Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering Faculty Research & Creative Works

Discipline
Keyword
Publication Year

Articles 3121 - 3150 of 3518

Full-Text Articles in Engineering

Simulation Studies With A Continuously Online Trained Artificial Neural Network Controller For A Micro-Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 1998

Simulation Studies With A Continuously Online Trained Artificial Neural Network Controller For A Micro-Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports on the simulation studies carried out using MATLAB/SIMULINK and the practical implementation of a continuously online trained (COT) artificial neural network (ANN) controller to identify the continuous changing complex nonlinear dynamics of the power system, and another COT ANN to control a micro-turbogenerator which consists of a turbine simulator and a micro-alternator connected to an infinite bus through a short transmission line in a laboratory environment. This neural network controller augments/replaces the traditional automatic voltage regulator (AVR) and the turbine governor of the generator. Simulation and practical results are presented to show that this COT ANN identifier/controller …

Go to article

Millimeter Wave Signals Detection By Means Of Monocrystal Hexagonal Ferrite Ellipsoid, Marina Koledintseva, Alexander A. Kitaytsev Jan 1998

Millimeter Wave Signals Detection By Means Of Monocrystal Hexagonal Ferrite Ellipsoid, Marina Koledintseva, Alexander A. Kitaytsev

Electrical and Computer Engineering Faculty Research & Creative Works

Stable nonlinear resonance effects (SNLREs) have been already studied in crystallographically "isotropic" ferrogarnet ferrite resonators (FR), employed as microwave detectors in the frequency range of 300 MHz to 30 GHz. Application of prospective hexagonal monocrystal ferrites with large field of crystallographic magnetic anisotropy leads to the possibility of a gyromagnetic converter (GC) design for mm waveband (from 30 to 200 GHz) without massive external magnets. This paper deals with the analysis of a more general case with taking into account both crystallographic and form anisotropy as well as the arbitrary orientation of the main crystallographic axis with respect to the …

Go to article

Substroke Matching By Segmenting And Merging For Online Korean Cursive Character Recognition, Chang-Soo Kim, Kang Ryoung Park, Byung Hwan Jun, Jaihie Kim Jan 1998

Substroke Matching By Segmenting And Merging For Online Korean Cursive Character Recognition, Chang-Soo Kim, Kang Ryoung Park, Byung Hwan Jun, Jaihie Kim

Electrical and Computer Engineering Faculty Research & Creative Works

The Korean character is composed of several alphabets in two-dimensional formation and the total number of Korean characters exceeds eleven thousand. Therefore, the previous approaches to Korean cursive characters pay most of their attention to segmenting a character into alphabets accurately. However, it is difficult because the boundaries of alphabets are not apparent in most cases. We propose an alphabet-based method without assuming accurate alphabet segmentation. In the proposed method, a cursive character is segmented into substrokes by a set of segmenting conditions. Then it is matched with the reference substrokes generated from alphabet models and ligatures by segmenting and …

Go to article

A Maximum Torque Per Ampere Control Strategy For Induction Motor Drives, O. Wasynczuk, Keith Corzine, S. D. Sudhoff, Jerry L. Tichenor, P. C. Krause, I. G. Hansen, L. M. Taylor Jan 1998

A Maximum Torque Per Ampere Control Strategy For Induction Motor Drives, O. Wasynczuk, Keith Corzine, S. D. Sudhoff, Jerry L. Tichenor, P. C. Krause, I. G. Hansen, L. M. Taylor

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new control strategy is proposed which is simple in structure and has the straightforward goal of minimizing the stator current amplitude for a given load torque. It is shown that the resulting induction motor efficiency is reasonably close to optimal and that the approach is insensitive to variations in rotor resistance. Although the torque response is not as fast as in field-oriented (FO) control strategies, the response is reasonably fast. In fact, if the mechanical time constant is large relative to the rotor time constant, which is frequently the case, the sacrifice in dynamic performance is …

Go to article

An Automated State Model Generation Algorithm For Simulation/Analysis Of Power Systems With Power Electronic Components, Steven Pekarek, E. A. Walters, T. L. Skvarenina, O. Wasynczuk Jan 1998

An Automated State Model Generation Algorithm For Simulation/Analysis Of Power Systems With Power Electronic Components, Steven Pekarek, E. A. Walters, T. L. Skvarenina, O. Wasynczuk

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a recently developed algorithmic method of deriving the state equations of power systems containing power electronic components is described. Therein the system is described by the pertinent branch parameters and the circuit topology; however, unlike circuit-based algorithms, the difference equations are not implemented at the branch level. Instead, the composite system state equations are established. A demonstration of the computer implementation of this algorithm to model a variable-speed, constant-frequency aircraft generation system is described. Because of the large number of states and complexity of the system, particular attention is placed on the development of a model structure …

Go to article

Simulation Of Madmel Power Systems Components, Timothy L. Skvarenina, Oleg Wasynczuk, Paul C. Krause, Steven Pekarek Jan 1998

Simulation Of Madmel Power Systems Components, Timothy L. Skvarenina, Oleg Wasynczuk, Paul C. Krause, Steven Pekarek

Electrical and Computer Engineering Faculty Research & Creative Works

Detailed computer models of system components for More Electric Aircraft have been developed using the Advanced Control System Language (ACSL) and its graphical front-end, Graphic Modeller. Among the devices modeled are a wound-rotor synchronous generator with parallel bridge-rectifier outputs, a switched-reluctance generator, and various loads including a DC-DC converter, an inverter-driven induction motor, and an electro-hydrostatic actuator. Results from the simulations are presented together with corroborating experimental test results. Copyright © 1998 Society of Automotive Engineers, Inc.

Go to article

Dc Link Stabilized Field Oriented Control Of Electric Propulsion Systems, Keith Corzine, S. D. Sudhoff, Steven F. Glover, H. J. Hegner, H. N. Robey Jan 1998

Dc Link Stabilized Field Oriented Control Of Electric Propulsion Systems, Keith Corzine, S. D. Sudhoff, Steven F. Glover, H. J. Hegner, H. N. Robey

Electrical and Computer Engineering Faculty Research & Creative Works

Induction motor based electric propulsion systems can be used in a wide variety of applications including locomotives, hybrid electric vehicles, and ships. Field oriented control of these drives is attractive since it allows the torque to be tightly and nearly instantaneously controlled. However, such systems can be prone to negative impedance instability of the DC link. This paper examines this type of instability and sets forth a readily implemented albeit nonlinear control strategy to mitigate this potential problem.

Go to article

A Practical Continually Online Trained Artificial Neural Network Controller For A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 1998

A Practical Continually Online Trained Artificial Neural Network Controller For A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports on the simulation and practical studies carried out on a single turbogenerator connected to an infinite bus through a short transmission line, with a continually online trained (COT) artificial neural network (ANN) controller to identify the turbogenerator, and another COT ANN to control the turbogenerator. This identifier/controller augments/replaces the automatic voltage regulator and the turbine governor. Results are presented to show that this COT ANN identifier/controller has the potential to allow turbogenerators to operate more closely to their steady-state stability limits and nevertheless “ride through” severe transient disturbances such as three phase faults. This allows greater usage …

Go to article

Open Hemispherical Imaging Dielectric Resonator With Whispering Gallery Modes, Sergey Kharkovsky, Z. E. Eremenko, Yuri F. Filipov Jan 1998

Open Hemispherical Imaging Dielectric Resonator With Whispering Gallery Modes, Sergey Kharkovsky, Z. E. Eremenko, Yuri F. Filipov

Electrical and Computer Engineering Faculty Research & Creative Works

The imaging dielectric resonators with whispering gallery modes (WGMs) for the creation of a new class of millimeter wave solid-state oscillators, devices for the investigation of high temperature superconductors, were suggested. They contain a dielectric element as a semidisk or a cylinder or a hemisphere and a flat metal mirror. The latter is a necessary element for placing in the resonator field active elements or conductor samples of materials. There is an important question about the dependence of the resonant frequencies and Q-factor of these resonators on impedance of the resonator mirror. In the present paper new investigation results of …

Go to article

Microwave Filtering Of Unwanted Oscillations On Base Of Hexagonal Ferrite Composite Thick Films, Marina Koledintseva, Alexander A. Kitaytsev, Andrey A. Shinkov Jan 1998

Microwave Filtering Of Unwanted Oscillations On Base Of Hexagonal Ferrite Composite Thick Films, Marina Koledintseva, Alexander A. Kitaytsev, Andrey A. Shinkov

Electrical and Computer Engineering Faculty Research & Creative Works

The paper is aimed at the design of waveguide filters of lower frequencies using composite thick films (CTF) made of high-anisotropy polycrystalline hexagonal ferrite powders. Theoretical and experimental results describing the possibility of forming the desired frequency characteristic of the filters are presented

Go to article

Excitation Of The Whispering-Gallery-Modes At The Shielded Hemispherical Dielectric Resonator, Sergey Kharkovsky, V. V. Kutuzov, A. E. Kogut, V. A. Solodovnik Jan 1998

Excitation Of The Whispering-Gallery-Modes At The Shielded Hemispherical Dielectric Resonator, Sergey Kharkovsky, V. V. Kutuzov, A. E. Kogut, V. A. Solodovnik

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Go to article

Comparative Study Of Stock Trend Prediction Using Time Delay, Recurrent And Probabilistic Neural Networks, Donald C. Wunsch, Emad W. Saad, Danil V. Prokhorov Jan 1998

Comparative Study Of Stock Trend Prediction Using Time Delay, Recurrent And Probabilistic Neural Networks, Donald C. Wunsch, Emad W. Saad, Danil V. Prokhorov

Electrical and Computer Engineering Faculty Research & Creative Works

Three networks are compared for low false alarm stock trend predictions. Short-term trends, particularly attractive for neural network analysis, can be used profitably in scenarios such as option trading, but only with significant risk. Therefore, we focus on limiting false alarms, which improves the risk/reward ratio by preventing losses. To predict stock trends, we exploit time delay, recurrent, and probabilistic neural networks (TDNN, RNN, and PNN, respectively), utilizing conjugate gradient and multistream extended Kalman filter training for TDNN and RNN. We also discuss different predictability analysis techniques and perform an analysis of predictability based on a history of daily closing …

Go to article

Voice Recognition Using Neural Networks, Ganesh K. Venayagamoorthy, Viresh Moonasar, K. Sandrasegaran Jan 1998

Voice Recognition Using Neural Networks, Ganesh K. Venayagamoorthy, Viresh Moonasar, K. Sandrasegaran

Electrical and Computer Engineering Faculty Research & Creative Works

One solution to the crime and illegal immigration problem in South Africa may be the use of biometric techniques and technology. Biometrics are methods for recognizing a user based on unique physiological and/or behavioural characteristics of the user. This paper presents the results of ongoing work into using neural networks for voice recognition

Go to article

A Novel Thin Film Transistor Using Double Amorphous Silicon Active Layer, Jong Hyuni Choi, Chang-Soo Kim, Byung Cheon Lim, Jin Jang Jan 1998

A Novel Thin Film Transistor Using Double Amorphous Silicon Active Layer, Jong Hyuni Choi, Chang-Soo Kim, Byung Cheon Lim, Jin Jang

Electrical and Computer Engineering Faculty Research & Creative Works

We have fabricated a novel low off-state leakage current thin-film transistor (TFT) using a chlorine incorporated amorphous silicon [a-Si:H(:Cl)] and amorphous silicon (a-Si:H) stacked active layer, in which conduction channel is formed in a-Si:H and a-Si:H(:Cl) is photo-insensitive material. The off-state photo-leakage current of the a-Si:H(:Cl)/a-Si:H TFT is much lower than that a conventional a-Si:H TFT.

Go to article

An Improved Method For Incorporating Magnetic Saturation In The Q-D Synchronous Machine Model, Keith Corzine, Brian T. Kuhn, S. D. Sudhoff, H. J. Hegner Jan 1998

An Improved Method For Incorporating Magnetic Saturation In The Q-D Synchronous Machine Model, Keith Corzine, Brian T. Kuhn, S. D. Sudhoff, H. J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

An improved technique for incorporating saturation into the q-d axis model (Park''s model) of a synchronous machine is proposed. By choosing magnetizing flux linkage as a state variable, iterative procedures required by traditional methods are avoided. The saturation function is represented by an arctangent function which has some distinct advantages over polynomial representations and look-up tables. In particular, the parameters of the proposed function all have physical significance and the proposed function is defined over an infinite range of flux linkage. The model is verified for steady-state and transient conditions using a laboratory synchronous machine-rectifier system similar to those commonly …

Go to article

Determination Of Aircraft Orientation For A Vision-Based System Using Artificial Neural Networks, Sanjeev Agarwal, Subhasis Chaudhuri Jan 1998

Determination Of Aircraft Orientation For A Vision-Based System Using Artificial Neural Networks, Sanjeev Agarwal, Subhasis Chaudhuri

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm for real-time estimation of 3-D orientation of an aircraft, given its monocular, binary image from an arbitrary viewing direction is presented. This being an inverse problem, we attempt to provide an approximate but a fast solution using the artificial neural network technique. A set of spatial moments (scale, translation, and planar rotation invariant) is used as features to characterize different views of the aircraft, which corresponds to the feature space representation of the aircraft. A new neural network topology is suggested in order to solve the resulting functional approximation problem for the input (feature vector)-output (viewing direction) relationship. …

Go to article

An Efficient, Fast Converging Adaptive Filter For Network Echo Cancellation, Steven L. Grant Jan 1998

An Efficient, Fast Converging Adaptive Filter For Network Echo Cancellation, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper discusses a fast efficient adaptive filtering algorithm for network echo cancellers PNLMS++ (proportionate normalized least mean squares ++). Compared to the conventional normalized least mean squares (NLMS) algorithm, PNLMSI++ converges much more quickly when the echo path is sparse. When the echo path is dispersive, the convergence rate is the same as NLMS. In addition, the new algorithm diverges at the same rate and to the same misalignment level as NLMS during periods of undetected double-talk. PNLMS++ is only 50% more computationally complex than NLMS and requires no additional memory

Go to article

An Analog Vlsi Circuit Implementing An Orthogonal Continuous Wavelet Transform, Dongwei Chen, John G. Harris Jan 1998

An Analog Vlsi Circuit Implementing An Orthogonal Continuous Wavelet Transform, Dongwei Chen, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We have developed the theory and analog hardware implementation for a Continuous Wavelet Transform (CWT). This novel circuit performs an orthogonal decomposition of temporal signals, such as speech, in a frequency range of 10 Hz to 20 kHz. This multiresolution processor expands the Laguerre structure originally developed by Lee (1960).

Go to article

Real-Time And On-Line Near-Field Microwave Inspection Of Surface Defects In Rolled Steel, R. Zoughi, Christian J. Huber, Nasser N. Qaddoumi, Emarit Ranu, Vladimir Otashevich, Radin Mirshahi, Stoyan I. Ganchev, Thomas Johnson Dec 1997

Real-Time And On-Line Near-Field Microwave Inspection Of Surface Defects In Rolled Steel, R. Zoughi, Christian J. Huber, Nasser N. Qaddoumi, Emarit Ranu, Vladimir Otashevich, Radin Mirshahi, Stoyan I. Ganchev, Thomas Johnson

Electrical and Computer Engineering Faculty Research & Creative Works

The potential and limitations of near-field microwave inspection techniques for detecting various surface defects in rolled steel have been investigated. The focus of this study has been to investigate this potential for tin mill products containing gross and subtle defects including steel induced defects, roll marks, holes, scratches and gouges.

Go to article

New Perspectives For Maximum Likelihood Time-Delay Estimation, John A. Stuller Dec 1997

New Perspectives For Maximum Likelihood Time-Delay Estimation, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Introduces a New Realization for Maximum Likelihood Time-Delay Estimation (TDE) that Illuminates the Relationships between Maximum Likelihood TDE and Other Methods. We Obtain the Result by Deriving the Likelihood Function using a Fundamental Method that Appears to Be New to the Field of Array Processing. This Method is a Natural Complement to the Generalized Karhunen-Loève Expansion. © 1997 IEEE.

Go to article

Analog Hardware Implementation Of Adaptive Filter Structures, Jui Kuo Juan, J. G. Harris, J. C. Principe Dec 1997

Analog Hardware Implementation Of Adaptive Filter Structures, Jui Kuo Juan, J. G. Harris, J. C. Principe

Electrical and Computer Engineering Faculty Research & Creative Works

We have implemented a four-tap adaptive filter in a continuous-time analog VLSI circuit. Since an ideal delay is impossible to implement in continuous-time hardware, we implemented the delay line as a cascade of low-pass filters (called the Gamma filter). Since many years of research in our lab has shown that the Gamma filter outperforms the delay line for a wide range of applications, the Gamma filter should not be considered merely a crude approximation of the ideal delay line. We show measured results from an analog chip that solves the problem of system identification-identifying an unknown linear circuit from its …

Go to article

A Hybrid Fem/Mom Technique For Electromagnetic Scattering And Radiation From Dielectric Objects With Attached Wires, Mohammad Wares Ali, Todd H. Hubing, James L. Drewniak Nov 1997

A Hybrid Fem/Mom Technique For Electromagnetic Scattering And Radiation From Dielectric Objects With Attached Wires, Mohammad Wares Ali, Todd H. Hubing, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid formulation is presented, which combines the method of moments (MOM) with the edge-based vector finite element method (FEM) to solve electromagnetic radiation problems from structures consisting of an inhomogeneous dielectric body of arbitrary shape attached to one or more perfectly conducting bodies. While either method alone fails to model these structures efficiently, a combination of both finite element and moment methods provides an excellent way to solve these problems. The FEM is employed to handle the interior domain of inhomogeneous dielectric bodies and the method of moments is used to develop surface integrals that relate the field quantities …

Go to article

Modeling Of Surface Hairline-Crack Detection In Metals Under Coatings Using An Open-Ended Rectangular Waveguide, Christian J. Huber, Habibollah Abiri, Stoyan I. Ganchev, R. Zoughi Nov 1997

Modeling Of Surface Hairline-Crack Detection In Metals Under Coatings Using An Open-Ended Rectangular Waveguide, Christian J. Huber, Habibollah Abiri, Stoyan I. Ganchev, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

A surface-breaking hairline crack or a narrow slot in a metallic specimen when scanned by an open-ended rectangular waveguide probe influences the reflection-coefficient properties of the incident dominant mode. Subsequent recording of a change in the standing-wave pattern while scanning such a surface results in what is known as the crack characteristic signal. Since microwave signals penetrate inside dielectric materials, this methodology is capable of detecting cracks under dielectric coatings of various electrical thicknesses as well. To electromagnetically model the interaction of an open-ended rectangular waveguide with a surface-breaking hairline crack under a dielectric coating, the dielectric-coating layer is modeled …

Go to article

Quantifying Emi Resulting From Finite-Impedance Reference Planes, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha, Cheung-Wei Lam, Lawrence Rubin Nov 1997

Quantifying Emi Resulting From Finite-Impedance Reference Planes, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha, Cheung-Wei Lam, Lawrence Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

Parasitic inductance in printed circuit board (PCB) geometries can detrimentally impact the electromagnetic interference(EMI) performance and signal integrity of high-speed digital designs. This paper identifies and quantifies the parameters that affect the inductance of some typical PCB geometries. Closed-form expressions are provided for estimating the inductances of simple trace and ground plane configurations.

Go to article

Radiation Imaging Operators Applied To The Detection Of Velocity And Density Contrast Boundaries, Md. Ishfaqur Raza, Richard E. Dubroff, James L. Drewniak Nov 1997

Radiation Imaging Operators Applied To The Detection Of Velocity And Density Contrast Boundaries, Md. Ishfaqur Raza, Richard E. Dubroff, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for imaging interfaces formed by simultaneous density and velocity contrasts in acoustic media is described. The procedure is based on the properties of radiation imaging operators - a class of linear differential operators parametrically dependent on the acoustic properties of the media. An example of this procedure is demonstrated through the use of numerical simulation. Results, in the form of interface images, are shown, assuming the bulk acoustic characteristics (velocity and density) on both sides of the interface are known.

Go to article

An Experimental Procedure For Characterizing Interconnects To The Dc Power Bus On A Multilayer Printed Circuit Board, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha Nov 1997

An Experimental Procedure For Characterizing Interconnects To The Dc Power Bus On A Multilayer Printed Circuit Board, Hao Shi, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha

Electrical and Computer Engineering Faculty Research & Creative Works

The effectiveness of dc power-bus decoupling is impacted by the inductance associated with interconnect vias in printed circuit boards (PCB's). Adequate characterization of these interconnects is necessary to facilitate modeling and simulation, and to assess the effectiveness of added decoupling. In this study, a measurement procedure is presented for determining the series inductance and resistance of an interconnect with a network analyzer. The validity and limitations of the procedure are discussed. Experimental results of interconnect parameters on an 8 × 10 in ten-layer test-board corroborate those measured with a precision impedance analyzer. The measured interconnect values are used to simulate …

Go to article

Design And Implementation Of Digital Controllers For Smart Structures Using Field Programmable Gate Arrays, Jamie S. Kelly, Vittal S. Rao, Hardy J. Pottinger, H. Clifford Bowman Oct 1997

Design And Implementation Of Digital Controllers For Smart Structures Using Field Programmable Gate Arrays, Jamie S. Kelly, Vittal S. Rao, Hardy J. Pottinger, H. Clifford Bowman

Electrical and Computer Engineering Faculty Research & Creative Works

Implementation issues represent an unfamiliar challenge to most control engineers, and many techniques for controller design ignore these issues outright. Consequently, the design of controlled for smart structural systems usually proceeds without regard for their eventual implementation, thus resulting either in serious performance degradation or in hardware requirements that squander power, complicate integration, and drive up cost the level of integration assumed by the smart patch further exacerbates these difficulties, and any design inefficiency may render the realization of a single-package sensor-controller-actuator system infeasible. The goal of this research is to automate the controller implementation process and to relieve the …

Go to article

Adaptive Critic Designs, Danil V. Prokhorov, Donald C. Wunsch Sep 1997

Adaptive Critic Designs, Danil V. Prokhorov, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

We discuss a variety of adaptive critic designs (ACDs) for neurocontrol. These are suitable for learning in noisy, nonlinear, and nonstationary environments. They have common roots as generalizations of dynamic programming for neural reinforcement learning approaches. Our discussion of these origins leads to an explanation of three design families: heuristic dynamic programming, dual heuristic programming, and globalized dual heuristic programming (GDHP). The main emphasis is on DHP and GDHP as advanced ACDs. We suggest two new modifications of the original GDHP design that are currently the only working implementations of GDHP. They promise to be useful for many engineering applications …

Go to article

Identifying An Emi Source And Coupling Path In A Computer System With Sub-Module Testing, S. Radu, Yun Ji, Joe Nuebel, James L. Drewniak, Thomas Van Doren, Todd H. Hubing Aug 1997

Identifying An Emi Source And Coupling Path In A Computer System With Sub-Module Testing, S. Radu, Yun Ji, Joe Nuebel, James L. Drewniak, Thomas Van Doren, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

EMI in a workstation server resulting from CPU clock harmonics was investigated. Mechanisms by which noise is coupled off the CPU PCB module were diagnosed from studies and measurements on the CPU PCB alone. A model was then developed. Modifications were made and tested in the fully functional system to support the model.

Go to article

Investigation Of Internal Partitioning In Metallic Enclosures For Emi Control, S. Radu, Min Li, Joe Nuebel, David M. Hockanson, Yun Ji, James L. Drewniak, Todd H. Hubing, Thomas Van Doren Aug 1997

Investigation Of Internal Partitioning In Metallic Enclosures For Emi Control, S. Radu, Min Li, Joe Nuebel, David M. Hockanson, Yun Ji, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

High clock frequencies and short-edge rates in present high-speed digital systems result in EMI problems at increasingly higher frequencies. At these speeds, clock harmonics have sufficient energy in the range above 500 MHz to excite cavity modes of a conducting enclosure, and to drive even small length slots and apertures that are unavoidable in a practical design, and can result in an EMI problem. One approach to mitigate these problems is to partition the enclosure into several smaller internal shielded compartments. To study the factors which affect this partitioning, a special enclosure that can be divided into two internal compartments …

Go to article

First Prev Next Last