude improvement in performance and integration density. The substitution of CMOS transistors with nano-devices is expected to not only continue along the exponential projection of Moore's Law, but also raise significant challenges and opportunities, especially in the field of electronic design automation. The major obstacles that the designers are experiencing with emerging nanotechnology design include: i) the existing computer-aided design (CAD) approaches in the context of conventional CMOS Boolean design cannot be directly employed in the nanoelectronic design process, because the intrinsic electrical characteristics of many nano-devices are not best suited for Boolean implementations but demonstrate strong capability for implementing non-conventional logic such as threshold logic and reversible logic; ii) due to the density and size factors of nano-devices, the defect rate of nanoelectronic system is much higher than conventional CMOS systems, therefore existing design paradigms cannot guarantee design quality and lead to even worse result in high failure ratio. Motivated by the compelling potentials and design challenges of emerging post-CMOS technologies, this dissertation work focuses on fundamental design methodologies to effectively and efficiently achieve high quality nanoscale design.
A novel programmable logic element (PLE) is first proposed to explore the versatile functionalities of threshold gates (TGs) and multi-threshold threshold gates (MTTGs). This PLE structure can realize all three- or four-variable logic functions through configuring binary control bits. This is the first single threshold logic structure that provides complete Boolean logic implementation. Based on the PLEs, a reconfigurable architecture is constructed to offer dynamic reconfigurability with little or no reconfiguration overhead, due to the intrinsic self-latching property of nanopipelining. Our reconfiguration data generation algorithm can further reduce the reconfiguration cost.
To fully take advantage of such threshold logic design using emerging nanotechnologies, we also developed a combinational equivalence checking (CEC) framework for threshold logic design. Based on the features of threshold logic gates and circuits, different techniques of formulating a given threshold logic in conjunctive normal form (CNF) are introduced to facilitate efficient SAT-based verification. Evaluated with mainstream benchmarks, our hybrid algorithm, which takes into account both input symmetry and input weight order of threshold gates, can efficiently generate CNF formulas in terms of both SAT solving time and CNF generating time.
Then the reversible logic synthesis problem is considered as we focus on efficient synthesis heuristics which can provide high quality synthesis results within a reasonable computation time. We have developed a weighted directed graph model for function representation and complexity measurement. An atomic transformation is constructed to associate the function complexity variation with reversible gates. The efficiency of our heuristic lies in maximally decreasing the function complexity during synthesis steps as well as the capability to climb out of local optimums. Thereafter, swarm intelligence, one of the machine learning techniques is employed in the space searching for reversible logic synthesis, which achieves further performance improvement.
To tackle the high defect-rate during the emerging nanotechnology manufacturing process, we have developed a novel defect-aware logic mapping framework for nanowire-based PLA architecture via Boolean satisfiability (SAT). The PLA defects of various types are formulated as covering and closure constraints. The defect-aware logic mapping is then solved efficiently by using available SAT solvers. This approach can generate valid logic mapping with a defect rate as high as 20%. The proposed method is universally suitable for various nanoscale PLAs, including AND/OR, NOR/NOR structures, etc.
In summary, this work provides some initial attempts to address two major problems confronting future nanoelectronic system designs: the development of electronic design automation tools and the reliability issues. However, there are still a lot of challenging open questions remain in this emerging and promising area. We hope our work can lay down stepstones on nano-scale circuit design optimization through exploiting the distinctive characteristics of emerging nanotechnologies.<br>Ph. D.
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Múdry, Peter. "Ustálený chod a zkratové poměry v síti 110 kV E.ON při paralelním provozu uzlových oblastí R Čebín a R Sokolnice." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220169.
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In the distribution network 110 kV of E.ON Company there are the nodal areas of Čebin substation and Sokolnice substation which are operated separately at the present time. There is one 400/110 kV transformer for each nodal area. In case of fault on one of these transformers or on busbar in which the set transformer is working, it comes to an outage of electric supply in the set nodal area. This problem has to be solved with help of the parallel operation of nodal areas of Čebín substation and Sokolnice substation. The main and also the practical task of this work is to design the bridge connection appropriate for parallel operation of nodal areas (supply transformers 400/110 kV). With help of a computing program there were made calculations of steady state and short-circuit conditions in distribution network 110 kV for separated and parallel operation of nodal areas. Voltage conditions, load of transformers (400/110 kV and 110/vn kV) and conditions on 110 kV lines are evaluated and controlled as the result of steady state calculations. Based on short-circuit conditions there is controlled the short-circuit resistance of the substations. Finally there are compared advantages and disadvantages of separated and parallel operations of nodal areas. If necessary, technical arrangements required for introduction of parallel operation of nodal areas of Čebín substation and Sokolnice substation will be designed. The theoretical part of the work deals with calculation of steady state with help of iterative methods, namely Newton´s and Gauss-Seidel methods. There are further described the method of calculating short-circuit currents, characteristic values and time behaviours of short-circuit current.
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Cirovic, Branislav. "Equivalence relations of synchronous schemes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0031/NQ62448.pdf.
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Youssef, Moez. "Rayonnement dans les convertisseurs d'électronique de puissance." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0175.
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L'étude de la compatibilité électromagnétique (CEM) est devenue un passage obligé pour les concepteurs de circuits d'électronique de puissance. La complexité des phénomènes qui entrent en jeu lors de cette étude fait de plus en plus sentir le besoin d'un outil CAO de prédiction des perturbations électromagnétiques conduites et rayonnées. I-e présent travail est consacré au calcul du champ rayonné par un circuit d'électronique de puissance. Comme première étape, le champ rayonné a été calculé à partir du courant mesuré. Ensuite, dans le but de développer un outil de simulation de circuits d'électronique de puissance, certaines méthodes de modélisation de câblage ont été étudiées. Notre choix s'est fixé sur la méthode rPEEC qui permet de modéliser chaque partie du câblage par un circuit électrique équivalent, qu'on peut facilement implanter dans un logiciel de simulation. Cette méthode a été appliquée pour deux géométries qu'on rencontre souvent on électronique de puissance ainsi qu'au cas de I'anterne. La validité de la méthode sur une large gamme de fréquence a été ainsi confirmée<br>The study of electromagnetic compatibility @MC) becomes an obliged transition for power electronics circuits designers. The complexity of phenomena confirms the need of a CAD tool for the prediction of conducted and radiated disturbances. This wor* deals with the calculation of field radiated by a power electronics converter. As a first step, fields are calculated from measured current. Afterwards, some methods of modeiing cabling are studied. We choose the rPEEC method that permits a modeling of every part of cabling by an equivalent electrical circuit, which can be used in a simulator. This method is applied for two classical geometry in power electronics. It's also apptied for the antenna. That's confirms the validity of the method on a large frequency range
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Bladh, Johan. "Hydropower generator and power system interaction." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182188.
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After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. At the same time, an extensive reinvestment programme has commenced where many old components and apparatus are being refurbished or replaced. Introduction of new technical solutions in existing power plants requires good systems knowledge and careful consideration. Important tools for research, development and analysis are suitable mathematical models, numerical simulation methods and laboratory equipment. This doctoral thesis is devoted to studies of the electromechanical interaction between hydropower units and the power system. The work encompasses development of mathematical models, empirical methods for system identification, as well as numerical and experimental studies of hydropower generator and power system interaction. Two generator modelling approaches are explored: one based on electromagnetic field theory and the finite element method, and one based on equivalent electric circuits. The finite element model is adapted for single-machine infinite-bus simulations by the addition of a network equivalent, a mechanical equation and a voltage regulator. Transient simulations using both finite element and equivalent circuit models indicate that the finite element model typically overestimates the synchronising and damping properties of the machine. Identification of model parameters is performed both numerically and experimentally. A complete set of equivalent circuit parameters is identified through finite element simulation of standard empirical test methods. Another machine model is identified experimentally through frequency response analysis. An extension to the well-known standstill frequency response (SSFR) test is explored, which involves measurement and analysis of damper winding quantities. The test is found to produce models that are suitable for transient power system analysis. Both experimental and numerical studies show that low resistance of the damper winding interpole connections are vital to achieve high attenuation of rotor angle oscillations. Hydropower generator and power system interaction is also studied experimentally during a full-scale startup test of the Nordic power system, where multiple synchronised data acquisition devices are used for measurement of both electrical and mechanical quantities. Observation of a subsynchronous power oscillation leads to an investigation of the torsional stability of hydropower units. In accordance with previous studies, hydropower units are found to be mechanically resilient to subsynchronous power oscillations. However, like any other generating unit, they are dependent on sufficient electrical and mechanical damping. Two experimentally obtained hydraulic damping coefficients for a large Francis turbine runner are presented in the thesis.
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Hamdi, Bilel. "Modélisation des circuits périodiques et quasi-périodiques alimentés par des sources arbitraires." Thesis, Toulouse, INPT, 2015. https://oatao.univ-toulouse.fr/25877/1/HAMDI_Bilel.pdf.
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Les réseaux d’antennes planaires sont réputés par leur grande directivité et leur facilité de mise en œuvre qui offre la possibilité d’avoir un diagramme de rayonnement commandable. Cependant l’étude globale tenant compte des différents couplages EM par une théorie électromagnétique rigoureuse nécessite un espace mémoire important et un temps de calcul considérable. Pour surmonter à ces inconvénients, nous proposons d’introduire une nouvelle approche théorique basée sur le théorème de Floquet permettant la réduction du volume d’analyse EM au niveau d’une seule cellule élémentaire. Nous allons focaliser notre étude à la détermination des termes de couplage dans une configuration répartie dans une trame presque-périodique et en particulier pour les réseaux d’antennes périodiques et quasi-périodiques alimentés par des sources arbitraires. Dans ce cas, nous utiliserons les décompositions en modes de Floquet (adaptées aux structures périodiques) pour extraire la matrice de couplage [S]. Ces décompositions sont des concepts établis de longue date et a priori démontrés par de supports théoriques solides. Par conséquent, cette analyse modale permet de simplifier la résolution du problème considéré surtout quand les éléments rayonnants sont fortement couplés. Une seule méthode numérique est adoptée afin de modéliser la structure proposée : la méthode des moments combinée avec le circuit équivalent généralisé : MoM-GEC. La validation de cette dernière sera réalisée par comparaison avec d’autres méthodes numériques exactes<br>Planar antenna arrays are renowned for their high directivity and ease of implementation, which offers the possibility of having a controllable radiation pattern. However the global study taking into account the different EM couplings by a rigorous electromagnetic theory requires a large memory space and a considerable computation time. To overcome these drawbacks, we propose to introduce a new theoretical approach based on the Floquet theorem allowing the reduction of the EM analysis volume at the level of a single elementary cell (basic cell). We will focus our study on the determination of coupling terms in a distributed configuration in an almost-periodic frame and in particular for periodic and quasi-periodic antenna arrays fed by arbitrary sources. In this case, we will use Floquet mode decompositions (adapted to periodic structures) to extract the coupling matrix [S]. These decompositions are concepts established for a long time and a priori demonstrated by solid theoretical supports. Consequently, this modal analysis makes it possible to simplify considerably the resolution of the problem, especially when the radiating elements are strongly coupled. A single numerical method is adopted in order to model the proposed structure: the method of moments combined with the generalized equivalent circuit: MoM-GEC. Validation of the latter will be done by comparison with other exact numerical methods
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Thakore, Vaibhav. "Nonlinear dynamic modeling, simulation and characterization of the mesoscale neuron-electrode interface." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5529.
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Extracellular neuroelectronic interfacing has important applications in the fields of neural prosthetics, biological computation and whole-cell biosensing for drug screening and toxin detection. While the field of neuroelectronic interfacing holds great promise, the recording of high-fidelity signals from extracellular devices has long suffered from the problem of low signal-to-noise ratios and changes in signal shapes due to the presence of highly dispersive dielectric medium in the neuron-microelectrode cleft. This has made it difficult to correlate the extracellularly recorded signals with the intracellular signals recorded using conventional patch-clamp electrophysiology. For bringing about an improvement in the signal-to-noise ratio of the signals recorded on the extracellular microelectrodes and to explore strategies for engineering the neuron-electrode interface there exists a need to model, simulate and characterize the cell-sensor interface to better understand the mechanism of signal transduction across the interface. Efforts to date for modeling the neuron-electrode interface have primarily focused on the use of point or area contact linear equivalent circuit models for a description of the interface with an assumption of passive linearity for the dynamics of the interfacial medium in the cell-electrode cleft. In this dissertation, results are presented from a nonlinear dynamic characterization of the neuroelectronic junction based on Volterra-Wiener modeling which showed that the process of signal transduction at the interface may have nonlinear contributions from the interfacial medium. An optimization based study of linear equivalent circuit models for representing signals recorded at the neuron-electrode interface subsequently proved conclusively that the process of signal transduction across the interface is indeed nonlinear. Following this a theoretical framework for the extraction of the complex nonlinear material parameters of the interfacial medium like the dielectric permittivity, conductivity and diffusivity tensors based on dynamic nonlinear Volterra-Wiener modeling was developed. Within this framework, the use of Gaussian bandlimited white noise for nonlinear impedance spectroscopy was shown to offer considerable advantages over the use of sinusoidal inputs for nonlinear harmonic analysis currently employed in impedance characterization of nonlinear electrochemical systems. Signal transduction at the neuron-microelectrode interface is mediated by the interfacial medium confined to a thin cleft with thickness on the scale of 20-110 nm giving rise to Knudsen numbers (ratio of mean free path to characteristic system length) in the range of 0.015 and 0.003 for ionic electrodiffusion. At these Knudsen numbers, the continuum assumptions made in the use of Poisson-Nernst-Planck system of equations for modeling ionic electrodiffusion are not valid. Therefore, a lattice Boltzmann method (LBM) based multiphysics solver suitable for modeling ionic electrodiffusion at the mesoscale neuron-microelectrode interface was developed. Additionally, a molecular speed dependent relaxation time was proposed for use in the lattice Boltzmann equation. Such a relaxation time holds promise for enhancing the numerical stability of lattice Boltzmann algorithms as it helped recover a physically correct description of microscopic phenomena related to particle collisions governed by their local density on the lattice. Next, using this multiphysics solver simulations were carried out for the charge relaxation dynamics of an electrolytic nanocapacitor with the intention of ultimately employing it for a simulation of the capacitive coupling between the neuron and the planar microelectrode on a microelectrode array (MEA). Simulations of the charge relaxation dynamics for a step potential applied at t = 0 to the capacitor electrodes were carried out for varying conditions of electric double layer (EDL) overlap, solvent viscosity, electrode spacing and ratio of cation to anion diffusivity. For a large EDL overlap, an anomalous plasma-like collective behavior of oscillating ions at a frequency much lower than the plasma frequency of the electrolyte was observed and as such it appears to be purely an effect of nanoscale confinement. Results from these simulations are then discussed in the context of the dynamics of the interfacial medium in the neuron-microelectrode cleft. In conclusion, a synergistic approach to engineering the neuron-microelectrode interface is outlined through a use of the nonlinear dynamic modeling, simulation and characterization tools developed as part of this dissertation research.<br>Ph.D.<br>Doctorate<br>Physics<br>Sciences<br>Physics
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Farrell, Troy W. "The mathematical modelling of primary alkaline battery cathodes." Thesis, Queensland University of Technology, 1998.
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Fialka, Jiří. "Měření parametrů piezoelektrických materiálů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217770.
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The master’s thesis deals with the piezoelectric coefficients, the resonance frequency and especially the piezoelectric constants verification. With the assistance of several devices, for instance LCR-meter HIOKI 3532, impedance analyzer Agilent 4294A and LCR-meter Agilent E4980A, the resonance and the anti-resonance frequencies as well as impedance and capacitance of samples are measured. The paper opens with the theory of the piezoelectric phenomenon and the difference between direct and indirect piezoelectric phenomenon, it also describes the basic behaviour of a piezoelectric ceramic element during mechanical straining or applied voltage. Further, the paper concerns the description of various piezoelectric constants and their calculations. Subsequent part of the paper is devoted to the temperature dependence of the main piezoelectric parameters of PZT ceramics. The materials coefficients are delineated as a function of temperature of the piezoelectric charge coefficients dij, relative permittivity r, electromechanical coupling factor kij and frequency constants Ni. One of the chapters also determines the piezoelectric charge constant d33 of PZT ceramics by laser interferometer and compares it with the value measured by resonance methods. The surface displacement was measured by a single-beam interferometer Polytec OFV-5000. The results of measurements of piezoelectric charge coefficients d33 acquired by the first and the second method are identical. The last section of the paper is focused on different methods of experimental studies on the characteristics of heat transfer by diffusing heat through conduction between the silver-plated surface of cylinder made of PZT ceramics. The effect on the resonance and the anti-resonance frequencies is monitored. There after, the real heat, determined by thermo camera and the physical model of heat transfer created in program COMSOL Multiphysics, is analysed.
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Pon, Jyun-Jie, and 彭俊傑. "Quantum-Mechanic Simulation using Equivalent-Circuit Method and k-matrix Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/43b57c.
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碩士<br>國立中央大學<br>電機工程研究所<br>94<br>In the thesis, we will use two methods to simulate the quantum mechanical systems. The first way is called the k-matrix method, and the other way is the equivalent-circuit method. We use these two methods to analyze periodic KP-model and non-periodic QM systems. The result obtained by these ways is the wave function of the Schrödinger wave equation. Additionally, we will compare the k-matrix method with the equivalent-circuit method and show these results of the k-matrix method are same as the equivalent-circuit method. We will also show the advantages and disadvantages of these two methods.
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YANG, JIA-WEI, and 楊家偉. "A Study on Property of Cement Paste Using Equivalent Circuit Method." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/c64rex.
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碩士<br>東南科技大學<br>營建與空間設計系營建科技與防災碩士班<br>105<br>The objective of this study is to discuss the application of the ac impedance and vicat needle to the cement paste and water-cement ratio. there are four kinds of equivalent circuit plots in our simulation test.
The results of our study show that it takes longer for initial setting and final setting if the
ratio of cement paste and water-cement is higher. besides, it also contributes to the same effect
if we add more fly ash and slag in the cement paste. furthermore, if the frequency range of the
fly ash and slag cement paste is fixed at 10000hz, we found that the susceptance of ac
impedance in our simulation test result will increase. the time is between 0 to 45 minutes and
it is close to the final setting time in the vicat needle. on the other hand, we also used four
kinds of equivalent circuit plot in our test, and we found that the results in mode1 and mode3
are close to the results of our simulation test, and the Rt(s+l)、Rs are also positively related to
the quantities of fly ash and slag that we add in the cement paste.
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WANG, SHI-JIE, and 王世杰. "Steady-state analysis of induction motors by a combined finite element-equivalent circuit method." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/93099151918966892925.
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Chang, Ting-Chen, and 張庭禎. "Parameter Derivation of Equivalent Circuit Model for Photovoltaic Panel with Ripple Current Orientation Method." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/66350592792619886531.
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碩士<br>國立中山大學<br>電機工程學系研究所<br>104<br>For a photovoltaic (PV) panel, an equivalent circuit with an additional parasitic capacitance on the conventionally used single-diode static model can be used to interpret the phase deviation between the output voltage and current and to simulate the dynamic characteristics. The parameters of the equivalent circuit can be derived simply from five test points when a boost converter is attached to the PV panel for maximum power point tracking (MPPT) drawing a rippled current. The circuit parameters of the static model are calculated from the open-circuit voltage, the maximum power, and the short-circuit current, which can be rapidly obtained by operating the boost converter at a designated ripple current. An equation to account for the variation of the parasitic capacitance can be derived from two arbitrary operation points with voltages less than the diode threshold voltage of the PV panel. The circuit parameters for different irradiations can be obtained from the ratio of the short circuit current to the pre-known short-circuit current. Experimental results have confirmed that fitness of the equivalent circuit model with parameter identification and demonstrated that it can be used for simulating the transient behaviors of a PV panel with a rippled current.
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Chen, Chun-chung, and 陳俊中. "Extracting MOSFET Small Signal Equivalent Circuit and Substrate Parameters with Four Port De-embedding Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/4322rd.
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碩士<br>國立中山大學<br>電機工程學系研究所<br>97<br>Characteristics of small signal components for circuit designers are very important in circuit design. Many researchers have been working hard on removing the unwanted parasitic effects which is used to get the intrinsic characteristics of the small signal parameters.
In this thesis, we propose a novel four-port de-embedding procedure which based on two-port cascade structure de-embedding procedure and combined with metal and polysilicon ground-shielded technology, and let four terminals of MOSFET are connected individually to four signal pads. With such de-embedding procedure, the intrinsic and substrate element values of small-signal model are extracted by different bias.
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Torchio, Riccardo. "Extending the Unstructured PEEC Method to Magnetic, Transient, and Stochastic Electromagnetic Problems." Doctoral thesis, 2019. http://hdl.handle.net/11577/3317792.
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L’obiettivo principale di questa tesi è di estendere e migliorare l’applicabilità e l’accuratezza del metodo Partial Element Equivalent Circuit (PEEC) non strutturato (Unstructured PEEC). L’interesse riguardo tale argomento è stimolato dalla crescente necessità di metodi numerici rapidi ed efficienti, che possono aiutare gli ingegneri durante la progettazione e altre fasi della produzione di componenti elettrici ed elettronici di nuova generazione. Durante la prima fase della tesi, il metodo PEEC (nella sua forma non strutturata) è esteso ai mezzi magnetici. A questo proposito, vengono sviluppate e confrontate due formulazioni: la prima, basata sull’interpretazione amperiana dei fenomeni di magnetizzazione, deriva dalla letteratura esistente relativa alla versione standard (strutturata) del metodo PEEC; il secondo, basato sull’interpretazione coulombiana dei fenomeni di magnetizzazione, è proposto dall’autore con l’obiettivo di collocare il metodo PEEC nel contesto dei metodi di integrali di volume (Volume Integral Equation). Successivamente, la ricerca si focalizza sull’utilizzo di tecniche di compressione a basso rango al fine di risolvere problemi PEEC in maniera computazionalmente efficiente, salvaguardando tempo e memoria di calcolo. A tal proposito, vengono applicati due metodi diversi: il primo si basa su matrici gerarchiche (matrici H e H2) mentre il secondo si basa su matrici gerarchiche-semi-separabili (HSS). I due metodi vengono confrontati e vengono analizzati i principali problemi numerici che emergono applicando tali tecniche di compressione a basso rango al metodo PEEC. In seguito, il metodo PEEC non strutturato viene combinato con l’approccio Marching On-In Time (MOT) per lo studio di fenomeni transitori rapidi con un ricco contenuto armonico. Infine, sono stati sviluppati due diversi metodi PEEC stocastici per la quantificazione dell’incertezza. Il primo si basa sull’espansione Polynomial Chaos, mentre il secondo si basa sulla tecnica di riduzione d’ordine parametrica (Parametric Model Order Reduction) unita all’espansione spettrale.
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Chang, Hsiao-Chen, and 張孝甄. "Equivalent Circuit Extraction of Embedded High-speed Interconnects by Combining FDTD method and Layer Peeling Technique." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/29438662626398788105.
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碩士<br>國立中山大學<br>電機工程學系研究所<br>90<br>We proposes an efficient algorithm for extracting SPICE-compatible circuits of embedded interconnect structures from FDTD-simulated time-domain reflections. A layer-peeling technique (LPT) is used to obtain the time-domain step response of the interconnects under extract (IUE) itself. A pencil matrix method is then used to get the pole-residue representation of the time-domain step response of the IUE. A pole-reducing procedure is implemented based on a bandwidth criterion to simplify pole-residue representation. Finally, the lumped equivalent models of the IUE are synthesized by an equivalent lumped-model extraction technique, in which four types of equivalent model bases are used. The equivalent circuit can be easily implemented in SPICE-like simulator. Several transmission line structures are presented as examples to demonstrate the validity of the proposed algorithm both in time and frequency domains.
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余昱穎. "Bias Dependence and Geometry Effect of SiGe HBTs Equivalent circuit Elements using Direct Parameter-Extraction Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/77801493815957913719.
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何浩榮. "Development of Time-domain Equivalent Circuit Method and Simulation of Nonlinear Distortion for the Speaker Modules." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/86871679047042298059.
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碩士<br>逢甲大學<br>電聲碩士學位學程<br>102<br>The objective of this study is to develop a simulation method of the nonlinear distortion for speaker modules with an aim to accelerate the speaker development cycle.
By using Matlab and the Runge-Kutta method as a calculation kernel, we have developed a time-domain equivalent circuit system for the nonlinear electro-mechanical-acoustical (EMA) equivalent circuit method. The conventional time-domain equivalent circuit method can calculate the total harmonic distortion for a speaker monomer only. The proposed nonlinear EMA equivalent circuit method can not only obtain the same results as the frequency-domain equivalent circuit method, but also can simulate the total harmonic distortion for speaker modules.
A finite element analysis (FEA) using COMSOL Multiphysics software is performed for the calculation of sound pressure level of the speaker module with or without a passive radiator. The nonlinear stiffness of the passive radiator is extracted through FEA and incorporated into the nonlinear EMA equivalent circuit method, and the simulated results show good agreement with those of FEA.
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Jhang, Wun-Siang, and 張文祥. "Analysis and Establishment of the Equivalent Circuit Model for the Single-Phase Brushless DC Motor by Finite-Element Method." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/28528673842380617409.
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碩士<br>國立雲林科技大學<br>電機工程系碩士班<br>94<br>The thesis mainly uses the finite-element method (FEM) to simulate the properties of magnetic fields and electrical circuits for the single-phase brushless dc motor. In addition, the author makes the complete analysis for the inductance of the motor and utilizes the related results computed by FEM to establish three kinds of simulation models for the motor driving system.
In the analyses of magnetic fields and electrical circuits, the distribution of static magnetic fields and the waveform of the cogging torque are simulated. Then the properties of electrical circuits including the inductance, back EMF voltage, and the actual condition of the motor operated at constant speed are simulated. The simulation results of electrical circuits are compared with the measurement results in order to understand the accuracy of the simulation. In addition, a single-phase brushless dc motor needs the asymmetric stator structure to obtain the starting torque, so the thesis also discusses the further effect of the asymmetric stator.
In the former analysis of the inductance, it doesn’t consider the effects of the rotor angle and coil current, so the author makes the further analysis about their affection. The symmetric condition of the magnetic fields is utilized to derive the corresponding results in order to reduce the computing time of simulation. At last, the related results computed by FEM are used to establish the three kinds of simulation models for the single-phase brushless dc motor driving system. The simulation results for the three kinds of models are finally compared with the measurement results and the comparative accuracy among them can be obtained from the related comparison.
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Zu-Cheng, Li, and 黎祖成. "A Comprehensive Parasitic RLC Extraction Method and Equivalent Circuit Model for High Frequency and RF Noise Analysis and Simulation in Multi-finger and Multi-ring nMOSFETs with Layout Dependent and Technology Scaling Effects." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/e538m3.
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碩士<br>國立交通大學<br>電子研究所<br>107<br>In this thesis, an extensive investigation has been carried out on the layout dependent effects in multi-finger (MF) and multi-ring (MR) nMOSFETs, and the impact on high frequency performance like most importantly unit gain cut-off frequency fT and maximum oscillation frequency fMAX, as well as RF noise in nanoscale CMOS technologies. A comprehensive extraction flow has been developed for accurate determination of the intrinsic device parameters as well as intrinsic parasitic resistances, inductances, and capacitances (RLC), which are key parameters governing fT and fMAX, and RF noise like NFmin and Rn. The impact of technology scaling on high frequency device parameters and performance appears as another critically important topic. In this thesis, 90nm and 40nm CMOS technologies from TSMC, namely TN90GUTM and TN40G have been adopted for MF and MR nMOSFETs design and fabrication. The aggressive scaling of layout rule and physical dimensions like poly gate length (Lg), poly gate thickness (TPO), contact plug thickness (TCO), and metal thickness (TM1) by around 52~60%, gate oxide thickness (Tox) by around 84%, and PO-to-CO space (LPO-CO) by 42~43% from TN90GUTM to TN40G will lead to complicated influence on the intrinsic device parameters, intrinsic parasitic RLC, and more importantly high frequency performance. Basically, the shrinkage of Lg, TPO, TCO, TM1, and layout dimensions can lead to the increase of gate resistance (Rg), contact resistance, and source parasitic resistance as well as inductance (RS and LS,int) in MF devices with extended source line, all of which may cause the penalties such as degradation of transconductance (gm), fT and fMAX, and even worse the increase of RF noise (Rn and NFmin). On the other hand, the scaling of Lg, TPO, TCO, and TM1 can help suppress the intrinsic parasitic capacitances like gate sidewall and finger-end fringing capacitances (Cof and Cf(poly-end)) and achieve smaller gate capacitance (Cgg). The experimental results indicate that more aggressive scaling in Lg than Tox (or Tox(inv)) can achieve higher gm and smaller Cgg, and thus significant boost of fT by around 60 ~110% in MF nMOSFETs attributed to technology scaling from TN90GUTM to TN40G. However, the higher fT cannot guarantee the higher fMAX because that the dramatic increase of Rg may overwhelm the advantage of fT and result in similar or even lower fMAX. It means that the complicated trade-off between the parasitic RLC associated with technology scaling and layout dependent effects becomes a valuable and challenging topic for high frequency devices design, parasitic RLC extraction, and equivalent circuit modeling.
In this thesis, a new method, namely matrix method for accurate extraction of extrinsic source and drain parasitic resistances, RS and RD in MF and MR MOSFETs, has been developed and proven with sufficient accuracy for effective mobility eff extraction in MF and MR nMOSFETs associated with TN90GUTM and TN40G technologies. This matrix method can accurately determine the current through every active channel (OD) finger and voltage at each source finger terminal, and thus solve the problem from previous assumption of uniform current distribution and equal source terminal voltage at every finger. The mentioned assumption may lead to sever over-estimation of extrinsic RS and an abnormal jump of eff extracted from MF nMOSFETs in case of larger finger number (NF). This problem becomes particularly worse in TN40G technology than TN90GUTM, due to the aggressive scaling of TM1~M3 and TCO, as well as significant increase of the metal sheet resistance and contact resistance (RCO). Furthermore, how to determine the physical Rg and real Rg through high frequencies responsible for fMAX, Rn, and NFmin becomes a challenging topic of controversy, particularly for MF and MR devices with extremely narrow finger width (WF) in case of very large NF. MR devices proposed as a solution for higher eff attributed to suppression of STI compressive transverse stress ⊥. However, some potential problems like the increase of Rg, Cof, and Cf(poly-end) may be detrimental to fT, fMAX, and RF noise (Rn, and NFmin). Some innovative MR layouts for simultaneous reduction of Rg, Cof, and Cf(poly-end) emerge as another topic worthy of further study. In addition, the intrinsic parasitic inductances like Lg,int, Ld,int, and Ls,int appear as critical elements with sophisticated layout dependence and influence on high frequency parameters, which are dispensable for actual intrinsic MOSFET models for high frequency simulation aimed at mm-wave circuits design.
Finally, the actual intrinsic MOSFET models can be integrated with our proprietary lossy substrate model to build up a full equivalent circuit model for both high frequency and RF noise simulation prior to deembedding. However, the aggressive thickness reduction of the stacked metal layers and inter-metal dielectric in technology scaling from TN90GUTM to TN40G causes dramatic increase of parasitic capacitances associated with the GSG pads and interconnection lines from the pads to the core devices. This kind of extrinsic parasitic capacitances may overwhelm the intrinsic channel and frigning capacitances (Cgg,int, Cof,, and Cf(poly-end)), which may lead to very minor difference between various MF layouts and difficulty in open deembedding. As a result, the intrinsic Y-parameters reveal anomalous frequency dependence and reverse of positive/negative sign. It emerges as a new challenge to precise deembedding and suggests more extensive research effort in the future for effective reduction of the extrinsic parasitic capacitances. To the end, our proprietary lossy substrate deembedding method can be applied for accurate extraction and simulation of intrinsic RF noise in MF and MR devices associated with TN90GUTM and TN40G technologies. This way can eliminate the problems of conventional noise correlation matrix method and facilitate device layouts optimization for high frequency and low noise design in nanoscale CMOS technologies.
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Ragsdale, Matthew. "Battery identification methods based on equivalent circuit model." 2009. http://hdl.handle.net/10106/1994.
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Bansiwal, Ashok. "Equivalent Circuit Analyses and Methods to Enhance Bandwidth of Klystron Reentrant Cavities." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4659.
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Klystron is used as an amplifier at microwave frequency range. Klystrons use cylindrical or rectangular reentrant cavities in their interaction structure. Characteristics of reentrant cavity can be defined using parameters such as resonant frequency, characteristic shunt impedance and quality factor, which can be computed either using 3D electromagnetic field solver or using equivalent circuit analysis. An equivalent circuit analysis is often preferred to quickly arrive at initial dimensions of the cavity as well as to analyse the effect of various dimensional variations on the cavity parameters.
Equivalent circuit analysis for the calculation of these parameters is available in the literature for cylindrical reentrant cavity with single beam-tunnel and single constituent material. However, practical cavities are normally made with dissimilar materials and have multiple beam-tunnels as in the case of multiple-beam klystron. A new formulation has been proposed for accounting the effects of single and multiple beam-tunnels in the calculation of cavity gap capacitance. Proposed formulation provides better estimation of resonant frequency for the cavities with multiple beam-tunnels as compared to that from the existing analysis. A new analysis has also been proposed for the calculation of unloaded quality factor of cylindrical reentrant cavity using Wheeler’s incremental inductance rule. Analysis provides estimation of quality factor within 15% deviation compared with simulations. In addition to analysing the cavities with dissimilar materials, the proposed approach provides better estimation of quality factor compared with existing approaches.
Since a similar equivalent circuit analysis was not available for the rectangular reentrant cavity, the same is proposed here through geometric approximation and analytical approaches. Both the analyses have been proposed for a rectangular reentrant cavity with circular cylindrical ferrule and operating in the TM110 mode. Unloaded quality factor has been obtained using Wheeler’s incremental inductance rule. Analyses, through geometric approximation and analytical approaches, estimate resonant frequencies within 3% and 4.5% deviations, characteristic shunt impedance within 17% and 13% deviations, and unloaded quality factor within 15% and 14% deviations, respectively, compared with 3D electromagnetic simulations. The proposed analyses have also been validated against measurements and a good agreement has been obtained.
Klystrons inherently suffer from bandwidth limitation and a lot of research is going on to enhance its instantaneous bandwidth. Bandwidth of klystron depends primarily on the quality factor of the output cavity circuit. Here, three methods for enhancing the bandwidth of a klystron have been proposed. The first method utilises tailoring the surface roughness, by which the unloaded quality factor of the cavities could be reduced by a maximum of 48%. In the second method, a ridge-loaded rectangular and cylindrical reentrant cavity has been proposed where the quality factor could be reduced by maximum of 80%. In the third method, a post-loaded rectangular reentrant cavity has been proposed to have even higher reduction in the quality factor (upto 90%). Measurements have been carried out on unloaded, ridge-loaded and post-loaded rectangular reentrant cavities for the validation of proposed methods. Measured unloaded quality factors have been found within 10% deviations compared with those obtained through the simulations.
Equivalent circuit analyses and methods for reducing the quality factor of reentrant cavities proposed in the thesis will be useful for klystron designers to arrive at preliminary geometrical parameters of cylindrical or rectangular reentrant cavities with dissimilar constituent materials and to bolster their efforts to meet broadband operation.<br>Defense Research and Development Organization (DRDO)
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Yeh, Chih-Ting, and 葉致廷. "Three Terminal and Four Terminal RF MOSFET Model Parameter Extraction Methods Development and Verification by Equivalent Circuit Simulation." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/01478305174414679454.
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碩士<br>國立交通大學<br>電子工程系所<br>94<br>Parameter extraction method development is very important for accuracy of simulation. In the past, foundries always provide customers with the 3T sample layout, whose source and body terminals are connected together. But foundries tend to provide customers with 4T sample layout for circuit designers’ purpose at present. And model card is constructed on 4T device to match the practical using way of circuit designers. In order to provide circuit designers with accurate model card, reliable parameter extraction method development is obviously important.
3T and 4T device in the thesis are put in 2-port pad to do RF measurement and parameters extraction. In this thesis, 2-port de-embedding and parameters extraction methods have been discussed in detail and used extracted parameters to verify the reliability and accuracy of small signal equivalent model. Obtaining correct small signal equivalent model represents that we can extract correct parameter values which could provide us with direction and thought to construct better model card.
The last part of this thesis is detailed discussion of parasitic capacitances. The results reveal that the simulation and analytical calculated are very matched. This represents the thought applied to calculating process is very correct. The success of analytical calculated model can accurately estimate the parasitic capacitances of specific structure. It is worthy to mention that the calculating method is more direct and simpler than other published references.
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Ameer, Abdul Kader Mohamed Basith Abdul. "Functional Verification of Arithmetic Circuits using Linear Algebra Methods." 2011. https://scholarworks.umass.edu/theses/657.
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This thesis describes an efficient method for speeding up functional verification of arithmetic circuits namely linear network such as wallace trees, counters using linear algebra techniques. The circuit is represented as a network of half adders, full adders and inverters, and modeled as a system of linear equations. The proof of functional correctness of the design is obtained by computing its algebraic signature using standard linear programming (LP) solver and comparing it with the reference signature provided by the designer. Initial experimental results and comparison with Satisfiability Modulo Theorem (SMT) solvers show that the method is efficient, scalable and applicable to complex arithmetic designs, including large multipliers. It is intended to provide a new front end theory/engine to enhance SMT solvers.
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Ou, Jyun-Rong, and 歐俊榮. "New Methods for Intrinsic Parasitic RLC Extraction and Small signal Equivalent Circuit Models for High Frequency and RF Noise Simulation in 3T and 4T Nanoscale Multi-finger MOSFETs." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3j8eev.
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碩士<br>國立交通大學<br>電子研究所<br>106<br>In this thesis, an extensive investigation has been performed on the three- and four-terminal (3T and 4T) multi-finger nMOSFETs for precise extraction of intrinsic parasitic RLC and development of truly accurate intrinsic MOSFET model aimed at high frequency and RF noise simulation for nano-CMOS RF circuits design. Gate resistance (Rg), source resistance (Rs,int), and gate sidewall as well as finger-end fringing capacitances (Cof and Cf(poly-end)) appear as most important intrinsic parasitic RC with critical impact on high frequency performance and RF noise, and bring tough challenges to the conventional extraction methods when applied to 3T and 4T multi-finger MOSFETs. For the first time, a new extraction flow has been established for precise determination of the intrinsic parasitic source and drain resistances (Rs,int and Rd,int) and channel resistance (Rch) in 3T and 4T multi-finger MOSFETs and enable accurate prediction of the asymmetric gate to source/drain capacitances, i.e. Cgs≠Cgd at VDS=0 with critical dependence on Rs,int, Rd,int, and Rch. Afterwards, a new method and analytical model have been derived for accurate extraction of Rg and prediction of Rg@Y-method incorporating the Rs,int and Rd,int coupled through the intrinsic gate to source and drain capacitances (Cgs,i and Cgd,i). In this thesis, one more innovation creates new structures, namely multi-finger field devices for direct and precise extraction of Cof and Cf(poly-end) from high frequency measurement, without resort to 3-D interconnect RC simulation like Raphael. The mentioned innovations lead to successful extraction of intrinsic parasitic RC with complicated layout dependence and the integration with intrinsic device parameters determined by our proprietary high precision device parameters extraction method (US patent 8,691,599 B2) can realize the actual intrinsic MOSFET model for 3T and 4T multi-finger MOSFETs with proven accuracy for layout dependent effects and sensitivity to lot-to-lot and die-to-die variations.
The actual intrinsic MOSEFT model has been extensively verified and the accuracy is proven by good agreement with high frequency Y-parameters after openM1 and shortM1 deembedding for 3T and 4T nMOSFETs with various multi-finger layouts. Furthermore, the intrinsic device parameters and parasitic RLC with proven accuracy, when applied to analytical models can reach accurate prediction of the high frequency performance like fT and fMAX associated with various multi-finger layouts and facilitate layout optimization. One of the important findings and conclusions is that 4T multi-finger MOSFETs with sufficient freedom for various circuit topologies like common source, common gate, and common drain (CS, CG, and CD) under various body biases, generally suffer significant degradation of fT and fMAX due to drastic increase of Rs,int and Ls,int. The mentioned achievements provide a useful and efficient solution for high frequency simulation and design, without resort to BSIM-4 with limited accuracy for specified sample layouts.
Finally, the actual intrinsic MOSFET models can be further integrated with our proprietary lossy substrate model to build up a full equivalent circuit model, which can accurately simulate the high frequency S-, Y- and noise parameters, prior to deembedding. Furthermore, the lossy substrate deembedding method can be applied to both 3T and 4T multi-finger MOSFETs as a reliable solution for accurate extraction of intrinsic RF noise, which can eliminate the problems of conventional noise correlation matrix method and successfully identify the layout dependent effects in the truly intrinsic RF noise for multi-finger MOSFETs optimization aimed at low noise circuits design.
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Liang, Yu-Tang, and 梁育堂. "New Methods for Accurate Extraction of Intrinsic RF and AC Performance and Equivalent Circuit Models for High Frequency and RF Noise Simulation in Nanoscale MOSFETs with Various Layouts." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5shvua.
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碩士<br>國立交通大學<br>電子研究所<br>106<br>In this thesis, one of our new proprietary structures, namely multi-finger field device has been designed and implemented in nanoscale CMOS processes like TN90GUTM and TN40G to realize direct and precise extraction of the gate sidewall and finger-end fringing capacitances, denoted as Cof and Cf(polyend). For the first time, the experimental Cof and Cf(polyend) can be achieved to serve as useful database for a serious calibration on the 3-D interconnect RC simulation like Raphael. Moreover, the multi-finger field devices can enable another innovative application, such as a truly clean deembedding of the Cof and Cf(polyend), namely field deembedding for the extraction of ideally intrinsic device parameters and high frequency performance parameters like fT and fMAX. For TN90GUTM and TN40G devices with gate length (Lg) pushed to the scales of 50 nm and 30nm, how to precisely separate and extract the intrinsic channel length (Lch) and source/drain extension (SDE) to gate overlap length (LSDE) becomes a very challenging work. Unfortunately, the original approach based on openM1 deembedding and Raphael simulation led to the abnormal results, such as signficant variation of LSDE and Lch associated with various finger width (WF), and the trend of shorter LSDE but longer Lch corresponding to the smaller WF i.e. the larger NF (finger number). In this thesis, the adoption of field deembedding method can eliminate the mentioned problem and achieve nearly constant LSDE among various WF and NF, i.e. nearly independent of WF and NF. It becomes an important progress to realize accurate extraction of the effective mobility associated with the intrinsic (inversion) channel and SDE (accumulation) regions, such as eff,ch and eff,acc, respectively. Furthermore, the ideal intrinsic Y- and H-parameters achieved after field deembedding can yield the ideally intrinsic gm, Cgg, and Cgd, and more importantly the ideal intrinsic fT and gate delay, int. For TN90GUTM nMOSFET, the ideal intrinsic peak fT can reach 227 GHz, which is around 27.5% higher than the actual intrinsic peak fT of 178 GHz. As For TN40G nMOSFET, there is around 75~100% enhancement of the peak fT compared to that of TN90GUTM, for actual and ideal intrinsic conditions. The ideal intrinsic peak fT can reach up to 473GHz, which is around 52% higher than the actual intrinsic peak fT of 312 GHz. The results reveal dramatic impact from the intrinsic parasitic RC on the high frequency performance and the impact increases in more advanced technology with further scaled devices.
Multi-OD (MOD) MOSFETs have been designed and fabricated in TN90RF as a potential solution for effective reduction of STI compressive transverse stress ⊥ and source resistance (RS), aimed at the increase of eff and gm and eventually fT improvement compared to the multi-finger MOSFETs with the same channel width (WOD). In this thesis, a new extraction flow has been developed for MOD MOSFETs with various WOD and NOD at the same WF=WOD×NOD and NF as those of multi-finger MOSFETs. The new features specific to MOD MOSFETs can be summarized as a new component of gate sidewall fringing capacitance originated from the gate on STI between adjacent OD (Cof,STI) and steeper STI sidewall profile due to the minimum OD-OD space, i.e. STI width. The basic device parameters extracted from the MOD MOSFETs indicate major differences in Lg and W and apparently smaller W compared to that of multi-finger MOSFETs, which is very critical for accurate determination of effective channel width (Weff) and extraction of eff. Through an extensive DC and RF characterization, the MOD nMOSFETs demonstrate some attractive features, such as the higher eff, smaller RS, larger gm, and most importantly the higher fT compared with the multi-finger MOSFETs with the same WOD. However, the MOD MOSFETs reveal two major drawbacks, such as larger DIBL and lower fMAX in comparison with the multi-finger MOSFETs. The former can be understood through an analysis of the finger-end and inter-OD fringing capacitances, i.e. Cf(poly-end) and Cof,STI, achieved from Raphael simulation. The results indicate that the significant increase of Cf(poly-end)NF in multi-finger MOSFETs with large NF becomes the dominant factor responsible for the effective suppression of DIBL. In comparison, the MOD MOSFET even with the addition of Cof,STINODNF but the combination of Cf(poly-end)NF and Cof,STINODNF with NF fixed at the minimum always keeps smaller than Cf(poly-end)NF with much larger NF and it leads to less suppression of DIBL. As for the much lower fMAX suffered by MOD MOSFETs even with higher fT, it accounts for the critical impact from the significant increase of gate resistance (Rg) and tough challenge to simultaneous optimization of fT and fMAX.
Full equivalent circuit models have been established with the actual intrinsic MOSFET models for multi-finger and MOD MOSFETs by adopting intrinsic parasitic RLC and lossy substrate RLC network for accurate simulation of high frequency characteristics and RF noise. The actual intrinsic MOSFET models including layout dependent device parameters and parasitic RLC with proven accuracy for various layouts can fix the problem of conventional compact model like BSIM-4 with limited accuracy for specific sample layouts in the PDK but severe deviation for the customer designed layouts beyond the PDK. RF noise simulation and intrinsic noise extraction appear as one more serious challenge to the conventional compact model. In this thesis, our developed equivalent circuit model can provide an effective solution for accurate simulation of the RF noise prior to deembedding and precise extraction of the actual intrinsic noise by using lossy substrate deembedding. Finally, the simulation by equivalent circuit model can facilitate the development of analytical models for quick calculation of intrinsic RF noise and assessment of layout dependent effects associated with multi-finger and MOD devices and impact from the parasitic RLC.
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Kuntze, Scott Beland. "Controlling Semiconductor Optical Amplifiers for Robust Integrated Photonic Signal Processing." Thesis, 2009. http://hdl.handle.net/1807/17470.
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How can we evaluate and design integrated photonic circuit performance systematically? Can active photonic circuits be controlled for optimized performance?
This work uses control theory to analyze, design, and optimize photonic integrated circuits based on versatile semiconductor optical amplifiers (SOAs). Control theory provides a mathematically robust set of tools for system analysis, design, and control. Although control theory is a rich and well-developed field, its application to the analysis and design of photonic circuits is not widespread.
Following control theoretic methods already used for fibreline systems we derive three interrelated state-space models: a core photonic model, a photonic model with gain compression, and a equivalent circuit optoelectronic model. We validate each model and calibrate the gain compression model by pump/probe experiments.
We then linearize the state-space models to design and analyze SOA controllers. We apply each linearized model to proof-of-concept SOA control applications such as suppressing interchannel crosstalk and regulating output power. We demonstrate the power of linearized state-space models in controller design and stability analysis.
To illustrate the importance of using the complete equivalent circuit model in controller design, we demonstrate an intuitive bias-current controller that fails due to the dynamics of the intervening parasitic circuitry of the SOA. We use the linearized state-space models to map a relationship between feedback delay and controller strength for stable operation, and demonstrate that SOAs pose unusual control difficulties due to their ultrafast dynamics.
Finally, we leverage the linearized models to design a novel and successful hybrid controller that uses one SOA to control another via feedback (for reliability) and feedforward (for speed) control. The feedback controller takes full advantage of the equivalent circuit modelling by sampling the voltage of the controlled SOA and using the error to drive the bias current of the controller SOA. Filtering in the feedback path is specified by transfer function analysis. The feedforward design uses a novel application of the linearized models to set the controller bias points correctly.
The modelling and design framework we develop is entirely general and opens the way to the robust optoelectronic control of integrated photonic circuits.