• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 6
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 46
  • 46
  • 13
  • 12
  • 8
  • 7
  • 7
  • 7
  • 7
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
1

Frequency and time domain modelling of integrated passives

McMullin, Gareth 12 June 2008 (has links)
Although the technology of integrated passives in power electronics has been receiving a lot of attention recently, behavior prediction of these integrated passive structures is still not on an acceptable level for widespread applications. A lot of work has been done recently on accurate electromagnetic modelling of these structures, but the complex models investigated are not practical for the average engineer in power electronics to apply, and integrated passives remain a subject of interest in research and academia, but very infrequently applied in industry. The aim of this dissertaion is to provide a bridge between the mathematical models currently being investigated, and circuit level behaviour prediction which may be used by practicing engineers to design power electronics circuits which make use of integrated passives. The history of integrated passives is first investigated, along with historical modelling techniques and their shortcomings. Two similar modern distributed circuit theory models are investigated and aspects of both are combined to form the model that is used as a mathematical foundation for this dissertation. This model is analysed, and some methods are proposed for integrating the resulting differential equations. A transformation is proposed for transforming the transmission network representa- tion of the structure, which results from integrating the differential equations, into a network of admittances, which may be used for applying the technique of nodal analysis to a circuit containing an integrated passive structure. This admittance network model is used to implement a frequency domain simulation model in a practical circuit simulator. i In the integration of the circuit differential equations, the method of modal analysis is applied. In this analysis a system of wave equations is derived and solved in the frequency domain. By applying the inverse fourier transform to these wave solutions it is found that the modal wave propogation is a simple time shift in the time domain for each propogating mode in lossless structures. Applying this observation a transient model is implemented in the circuit simulator for lossless integrated passive structures. Although this is limited to the lossless case, the simulator still appears to be giving good results. The zero voltage switching two inductor boost converter was then investigated to construct a case study for the simulator. The topology was analysed, and a design method found. A discrete converter was constucted to verify the analysis. The design of an integrated passive structure for this converter is then presented, and the simulation results show that the simulator may is robust enough to be applied to practical problems. The integrated converter could unfortunately not be constructed due to materials processing limitations, and thus the simulation result remain to be experimentally verified. The results do however closely match those predicted by the widely used lumped element models, apart from some high order effects. / Prof. I.W. Hofsajer
2

Design of compact folded-line RF power dividers /

Lim, Chi-young. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2004. / Printout. Includes bibliographical references (leaves 61-62). Also available on the World Wide Web.
3

Low cost test fixture for self-resonant frequency measurements of passive chip components

Akambi, Aboudou S. January 2005 (has links)
Thesis (Ph.D.)--University of Nevada, Reno, 2005. / "August, 2005." Includes bibliographical references (leaves 74-75). Online version available on the World Wide Web.
4

Business Valuation and Acquisition Performance¡ÐDid Yageo Pay too much for Philips Passive Component Division?

Lin, Shih-Jie 27 June 2011 (has links)
The M&A of Yageo and Philips¡¦s global passive components department in 2000 is a well-known failure case. This study investigates this 18.8 billion M&A case using business evaluation in order to explore its synergy and whether the offer price is reasonable. Contrary to media reports, this study found that the price was somehow high but reasonable during the period. Research shows taking out this M&A deal will erode shareholders¡¦ interest by NTD$31 billion. Yageo¡¦s current state of core business value is analyzed to find that Yageo¡¦s value increases at least NTD$40 billion. A decade after the M&A, Orion ¡V reinvested by Yageo Chairman Chen Taiming - announced to obtain 100% of Yageo¡¦s equity of NTD$16.1 per share in early April, 2011. Such action indicates Chairman Chen foresaw potential profitability in Yageo. In addition, the previous M&A of Philips Passive Components Division has a great influence in recent growth and points out that the M&A decision are not wrong. The findings of the study show that post-merger integration is implemented properly can gain positive benefits for shareholders through the M&A of Philips Passive Components Division.
5

How electronic component agents respond to changing market conditions - a case study of a listed company in Taiwan

Lin, Xuan-Yu 22 August 2011 (has links)
Abstract As technology advances, new computer, telecommunications and consumer electronic products are constantly being introduced, giving consumers more choice than in the past. However, fluctuations in the business cycle mean that competitors fight to gain market share and this often results in an oversupply of 3C products and a decline in prices. Taiwan's notebook industry is world-famous, but because of pressure from foreign companies profit margins are relatively low. The notebook producers try to control the price of the components by putting pressure on component makers. This leads to a price war between the suppliers and even the winners of this war still have to cut prices on a quarterly basis. Technology, consumer preferences and prices are all changing rapidly. Component agents are being squeezed between suppliers, who want to maintain a fixed price, and customers who want prices to be cut. This has reduced profit margins. This research focuses on how passive component agents change in response to this situation and meet the demands for higher quality, better service, lower prices and faster delivery. The case study concerns Company A, which originally acted solely as a passive component agent. It examines how, between 2002-2010, the company restructured its business and supply chain and developed its own-brand components to gain key competitive advantage and establish an operating platform. This study researched the relevant literature and information concerning Company A to produce a summary of the company's transition strategy and how it was implemented. It is hoped that this research will provide a reference for other agents which are going through a similar transition. Keywords: passive components, OEM, own-brand, competitive advantage
6

RF/microwave integrated passives for system on package module development

Davis, Mekita F. 08 1900 (has links)
No description available.
7

High Q inductors on ultra thin organic substrates

Athreya, Dhanya. January 2008 (has links)
Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Prof. Rao Tummala; Committee Member: Prof. G.K. Chang; Committee Member: Prof. Maysam Ghovanloo.
8

Infrared and passive microwave satellite rainfall estimate over tropics

Saw, Bun Liong. January 2005 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (December 19, 2006) Includes bibliographical references.
9

A low power signal front-end for passive UHF RFID transponders with a new clock recovery circuit.

January 2009 (has links)
Chan, Chi Fat. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.2 / 摘要 --- p.5 / Acknowledgement --- p.7 / Table of Contents --- p.9 / List of Figures --- p.11 / List of Tables --- p.14 / Chapter 1. --- Introduction --- p.15 / Chapter 1.2. --- Research Objectives --- p.16 / Chapter 1.3. --- Thesis Organization --- p.18 / Chapter 1.4. --- References --- p.19 / Chapter 2. --- Overview of Passive UHF RFID Transponders --- p.20 / Chapter 2.1. --- Types of RFID Transponders and Design Challenges of Passive RFID Transponder --- p.20 / Chapter 2.2. --- Selection of Carrier Frequency --- p.22 / Chapter 2.3. --- Description of Transponder Construction --- p.22 / Chapter 2.3.1. --- Power-Generating Circuits --- p.23 / Chapter 2.3.2. --- Base Band Processor --- p.28 / Chapter 2.3.3. --- Signal Front-End --- p.29 / Chapter 2.4. --- Summary --- p.30 / Chapter 2.5. --- References --- p.31 / Chapter 3. --- ASK Demodulator for EPC C-l G-2 Transponder --- p.32 / Chapter 3.1. --- ASK Demodulator Design Considerations --- p.32 / Chapter 3.1.1. --- Recovered Envelope Distortion --- p.32 / Chapter 3.1.2. --- Input Power Level Considerations --- p.34 / Chapter 3.1.3. --- Input RF power Intercepted by ASK Demodulator --- p.36 / Chapter 3.2. --- ASK Demodulator Design From [3-4] --- p.36 / Chapter 3.2.1. --- Envelope Waveform Recovery Design --- p.37 / Chapter 3.2.1.1. --- Voltage Multiplier Branch for Generating Venv --- p.39 / Chapter 3.2.1.2. --- Voltage Multiplier Branch for Generating Vref --- p.41 / Chapter 3.2.2. --- Design Considerations for Sensitivity of ASK Demodulator --- p.41 / Chapter 3.2.3. --- RF Input Power Sharing with Voltage Multiplier --- p.44 / Chapter 3.2.4. --- ASK Demodulator and Voltage Multiplier Integrated Estimations for Maximum RF Power Input --- p.47 / Chapter 3.2.5. --- Measurement result and Discussion --- p.49 / Chapter 3.3. --- Proposed Envelope Detector Circuit --- p.52 / Chapter 3.3.1. --- Sensitivity Estimation --- p.52 / Chapter 3.3.2. --- Maximum Tolerable Input Power Estimation --- p.53 / Chapter 3.3.3. --- Envelope Waveform Recovery of the Proposed Envelope Detector --- p.54 / Chapter 3.4. --- Summary --- p.57 / Chapter 3.5. --- References --- p.58 / Chapter 4. --- Clock Generator for EPC C-l G-2 Transponder --- p.59 / Chapter 4.1. --- Design Challenges Overview of Clock Generator --- p.59 / Chapter 4.2. --- Brief Review of PIE Symbols in EPC C1G2 Standard --- p.62 / Chapter 4.3. --- Proposed Clock Recovery Circuit Based on PIE Symbols for Clock Frequency Calibration --- p.64 / Chapter 4.3.1. --- Illustration on PIE Symbols for Clock Frequency Calibration --- p.64 / Chapter 4.3.2. --- Symbol time-length counter --- p.72 / Chapter 4.3.3. --- The M2.56MHZ Reference Generator and Sampling Frequency Requirement --- p.75 / Chapter 4.3.4. --- Symbol Length Reconfiguration for Different Tari and FLL Stability --- p.80 / Chapter 4.3.5. --- Frequency Detector and Loop Filter --- p.83 / Chapter 4.3.6. --- Proposed DCO Design --- p.84 / Chapter 4.3.7. --- Measurement Results and Discussions --- p.88 / Chapter 4.3.7.1. --- Frequency Calibration Measurement Results --- p.89 / Chapter 4.3.7.2. --- Number x and Tari Variation --- p.92 / Chapter 4.3.7.3. --- Temperature and Supply Variation --- p.93 / Chapter 4.3.7.4. --- Transient Supply Variation --- p.94 / Chapter 4.3.8. --- Works Comparison --- p.95 / Chapter 4.4. --- Clock Generator with Embedded PIE Decoder --- p.96 / Chapter 4.4.1. --- Clock Generator for Transponder Review --- p.96 / Chapter 4.4.2. --- PIE Decoder Review --- p.97 / Chapter 4.4.3. --- Proposed Clock Generator with Embedded PIE Decoder --- p.97 / Chapter 4.4.4. --- Measurement Results and Discussions --- p.100 / Chapter 4.5. --- Summary --- p.103 / Chapter 4.6. --- References --- p.105 / Chapter 5. --- ASK Modulator --- p.107 / Chapter 5.1. --- Introduction to ASK Modulator in RFD Transponder --- p.107 / Chapter 5.2. --- ASK Modulator Design --- p.109 / Chapter 5.3. --- ASK Modulator Measurement --- p.110 / Chapter 5.4. --- Summary --- p.113 / Chapter 5.5. --- References --- p.113 / Chapter 6. --- Conclusions --- p.114 / Chapter 6.1. --- Contribution --- p.114 / Chapter 6.2. --- Future Development --- p.116
10

Passive wireless sensor based on reflected electro-material signatures

Hasan, Azhar 06 April 2012 (has links)
The objective of the proposed research is to devise a methodology for sensing and tracking environmental variables using a passive wireless sensor based on reflected electro-material signatures. Viability of item level tracking demands the sensor to be extraordinary low cost, thus eliminating the use of any active sensor or memory circuitry. Recent developments of materials whose electrical properties can change significantly with the environmental conditions suggest the possibility of developing a passive sensor that can be interrogated remotely to extract data about the time tracked environmental changes at the sensor. A simple passive sensor, based on the concept of reflected electro-material signatures (REMS), consists of an antenna attached to a microstrip transmission line, which in turn is routed over one or more sections of variable permittivity material before being terminated in a load. The basic idea revolves around sensing the electrical properties of thermotropic liquid crystal (LCs) trapped in a polymer substrate to record the temperature data. As the temperature changes with time, the polymerization process through the material line records the historical temperature profile in the spatial distribution of the electrical properties, thus enabling the system to extract the historical profile of temperature without using any active memory circuitry. This concept can possibly be used to track a variety of variables of interest; however, the proposed research is focused on sensing and extracting the time profile of temperature. The problem of identifying medium properties from waves reflected from a device of this type is a form of the classical one dimensional inverse scattering problem. For profile inversion in a lossy inhomogeneous media, analytical techniques are difficult to implement in most practical situations. In the proposed research, neural networks with a back-propagation algorithm are used to reconstruct the historical temperature profile of the material by extracting the spatially distributed material properties of the electro-material line. After the initial proof of concept for a lossless medium, the methodology is extended to extract spatially distributed properties for a dissipative medium. Finally, for the implementation of REMS sensor concept, a neural network based methodology is developed to reconstruct the spatially distributed permittivity profile of a lossy electro-material line.

Page generated in 0.2812 seconds