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Analysis and design of a low-ripple coupled-inductor boost topologyButler, Stephen J. 31 October 2009 (has links)
This thesis presents the development, analysis, and design of a new low-ripple coupled-inductor boost topology. This topology is proposed for applications in which the conventional boost requires an input filter and two-stage output filter. One "zero-ripple" coupled magnetic provides both energy storage and second-order filtering of the input and output currents. Dc analysis is presented along with design guidelines. A novel magnetic structure is proposed which simplifies design and manufacture, while improving reliability. Small signal models for the proposed topology are presented along with hardware verification. It is found that, with proper damping, the small signal characteristics of the coupled-inductor topology are very similar to those of the conventional boost. This new boost topology offers a compact alternative to the conventional boost without sacrificing performance. / Master of Science
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High Q inductors on ultra thin organic substratesAthreya, Dhanya 11 July 2008 (has links)
One of the chief components in a RF/microwave circuit is the inductor. The performance of the inductor affects the performance of widely used circuits such as the voltage controlled oscillator (VCO), low noise amplifier, and filter in the RF front end. It is very important to design inductors for accurate values of inductances and sufficiently high quality factors for these microwave applications. A key challenge in achieving high unloaded Q for an inductor in a thin substrate is the ground separation. This thesis aims at addressing this issue and achieving high unloaded Q's in the range 150 - 200 for a ground separation of about 100 - 140 microns in the frequency range of 1 - 15 GHz. One port and inductors will be designed using Electromagnetic field solvers. Various topologies will be explored for 2D and 3D inductors with the aim of achieving the desired inductance density and Q parameters in a minimum area possible. In order to address the issue of ground separation, design modifications will include the use of patterned grounds to take advantage of the reduced parasitic capacitive coupling which enables a high Q factor. The objective of the thesis also includes demonstration of the usefulness of these high quality inductors in RF front ends. To this effect, proof of concept designs of LC band pass filters will be presented. To enable this design, capacitors will also be designed. An extensive library of the designed inductors will be presented as a part of the thesis.
The designed components will be fabricated at the Packaging Research Center (PRC), Georgia Tech using organic substrate compatible processes. High frequency measurements will be made with the Vector Network Analyzer (VNA) along with suitable de - embedding to demonstrate the correlation between designed and fabricated results. Following this, circuit models will be built for the characterized inductors.
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Integrated Inductors with Micro-Patterned Magnetic Thin Films for RF and Power ApplicationsJanuary 2013 (has links)
abstract: With increasing demand for System on Chip (SoC) and System in Package (SiP) design in computer and communication technologies, integrated inductor which is an essential passive component has been widely used in numerous integrated circuits (ICs) such as in voltage regulators and RF circuits. In this work, soft ferromagnetic core material, amorphous Co-Zr-Ta-B, was incorporated into on-chip and in-package inductors in order to scale down inductors and improve inductors performance in both inductance density and quality factor. With two layers of 500 nm Co-Zr-Ta-B films a 3.5X increase in inductance and a 3.9X increase in quality factor over inductors without magnetic films were measured at frequencies as high as 1 GHz. By laminating technology, up to 9.1X increase in inductance and more than 5X increase in quality factor (Q) were obtained from stripline inductors incorporated with 50 nm by 10 laminated films with a peak Q at 300 MHz. It was also demonstrated that this peak Q can be pushed towards high frequency as far as 1GHz by a combination of patterning magnetic films into fine bars and laminations. The role of magnetic vias in magnetic flux and eddy current control was investigated by both simulation and experiment using different patterning techniques and by altering the magnetic via width. Finger-shaped magnetic vias were designed and integrated into on-chip RF inductors improving the frequency of peak quality factor from 400 MHz to 800 MHz without sacrificing inductance enhancement. Eddy current and magnetic flux density in different areas of magnetic vias were analyzed by HFSS 3D EM simulation. With optimized magnetic vias, high frequency response of up to 2 GHz was achieved. Furthermore, the effect of applied magnetic field on on-chip inductors was investigated for high power applications. It was observed that as applied magnetic field along the hard axis (HA) increases, inductance maintains similar value initially at low fields, but decreases at larger fields until the magnetic films become saturated. The high frequency quality factor showed an opposite trend which is correlated to the reduction of ferromagnetic resonant absorption in the magnetic film. In addition, experiments showed that this field-dependent inductance change varied with different patterned magnetic film structures, including bars/slots and fingers structures. Magnetic properties of Co-Zr-Ta-B films on standard organic package substrates including ABF and polyimide were also characterized. Effects of substrate roughness and stress were analyzed and simulated which provide strategies for integrating Co-Zr-Ta-B into package inductors and improving inductors performance. Stripline and spiral inductors with Co-Zr-Ta-B films were fabricated on both ABF and polyimide substrates. Maximum 90% inductance increase in hundreds MHz frequency range were achieved in stripline inductors which are suitable for power delivery applications. Spiral inductors with Co-Zr-Ta-B films showed 18% inductance increase with quality factor of 4 at frequency up to 3 GHz. / Dissertation/Thesis / Ph.D. Electrical Engineering 2013
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Design Of Transformers And Inductors At Power-Frequency - A Modified Area-Product MethodMurthy, G S Ramana 03 1900 (has links) (PDF)
No description available.
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Inductors in LTCC utilizing full tape thickness featuresBoutz, Adam January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Inductors have been produced in LTCC in a unique manner that increases the cross-sectional area of the conductor. The method uses metal-filled trenches and cavities in the tape to create conductors which are as thick as an entire layer of tape. This geometry helps to compensate for high-frequency non-idealities such as skin effect, current crowding, and proximity effect. An array of test structures has been fabricated. The measured results achieved inductors with Qs of 60 and suggest that Qs up to 100 are possible. Accurate measurements of such values require careful consideration of error sources and are discussed. A potential application of the inductors is presented in a two-pole filter, which has been modeled and fabricated. Lastly, a list of conclusions which would be helpful for future work on this subject is presented.
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Silicon-embedded magnetic components for on-chip integrated power applicationsYu, Xuehong 07 January 2016 (has links)
The objective of the proposed research is to design, fabricate, characterize and test silicon-embedded magnetic components for on-chip integrated power applications.
Driven by the trend towards continued system multi-functionality and miniaturization, MEMS technology can be used to enable fabrication of three-dimensional (3-D) functional devices into the silicon bulk, taking advantage of the 'dead volume' in the substrate and achieving a greater level of miniaturization and integration. As an example, one of the challenges in realizing ultra-compact high-frequency power converters lies in the integration of magnetic components due to their relatively large volume.
Embedding 3-D magnetic components within the wafer volume and implementing high-power, through-wafer interconnect for connection to circuitry on the wafer surface is a promising solution for achieving ultra-compact power converters, in which digital control circuitry and power switches are located on the wafer surface, and suitable magnetic components are embedded within the silicon substrate. In order to do this, key tasks in the following areas have been accomplished: development of new fabrication technologies for silicon embedding and 3-D structure realization; creation of high-current, through-wafer interconnects for connection of the device to circuitry; ability to incorporate a variety of magnetic materials when performance enhancement of the device is needed; exploration of a new design space for the devices due to ultra-compactness and silicon interaction; understanding of the complicated loss mechanisms in the embedded devices; and demonstration of device performance and in-circuit operation.
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A digital-PID-control single-inductor triple-output (SITO) DC-DC converter with pre-sub-period inductor-current regulation. / CUHK electronic theses & dissertations collection / Digital dissertation consortiumJanuary 2010 (has links)
In this thesis, a digital-PID-control single-inductor triple-output (SITO) DC-DC converter is realized in AMS 0.35mum CMOS technology. The size of the chip is about 1600 mum x 1700 mum. To improve load current and reduce cross regulation, a Pre-Sub-Period inductor-current regulation is proposed. Based on the maximum duty cycle limiter, an adaptive inductor current adjustment is realized when the duty cycle of the digital PWM signal is larger than the set maximum duty cycle. By an optimized phase control sequence, the S&H stages of the feedback switching and ADC are controlled to on/off with a minimized delay time. Moreover, the control sequence can virtually remove the setting time. / Multiple voltage supplies are necessary to satisfy the different voltage supply requirements of the different on-chip blocks to reduce power consumption in modem electronic devices, such as the modem embedded systems, the portable devices, personal computing devices and wireless communications and imaging systems. For example, WiMAX transmitter includes different sub-blocks: Baseband processor, IQ modulator and power amplifier. Different blocks should operate with the different power supply voltages to satisfy the different requirements. / Single-input multiple-output DC-DC converter is presented to provide the different voltage supplies and reduce the cost on the elements such as the inductor on PCB and save PCB area. Meanwhile, to remove cross regulation and improve load driving capability, the DC-DC converter should operate in the pseudo-continuous mode/discontinuous mode (P-CCM/DCM). However, in the previous designs, the DC current in the inductor is fixed. When the load becomes heavy enough, cross regulation will significantly affect across the different sub-converters. / Jia, Jingbin. / "December 2009." / Adviser: KaNang Leung Alex. / Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 121-124). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Analysis and modeling of single-ended and differential spiral inductors in silicon-based RFICsWatson, Adam C. 02 December 2003 (has links)
A new comprehensive wide-band compact modeling methodology for
single-ended spiral inductors and differential spiral inductors is presented. The
new modeling methodology creates an equivalent circuit model consisting of
frequency-independent circuit elements for use in circuit simulators. A fast automated
extraction procedure is developed for determining the circuit element
values from two-port S-parameter measurement data. The methodology is extremely
flexible in allowing for accurate modeling of general classes of inductors
on high or low resistivity substrate and for large spirals exhibiting distributed
trends. The new modeling methodology is applied to general classes of spirals
with various sizes and substrate parameters.
The presented compact modeling methodology has major benefits including
greatly reducing model extraction time in comparison with currently available
models based on optimization methods. To demonstrate the accuracy in comparison
with past models a number of measurement data sets are used for sample
extractions. A developed computer program is presented and used for circuit
model extractions. Results are presented when the computer program is applied
to a high-volume inductor extraction. The extracted models show excellent agreement
with the measured data sets over the frequency range of 0.1 to 10 GHz. / Graduation date: 2004
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Caracterització de la mort cel·lular en línies de neuroblastoma humàFrancisco Bordas, Roser 10 May 2010 (has links)
L'objectiu d'aquesta tesi ha estat buscar nous agents inductors de diferenciació, aturada del cicle cel·lular o mort cel·lular, per a les cèl·lules de neuroblastoma humà, més eficaços i més selectius que els fàrmacs utilitzats en la teràpia actual. Amb aquesta finalitat, hem estudiat l'efecte ex vivo en diferents línies cel·lulars de neuroblastoma humà de dos compostos, el pigment bacterià prodigiosina, i l'inhibidor general d'histona desacetilases de classe I/II tricostatina A. La PG ha mostrat tenir un efecte citotòxic i citostàtic en les línies de neuroblastoma. Indueix mort cel·lular per mecanismes apoptòtics dependents de caspases, i especialment en les cèl·lules de neuroblastoma tipus N, les fenotípicament més agressives. No obstant la inhibició de l'activació de les caspases no reverteix complertament la mort cel·lular, indicant la implicació d'altres mecanismes de mort cel·lular en el procés desencadenat per PG. L'aturada de la proliferació cel·lular és en canvi molt més acusada en les cèl·lules tipus S, tot i que és un fenomen observat en totes les cèl·lules estudiades. A més a més, en el present treball hem descrit com la PG, després de la seva entrada per difusió en la cèl·lula, s'acumula especialment en els mitocondris, induint un efecte desacoblant entre la cadena respiratòria i l'activitat de l'ATPasa-F0-F1 mitocondrial de les cèl·lules de neuroblastoma. Com a resultat, la producció d'ATP es veu disminuïda notablement però la taxa de consum d'oxigen no s'altera. Nosaltres suggerim que l'explicació a aquest fet podria trobar-se en l'habilitat que té la PG per a atrapar protons a pH fisiològic, modificant així els gradients de pH intracel·lulars, no tant sols els vesiculars i els lisosomals, si no també molt possiblement els intramitocondrials. Al capítol dos es descriuen els resultats de l'estudi del tractament de les cèl·lules de neuroblastoma amb TSA. El TSA indueix una aturada del cicle cel·lular en G2/M i apoptosi, però també autofàgia, procés fins al moment no descrit en aquestes cèl·lules com a resposta a l'exposició a HDIs, no havent-se observat diferències en aquests efectes entre les cèl·lules neuroblàstiques tipus N, S i I. En concordança amb estudis previs, la disminució de la proliferació i l'aturada en G2/M ha resultat ser conseqüència d'un procés independent de les caspases. Probablement associat a l'augment d'expressió de l'inhibidor de CDKs p21WAF/Cip1 i a l'activació de la via supressora de tumors del RB, tal i com suggereix la disminució de l'expressió de N-Myc, E2F-1 i Survivina, tots ells implicats en aquesta via, i a més a més marcadors de mal pronòstic en el neuroblastoma. Podent ser la disminució de la Survivina responsable per si sola del desencadenament de l'apoptosi. No obstant, l'efecte del TSA no ha estat el mateix en totes les línies cel·lulars de neuroblastoma estudiades, sent les cèl·lules SK-N-AS les més resistents. En aquestes cèl·lules, tot i activar-se els mateixos mecanismes que en la resta de cèl·lules estudiades, la disminució de la viabilitat és molt reduïda i, a les dosis utilitzades, sembla prevaldre un efecte citostàtic. És més, mentre en les cèl·lules LA1-55N, SK-N-JD i LA1-5S, apoptosi i autofàgia semblen estar induint-se simultàniament i col·laborar en la mort cel·lular induïda pel TSA, en les SK-N-AS els resultats suggereixen que aquests dos mecanismes tenen finalitats antagòniques, de manera que l'autofàgia promou la supervivència cel·lular. Així doncs, els resultats obtinguts indiquen que els dos compostos són capaços d'induir una disminució de la viabilitat cel·lular deguda a una aturada de la proliferació i/o a la mort cel·lular. A més a més, els resultats de l'exposició de les cèl·lules als dos compostos són prou diferents als produïts pels anticancerígens convencionals, com per considerar-se el seu assaig en diferents combinacions amb altres quimioteràpics. / "Characterization of cell death in human neuroblastoma cell lines."TEXT:The objective of this thesis was to look for new agents capable to induce differentiation, cell cycle arrest or cell death in neuroblastoma human cells, more efficient and selective than the ones use in actual therapy. With this purpose, we have studied the ex vivo effect of two compounds in different human neuroblastoma cell lines, the red pigment prodigiosin, and trichostatin A, a general inhibitor of histone deacetylases of class I/II. Prodigiosin showed a cytotoxic and cytostatic effect in neuroblastoma cells. It induced cell death through caspase-dependent apoptotic mechanisms, especially in N-type neuroblastoma cells, the more aggressive ones. We suggest this effect could be explained by prodigiosin ability to capture protons at physiologic pH, modifying the intracellular pH gradients.At the second chapter we described the effect of trichostatin A in this cell model. Trichostatin-A induces a G2/M-cycle arrest, apoptosis and authopagy in the three types of neuroblastoma cells, N-, I- and S-type. However, not all the cells exhibited the same sensibility, being the SK-N-AS cells the more resistant to this compound. Moreover, while in LA1-55N, SK-N-JD and LA1-5S cells apoptosis and autophagy seem to be induced simultaneously and to collaborate in TSA-induced cell death, in SK-N-AS cells these two mechanisms seem to have antagonic purposes, leading autophagy to cell survival.In conclusion, the results indicate that these two agents are able to induce a decrease in cell viability because of cell-cycle arrest and/or cell death. Furthermore, the consequences of the exposition of the cells to these compounds are different enough to the obtained by conventional therapy, to consider its assay with different combinations of other chemotherapy agents.
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Low Temperature RF MEMS Inductors Using Porous Anodic AluminaOogarah, Tania Brinda January 2008 (has links)
In today’s communication devices, the need for high performance inductors is increasing as they are extensively used in RF integrated circuits (RFICs). This need is even more pronounced for variable inductors as they are widely required in tunable filters, voltage controlled amplifiers (VCO) and low noise amplifiers (LNA). For RFICs, the main tuning elements are solid state varactors that are used in conjunction with invariable inductors. However, they have limited linearity, high resistive losses, and low self resonant frequencies. This emphasizes the need for developing another tuning element that can be fabricated monolithically with ICs and can offer high range of tuning.
Due to the ease of CMOS integration and low cost silicon based IC fabrication, the inductors currently used are a major source of energy loss, therefore driving the overall quality factor and performance of the chip down. During the last decade there has been an increase in research in RF MicroelectroMechanical Systems (RF MEMS) to develop high quality on chip tunable RF components. MEMS capacitors were initially proposed to substitute the existing varactors, however they can not be easily integrated on top of CMOS circuits. RF MEMS variable inductors have recently attracted attention as a better alternative.
The research presented here explores using porous anodic alumina (PAA) in CMOS and MEMS fabrication. Due to its low cost and low temperature processing, PAA is an excellent candidate for silicon system integration.
At first, PAA is explored as an isolation layer between the inductor and the lossy silicon substrate. Simulations show that although the dielectric constant of the PAA is tunable, the stress produced by the required thicker layers is problematic.
Nevertheless, the use of PAA as a MEMS material shows much more promise. Tunable RF MEMS inductors based on bimorph sandwich layer of aluminum PAA and aluminum are fabricated and tested. A tuning range of 31% is achieved for an inductance variation of 5.8 nH to 7.6 nH at 3 GHz.
To further improve the Q, bimorph layers of gold and PAA are fabricated on Alumina substrates. A lower tuning range is produced; however the quality factor performance is greatly improved. A peak Q of over 30 with a demonstrated 3% tuning range is presented.
Depending on the need for either high performance or tunability, two types of tunable RF MEMS inductors are presented. Although PAA shows promise as a mechanical material for MEMS, the processing parameters (mainly stress and loss tangent) need to be improved if used as an isolation layer. To our knowledge, this is the first time this material has been proposed and successfully used as a structural material for MEMS devices and CMOS processes.
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