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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.
91

Effect of Ground Bounce Noise on the Power Integrity and EMI Performance in Multi-Layered High-Speed Digital PCB: FDTD Modeling and Measurement

Hwang, Jiunn-Nan 20 June 2002 (has links)
In this thesis, we study the electromagnetic effect of the high-speed digital PCB in three sections. In first section, based on the FDTD modeling approach, the bridging effect of the isolation moat on the EMI caused by the ground bounce noise is investigated. We find that isolating the noise source by slits is effective to eliminate the EMI, but bridges connecting between two sides of the slits will significantly degrade the effect of EMI protection. In second section, we investigate both in time and frequency domains the power plane noise coupling to signal trace with via transition in multi-layered PCB. Separating the power plane with slits is effective in reducing noise coupling in high frequency but a new resonant mode will be excited at lower frequency. Current distribution pattern of this new resonant mode between the power planes helps us to understand this phenomenon more clearly. In final section, by using FDTD link SPICE method, we can predict the electromagnetic behavior of the PCB with active device effectively.
92

Fast methods for full-wave electromagnetic simulations of integrated circuit package modules

Terizhandur Varadharajan, Narayanan 25 April 2011 (has links)
Fast methods for the electromagnetic simulation of integrated circuit (IC) package modules through model order reduction are demonstrated. The 3D integration of multiple functional IC chip/package modules on a single platform gives rise to geometrically complex structures with strong electromagnetic phenomena. This motivates our work on a fast full-wave solution for the analysis of such modules, thus contributing to the reduction in design cycle time without loss of accuracy. Traditionally, fast design approaches consider only approximate electromagnetic effects, giving rise to lumped-circuit models, and therefore may fail to accurately capture the signal integrity, power integrity, and electromagnetic interference effects. As part of this research, a second order frequency domain full-wave susceptance element equivalent circuit (SEEC) model will be extracted from a given structural layout. The model so obtained is suitably reduced using model order reduction techniques. As part of this effort, algorithms are developed to produce stable and passive reduced models of the original system, enabling fast frequency sweep analysis. Two distinct projection-based second order model reduction approaches will be considered: 1) matching moments, and 2) matching Laguerre coefficients, of the original system's transfer function. Further, the selection of multiple frequency shifts in these schemes to produce a globally representative model is also studied. Use of a second level preconditioned Krylov subspace process allows for a memory-efficient way to address large size problems.
93

Unitary space-time transmit diversity for multiple antenna self-interference suppression /

Anderson, Adam L. January 2004 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 73).
94

Architecture and implementation of intelligent transceivers for ultra-wideband communications

Hsieh, Tien-ling, 1975- 02 October 2012 (has links)
The wide bandwidth employed in the UWB system allows for high data-rate communications, while its broadband nature requires it to coexist with other systems. For instance, several communication systems, such as digital TV, wireless LANs, WiMAX, and satellite receivers, utilize spectrum that is in the UWB band. According to Federal Communications Commission (FCC) regulations, the power spectral density (PSD) of UWB devices for communication applications is limited to less than -41.25dBm/MHz in the 3.1-10.6GHz frequency band, to minimize the impact of UWB on other systems. The impact of narrowband signals on UWB systems can also be significant, even though these signals may occupy a small part of the UWB spectrum, due to their much larger power. The performance and capacity of UWB systems can be significantly degraded by these narrowband interferers. In-band interference can be tolerated by increasing the dynamic-range of the receiver such that the interferers are accommodated within the linear range of the receiver. Alternatively, if the interferers can be avoided altogether, the excessive linearity requirements imposed by the interferers can be relaxed. Such an avoidance mechanism requires the ability to detect interferers. This work presents a low-power and low-cost detector for this purpose that can be employed in multi-band approaches to UWB, including pulse-based schemes, and those employing OFDM. The UWB band is divided into narrower sub-bands in these schemes. During transmission, the carrier hops to a new sub-band every symbol. The detector is designed to provide a profile of interference over the entire UWB spectrum, during each symbol period. This information would be available to the main-path UWB receiver to decide a frequency sequence of sub-band hopping, in order to avoid sub-bands occupied by large interferers. This relaxes the dynamic-range requirement, and hence the power dissipation of the main-path receiver, thus compensating for the extra power dissipation of the detector. The detector is based on a cascade of image-reject downconverter stages. An implementation of the architecture is demonstrated in a 0.13[mu]m CMOS process. / text
95

Performance Evaluation of a Wireless Protocol for Mesh Networking under the Influence of Broadband Electromagnetic Noise

Woo, Lily Lai Yam 09 April 2010 (has links)
Migrating from a wired to a wireless implementation for communication system used in industrial applications is a logical move to avoid the many shortcomings associated with wires. When operated under harsh environments, those wires can break and could cause not only damage to the system but also endanger human lives. However, it is not well documented how well a wireless protocol can work under such harsh industrial environments. This thesis attempts to answer this research question in the point of view of gauging the performance of a wireless protocol under the influence of electromagnetic noise. More specifically, the type of noise signal that is the focus of this investigation is the random, pulsed type (e.g., discharges caused by sparking) that creates a hyperbolic broadband disturbance in the frequency domain. Consequently, a fractal noise model is used to study noise of this nature. The steps toward achieving this goal include: requirements gathering, wireless technology selection; noise modelling and synthesis; real noise capture and analysis to validate the chosen noise model; high-frequency fractal noise emulation in hardware; the use of a novel noise injection method for empirical work; and the conducting of a controlled synthetic noise-to-wireless node performance evaluation to obtain performance measure in the form of packet error rate (PER). Performance data in terms of PER versus signal-to-noise ratio (SNR) for various nodes separation have been collected. There were three significant findings: the obtained performance curves follow the standard 'S' trend; for a specific desired reliability (denoted by a certain PER), the SNR at the transmitter needs to be boosted as the correlation of the noise being present increases; and the maximum distance between nodes separation for a certain reliability to be achieved depends exponentially with the transmitter‟s SNR. The relationship in the third finding assists in placement of wireless nodes, which in turn can determine the minimum amount of wireless nodes required for an industrial system to reach the desired system reliability, thus boasting network cost saving.
96

Performance Evaluation of a Wireless Protocol for Mesh Networking under the Influence of Broadband Electromagnetic Noise

Woo, Lily Lai Yam 09 April 2010 (has links)
Migrating from a wired to a wireless implementation for communication system used in industrial applications is a logical move to avoid the many shortcomings associated with wires. When operated under harsh environments, those wires can break and could cause not only damage to the system but also endanger human lives. However, it is not well documented how well a wireless protocol can work under such harsh industrial environments. This thesis attempts to answer this research question in the point of view of gauging the performance of a wireless protocol under the influence of electromagnetic noise. More specifically, the type of noise signal that is the focus of this investigation is the random, pulsed type (e.g., discharges caused by sparking) that creates a hyperbolic broadband disturbance in the frequency domain. Consequently, a fractal noise model is used to study noise of this nature. The steps toward achieving this goal include: requirements gathering, wireless technology selection; noise modelling and synthesis; real noise capture and analysis to validate the chosen noise model; high-frequency fractal noise emulation in hardware; the use of a novel noise injection method for empirical work; and the conducting of a controlled synthetic noise-to-wireless node performance evaluation to obtain performance measure in the form of packet error rate (PER). Performance data in terms of PER versus signal-to-noise ratio (SNR) for various nodes separation have been collected. There were three significant findings: the obtained performance curves follow the standard 'S' trend; for a specific desired reliability (denoted by a certain PER), the SNR at the transmitter needs to be boosted as the correlation of the noise being present increases; and the maximum distance between nodes separation for a certain reliability to be achieved depends exponentially with the transmitter‟s SNR. The relationship in the third finding assists in placement of wireless nodes, which in turn can determine the minimum amount of wireless nodes required for an industrial system to reach the desired system reliability, thus boasting network cost saving.
97

Electromagnetic Interference (EMI) Resisting Analog Integrated Circuit Design Tutorial

Yu, Jingjing 2012 August 1900 (has links)
This work introduces fundamental knowledge of EMI, and presents three basic features correlated to EMI susceptibility: nonlinear distortion, asymmetric slew rate (SR) and parasitic capacitance. Different existing EMI-resisting techniques are analyzed and compared to each other in terms of EMI-Induced input offset voltage and other important specifications such as current consumption. In this work, EMI-robust analog circuits are proposed, of which the architecture is based on source-buffered differential pair in the previous publications. The EMI performance of the proposed topologies has been verified within a test IC which was fabricated in NCSU 0.5um CMOS technology. Experimental results are presented when an EMI disturbance signal of 400mV and 800mV amplitude was injected at the input terminals, and compared with a conventional and an existing topology. The tested maximal EMI-induced input offset voltage corresponds to -222mV for the new structure, which is compared to -712mV for the conventional one and -368mV for the one using existing source-buffered technique in literature. Furthermore the overall performances of the circuits such as current consumption or input referred noise are also provided with the corresponding simulation results.
98

Performance improvements of automobile communication protocols in electromagnetic interference environments

Ren, Fei, January 2007 (has links) (PDF)
Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed March 27, 2008) Includes bibliographical references (p. 55-56).
99

Application of hybrid ARQ to controller area networks

Emani, Krishna Chaitanya Suryavenkata, January 2007 (has links) (PDF)
Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2008) Includes bibliographical references (p. 48).
100

Robust wireless communications under co-channel interference and jamming

M.M., Galib Asadullah. January 2008 (has links)
Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Gordon L. Stuber; Committee Member: Alfred D. Andrew; Committee Member: John A. Buck; Committee Member: Steven W. McLaughlin; Committee Member: Ye (Geoffrey) Li.

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