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Dissertations / Theses on the topic 'Inductor capacitor'
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1
Nakibuuka, Norah Elena. "A hybrid switched-capacitor/inductor converter for small conversion ratios." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85453.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2013."May 2013." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 67-69).
A hybrid three-switch DC-DC step-up power converter for on chip applications is proposed. It is shown that the hybrid-three switch step-up converter can offer advantages such as reduced size of magnetic components, reduced MOSFET voltage stresses, improved closed loop control and can offer high efficiency compared to a standard boost converter of the same IC package size. These improvements are made possible by adding a flying capacitor that reduces the voltage stresses on the switches and decreases the inductor size by reducing the volt-second across the inductor. The converter is implemented as an integrated circuit built in a 0.25[mu]m 5V CMOS process. Experimental verification shows the gains.
by Norah Elena Nakibuuka.
M. Eng.
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Wang, Yu. "Tunable C Band Coupled-C BPF with Resonators Using Active Capacitor and Inductor." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1472479817.
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Korkmaz, Hakan. "Hmic Miniaturization Techniques And Application On An Fmcw Range Sensor Transceiver." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611813/index.pdf.
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This thesis includes the study of hybrid microwave integrated circuits (HMIC), miniaturization techniques applied on HMICs and its application on a frequency modulated continuous wave (FMCW) range sensor transceiver. In the scope of
study, hybrid and monolithic microwave integrated circuits (HMIC and MMIC) are introduced, advantages and disadvantages of these two types are discussed. Large
size of HMICs is the main disadvantage especially for military and civil applications requiring miniature volumes. This thesis is mainly devoted on miniaturization work of HMICs in order to cope with this problem. In this scope, miniaturization
techniques of some HMICs such as 3 dB hybrid couplers and stubs are examined and analyzed. Their simulation and measurement results cohere with original circuit
results. Nevertheless, considerable size reduction up to 80% is achieved. Moreover, planar interdigital capacitors (IDC), spiral inductors (SI) and their equivalent circuit
models are introduced. Design technique is discussed with illustrative electromagnetic (EM) simulations. Furthermore, FMCW radar is introduced with its
basic operation principles, brief history and usage areas. In addition, FMCW range sensor transceiver is designed with its sub‐
parts
power amplifier, low noise amplifier (LNA), coupler and front end. Multi technology based on chip transistors, interdigital capacitors, spiral inductors and hybrid couplers with wire&
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bond connections is used in the design. As the result of using hybrid miniaturized components small layout size is achieved for the transceiver system with its all components.
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Wang, Yu. "Design and Implementation of Fully Integrated CMOS On-chip Bandpass Filter with Wideband High-Gain Low Noise Amplifier." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1629373771035261.
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Horn, Jacqueline Marie. "Design of a Wearable Flexible Resonant Body Temperature Sensor with Inkjet-Printing." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703340/.
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A wearable body temperature sensor would allow for early detection of fever or infection, as well as frequent and accurate hassle-free recording. This thesis explores the design of a body-temperature-sensing device inkjet-printed on a flexible substrate. All structures were first modeled by first-principles, theoretical calculations, and then simulated in HFSS. A variety of planar square inductor geometries were studied before selecting an optimal design. The designs were fabricated using multiple techniques and compared to the simulation results. It was determined that inductance must be carefully measured and documented to ensure good functionality. The same is true for parallel-plate and interdigitated capacitors. While inductance remains relatively constant with temperature, the capacitance of the device with a temperature-sensitive dielectric layer will result in a shift in the resonant frequency as environmental or ambient temperature changes. This resonant frequency can be wirelessly detected, with no battery required for the sensing device, from which the temperature can be deduced. From this work, the optimized version of the design comprises of conductive silver in with a temperature-sensitive graphene oxide layer, intended for inkjet-printing on flexible polyimide substrates. Graphene oxide demonstrates a high dielectric permittivity with good sensing capabilities and high accuracy. This work pushes the state-of-the-art in applying these novel materials and techniques to enable flexible body temperature sensors for future biomedical applications.
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Hanlon, Patrick A. "Optimization and Characterization of an Inkjet Process for Printed Electronics." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1524839898636862.
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Temocin, Engin Ufuk. "Design And Implementation Of Microwave Lumped Components And System Integration Using Mems Technology." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607519/index.pdf.
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This thesis presents the design and fabrication of coplanar waveguide to microstrip transitions and planar spiral inductors, and the design of metal-insulator-metal capacitors, a planar band-pass, and a low-pass filter structures as an application for the inductors and capacitors using the RF MEMS technology. This thesis also includes a packaging method for RF MEMS devices with the use of benzocyclobutene as bonding material.
The transition structures are formed by four different methods between coplanar waveguide end and microstrip end, and they are analyzed in 1-20 GHz. Very low loss transitions are obtained by maintaining constant characteristic impedance which is the same as the port impedance through the transition structures.
The planar inductors are formed by square microstrip spirals on a glass substrate. Using the self-inductance propery of a conductive strip and the mutual inductance between two conductor strips in a proper arrangement, the inductance value of each structure is defined. Inductors from 0.7 nH up to 20 nH have been designed and fabricated.
The metal-insulator-metal capacitors are formed by two coplanar waveguide structures. In the intersection, one end of a coplanar waveguide is placed on top of the end of the other coplanar waveguide with a dielectric layer in between. Using the theory of parallel plate capacitors, the capacitance of each structure is adjusted by the dimensions of the coplanar waveguides, which obviously adjust the area of intersection. Capacitors from 0.3 pF up to 9.8 pF have been designed.
A low-pass filter and a band-pass filter are designed using the capacitors and inductors developed in this thesis. In addition to lumped elements, the interconnecting transmission lines, junctions and input-output lines are added to filter topologies.
The RF MEMS packaging is realized on a coplanar waveguide structure which stands on a silicon wafer and encapsulated by a silicon wafer. The capping chip stands on the BCB outer ring which promotes adhesion and provides semi hermeticity.
Keywords: Transition between transmission lines, planar spiral inductor, metal-insulator-metal capacitor, RF MEMS packaging, surface micromachining.
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Song, Keum Su. "Non-Foster Impedance Matching and Loading Networks for Electrically Small Antennas." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1308313555.
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Yoon, Yong-Kyu. "Micromachined Components for RF Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5264.
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Several fabrication techniques for surface micromachined 3-D structures have been developed for RF components. The fabrication techniques all have in common the use of epoxy patterning and subsequent metallization. Techniques and structures such as embedded conductors, epoxy-core conductors, a reverse-side exposure technique, a multi-exposure scheme, and inclined patterning are presented. The epoxy-core conductor technique makes it easy to fabricate high-aspect-ratio (10-20:1), tall (~1mm) RF subelements as well as potentially very complex structures by taking advantage of advanced epoxy processes. To demonstrate feasibility and usefulness of the developed fabrication techniques for RF applications, two test vehicles are employed. One is a solenoid type RF inductor, and the other is a millimeter wave radiating structure such as a W-band quarter-wavelength monopole antenna. The embedded inductor approach provides mechanical robustness and package compatibility as well as good electrical performance. An inductor with a peak Q-factor of 21 and an inductance of 2.6nH at 4.5GHz has been fabricated on a silicon substrate. In addition, successful integration with a CMOS power amplifier has been demonstrated. A high-aspect-ratio inductor fabricated using epoxy core conductors shows a maximum Q-factor of 84 and an inductance of 1.17nH at 2.6GHz on a glass substrate with a height of 900um and a single turn. Successful W-band monopole antenna fabrication is demonstrated. A monopole with a height of 800um shows its radiating resonance at 85GHz with a return loss of 16dB.
In addition to the epoxy-based devices, an advanced tunable ferroelectric device architecture is introduced. This architecture enables a low-loss conductor device; a reduced intermodulation distortion (IMD) device; and a compact tunable LC module. A single-finger capacitor having a low-loss conductor with an electrode gap of 1.2um and an electrode thickness of 2.2um has been fabricated using a reverse-side exposure technique, showing a tunability of 33% at 10V. It shows an improved Q-factor of 21.5. Reduced IMD capacitors consist of wide RF gaps and narrowly spaced high resistivity electrodes with a gap of 2um and a width of 2um within the wide gap. A 14um gap and a 20um gap capacitor show improved IMD performance compared to a 4um gap capacitor by 6dB and 15dB, respectively, while the tunability is approximately 21% at 30V for all three devices due to the narrowly spaced multi-pair high resistivity DC electrodes within the gap. Finally, a compact tunable LC module is implemented by forming the narrow gap capacitor in an inductor shape. The resonance frequency of this device is variable as a function of DC bias and a frequency tunability of 1.1%/V is achieved. The RF components developed in this thesis illustrate the usefulness of the application of micromachining technology to this application area, especially as frequencies of operation of RF systems continue to increase (and therefore wavelengths continue to shrink).
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Zhou, An. "Modèles de composants passifs et couplage électromagnétique pour filtres HF de puissance : optimisation du placement." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10032/document.
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Les filtres CEM sont largement utilisés dans les systèmes électroniques de puissance pour la suppression des interférences électromagnétiques. Ils sont en général composés d'une succession de condensateurs et de selfs. En haute fréquence, on est amené à compléter le modèle des composants par des éléments parasites. Ce travail de thèse est consacré à l'étude de l'influence du couplage inter composants sur la performance du filtre CEM. Une étude mathématique a été réalisée sur un filtre LC de type Γ. Cette dernière nous a permis de déduire qu'un meilleur comportement du filtre est obtenu quand le couplage magnétique inter-composants annule l'inductance parasite du condensateur (ESL=M). Pour atteindre cet objectif, une méthodologie permettant d'optimiser les emplacements des composants a été développée en se basant sur des modèles 3D simplifiés des composants du filtre. Dans ce travail de thèse, un condensateur film métallisé est présenté par un modèle 3D constitue d'un volume unique de conducteur. Les bobines avec ferrite sont modélisées en 3D en prenant en compte les propriétés physiques et géométriques. Ces modèles de condensateurs et de bobines ont été étudiés dans le cas de plusieurs configurations pour différents positionnements des composants. Les résultats obtenus ont montré leurs capacités de prédire à la fois les paramètres intrinsèques (Inductance parasite ESL pour le condensateur, Inductance L pour la bobine) et l'inductance mutuelle M inter-composants. Finalement, la méthodologie d'optimisation a été validée expérimentalement sur un filtre CEM de type Γ (condensateur film et bobine bâtonnet avec ferrite) intégré dans un moteur d'essuie-glaceEMC filters are widely used in power electronic systems for electromagnetic interference suppression. They usually consist of a series of capacitors and inductors. At high frequencies, it is necessary to complete the model of component with parasitic elements. This work is devoted to the study of the influence of inter-component coupling on the performance of the EMC filter. A mathematical study was performed on an LC filter in type Γ. The latter allowed us to deduce a better behavior of the filter can be obtained when the magnetic coupling inter-component cancels the parasitic inductance of the capacitor (ESL = M). To achieve this goal, a methodology to optimize the locations of components has been developed based on their 3D models simplified. In this thesis, a metalized film capacitor is presented by a 3D model constituting a single volume conductor. The inductor with ferrite is modeled by taking into account the physical and geometrical properties. These models of capacitors and inductors have been studied in several configurations for different positions of the components. The results have shown their ability to predict both the intrinsic parameters (parasitic inductance ESL for the capacitor, inductance L for the inductor) and mutual inductance M inter-components. Finally, the optimization method was validated experimentally with an EMC filter type Γ (film capacitor and ferrite-rod inductor) built in a wiper motor
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Zvolenský, Tomáš. "Modelování mikrovlnných rezonátorů z metamateriálů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-217692.
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Práce je věnována modelování mikrovlnných rezonátorů z metamateriálů (materiálů se záporným indexem lomu). V úvodu je rozebráno, co metamateriály jsou, jak se vytvářejí a které jejich vlastnosti jsou podstatné při návrhu rezonátorů. Následuje návrh planárního rezonátoru z metamateriálů. Pro tento účel byly naprogramovány funkce počítající rozměry jednotlivých součástí struktury. Simulace navržené struktury probíhala v programu Zeland IE3D. Simulované struktury byly optimalizovány s ohledem na požadované kmitočty rezonance. První rezonátor sestával z jedné elementární buňky, druhý ze dvou buněk, naladěných na rozdílné kmitočty. Rezonátory byly vyrobeny a experimentálně byly ověřeny jejich vlastnosti.
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Prasai, Anish. "Direct dynamic control of impedance for VAR and harmonic compensation." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42816.
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Reactive power is critical to reliable operation of the modern AC power system. There is a plethora of motor-loads, transformers, and power-electronic loads connected to the power grid, which consume reactive power for normal operation. Transmission lines also consume reactive power when they are loaded above their surge impedance loading (SIL). Reactive power can exact opportunity cost due to reduced capacity of the lines to carry real power, which in turn lowers revenue. Most transmission owners (TOs) levy large penalties against load serving entities (LSEs), industrial facilities, and other end-use customers, who consume more than their allotted amount, as measured by their power factor. These penalties are to incentivize their customers to meet their reactive power needs locally as well as to recuperate the TOs' financial losses.
Harmonic pollution is another factor that prevents the optimal operation of the grid and the connected loads. Harmonics are attributable to proliferation of the diode-rectifier- or thyristor-rectifier-interfaced loads such as variable speed ac drives and power supplies in server farms, electric arc furnaces, and other non-linear loads, which are widely employed by the industrial sector. With wider adoption of harmonic-rich loads by the consumer sector as well, such as HDTVs and compact fluorescent lamps (CFLs), greater level of triplen harmonics associated with single-phase loads are also increasingly seen on the distribution grid. The increasing penetration of renewable resources and electrification of light-duty vehicles are expected to further aggravate the stresses and congestion on the utility grid.
Reactive power compensation is necessary for supporting the AC grid and maintaining a healthy voltage stability margin. Compensation can also enhance the utilization of system capacity, lower system losses, provide fault ride-through, and enable a quick fault recovery. Existing VAR and harmonic compensation technologies are either too expensive or inadequate to meet the dynamic needs of the modern and the future power system.
This dissertation presents a novel class of Dynamic VAR and Harmonic Compensators (DVHCs) for supplying or absorbing reactive power and providing harmonic filtering, where the compensation is in shunt with the line and the load. The underlying concept is based on augmenting a static or passive component like a capacitor or an inductor with a direct AC converter and imbuing the passive component with dynamic properties. The direct AC converter can be configured as a buck, a boost, or a buck-boost. A `fail-normal' switch is an integral part of the DVHCs that bypasses the converter when it fails, preserving the original functionality and the reliability of the passive component. The DVHCs are modular and scalable such that they can be employed in applications ranging from residential and industrial with voltages less than 480 V, to power distribution level with voltages as high as 35 kV. The Dynamic Inductor (D-IND) and the Dynamic Capacitor (D-CAP) are subclasses of the DVHCs. As the applications for supplying leading VARs are more prevalent, the primary focus of this work is on the buck, the boost, and the buck-boost configurations of the D-CAP.
To understand the characteristics and operation of the DVHCs, this work has developed time-domain models for analyzing the transient and dynamic behavior; frequency-domain models for understanding the harmonic interactions and the steady-state relationships between switch duty and current harmonics; and small-signal models for studying the dynamics of the converter due to various perturbations. The small-signal models also enable extraction of transfer functions in designing controllers and assessing stability margins.
Control architectures and techniques are presented for effectively controlling the D-CAP when commutating the semiconductor devices with both high and low switching frequencies.
In modularly scaling the DVHCs to higher voltages, three medium-voltage topologies are discussed. They are based on series-connecting fractionally-rated devices, AC flying capacitors, and series cascading multiple two-level cells. These implementations allow direct connect to the medium-voltage grid, thereby obviating the use of transformers, and subsequently reducing the losses, cost, complexity, and footprint. A novel AC snubber concept is proposed to provide safe commutation of the AC switches, fault tolerance by managing the energy trapped in parasitics and filters, and to enable dynamic and static voltage sharing when integrated around the series-connected devices.
Design equations for selecting and rating the devices and components in the buck, the boost, and the buck-boost configurations of the D-CAP are presented. Three sets of example designs, with one at low-voltage and two at medium-voltage, are discussed to demonstrate the typical size and ratings of the various components under realistic operating conditions.
Measurements and the related discussions of a 40 kVA buck D-CAP prototype built to validate the effectiveness of the proposed concepts are presented.
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Zuber, Zalán. "Měniče pro svítidla s LED diodami." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218762.
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The master‘s thesis deals with DC/DC converters for power LED diodes. Gives an overview of the field of LED lighting technology, analyzes various types of converters and shows their principle of operation. Furthermore presents some possible circuit designs for three different voltage levels and the calculations for each part. As an approval of their functionality the results of their measurements are plotted followed by the data evaluation.
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Eldredge, Zachary L. "The Modified-Multiphase Boost Converter: Combined Inductors and Capacitors Topology." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1910.
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In this work, a modified boost converter design has been implemented in a multiphase configuration with a condensed topology. The modified aspect of the design has already been proven to drastically reduce input current ripple by about 40% in a single-phase implementation. By placing two modified boost converters in parallel with interleaving main switches (multiphase), the input inductors and modified capacitors of the modified topology can be reduced to just one of each, lowering the number of components, size, and cost. Additionally, multiphase DC/DC converters lower input/output voltage and current ripples while delivering more power compared to single-phase converters. By combining the modified and multiphase benefits, this thesis creates a topology with low ripple and noise while providing high power capability. This thesis covers the analysis, simulation, hardware implementation, and testing of the Modified-Multiphase Boost Converter as well as an equivalent Standard-Multiphase Boost Converter for comparison. Simulation and hardware test results exhibited a 9% input current ripple reduction with the Modified-Multiphase design, presenting a high-power converter with considerable input noise reduction.
Keywords: dc/dc, boost, multiphase, interleave, modified, power, ripple
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Buurma, Andrew W. "Wideband lumped circuit models for integrated spiral inductors and capacitors." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1302624174.
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VEGA, JORGE LEONIDAS LAFITTE. "VOLTAGE SECURITY ASSESSMENT IN THE PRESENCE OF INDUCTION MOTORS AND SWITCHABLE CAPACITORS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6349@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORApós a incidência de inúmeros colapsos ocorridos nos sistemas de transmissão de energia devido ao uso extremo das linhas de transmissão, a estabilidade, ou mais adequadamente, a segurança de tensão tornou-se um assunto importante os últimos anos. A correta representação de cargas e de dispositivos de controle de tensão é cada vez mais importante na análise de segurança de tensão do sistema elétrico, em função da sua complexidade crescente e da necessidade de ações operativas mais precisas. A avaliação das condições de segurança de tensão é realizada com base em um modelo linearizado das equações de fluxo de carga, incluindo toda e qualquer equação de controle, e os índices resultantes são calculados a partir de um determinado ponto de operação. Em estudos off-line, este ponto é usualmente proveniente do resultado de um problema de fluxo de carga. É importante que os modelos matemáticos do sistema e seus componentes, de controles e de limites sejam compatíveis nos dois programas computacionais. Estuda-se neste trabalho a modelagem em regime permanente, e a incorporação à função de avaliação da segurança de tensão, de cargas do tipo motor de indução e do controle de tensão por faixa através de capacitores chaveáveis. Aspectos fundamentais da presença de motores de indução e capacitores chaveáveis na avaliação da segurança de tensão são apresentados e discutidos. São mostrados exemplos numéricos de avaliação dos índices de estabilidade de tensão que ilustram a necessidade de uma modelagem realista.
After the incidence of innumerable collapses occurred in the energy transmission systems due to the extreme use of the transmission lines, the voltage stability, or more adequately, the voltage security became an important issue in the last years. The correct representation of loads and voltage control devices is important in the analysis of voltage security of the electrical system, due to its increasing complexity and to the necessity of more accurate and secure operative actions. The voltage security assessment is based on a linear model of the load flow equations, including all and any control equation, and the resulting indexes are calculated for a specified operating point. In off-line studies the operating point is usually obtained from a load flow algorithm. It is important that the system and its components mathematical models, control devices and limits are compatible in both computational programs. This work is concerned with the steady state modelling and its incorporation into the voltage security assessment function, of induction motor type loads and band voltage control by switchable capacitors. Fundamental aspects of induction motors and switchable capacitors in the assessment of voltage security are presented and discussed. Numerical examples of voltage stability assessment indexes are presented to illustrate the necessity of realistic modelling.
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Deib, Deib Ali. "Induction motor operation with series capacitance." Ohio : Ohio University, 1986. http://www.ohiolink.edu/etd/view.cgi?ohiou1183129403.
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Capwell, John. "Characterization and Modeling of Planar Spiral Inductors and Pad Stack Parasitic Effects." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000144.
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Kartci, Aslihan. "Analogová implementace prvků neceločíselného řádu a jejich aplikace." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-402652.
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S pokroky v teorii počtu neceločíselného řádu a také s rozšířením inženýrských aplikací systémů neceločíselného řádu byla značná pozornost věnována analogové implementaci integrátorů a derivátorů neceločíselného řádu. Je to dáno tím, že tento mocný matematický nástroj nám umožňuje přesněji popsat a modelovat fenomén reálného světa ve srovnání s klasickými „celočíselnými“ metodami. Navíc nám jejich dodatečný stupeň volnosti umožňuje navrhovat přesnější a robustnější systémy, které by s konvenčními kondenzátory bylo nepraktické nebo nemožné realizovat. V předložené disertační práci je věnována pozornost širokému spektru problémů spojených s návrhem analogových obvodů systémů neceločíselného řádu: optimalizace rezistivně-kapacitních a rezistivně-induktivních typů prvků neceločíselného řádu, realizace aktivních kapacitorů neceločíselného řádu, analogová implementace integrátoru neceločíselného řádů, robustní návrh proporcionálně-integračního regulátoru neceločíselného řádu, výzkum různých materiálů pro výrobu kapacitorů neceločíselného řádu s ultraširokým kmitočtovým pásmem a malou fázovou chybou, možná realizace nízkofrekvenčních a vysokofrekvenčních oscilátorů neceločíselného řádu v analogové oblasti, matematická a experimentální studie kapacitorů s pevným dielektrikem neceločíselného řádu v sériových, paralelních a složených obvodech. Navrhované přístupy v této práci jsou důležitými faktory v rámci budoucích studií dynamických systémů neceločíselného řádu.
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Reeves, Kevin. "Dynamic-systems analysis of self-excitation associated with a capacitor-coupled substation (CCS) - induction machine system." Master's thesis, University of Cape Town, 2006. http://hdl.handle.net/11427/5116.
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Includes bibliographical references.The purpose of this thesis is therefore to establish the cause of SSR at the Meru-Petronet system, and other similar systems, and investigate various compensation techniques.
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Gallé, William Preston. "MEMS-based fabrication of power electronics components for advanced power converters." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45821.
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Fabrication technology, based on MEMS processes, for constructing components for use in switched-mode power supplies are developed and presented. Capacitors, magnetic cores, and inductors based on sacrificial multilayer electroplating are designed, fabricated, and characterized. Characterization of the produced inductors' core losses at high frequency and high flux is presented, confirming the aptness of the featured microfabrication processes for reducing eddy current losses in magnetic cores. As well, the demonstration of the same inductors in DC/DC converters at high switching frequencies, up to 6 MHz, is presented.
Initial work addressing the top-down development of a fully-integrated DC/DC converter is presented. As well, the comprehensive advancement of the central process - sacrificial multilayer electroplating - is presented, including the development of a second-generation automated multilayer electroplating system. The advanced sacrificial multilayer plating process is applied to produce microfabricated capacitors, which achieved in excess of 1.5 nF/mm² capacitance density,
The fabrication of highly-laminated magnetic cores and power inductors based on sacrificial multilayer electroplating is presented, along with the design and development of a system for characterizing inductor behavior at high-frequency, high-flux conditions. The design and operation of both buck and boost DC/DC converters, switching at up to 6 MHz, built around these highly-laminated-core inductors are presented.
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Suciu, Constantin. "Switch mode emulation of large value capacitors in the rotor circuit to improve the induction motor performance." Thesis, Nottingham Trent University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314331.
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Yang, L. "Odontogenic induction capacity of in vitro expanded dental mesenchymal cells in whole tooth bioengineering." Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/odontogenic-induction-capacity-of-in-vitro-expanded-dental-mesenchymal-cells-in-whole-tooth-bioengineering(6551cf25-e376-4078-adf7-a0d985d3d89f).html.
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Whole tooth bioengineering has been achieved in mice using non-cultured embryonic dental mesenchymal cells (DMCs). In vitro expanded postnatal DMCs can also contribute to tooth formation but only as cells that respond to inductive signals. Since large cell numbers are required for clinical application, enabling in vitro expanded cell populations to induce de novo odontogenesis is the main challenge. To investigate if cultured DMCs can contribute to tooth formation as inductive cells, genetically-labelled cultured embryonic or postnatal DMCs were mixed with wild-type fresh inductive embryonic DMCs in different ratios, and then recombined with responsive epithelium. It is shown that although unable to initiate, cultured embryonic DMCs do not lose their ability to contribute to tooth induction; while postnatal pulp cells can neither initiate nor contribute. Microenvironmental modification of proliferating embryonic DMCs via 3D culture and co-culture systems were attempted to restore or retain the odontogenic induction ability. Although with increased expression of odontogenic genes Pax9 and Msx1, 3D cultured and co-cultured cells failed to initiate odontogenesis. Embryonic DMCs cultured for short periods (within 48 hours) maintained tooth inducing ability. Gene expression profiling was carried out with RNA sequencing data of cultured DMCs collected at different time points to study the molecular basis of the progressively reduced inductivity. In combination with gene expression comparisons between epithelial odontogenic and non-odontogenic tissues, the Wnt signalling pathway and Dlk1 were found to have a strong correlation with maintenance of odontogenic induction capacity.
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Opperman, Tjaart Adriaan Kruger. "A 5 GHz BiCMOS I/Q VCO with 360° variable phase outputs using the vector sum method." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-04082009-171225/.
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Thesis (M.Eng.(Microelectronic Engineering))--University of Pretoria, 2009.Includes summaries in Afrikaans and English. Includes bibliographical references (leaves [74]-78). Mode of access: World Wide Web.
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Pelizari, Ademir. "Um estudo da influência das configurações dos enrolamentos no desempenho de motores de indução monofásicos com capacitor de partida." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-05082009-221845/.
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Os motores de indução monofásicos necessitam de dois enrolamentos estatóricos para criação de um campo magnético girante: um enrolamento principal e um enrolamento auxiliar. Este último tem o objetivo de criar um campo girante apenas na partida do motor, desligando-se logo em seguida, através de um interruptor centrífugo acoplado ao eixo do rotor da máquina. O objetivo deste trabalho é avaliar a influência das diferentes configurações de enrolamentos sobre as características externas do motor de indução monofásico. Sendo assim, através desta análise, pretende-se verificar se há algum benefício em seu desempenho. Neste trabalho, duas configurações de enrolamentos foram desenvolvidas e testadas em laboratório. Na primeira configuração, o enrolamento principal foi alocado na parte inferior das ranhuras. Na segunda configuração, as posições dos enrolamentos foram invertidas. As duas configurações de enrolamento foram aplicadas a um protótipo de 0,37 kW, quatro pólos. A simulação foi realizada através de um programa computacional de elementos finitos, possibilitando a extração e análise de resultados, com as densidades de fluxo nas duas configurações. Os resultados dos ensaios realizados no protótipo permitiram analisar o comportamento de grandezas como corrente elétrica, torque, potência e rendimento que são apresentados e comparados no final deste trabalho.The single phase induction motor needs two stator windings to produce the rotating magnetic field: a main winding and an auxiliary winding. The aim of the auxiliary winding is to create the rotating electromagnetic field when the machine is starting and afterwards turned off, generally through a centrifugal switch coupled to the shaft of the machine. The main purpose of this work is to evaluate the influence that the position of the two windings have on the external characteristics of the single phase induction motor. For this purpose, two different kinds of winding configurations were carried out and simulated in a prototype. In the first configuration, the main winding was located in the bottom of the slot. In the second configuration, the positions of the windings were inverted. Performance analysis and computational simulation by Finite Element Method were carried out after the prototype 0.37 kW, four poles was prepared. In this way, through this analysis, improvements on its performance are expected. The electrical quantities such as flux density, electric current, torque, power and efficiency are compared in the end of this document.
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Diarra, Alimata. "Mesures de propriétés thermiques des métaux par procédé électromagnétique." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI019/document.
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L’industrie de métallurgie est demandeuse de propriétés thermophysiques essentielles pour la modélisation et l’optimisation des procédés d’élaborations.Les propriétés thermophysiques des métaux et des alliages métalliques à l’état liquide sont mal connues. Ces propriétés dépendent de la température et sont difficiles à mesurer surtout à haute température. A l’état liquide, le métal est réactif et facilement polluable. Dans les années 1980, Egry a développé un lévitateur électromagnétique TEMPUS pour mesurer en apesanteur sans contact matériel les propriétés thermophysiques des métaux et alliages en fusion. Dans l’espace, les effets du brassage électromagnétique et de la déformation des échantillons fondus sont beaucoup plus faibles que sur terre.L’emploi de cet outil spatial est coûteux. C’est pour, à terme, diminuer les coûts tout en maintenant voire améliorant la qualité des mesures, que nous avons souhaité remplacer la microgravité par un champ magnétique continu.Les travaux réalisés dans cette thèse consistent à mesurer les propriétés thermiques des métaux par procédé électromagnétique en utilisant une méthode de calorimétrie modulée.Elle comporte deux parties.-Une partie numérique dans laquelle nous avons simulé d’une part le lévitateur spatial TEMPUS et d’autre part le lévitateur terrestre AEXAM.La simulation du lévitateur spatial TEMPUS a pour but de déterminer l’effet de la superposition de courants inducteurs de fréquences différentes (courants de chauffage et de centrage) sur les comportements hydrodynamique et thermique de la goutte. Les résultats des calculs nous ont montré que le courant de centrage est susceptible d’agir sur les mesures.La simulation du lévitateur terrestre AEXAM consiste à déterminer la fréquence d’oscillation verticale de la goutte, la puissance Joule dissipée dans celle-ci, les champs de vitesse et de température. La goutte prend la forme d’une poire et elle oscille à une fréquence de 7 Hz. La puissance Joule dissipée dans la charge est maximale vers le bas de la charge dans les premiers millimètres à mi-hauteur entre l’équateur et le pôle. Elle diminue en pénétrant dans la charge et est nul sur l’axe de symétrie. La convection dans la goutte crée un brassage électromagnétique et homogénéise le champ de température.-Une partie expérimentale dans laquelle le lévitateur AEXAM a été placé dans un champ magnétique continu horizontal pour amortir l’oscillation verticale et le brassage électro-magnétique de la goutte mentionnée dans les calculs. Ceci nous a permis la mise en œuvre d’un protocole de mesure original sur un métal liquide. Ce protocole est un programme de traitement des donnés basé sur le comportement du champ de température lorsque les sources thermiques internes à l’échantillon sont instationnaires. Dans ce programme, nous avons utilisé une fonction d’identification qui permet d’obtenir un modèle mathématique à partir de mesures. Pour obtenir un modèle mathématique consistant, il est important d'exciter le système avec toutes les fréquences de sa plage de fonctionnement. C’est ce que nous faisons quand nous appliquons un bruit blanc sur la consigne d’entrée du générateur. Nous avons précédemment validé le protocole sur du solide en remontant aux valeurs de la capacité calorifique et de la conductivité thermique.Pour optimiser les pertes de masse, les instabilités sur les mesures du courant inducteur et la bonne reproductivité des mesures sur une goutte, nous avons choisi une masse initiale de 3,5 g pour faire les mesures avec modulation du courant inducteur dans un champ magnétique continu de 1 Tesla. Nous avons obtenu les valeurs de la capacité calorifique et de la conductivité thermique de la goutte. Celles-ci sont voisines des valeurs données par la littérature. Ce qui nous a permis de valider en partie le protocole de traitement des mesures.Dans le futur, ce protocole peut être appliqué sur des alliages métalliquesThe metal industry is requesting essential thermophysical properties for modeling and optimizing elaboration processes.Thermophysical properties of metals and metal alloys in liquid state are well known. These properties depend on the temperature and are difficult to measure especially at high temperature. In the liquid state, the metal is reactive and easily contaminated .In the 1980s, Egry developed an electromagnetic levitator TEMPUS developed an electromagnetic levitator TEMPUS to measure thermophysical properties of molten metals and alloys using a contactless technique under microgravity conditions. In space, the effects of electromagnetic stirring and deformation in molten samples are much lower than on Earth.The use of this space tool is expensive. In order to reduce the cost while maintaining or even improving the quality of measurements, we wanted to replace microgravity by a continuous magnetic field.The work in this thesis includes measuring the thermal properties of metals by electromagnetic method using a modulated calorimetry technique.The work has been divided in two parts:-The first consisted in the numerical simulation of space levitator TEMPUS and a terrestrial levitator AEXAM.The numerical simulation of space levitator TEMPUS aims to determine the effect of the superposition currents of different induction frequencies (heating currents and centering) on the hydrodynamic and thermal behavior of the drop. Calculation results showed that in some cases the centering current is likely to act on the measures and therefore it should be taking into account.The numerical simulation of terrestrial levitator AEXAM was destined to determine the vertical oscillation frequency of the drop, the power dissipated, the velocity fields developed inside and temperature. The drop takes the form of a pear and oscillates at a frequency of 7 Hz. The Joule power dissipated in the load is maximum on the lower part of the drop and decreases towards the interior of the drop vanishing at the center. Convection in the drop creates an electromagnetic stirring and homogenizing the temperature field.-The second part present the experiments performed using the levitator AEXAM placed in a horizontal continuous magnetic field for dampening the vertical oscillation and the turbulence produced by the effect of the electromagnetic stirring as it was mentioned in the calculations.This allowed us the implementation of a new protocol for measuring thermal properties in liquid metals.The protocol is a post processing program based on the temperature field variation resulting from unsteady joule power dissipation in the charge. An implemented identification function provides a mathematical model based on performed measurements. The use of a wide range of system frequencies was required to obtain a robust mathematical model. This was achieved by using pseudo-white noise perturbation at the generator inlet. The program has been validated successfully on solid matter by reverse determination of thermal conductivity and heat capacity.The preliminary studies under continuous magnetic field without modulation have mounted for a maximum initial weight of 3.5, we have less mass loss and improved measurement stability of the inductor current, as well as the reproductivity of the measurements.The protocol was validated successfully on the liquid charge using modulated perturbation under a continuous magnetic field of 1 Tesla. The obtained values of the heat capacity and thermal conductivity were comparable to the values given by the literature which partially validates the protocol.As a perspective, this protocol can be applied to a wide range of metal alloys
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Bustamante, Danilo. "High-Precision, Mixed-Signal Mismatch Measurement of Metal-Oxide-Metal Capacitors and a 13-GHz 5-bit 360-Degree Phase Shifter." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/9240.
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A high-precision mixed-signal mismatch measurement technique for metal-oxide metal (MoM) capacitors as well as the design of a 13-GHz 5-bit 360-degree phase shifter are presented. This thesis presents a high-precision, mixed-signal mismatch measurement technique for metal-oxide–metal capacitors. The proposed technique incorporates a switched-capacitor op amp within the measurement circuit to significantly improve the measurement precision while relaxing the resolution requirement on the backend analog-to-digital converter (ADC). The proposed technique is also robust against multiple types of errors. A detailed analysis is presented to quantify the sensitivity improvement of the proposed technique over the conventional one. In addition, this thesis proposes a multiplexing technique to measure a large number of capacitors in a single chip and a new layout to improve matching. A prototype fabricated in 180 nm CMOS technology demonstrates the ability to sense capacitor mismatch standard deviation as low as 0.045% with excellent repeatability, all without the need of a high-resolution ADC. The 13-GHz 5-bit 360-degree phase shifter consists of 2 stages. The first stage utilizes a delay line for 4-bit 180-degree phase shift. A second stage provides 1-bit 180-degree phase shift. The phase shifter includes gain tuning so as to allow a gain variation of less than 1 dB. The design has been fabricated in 180 nm CMOS technology and measurement results show a complete 360◦ phase shift with an average step size of 10.7◦ at 13-GHz. After calibration the phase shifter presented an output gain S21 of 0.5 dB with a gain variation of less than 1 dB across all codes at 13-GHz. The remaining s-parameter testing showed a S22 and S11 below -11 dB and a S12 below -49 dB at 13 GHz.
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Volf, Lukáš. "Výpočet jednofázového asynchronního motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219750.
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This work is in the first chapter deals with the basic properties of single phase and three-phase induction motors. The following describes the procedure for obtaining a starting torque of single-phase asynchronous motor. In the second part of the calculation is carried out single-phase induction motor with a permanently connected capacitor and its control, calculation of output values, the program proposed solution to this calculation in Microsoft Excel 2007 and calculated parameters of the development of methods of calculation were compared with measured, the values supplied by ATAS Náchod.
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Maamoun, Hatem. "Heme oxygenase (HO)-1 induction prevents endoplasmic reticulum stress-mediated endothelial cell death and impaired angiogenic capacity induced by high glucose." Thesis, University of Surrey, 2017. http://epubs.surrey.ac.uk/842136/.
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Most diabetic cardiovascular complications are mediated by endothelial dysfunction and impaired angiogenesis. Endoplasmic Reticulum [ER] and oxidative stresses were shown to play a pivotal role in the development of endothelial dysfunction in diabetes. The cytoprotective effects of Hemeoxygenase-1 [HO-1] were extensively studied; however, its role in alleviating ER stress-induced endothelial dysfunction remains elusive. We aim here to test the role of HO-1 against high glucose-mediated ER stress response and endothelial dysfunction and understand the underlying mechanisms with special emphasis on oxidative stress, inflammation and cell death. Primary Human Umbilical Vein Endothelial cells [HUVECs] were harbored in culture medium containing high glucose (33 mM) for 5 days with 8 hrs intermittent recovery periods to mimic the diabetic milieu. Using a wide array of molecular biology techniques, we were able to show that this chronic and intermittent exposure of HUVECs to high glucose significantly increased mRNA and protein expression of key ER stress markers namely, binding immunoglobulin protein [BiP], activation transcription factor-4 [ATF-4], CCAAT-enhancer-binding protein homologous protein [CHOP], and phosphorylated eukaryotic initiation factor2α [p-eIF-2α]. In addition, there was a significant elevation in ROS associated with significant increased phosphorylation of p47phox regulatory subunit of NADPH oxidase [NOX]. Moreover, inflammatory and apoptotic responses were also elicited, featured mainly by significant increase in phosphorylation/activation of IκB kinase [IKK] and c-Jun, and upregulation of IL-6, whereas apoptosis was featured by showing significantly increased caspase3/7 activity and cell death. Vascular endothelial growth factor-A [VEGF-A] expression, Nitric Oxide [NO] production, and tube formation capacity were also significantly inhibited by high glucose. Pre-treatment by HO-1 inducer Cobalt protoporphyrin IX [CoPP] significantly abolished all the observed effects with high glucose. Altogether, to the best of our knowledge, we present for the first time the role of HO-1 induction as a potential antagonist to ER stress response against high glucose mediated endothelial dysfunction and impaired angiogenesis.
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Mochamad, Arief Soleh. "Diversity and Mechanism of the Photosynthetic Induction Response among Various Soybean [Glycine max (L.) Merr.] Genotypes." Kyoto University, 2016. http://hdl.handle.net/2433/215607.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第19781号
農博第2177号
新制||農||1041(附属図書館)
学位論文||H28||N4997(農学部図書室)
32817
京都大学大学院農学研究科農学専攻
(主査)教授 白岩 立彦, 教授 奥本 裕, 教授 稲村 達也
学位規則第4条第1項該当
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Bauw, Grégory. "Amélioration des performances acoustiques et vibratoires des machines asynchrones par enroulement amortisseur." Thesis, Artois, 2018. http://www.theses.fr/2018ARTO0206.
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Ce travail présente une nouvelle technique permettant la réduction passive des bruits et vibrations d’origine magnétique des machines asynchrones triphasées grâce à un enroulement amortisseur connecté à des condensateurs. Les éléments nécessaires à la compréhension des phénomènes électromagnétiques, mécaniques et acoustiques, ainsi qu’un état de l’art des différentes techniques de réduction de bruit et vibrations sont d’abord donnés. Une partie de l’étude est ensuite consacrée au modèle de la machine asynchrone à enroulement amortisseur. Cette modélisation est basée sur le schéma monophasé équivalent de la machine et permet de mettre en évidence la réduction des harmoniques d’induction à l’origine des bruits et vibrations. Deux types de réduction de bruit sont décrits dans ce mémoire : celle du bruit provenant d’une alimentation de type M.L.I, d’une part, et du bruit provenant de phénomènes internes à la machine, d’autre part, comme les phénomènes d’encoches, la saturation ou l’excentricité. Pour chacun des deux cas, le schéma équivalent permettant de traduire le comportement de la machine est adapté et permet de choisir de manière optimale la valeur de condensateur à connecter à l’enroulement amortisseur. Une étude de dimensionnement permet également de discuter de l’impact de l’ajout de l’amortisseur sur l’encombrement, la masse et les performances de la machine. Des résultats expérimentaux montrent la validité et l’efficacité du système en termes de réduction des bruits et vibrations. La réduction du niveau de bruit global de la machine étudiée atteint 5dB(A) en alimentation réseau, et jusqu’à 10dB(A) en M.L.IThis work presents a new method allowing the passive reduction of magnetic noise and vibrations of three-phase induction machines using a damper winding connected to capacitors. The elements required for the understanding of the electromagnetic, mechanical and acoustic phenomena, as well as a state of the art of the different noise and vibrations reduction techniques are first given. A part of the study is then dedicated to the model of the induction machine with damper winding. This modeling is based on the equivalent single-phase circuit of the machine and makes it possible to highlight the reduction of the flux density harmonics responsible for noises and vibrations. Two types of noise reduction are described in this thesis: that of the noise due to PWM power supply on the one hand, and on the other, the noise due to internal phenomena such as slotting effects, saturation or eccentricity. For each case, the equivalent circuit allowing to translate the behavior of the machine is adapted and makes it possible to optimally choose the capacitor value to be connected to the damper. A design study also allows to discuss the impact of the addition of the damper on the size, weight and performances of the machine. Experimental results show the validity and effectiveness of the system in terms of noise and vibrations reduction. The global noise level reduction of the studied machine reaches 5dB(A) when the machine is fed by sine voltage, and up to 10dB(A) when PWM-fed
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Shah, Umer. "Novel RF MEMS Devices Enabled by Three-Dimensional Micromachining." Doctoral thesis, KTH, Mikro- och nanosystemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143757.
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This thesis presents novel radio frequency microelectromechanical (RF MEMS) circuits based on the three-dimensional (3-D) micromachined coplanar transmission lines whose geometry is re-configured by integrated microelectromechanical actuators. Two types of novel RF MEMS devices are proposed. The first is a concept of MEMS capacitors tuneable in multiple discrete and well-defined steps, implemented by in-plane moving of the ground side-walls of a 3-D micromachined coplanar waveguide transmission line. The MEMS actuators are completely embedded in the ground layer of the transmission line, and fabricated using a single-mask silicon-on-insulator (SOI) RF MEMS fabrication process. The resulting device achieves low insertion loss, a very high quality factor, high reliability, high linearity and high self actuation robustness. The second type introduces two novel concepts of area efficient, ultra-wideband, MEMS-reconfigurable coupled line directional couplers, whose coupling is tuned by mechanically changing the geometry of 3-D micromachined coupled transmission lines, utilizing integrated MEMS electrostatic actuators. The coupling is achieved by tuning both the ground and the signal line coupling, obtaining a large tuneable coupling ratio while maintaining an excellent impedance match, along with high isolation and a very high directivity over a very large bandwidth. This thesis also presents for the first time on RF nonlinearity analysis of complex multi-device RF MEMS circuits. Closed-form analytical formulas for the IIP3 of MEMS multi-device circuit concepts are derived. A nonlinearity analysis, based on these formulas and on measured device parameters, is performed for different circuit concepts and compared to the simulation results of multi-device conlinear electromechanical circuit models. The degradation of the overall circuit nonlinearity with increasing number of device stages is investigated. Design rules are presented so that the mechanical parameters and thus the IIP3 of the individual device stages can be optimized to achieve a highest overall IIP3 for the whole circuit.The thesis further investigates un-patterned ferromagnetic NiFe/AlN multilayer composites used as advanced magnetic core materials for on-chip inductances. The approach used is to increase the thickness of the ferromagnetic material without increasing its conductivity, by using multilayer NiFe and AlN sandwich structure. This suppresses the induced currents very effectively and at the same time increases the ferromagnetic resonance, which is by a factor of 7.1 higher than for homogeneous NiFe layers of same thickness. The so far highest permeability values above 1 GHz for on-chip integrated un-patterned NiFe layers were achieved.QC 20140328
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Ferreyre, Frédéric. "Conception de commandes sécurisées de volet roulant sans capteur de vitesse." Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00838016.
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Les moteurs asynchrones diphasés sont largement utilisés dans des applications de moins d'un kW, où le prix est un facteur important de choix, en particulier pour les volets roulants. Ces applications, pour des raisons de sécurité, nécessitent une détection précoce des obstacles et donc l'implantation d'un capteur de vitesse. Dans un souci de réduction de coût, une des pistes intéressantes est l'estimation de la vitesse à partir de la mesure des courants et des tensions, de manière à faire l'économie du capteur de vitesse. La première partie de notre travail a consisté à étudier et réaliser différentes alimentations : sur le secteur avec condensateur de déphasage ou par convertisseur statique. Dans une seconde partie, la modélisation du moteur en régime permanent et transitoire et celle du volet (tablier, frein, réducteur) nous a permis d'établir les caractéristiques électromagnétiques du motoréducteur et le comportement mécanique de la charge. Les paramètres de ces modèles ont été identifiés et les résultats analysés. Dans la troisième partie, à partir de ces modèles, différentes stratégies de détection de fin de course du volet sans capteur, d'arrêt sur obstacles ainsi qu'une commande de limitation de couple ont été mises au point et validées expérimentalement. Une carte électronique économique a été réalisée.
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Zhou, Tao. "Etude de composants passifs hyperfréquences à base de métamatériaux et de ferrite." Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00782328.
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Ce travail de thèse, qui se rattache au domaine des composants télécom, concerne l'étude de composants passifs élémentaires constitués de lignes de transmission coplanaires alliant ferrite et métamatériaux. Ces composants sont susceptibles de réaliser de nouvelles fonctions en électronique des hautes fréquences en combinant plusieurs phénomènes comme ceux de non réciprocité, des comportements main droite - main gauche et l'agilité en fréquence. Les applications visées portent sur un grand champ de composants microondes comme des antennes, des isolateurs, déphaseurs, coupleurs, filtres - agiles et performants. La modélisation, la fabrication et la caractérisation de ces composants ont été effectuées dans le cadre d'une collaboration entre l'INL et le LT2C. Les outils mis en œuvre dans ce travail comprennent la réalisation de ces composants en salle blanche, leur caractérisation en hyperfréquences (en général jusqu'à 20 GHz), leur simulation par un logiciel commercial de simulation par éléments finis (COMSOL) ainsi que le développement de techniques d'extraction de paramètres (Matlab). La mise en œuvre de ces outils a permis d'appréhender le comportement de ces lignes en termes de constante de propagation et de diagramme de dispersion. Sur le plan pratique, des composants inductifs et/ou capacitifs (capacités à fente ou interdigitées) ont été intégrés à des lignes de transmission coplanaires sur 2 types de substrats. Le premier substrat, diélectrique (Al203), sert de référence, tandis que le second est ferrimagnétique (YIG ou Y3Fe5O12) et présente un effet de non-réciprocité de la propagation du signal dans la configuration retenue. Sur alumine, les valeurs des capacités et des inductances intégrées atteignent 80 fF et 400 pH respectivement. Sur YIG, à partir d'études paramétriques originales sur différentes topologies de structures de test, les effets de non réciprocité attendus ainsi que les phénomènes de résonance gyromagnétique ont bien été mis en évidence. La simulation électromagnétique des structures est validée par un accord correct entre simulations et mesures. Il ressort de cette étude que la non réciprocité d'une ligne sur YIG chargée par des inductances parallèles peut être améliorée jusqu'à 15 dB environ par rapport à une simple ligne coplanaire sur YIG pour certaines bandes de fréquences. Enfin l'agilité en fréquence de la structure de bande des lignes CRLH est établie. Ces travaux ouvrent de très intéressantes perspectives pour le développement de nouveaux composants microondes et sont susceptibles de constituer un socle solide pour une suite des activités dans cette thématique.
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Atrous, Sofiane. "Mise en place d'une méthodologie de caractérisation en immunité champ proche de dispositifs électroniques." Rouen, 2009. http://www.theses.fr/2009ROUES030.
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Les exigences CEM sont de plus en plus sévères et doivent être prises en compte dès la phase de conception des dispositifs électroniques. Pour cela, il est nécessaire de disposer de modèles traduisant le comportement électromagnétique des cartes et composants que ce soit en émission ou en immunité. Actuellement, les études menées concernent principalement la caractérisation des composants en émissions conduite et rayonnée et en immunité conduite. Pour compléter ces travaux, des études en immunité rayonnée doivent être effectuées. Cette thèse a pour objectif de mettre en place une méthodologie de caractérisation des composants et de modélisation des circuits imprimés lorsque ces derniers sont soumis à une agression électromagnétique. A partir de l'étude bibliographique sur les méthodes expérimentales et sur les méthodologies de modélisations permettant d'étudier le couplage par rayonnement entre les ondes électromagnétiques et les cartes électronique nous avons travaillé sur deux axes : 1. L'étude et à la modélisation du couplage entre les ondes électromagnétiques et les pistes des circuits imprimés en utilisant un modèle analytique basé sur la théorie des lignes de transmission (modèle d'Agrawal et résolution par les équations BLT). 2. Le développement d'une nouvelle méthodologie d'agression en champ proche. Cette technique basée sur l'utilisation des sondes électromagnétiques permet la génération de champs perturbateurs localisés avec de fortes amplitudes sans nécessité de fortes puissances. Nous avons e��tudié plus particulièrement le cas d'un circuit intégré analogique simple : un inverseur logiqueEMC requirements are becoming stricter and must be taken into account during the design phase of electronic devices. For that reason, it is necessary to have models representing electromagnetic emission and immunity of components. Now a day, the main studies concern the characterization of conducted immunity and radiated emission of components. To complete this model, a study of radiated immunity must be made. This thesis aims to develop a methodology for components characterization and modeling when they are exposed to electromagnetic aggression. Starting from the different experimental methods and models developed previously to study coupling. The work in this thesis was focused more particularly in two axes : 1. The study and the modeling of coupling between electromagnetic waves and the printed circuit boards (PCB) using an analytical model based on the transmission lines theory (Agrawal model solved using BLT equations). 2. The developement of a new near field perturbation methodology. This technique use electromagnetic probes which allows the generation of localized fields with high amplitudes without need a strong powers. We have studied more particularly the case of a simple analog integrated circuit (logic inverter)
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Mombo, Boussougou Yves Constant. "Intérêt et faisabilité des interconnexions radiofréquences : caractérisation électromagnétique du canal et études des modes d'accès." Brest, 2011. http://www.theses.fr/2011BRES2021.
Full textAbstract:
Pour pallier les limitations des interconnexions classiques (puissance dissipée, débit), engendrées par l’augmentation des performances des systèmes, plusieurs solutions sont envisagées notamment dans l’ITRS. Citons notamment les interconnexions optiques, les interconnexions 3D et les interconnexions radiofréquences. Dans ce travail nous nous sommes intéressés aux interconnexions radiofréquences, utilisant des moyens de communication radiofréquence, offrant plusieurs avantages notamment en tenue de reconfigurabilité, de débit et de coût. Le but de ce travail est d’estimer l’intérêt et la faisabilité de cette approche à travers la caractérisation de différents canaux RF, et de l’étude de différents modes d’accès. Pour valider ce concept par la transmission simultanée de plusieurs bits d’information à l’aide d’une interconnexion RF, nous associons des canaux de transmission réalistes avec deux types de techniques d’accès multiple différents. Ainsi, pour des communications intra-puces, nous proposons l’utilisation d’un accès FDMA associé à un canal avec couplage capacitif. Malgré des résultats prometteurs, la complexité et la surface des circuits à réaliser semblent encore trop importantes pour valider cette approche pour des communications. En ce qui concerne le cas des communications inter-puces sur carte PCB, nous présentons un exemple utilisant une technique CDMA et un canal RF avec des transitions microruban-fente. Pour ce type d’application les résultats obtenus nous permettent de valider la topologie retenue et même de proposer l’architecture d’un circuit d’interface facilitant ce type de communicationsTo overcome the limitations of conventional interconnects (power loss, data rate), caused by the increase in system performance, several solutions are being considered including in the ITRS. These include optical interconnects, 3D interconnects and radio frequency interconnects. In this work we focused on radio frequency interconnects, using radio frequency communication channels, providing several advantages especially in terms of reconfigurability, data rate and cost. The purpose of this study was to assess die desirability and feasibility of this approach through the characterization of different RF channels, and the study of different modes of access. To validate this concept by the simultaneous transmission of several bits of information using an RF interconnect, we combine realistic transmission channels with two types of different multiple access techniques. Thus, for intra-chip communications, we propose the use of FDMA access to a channel associated with capacitive coupling. Despite promising results, the complexity and the surface of the circuit to achieve seem ton important to validate this approach to communications. Regarding tire case of inter-chip communications on board PCB, we present an example using a CDMA and a RF channel with microstrip-slot transitions. For this application tire results allow us to validate die topology chosen to offer and even die architecture of an interface circuit to facilitate such communications
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Tokgoz, Korkut Kaan. "Broadband Phase Shifter Realization With Surface Micromachined Lumped Components." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614652/index.pdf.
Full textAbstract:
Phase Shifters are one of the most important building cells of the applications in microwave and millimeter-wave range, especially for communications and radar applicationsto steer the main beam for electronic scanning. This thesis includes all of the stages starting from the theoretical design stage to the measurements of the phase shifters. In detail, all-pass network phase shifter configuration is used to achieve broadband and ultra wide-band differential phase characteristics. For these reasons, 1 to 2 GHz, 2 to 4 GHz, and 3 to 6 GHz 4-bit, 22.5°
phase resolution phase shifter realization with surface micromachined lumped components are designed, simulated, fabricated and measured. Basic building blocks of the phase shifters, i.e., surface micromachined lumped components, square planar spiral inductors and Metal-Insulator-Metal capacitors are designed with EM simulation and lumped equivalent model extractions. The validation of the designed square planar spiral inductors is done with fabrication and measurement steps, very low error, below 1%, between the designs and fabricated samples are observed. Using this knowledge on lumped elements finally phase shifters are designed with surface micromachined lumped components, fabricated using an in house technology provided by METU-MEMS facilities, RF MEMS group. Low phase rms error, good return and insertion loss considerations are aimed, and achieved. In addition to the main work of this thesis, a generalized theoretical calculation method for 2n-1 number of stages all-pass network phase shifters is presented for the first time in literature. A different, new, broadband, and combined phase shifter topology using two-stage all-pass filters is presented. Moreover, the implementation of this idea is proved to be practical to 3 to 6 GHz 5.625°
and 11.25°
combined phase shifter. A new approach for stage numbers other than power of 2 is indicated, which is different from what is already presented in the literature. An example practical implementation results are provided for the three-stage 4-bit 1 to 6 GHz phase shifter. Also, a small improvement in SRF of the high inductance valued inductors is achieved with the mitering of the corners of square planar spiral inductors. Comparison of the measured data between the normal inductors and mitered versions shows that the first SRF of the inductors are increased about 80 MHz, and second SRF of the inductors are increased about 200 MHz.
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Du, Sijun. "Energy-efficient interfaces for vibration energy harvesting." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270359.
Full textAbstract:
Ultra low power wireless sensors and sensor systems are of increasing interest in a variety of applications ranging from structural health monitoring to industrial process control. Electrochemical batteries have thus far remained the primary energy sources for such systems despite the finite associated lifetimes imposed due to limitations associated with energy density. However, certain applications (such as implantable biomedical electronic devices and tire pressure sensors) require the operation of sensors and sensor systems over significant periods of time, where battery usage may be impractical and add cost due to the requirement for periodic re-charging and/or replacement. In order to address this challenge and extend the operational lifetime of wireless sensors, there has been an emerging research interest on harvesting ambient vibration energy. Vibration energy harvesting is a technology that generates electrical energy from ambient kinetic energy. Despite numerous research publications in this field over the past decade, low power density and variable ambient conditions remain as the key limitations of vibration energy harvesting. In terms of the piezoelectric transducers, the open-circuit voltage is usually low, which limits its power while extracted by a full-bridge rectifier. In terms of the interface circuits, most reported circuits are limited by the power efficiency, suitability to real-world vibration conditions and system volume due to large off-chip components required. The research reported in this thesis is focused on increasing power output of piezoelectric transducers and power extraction efficiency of interface circuits. There are five main chapters describing two new design topologies of piezoelectric transducers and three novel active interface circuits implemented with CMOS technology. In order to improve the power output of a piezoelectric transducer, a series connection configuration scheme is proposed, which splits the electrode of a harvester into multiple equal regions connected in series to inherently increase the open-circuit voltage generated by the harvester. This topology passively increases the rectified power while using a full-bridge rectifier. While most of piezoelectric transducers are designed with piezoelectric layers fully covered by electrodes, this thesis proposes a new electrode design topology, which maximizes the raw AC output power of a piezoelectric harvester by finding an optimal electrode coverage. In order to extract power from a piezoelectric harvester, three active interface circuits are proposed in this thesis. The first one improves the conventional SSHI (synchronized switch harvesting on inductor) by employing a startup circuitry to enable the system to start operating under much lower vibration excitation levels. The second one dynamically configures the connection of the two regions of a piezoelectric transducer to increase the operational range and output power under a variety of excitation levels. The third one is a novel SSH architecture which employs capacitors instead of inductors to perform synchronous voltage flip. This new architecture is named as SSHC (synchronized switch harvesting on capacitors) to distinguish from SSHI rectifiers and indicate its inductorless architecture.
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Postariu, Dragos Mihai. "Contribution à l'étude des courants de palier dans les moteurs de traction." Phd thesis, Université Joseph Fourier (Grenoble), 2009. http://tel.archives-ouvertes.fr/tel-00459803.
Full textAbstract:
La fiabilité est l'un des principaux objectifs de tout fabricant de moteurs électriques. Au cours des 20 dernières années, l'apparition de l'électronique de puissance dans la partie alimentation es moteurs électriques de traction a donné la possibilité de contrôle de couple à toute vitesse de rotation. En utilisant ce type d'alimentation pour les moteurs asynchrones, ceux-ci sont devenus une alternative à coût réduit et très fiable aux moteurs synchrones utilisés auparavant dans la traction. L'inconvénient de l'électronique de puissance, c'est que des fronts dV/dt sont appliqués aux moteurs. Ces fronts excitent les couplages parasites dans les moteurs, de sorte que les courants vagabonds peuvent circuler dans le moteur, et passer par les roulements. Cela amène à une augmentation du taux de défaillance. L'objectif de ce travail est de développer un modèle analytique, utilisable à partir de la phase de conception du moteur, qui permet de prévoir le type et la quantité des courants qui sont susceptibles de se produire.
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Addou, Mohammed Adnan. "Filtrage actif intégré reconfigurable pour la téléphonie sans fil." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0123/document.
Full textAbstract:
Ce travail de thèse porte sur la conception de dispositifs filtrants accordables, c'est-à-dire pouvant commuter leurs caractéristiques d'un standard à un autre afin de réduire l’encombrement des chaines émission/réception d’un dispositif multistandard. Les filtres les plus utilisés actuellement sont des filtres acoustiques. En effet, ces filtres sont difficilement intégrables dans une technologie silicium et ils restent parmi les dispositifs passifs les plus encombrants du front-end RF. De plus, ils ne permettent pas d’avoir de bonnes performances en pertes d’insertion, en sélectivité et en accordabilité fréquentielle. De ce fait, des solutions alternatives sont à l’origine de ces travaux de thèse. Nous avons considéré tout d’abord un filtre actif qui a la possibilité de régler sa fréquence de résonnance, d’une part à la fréquence de résonnance du système Wifi et d’autre part, à la fréquence de résonnance du système Zigbee. Ensuite, une autre solution a été proposée dans le dernier chapitre qui consiste à réaliser une structure active filtrante bi-bande intégrée. Cette solution a pour avantage de récolter simultanément les données des systèmes opérant dans les deux bandes de fréquences visés. Les résultats obtenus des circuits réalisés sont validés par des simulations et de mesuresThis thesis concerns the design of tunable filter devices that can switch theirs characteristics from one standard to another in order to reduce the congestion of emission/reception chain of multi-standard systems. The most commonly used filters are acoustic filters. Indeed, these filters are difficult to be integrated in silicon technology and they remain one of the most bulky passive devices of the RF front-end. In addition, they don’t achieve good performance in insertion loss, frequency selectivity and tunability. Therefore, alternative solutions are at the origin of this thesis. An active filter is considered with the possibility of adjusting the resonance frequency: the resonant frequency of the Wifi system and the resonance frequency of the Zigbee system. Moreover, another solution is proposed in the last chapter, which consists to achieve a dual band structure of integrated active filter. This solution has the advantage to simultaneously collect data provided from the operating systems located in the two specified frequencies bands. Simulations and measurements validate the results of the realized circuits
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Toure, Baïdy Birame. "Modélisation haute-fréquence des variateurs de vitesse pour aéronefs : contribution au dimensionnement et à l'optimisation de filtres CEM." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT038/document.
Full textAbstract:
Depuis une bonne dizaine d'année, l'aéronautique a entamé sa mutation vers le "plus électrique".L'objectif étant de réduire la consommation de carburant, une des contraintes majeures de ces nouvelles solutions est de réduire la masse embarquée. Les filtres dimensionnés pour les convertisseurs statiques doivent donc être optimisés au mieux vis-à-vis de ce critère, ainsi que du volume. Il y a donc un fort besoin du côté des concepteurs d’avions de savoir quels choix parmi les différentes possibilités technologiques sont optimaux, et de connaître l'impact de ces choix sur le poids, le coût global et le volume de l'équipement. Le filtre CEM représente généralement environ 30% du coût et du volume d'un convertisseur électronique de puissance. Il va de soi que le volume et/ou la masse de ces filtres doit être optimisé. L'impact de la loi de commande du convertisseur, le choix des semi-conducteurs, du packaging, câbles (longueur et intégration dans l’avion), des machines électriques,...doivent être parfaitement connus pour atteindre un dimensionnement optimal.Dans cette perspective, les objectifs de ces travaux de thèse visent à fournir non seulement une démarche méthodologique pour la modélisation haute fréquence des variateurs de vitesse dédiés aux applications aéronautiques mais aussi une approche de dimensionnement par optimisation des filtres CEM. Pour cela, un outil logiciel évolutif d’aide à la génération rapide des modèles CEM est proposé. Une description modulaire et une mise en équation automatique du modèle fréquentiel complet ainsi que des gradients en facilitent l'utilisation en procédures d’optimisation sous contraintes. L’approche présentée dans ces travaux est relativement générique : la topologie du filtre, de la structure du convertisseur, du câblage et la loi de commande peuvent être facilement recalculées, grâce à cet environnement logicielThe More Electrical Aircraft concept is very promising regarding energy saves, but generates new problems, and especially the emergence of new power electronics loads on the electrical network. Keeping the same level of safety in the aircraft means developing these switching mode converters in accordance with the aircraft standards, as the DO160. This is not obvious since weights of equipments are especially constrained: indeed, the objective of weight and energy save needs to be balanced with the additional weight and volume of the required EMI filters. There is thus a strong need in helping the aircraft designers to choose among the various technological possibilities, and to know the impact of these choices on the global weight, cost and volume of the embedded equipments. The EMI filter usually represents roughly 30% of the cost and volume of a power electronics converter, and it is very important to optimize it. The impact of the converter control law, semiconductors choice, interconnects realization, harness selection and placement, electrical motors characteristics… should be perfectly known in order to reach a good system design. In this perspective, the objectives of this thesis are to provide not only an approach for modelling high frequency variable speed drives dedicated to aerospace applications but also a methodology to optimize the required EMI filters. For this purpose, new architecture software dedicated to the rapid generation of EMC models is proposed. A modular description and a complete automatic model generation facilitate the use by the designer in optimization procedures thanks to automatic gradient computation.The methodology presented in this work is not specifically developed for a given application. It is a very generic approach: the topology of the filter, the structure of the inverters, interconnects and the control law can be easily recalculated, using this software environment. Consequently, the impact of all these elements on the electromagnetic disturbances can be characterized, and the EMI filter optimized
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Eid, Elie. "Caractérisation et modélisation électrique des phénomènes de couplage par les substrats de silicium dans les empilements 3D de circuits intègrés." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENT021.
Full textAbstract:
Afin d’améliorer les performances électriques dans les circuits intégrés en 3D, une large modélisation électromagnétique et une caractérisation haute fréquence sont requises. Cela a pour but de quantifier et prédire les phénomènes de couplage par le substrat qui peuvent survenir dans ces circuits intégrés. Ces couplages sont principalement dus aux nombreuses interconnexions verticales par unité de volume qui traversent le silicium et que l’on nomme « Through Silicon Vias » (TSV).L’objectif de cette thèse est de proposer des règles d’optimisation des performances, à savoir la minimisation des effets de couplage par les substrats en RF. Pour cela, différentes configurations de structures de test utilisées pour analyser le couplage sont caractérisées.Les caractérisations sont effectuées sur un très large spectre de fréquence. Les paramètres d’analyse sont les épaisseurs du substrat, les architectures des vias traversant (diamètres, densités, types de barrières), ainsi que la nature des matériaux utilisés. Des modèles électriques permettant de prédire les phénomènes de couplage sont extraits. Différents outils pour l’analyse de ces effets, sont développés dans notre laboratoire. Parallèlement un important travail de modélisation 3D est mené de façon à confronter mesure et simulation et valider nos résultats. Des stratégies d’optimisation pour réduire ces phénomènes dans les circuits 3D ont été proposées, ce qui a permis de fournir de riches informations aux designersIn order to improve the electrical performance in 3D integrated circuits, a large electromagnetic modeling and a high frequency characterization are required. This has for goal to quantifiy and predicts the substrate coupling phenomena that can occur in these integrated circuits. These couplings are mainly due to the numerous vertical interconnections existing in a small volume and passing through the silicon, and so called “Through Silicon Vias” (TSV). The objective of this thesis is to propose rules for electrical performance optimization, in order to minimize the coupling effects in RF substrates. For this reason, different test structures configurations used to analyze the coupling are characterized.The characterizations are performed on a very wide frequency spectrum. The analysis parameters are the thicknesses of the substrate, the TSV architectures (diameters, densities, types of barriers), and the nature of the used materials. Electrical models for predicting the coupling phenomena are extracted. Different tools for the analysis of these effects are developed in our laboratory. At the same time, a considerable amount of 3D modeling is conducted to compare measurements with simulations and validate our results. Optimization strategies to reduce coupling phenomena in 3D circuits have been proposed; this has provided a wealth of information to designers
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Vácha, Pavel. "Výpočet jednofázového asynchronního motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219186.
Full textAbstract:
The master´s thesis deal with the thesis of a single-phase induction motor that is more and more used all over the world. Its aim is assembling the information about this type of motor and its calculation. The content of the first part is the theoretical analysis of a single-phase induction motor and acquirement ways of the stroke moment. Than the work contains a project of basic schema of the single-phase induction motor with an auxiliary phase. The practical part is devoted to an elaboration of demonstration example of the single-phase induction motor with concrete parameters calculation, its method was projected before. Than there is practising successived measuring on the motor of the same parameters made firm EMP s.r.o. Slavkov by Brno in this part. In the conclusion there is the evaluation of the whole process with reached results.
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Štaffa, Jiří. "Ztráty jednofázového asynchronního motoru s trvale připojeným kondenzátorem." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221263.
Full textAbstract:
This project deals with increasing efficiency of one phase induction motor with permanent split capacitor. We can whole thesis divide into two parts, the first one is basic and the second is interested in analysis and measurement. First part handles with construction of single phase induction motor, explanation of function principle, start and run of motor. Calculating of efficiency including type of losses, which reduce efficiency. Second part concerns analysis losses including moment load characteristic, motor measurement while rotor is locked, with no load operation, measuring mechanical and additional losses. Further there will be measured useful values for creation model for simulation (reactance of windings etc.). Than will be the model created in ANSYS Maxwell with module RMxprt. After analytic calculation in RMxprt and using Finite Element Method (FEM) load characteristics will be compared together. This comparison gives us information about accuracy of model for simulation. Simulation and measurement will be carried out on another engine with high quality ferromagnetic material used for magnetic circuit of motor. Further will be done simulation of motor with modifications shown in previous chapter for high efficiency.
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Chang, Tso-Jung, and 張祚榮. "Design Reflection Amplifier Using Shunt Capacitor and Inductor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/81677369576000914001.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
102
This thesis presents the design of reflection-type amplifier using shunt inductor and capacitor at the transistor source termination. The basic theory of oscillation condition is discussed in Chapter 1. In Chapter 2, analysis of the input impedance at the gate termination of a transistor with drain termination shorted and source terminated with a shunt LC resonator gives the operational bandwidth of a reflection amplifier. Furthermore, the design flow of choosing element values of the shunt inductor and capacitor is provided in Chapter 3, based on the required operational bandwidth as a reference for the circuit designer.
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Yi-ChunLin and 林怡均. "Seven-Level Inverter Using Coupled Inductor and Switched Capacitor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/74120921227167655812.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
This thesis proposes a novel single-phase seven-level inverter. The topology of the proposed structure is composed of a DC source, a switched-capacitor circuit, and a coupled inductor. Compared to traditional seven-level inverter structure, the numbers of switches and diodes are reduced. The novel single-phase seven-level inverter reduces the number of capacitor by one, increasing the stability and life cycle of the circuit. The voltages of capacitors are self-balanced by switched-capacitor circuit and coupled inductor without complex control method. Therefore, the output voltage total harmonic distortion of the proposed structure can be reduced. Finally, the simulation and experimental results show the 350-Vdc input voltage, 380-Vac output voltage, and 0.52 % output total harmonic distortion under 3 kW output power condition to verify the feasibility of the proposed multilevel inverter.
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Lee, Cheng-Yeh, and 李承曄. "CMOS Compatible Highly Tunable Contact Mode Capacitor and Inductor." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/30283217850239431379.
Full textAbstract:
碩士國立臺北科技大學
機電整合研究所
92
This thesis presents a highly tunable capacitor and inductor by using CMOS processes and extra post-process techniques of MEMS. Contact mode capacitor and inductor consists voltage-control actuator and stationary electrode, such as capacitor or inductor. The voltage-control actuator is cantilever beam and the diaphragm will deform in response to applied electrostatic voltage and change the gap between the two actuator-electrodes. Even after the movable electrode begin to touch the stationary electrode of capacitor or inductor the actuator can still increase its voltage until the movable electrode fully touch the stationary electrode of capacitor or inductor. The contact mode capacitor and inductor can achieve large operating voltage range, reduce area, and ultra-wide tuning range of capacitance and inductance. This thesis also presents a dynamic mathematic model. The dynamic model can reduce the simulation time and predict microstructure performance, such as driving voltage, contact area, and cantilever’s displacement…etc.
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Feng-ChengChiu and 邱豐正. "Using the Inductor-Capacitor Model to Design Mid-Infrared Absorbers." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/69445163329934018180.
Full textAbstract:
碩士國立成功大學
機械工程學系碩博士班
101
Wavelength-selective absorbers for sensing human thermal radiation were numerically developed with a SiO2 spacer sandwiched between a gold substrate and gratings. All dimensions were determined with an LC (inductor-capacitor) circuit model which could induce MP (magnetic polariton) excitation at the target wavelength. Although the maximum absorptance is higher than 0.8 when the incident wavelength is near 10 μm, the absorptance is close to 0 in other wavelengths. Absorptance spectra and electromagnetic fields were acquired from programmed codes based on RCWA (rigorous coupled-wave analysis). This thesis demonstrates that the LC circuit model can be used to obtain suitable structure parameters and save time as compared to other optimized methods.
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Chia-HuaYeh and 葉佳樺. "A Novel Electrolytic Capacitor-Less Multilevel Inverter with Coupled Inductor." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/37221899383670942408.
Full textAbstract:
碩士國立成功大學
電機工程學系
102
In this thesis, a novel multilevel electrolytic capacitor-less inverter is proposed. With the three-winding coupled inductor, input voltage can be divided without electrolytic capacitors. Hence, no voltage-balancing circuit is needed. Less power switches are required for the proposed circuit compared to the existing topologies. Only ten switches are required to generate seven-level output. The operating principle, mode analysis and modulation method are introduced. The control scheme is implemented by TMS320F28035. Finally, a laboratory prototype of seven-level inverter with 320V input voltage and 220 Vrms/3kW output is implemented. The efficiency under full load is 94.82%, the maximum efficiency is 96.39% under 74.34 % load. Lastly, extended circuits are also proposed.
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Jian-LiLin and 林建利. "A High Step-down Buck Converter with Coupled Inductor and Switched Capacitor." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/68361401114524967208.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
This thesis proposes a buck converter with coupled inductor and switched-capacitor techniques. By employing the proposed topology, the DC-DC converter achieves high voltage conversion ratio. The switched-capacitor cell is not only used to achieve high step-down voltage gain, but eliminate the voltage spike induced by the trapped energy in the leakage inductance of the coupled inductor. Besides, the auxiliary switch in switched-capacitor cell has zero-voltage-switching (ZVS) feature. Thus, the main switch of the converter can sustain a lower duty ratio and a lower voltage stress. Moreover, the inductor current flows in the opposite direction while it drops to zero, and the main switch can be turned on with zero-voltage-switching. Since both main and auxiliary switches have ZVS feature, switching loss can be reduced, and conversion efficiency can, therefore, be improved significantly. A prototype circuit of 200W, 200V input-voltage, and 24V output-voltage has been implemented to verify the proposed converter. The experimental results have shown that voltage spike can be greatly suppressed and the maximum efficiency can reach 95.8% and the overall efficiency is almost above 93%.