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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Design And Implementation Of Coupled Inductor Cuk Converter Operating In Continuous Conduction Mode

Ayhan, Mustafa Tufan 01 December 2011 (has links) (PDF)
The study involves the following stages: First, coupled-inductor and integrated magnetic structure used in Cuk converter circuit topologies are analyzed and the necessary information about these elements in circuit design is gathered. Also, benefits of using these magnetic elements are presented. Secondly / steady-state model, dynamic model and transfer functions of coupled-inductor Cuk converter topology are obtained via state-space averaging method. Third stage deals with determining the design criteria to be fulfilled by the implemented circuit. The selection of the circuit components and the design of the coupled-inductor providing ripple-free input current waveform are performed at this stage. Fourth stage introduces the experimental results of the implemented circuit operating in open loop mode. Besides, the controller design is carried out and the closed loop performance of the implemented circuit is presented in this stage.
62

Design and Fabrication of High Quality-factor Suspending Microinductors

Jiang, Zong-Nan 27 August 2008 (has links)
For the application of 4G wireless communication system, this thesis aims to develop a high-quality-factor and low-power-dissipation suspending micro-inductor using electrochemical deposition and surface micromachining technologies. This research presents three technical points to improve the quality factor and reduce the power dissipation of micro inductor, including (i) to adopt a low resistivity material (copper) as the conducting layer to decrease the Eddy current due to the skin effect and reduce the total series resistance and energy loss, (ii) to utilize a suspending structure to diminish the power loss through the substrate and (iii) to replace the silicon wafer with a high resistance substrate (Corning 7740) to compress effectively the power dissipation in high frequency operation. The implemented suspending micro-inductors were characterized by a commercial network analyzer (Agilent E5071C) under 0.5~20 GHz testing frequency range. All the inductances and quality factors of the micro-inductors proposed in this thesis are extracted by the Agilent ADS software. The optimized value of the quality factor is around to 24.9 and the corresponding inductance is equal to 5.43 nH .
63

Passive inductively coupled wireless sensor for dielectric constant sensing

Zhang, Sheng, active 2013 24 October 2013 (has links)
In order to address the challenges of capacitive sensing in harsh environment, self resonant passive wireless sensors are studied. The capacitive sensing elements based on interdigitated capacitor (IDC) sensor are used. A semi-empirical model providing accurate capacitance calculation for IDCs over a wide range of dimensions and dielectric constants is developed. An equivalent circuit model based on electric field distribution is proposed, leading to a closed form approximation for IDC capacitance calculation. The conductivity of the material under test is also considered and a model is proposed to calculate effective capacitance as a function of conductivity and measurement frequency. The model is used to study the design optimization of IDC sensor and suggested design procedure is proposed. To wirelessly interrogate the capacitive sensor, it is connected to an inductive element to form a resonant circuit, while the measurement is made at remote reader coil. Advantages and disadvantages of different type of resonant structure design are analyzed. In order to assist the design process, a SPICE circuit model is developed to estimate the resonant frequency of the self resonant sensor. Miniaturized sensors with different dimensions are designed, fabricated and tested. The sensor is integrated with silicon nanowire fabric coated with polymer. Measurements are made to illustrate the enhancement in sensing capability by integrating chemical selective material. / text
64

Measurement and modeling of the anhysteretic magnetization of magnetic cores for temperature and frequency dependent effects

Walker, Jeremy M 01 June 2007 (has links)
Inductors and transformers are electrical devices critical to power conversion systems. The current-voltage (I-V) behavior of these devices is very nonlinear as a result of the magnetic cores used in their construction. However, in the design of these power conversion systems the present state of Spice-based models is limited to low frequency and room temperature effects. An addition to the present model found in many Spice type environments, Jiles-Atherton, is the subject of this work. Chapter 1 of this dissertation introduces the source of these nonlinearities as being a result of the relationship between the magnetic flux density, B, and the applied magnetic field, H. Chapter two then derives the original mathematical model used in the Spice, Jiles-Atherton, to provide a physical basis of the addition to the model. The original derivation as it can be found in the referenced literature shows that a temperature and frequency dependence on the model does not exist. This work will seek to add such a dependence on temperature first followed by frequency. Using this approach, the temperature dependence can be modeled without the core experiencing self-heating. The model therefore must be capable of being further modified after the temperature dependence is added.
65

Integrated Switching DC-DC Converters with Hybrid Control Schemes

Luo, Feng January 2009 (has links)
In the modern world of technology, highly sophisticated electronic systems pave the way for future's information technology breakthroughs. However, rapid growth on complexity and functions in such systems has also been a harbinger for the power increase. Power management techniques have thus been introduced to mitigate this urgent power crisis. Switching power converters are considered to be the best candidate due to their high efficiency and voltage conversion flexibility. Moreover, switching power converter systems are highly nonlinear, discontinuous in time, and variable. This makes it viable over a wide operating range, under various load and line disturbances. However, only one control scheme cannot optimize the whole system in different scenarios. Hybrid control schemes are thus employed in the power converters to operate jointly and seamlessly for performance optimization during start-up, steady state and dynamic voltage/load transient state.In this dissertation, three switching power converter topologies, along with different hybrid control schemes are studied. First, an integrated switching buck converter with a dual-mode control scheme is proposed. A pulse-train (PT) control, employing a combination of four pulse control patterns, is proposed to achieve optimal regulation performance. Meanwhile, a high-frequency pulse-width modulation (PWM) control is adopted to ensure low output ripples and avoid digital limit cycling. Second, an integrated buck-boost converter with a tri-mode digital control is presented. It employs adaptive step-up/down voltage conversion to enable a wide range of output voltage. This is beneficial to ever-increasing dynamic voltage scaling (DVS) enabled, modern power-efficient VLSI systems. DVS adaptively adjusts the supply voltage and operation frequency according to instantaneous power and performance demand, such that a system is constantly operated at the lowest possible power level without compromising its performance. Third, a digital integrated single-inductor multiple-output (SIMO) converter, tailored for DVS-enabled multicore systems is addressed. With a multi-mode control algorithm, DVS tracking speed and line/load regulation are significantly improved, while the converter still retains low cross regulation.All three integrated CMOS DC-DC converters have been designed and fabricated successfully, demonstrating the techniques proposed in this research. The measurements results illustrate superior line and load regulation performances and dynamic response in all these designs.
66

Stiprių magnetinių laukų daugkartinio naudojimo induktorių tyrimas / The Investigation of High Magnetic Field Long-Life Operation Inductors

Bartkevičius, Saulius 15 June 2009 (has links)
Disertacijoje nagrinėjami stipraus impulsinio magnetinio lauko induktoriai, kurių ilgaamžiškumas priklauso nuo daugelio jų fizikinių parametrų. Sukūrus induktorių geometrijos sintezės metodiką, sudaryti induktorių matematiniai ir kompiuteriniai modeliai, ištirti impulso metu skirtingų parametrų induktorių apvijose vykstantys procesai, atlikta daugkartinio naudojimo induktorių geometrijų paieška. Sukurtas programinis aprūpinimas induktorių skaičiavimams įgalina nustatyti induktorių, tinkamų daugkartiniam impulsiniam magnetiniam laukui generuoti, parametrus. Darbo rezultatai pritaikyti kuriant induktorių prototipus. Disertaciją sudaro įvadas, keturi skyriai, bendrosios išvados, literatūros ir publikacijų disertacijos tema sąrašas. Įvadiniame skyriuje aprašomas problemos aktualumas, formuluojamas darbo tikslas ir uždaviniai, pristatomi autoriaus pranešimai ir publikacijos, pateikiama disertacijos struktūra. Pirmajame skyriuje aptariama stipraus magnetinio lauko reikšmė šiuolaikiniam mokslui, pristatomi stipraus magnetinio lauko generavimo būdai, analizuojami impulsiniai induktoriai, jų kompiuterinių modelių sudarymo problematika, geometrijos optimizavimas. Antrajame skyriuje aprašoma induktorių geometrijos ir medžiagų sudėties sintezės metodika, sukuriamas induktoriaus matematinis-kompiuterinis modelis, apibrėžiama daugkartinio naudojimo induktorių pagrindinių parametrų visuma – „gyvavimo zona“, pateikiamas daugkartinio naudojimo induktorių geometrijų paieškos algoritmas... [toliau žr. visą tekstą] / The aim of the dissertation is the analysis of high pulsed magnetic field inductors in order to determine their electrophysical parameters for non-destructive magnetic field generation. To obtain that effective method to synthesize inductor geometrical and material models was developed, inductor mathematical and computer models created, electrophysical processes during the pulse in windings of various inductors were examined. Finally, retrievals of nondestructive inductor geometrical configurations were performed. Software developed and results gained were successfully used to design new pulsed inductor prototypes. Dissertation content: introduction, four chapters, general conclusions, list of references and list of author’s publications on the subject of dissertation. The introduction contains the topicality of the problem, aim of the work, main tasks, scientific novelty, practical value, result approval, defended statements and structure description. Overview of different high magnetic field generation techniques, pulsed inductor design, geometry optimization problems and software used for these tasks are the objectives of the first chapter. The second chapter is dedicated to development of technique for inductor geometrical-material model synthesis, creation of mathematical-computer inductor model, definition of long-life operation inductor parameters – their “vitality zone” and design of non-destructive inductor geometries retrieval algorithm. In the third chapter... [to full text]
67

The Investigation of High Magnetic Field Long-Life Operation Inductors / Stiprių magnetinių laukų daugkartinio naudojimo induktorių tyrimas

Bartkevičius, Saulius 15 June 2009 (has links)
The aim of the dissertation is the analysis of high pulsed magnetic field in-ductors in order to determine their electrophysical parameters for non-destructive magnetic field generation. To obtain that effective method to synthe-size inductor geometrical and material models was developed, inductor mathe-matical and computer models created, electrophysical processes during the pulse in windings of various inductors were examined. Finally, retrievals of non-destructive inductor geometrical configurations were performed. Software de-veloped and results gained were successfully used to design new pulsed inductor prototypes. Dissertation content: introduction, four chapters, general conclusions, list of references and list of author’s publications on the subject of dissertation. The introduction contains the topicality of the problem, aim of the work, main tasks, scientific novelty, practical value, result approval, defended state-ments and structure description. Overview of different high magnetic field generation techniques, pulsed in-ductor design, geometry optimization problems and software used for these tasks are the objectives of the first chapter. The second chapter is dedicated to development of technique for inductor geometrical-material model synthesis, creation of mathematical-computer induc-tor model, definition of long-life operation inductor parameters – their “vitality zone” and design of non-destructive inductor geometries retrieval algorithm. In the third chapter... [to full text] / Disertacijoje nagrinėjami stipraus impulsinio magnetinio lauko induktoriai, kurių ilgaamžiškumas priklauso nuo daugelio jų fizikinių parametrų. Sukūrus induktorių geometrijos sintezės metodiką, sudaryti induktorių matematiniai ir kompiuteriniai modeliai, ištirti impulso metu skirtingų parametrų induktorių ap-vijose vykstantys procesai, atlikta daugkartinio naudojimo induktorių geometrijų paieška. Sukurtas programinis aprūpinimas induktorių skaičiavimams įgalina nustatyti induktorių, tinkamų daugkartiniam impulsiniam magnetiniam laukui generuoti, parametrus. Darbo rezultatai pritaikyti kuriant induktorių prototipus. Disertaciją sudaro įvadas, keturi skyriai, bendrosios išvados, literatūros ir publikacijų disertacijos tema sąrašas. Įvadiniame skyriuje aprašomas problemos aktualumas, formuluojamas dar-bo tikslas ir uždaviniai, pristatomi autoriaus pranešimai ir publikacijos, patei-kiama disertacijos struktūra. Pirmajame skyriuje aptariama stipraus magnetinio lauko reikšmė šiuolaiki-niam mokslui, pristatomi stipraus magnetinio lauko generavimo būdai, analizuo-jami impulsiniai induktoriai, jų kompiuterinių modelių sudarymo problematika, geometrijos optimizavimas. Antrajame skyriuje aprašoma induktorių geometrijos ir medžiagų sudėties sintezės metodika, sukuriamas induktoriaus matematinis-kompiuterinis modelis, apibrėžiama daugkartinio naudojimo induktorių pagrindinių parametrų visuma – „gyvavimo zona“, pateikiamas daugkartinio naudojimo induktorių geometrijų paieškos algoritmas... [toliau žr. visą tekstą]
68

Multilevel Space Vector PWM for Multilevel Coupled Inductor Inverters

Vafakhah, Behzad Unknown Date
No description available.
69

A Novel Variable Inductor-Based VCO Design with 17% Frequency Tuning Range for IEEE 802.11AD Applications

Meng, YIN FEI 23 January 2014 (has links)
This thesis focuses on the design and analysis of a novel variable inductor (VID) based VCO solution to the frequency tuning range (TR) limitation of the IEEE 802.11ad compliant radio systems. The IEEE 802.11ad standard has drawn strong attention from the industry as the next generation affordable multi-gigabit speed wireless communication standard. Prepared for the global market, IEEE 802.11ad compliant systems are required to cover a broad 8 GHz TR centered on 60 GHz. This wide TR at V band imposes significant challenge to the VCO design in radio transceivers, and makes the TR of the integrated VCO a major bottleneck to the successful commercialization of many IEEE 802.11ad compliant radio systems today. As an effort to solve the current TR problem for the IEEE 802.11ad compliant radio systems, 2 VCOs designs based on this novel VID-based solution and a conventional Colpitts-Clapp VCO design are presented in this thesis report. The novel VCOs integrate a VID into the differential Colpitts configuration to create a feasible solution to the aforementioned TR problem. The VID in the VCO tank eliminates the base node varactors and their fixed parasitic capacitance that degrades TR in conventional VCO designs, while the differential Colpitts configuration provides advantageous performance at mm-wave frequencies and high output power for real-world applications. Also, a fundamental 30 GHz Colpitts-Clapp VCO was developed in conjunction with the other 2 VCOs for comparison purposes. One of the 2 VID-based VCO designs is a fundamental 30 GHz VID-based Colpitts VCO that covers 17% TR for proof of concept to the novel topology. Another is an IEEE 802.11ad compliant 60 GHz VCO chain consists of the 30 GHz VID-based Colpitts VCO and a frequency doubler covering 17% TR with 3 dBm output power and -115.7 dBc/Hz phase noise at 10 MHz offset. The conventional Colpitts-Clapp VCO is used to compare with the other 2 VID-based VCOs. As the measurement results indicate, this VID-based VCO topology provides a viable solution to overcome the TR bottleneck in the current IEEE 802.11ad compliant VCO development. All 3 VCOs are fabricated using a 130 nm SiGe BiCMOS process. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-01-23 13:40:31.258
70

Indutores integrados passivos para aplicações em radio frequencia / Integrated passive inductors for radio frequency applications

Fonseca Junior, Paulo Nazareno Lagoia 12 August 2018 (has links)
Orientador: Luiz Carlos Kretly / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-12T09:54:12Z (GMT). No. of bitstreams: 1 FonsecaJunior_PauloNazarenoLagoia.pdf: 5632530 bytes, checksum: ea9f82363483a872a3effe7dbd527b5f (MD5) Previous issue date: 2008 / Resumo: Este trabalho tem como finalidade a implementação de indutores integrados passivos baseados nas tecnologias de fabricação CMOS e BiCMOS. Os indutores são dispositivos fundamentais em aplicações de rádio freqüência e estão presentes na maioria dos circuitos de RF como amplificadores e osciladores. Os Indutores integrados passivos têm seus desempenhos degradados principalmente pelas perdas associadas ao metal e substrato. E apesar da existência de vários métodos de otimização, as foundries em geral, ainda oferecem um número reduzido de componentes, o que dificulta a escolha do melhor dispositivo para cada circuito. Sendo assim, a partir do projeto e implementação de indutores integrados o projetista é capaz de desenvolver novos dispositivos para cada aplicação. Este trabalho apresenta os resultados experimentais de indutores CMOS otimizados com a técnica de empilhamento para a redução de perdas ôhmicas e de PGS para a redução de perdas pelo substrato. Apresenta-se também indutores projetados na tecnologia BiCMOS com dupla camada de PGS; enterrada n+ e silício policristalino. / Abstract: This work aims the design and implementation of integrated passive inductors based on CMOS and BiCMOS processes. The inductors are essential devices in radio frequency applications and are used in many RF circuits such as amplifiers and oscillators. The inductors' performance is mainly limited by metal and substrate losses. Although various methods of improvement have been proposed, the foundries still offer a reduced number of components, making far more difficult to choose the best device for each circuit. In this way, from the design and implementation of integrated inductors, the designer is able to enhance and develop new devices for each application. This works presents the experimental results of inductors based on CMOS process. These inductors have been improved with two techniques; multilevel and PGS, the first one reduce the metal losses and the second to reduce the substrate losses. This work also shows inductors improved with double PGS based on BiCMOS process. The double PGS was designed with polysilicon and n+ buried layer. / Universidade Estadual de Campi / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

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