Engineering Commons^™

A Cn-Fdtd Scheme And Its Application To Vlsi Interconnects/Substrate Modeling, Rui Qiang, Dagang Wu, Ji Chen, Chen Wang, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a two-dimensional (2D) Crank-Nicholason (CN) finite difference time domain (FDTD) method is proposed for VLSI interconnect/substrate characterization. Through rigorous truncation and dispersion error analyses, a guideline on using this technique is presented. Several iterative solvers are investigated to accelerate the solution of the CN-FDTD scheme. Numerical examples are given to demonstrate the accuracy and the efficiency of the proposed algorithm.

Radiation Mechanisms For Semiconductor Devices And Packages, Todd H. Hubing, Daryl G. Beetner, Shaowei Deng, Xiaopeng Dong

Electrical and Computer Engineering Faculty Research & Creative Works

VLSI semiconductor devices are often the source of radiated electromagnetic emissions from electronic devices. Noise coupled from these devices to resonant structures on the printed circuit board, resonant cables or resonant enclosures can result in EMI problems that are difficult or expensive to solve at the board or system level. This paper reviews three mechanisms by which noise can be coupled from semiconductor devices and packages resulting in radiated electromagnetic emissions.

Extracting R, L, G, C Parameters Of Dispersive Planar Transmission Lines From Measured S-Parameters Using A Genetic Algorithm, Jianmin Zhang, Marina Koledintseva, James L. Drewniak, Giulio Antonini, Antonio Orlandi, Konstantin Rozanov

Electrical and Computer Engineering Faculty Research & Creative Works

Signal integrity (SI) analysis of printed circuit boards for high-speed digital design requires information on the perunit-length R, L, G, C parameters of the transmission lines. However, these are not always available when the property of the dielectric medium used in the board is unknown. A method to extract R, L, G, and C parameters from parallel-plate and strip transmission line geometries is proposed. It is based on measured scattering parameters and analytical modeling. A genetic algorithm (GA) is used to optimize the extraction by minimizing the frequency domain discrepancy between an objective function, which is the measured scattering matrix …

Extraction Of Spice-Type Equivalent Circuits Of Signal Via Transitions Using The Peec Method, Jingkun Mao, James L. Drewniak, Giulio Antonini, Antonio Orlandi

Electrical and Computer Engineering Faculty Research & Creative Works

Digital devices and discontinuities are typically analyzed by inserting their equivalent circuits into SPICE-type simulators. The partial element equivalent circuit method has been proven to be very useful for electromagnetic modeling. It can be used in both the time and the frequency domain. In this paper, the PEEC technique is employed as an efficient full-wave modeling tool to derive SPICE-type equivalent circuits of signal via transition structures. A nodal analysis technique is utilized in conjunction with the optimization algorithm to extract the equivalent circuits, whose component values are the parameters optimized. The good agreement between different approaches demonstrates that the …

Representation Of Permittivity For Multiphase Dielectric Mixtures In Fdtd Modeling, Marina Koledintseva, J. Wu, H. Zhang, James L. Drewniak, Konstantin Rozanov

Electrical and Computer Engineering Faculty Research & Creative Works

A simple method of approximating frequency characteristics of composites in a form convenient for time-domain numerical modeling is proposed. The frequency characteristics can be obtained from experiment or calculations based on the Maxwell Garnett mixing formalism. The resultant frequency characteristic might be of a complex shape corresponding to a combination of a number of absorption peaks. The approximation is made by a series of Debye-like terms using a genetic algorithm (GA). This leads to the necessity of taking a number of terms in the approximating series. Every term corresponds to its pole, i.e., the frequency where the maximum loss occurs. …

Validation Of Equivalent Circuits Extracted From S-Parameter Data For Eye-Pattern Evaluation, Giuseppe Selli, Mauro Lai, Shaofeng Luan, James L. Drewniak, Richard E. Dubroff, Jun Fan, James L. Knighten, Norman W. Smith, Giulio Antonini, Antonio Orlandi, Bruce Archambeault, Samuel R. Connor

Electrical and Computer Engineering Faculty Research & Creative Works

S-parameter circuit model extraction is usually characterized by a trade off between accuracy and complexity. Trading one feature for another may or may not affect the goodness of the reconstructed S-parameter data, which are obtained from frequency domain simulations of the models extracted. However, the ultimate test for the validity of these equivalent circuit representations should be left to eye-diagram simulations, which provide useful insights, from an SI point of view, about the degradation of the signal, as it travels through the system. Physics based simplication procedures can be used to tune the models and achieve less complexity, whereas the …

A Three-Dimensional Fdtd Subgridding Algorithm Based On Interpolation Of Current Density, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A three-dimensional subgridding algorithm for the finite difference time domain (FDTD) method is proposed in this paper. The method is based on interpolation of electric and magnetic current densities. The coarse-fine mesh ratio can be either 1:2 or 1:3. Results of a test model utilizing a lossless cavity excited with a dipole show no tendency of instability after 500000 time steps. The reflection in time domain at the subgridding interface was calculated to test the accuracy of the subgridding algorithm.

A Time Domain Approach To Estimate Current Draw From Smt Decoupling Capacitors, Lin Zhang, Bruce Archambeault, Samuel Conner, James L. Knighten, Jun Fan, Norman W. Smith, Ray Alexander, Richard E. Dubroff, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A time domain approach to investigate and predict impedances and scattering parameters of a DC power bus is proposed. This approach is based on a cavity model and is achieved using a circuit simulation tool - SPICE. A SPICE-based circuit model for triangular power plane segments is described, verified and applied to simulate both the frequency and time domain characteristics of an irregularly shaped two-layer PCB board. Furthermore, the current draw from a surface mount technology (SMT) decoupling capacitor is simulated and estimated using this approach. Near-field electromagnetic loop probes are used to validate the current estimation qualitatively. Additionally the …

Effects Of Open Stubs Associated With Plated Through-Hole Vias In Backpanel Designs, Shaowei Deng, Jingkun Mao, Todd H. Hubing, James L. Drewniak, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, Chen Wang

Electrical and Computer Engineering Faculty Research & Creative Works

Plated through-hole (PTH) vias are commonly used in printed circuit boards. They usually leave open stubs if the signal(s) does not transition the entire depth of the board. These open stubs can have a negative impact on signal transmission. This summary reports the investigation of the impact of the open via stubs in a typical backpanel design.

Microwave Reflection Properties Of Concrete Periodically Exposed To Chloride Solution Of 3% Salinity And Compression Force, Joseph Toby Case, Shanup Peer, Eric Gallaher, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Corrosion of steel rebar in a concrete structure compromises its structural integrity and hence its performance. Chloride intrusion into concrete can lead to depassivation of the steel and initiation of corrosion. Methods exist to detect chlorides in concrete, but the practical use of many of these may be problematic because they are destructive and time consuming, and cannot be used to analyze large structures. Microwave nondestructive evaluation techniques applied to mortar have proven successful for detecting mixture constituents, chloride ingress, and cure-state monitoring. In this paper several concrete samples are cyclically soaked in distilled water and saltwater while also experiencing …

Series-Parallel Approaches And Clamp Methods For Extreme Dynamic Response With Advanced Digital Loads, Philip T. Krein, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

The series-input parallel-output dc-dc converter combination provides inherent sharing among the converters. With conventional controls, however, this sharing is unstable. Recent literature work proposes complicated feedback loops to correct the problem, at the cost of dynamic performance. This paper shows that a simple sensorless current mode control stabilizes sharing with fast dynamics suitable for advanced digital loads. With this control in place, a "super-matched" current sharing control emerges. Sharing occurs through transients, limited only by the energy limits of the converters. The control approach has considerable promise for high-performance voltage regulator modules. For even faster response, clamping techniques are proposed.

A Study On The Correspondence Of Common-Mode Current In Electromagnetic Radiation From A Pcb With A Guard-Band, Yoshiki Kayano, Motoshi Tanaka, Hiroshi Inoue, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A PCB, in which the ground plane has a finite width and the trace has unbalanced positioning, can result in common-mode (CM) radiation. So far, CM current which is generated by the unbalance of a trace and ground plane has been investigated by experiment and numerical method. It was clarified that CM current is well explained the radiation from PCB up to a few hundred megahertz, and addition of a guard band geometry, which is well connected to the ground plane, can be effective in suppressing the CM current. But it is seemed to be insufficient description for the phenomena …

Microwave Remote Sensing Of The Greenland Ice Sheet: Models And Applications, Ivan S. Ashcraft

Theses and Dissertations

Spaceborne microwave sensors are powerful tools for monitoring the impacts of global climate change on the Greenland ice sheet. This dissertation focuses on refining methods for applying microwave data in Greenland studies by using new simple theoretical and empirical models to investigate (1) azimuth anisotropies in the data, (2) the microwave signature of the snow surface, (3) detection of snow melt, and (4) classification of snow melt. The results are applicable for identifying geophysical properties of the snow surface and monitoring changes on the ice sheet in relation to melt duration/extent, accumulation, and wind patterns. Azimuth dependence of the normalized …

A New Method For Melt Detection On Antarctic Ice-Shelves And Scatterometer Calibration Verification, Lukas Brad Kunz

Theses and Dissertations

Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat scatterometer and microwave radiometer measurements from the Special Sensor Microwave/Imager (SSM/I) are used to determine periods of surface melt and freeze in the Antarctic ice-shelves. The normalized radar backscatter (sigma-0) and backscatter polarization ratio (PR) are used in the maximum likelihood estimation of the ice-state. This method is used to infer the daily ice-surface conditions for 25 selected study points located on the Ronne, Ross, Larsen, Fimbul, Amery, and Shackleton Ice-shelves. The temporal and spatial variations of the radar response are also observed for various neighborhood sizes surrounding each given …

Improving Electromagnetic Bias Estimates, Floyd W. Millet

Theses and Dissertations

The electromagnetic (EM) bias is the largest source of error in the TOPEX/Poseidon and Jason-1 satellite sea surface height (SSH) estimates. Due to incomplete understanding of the physical processes which cause the bias, current operational models are based on empirical relationships between the bias wind speed and significant wave height. These models reduce RMS estimation errors of the EM bias to approximately 4 cm.

To improve EM bias estimation the correlation between the bias and RMS long wave slope is studies using data from tower-based experiments in the Gulf of Mexico and Bass Straight, Australia. Models based on significant wave …

3d Analysis Of Hybrid Photonic Crystal/Conventional Waveguide 90° Bend, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We present a three-dimensional (3D) analysis of a hybrid photonic crystal conventional waveguide 90° bend proposed previously [Opt. Express 10, 1334 (2002)] as an ultracompact component for large-scale planar lightwave circuit integration. Both rigorous 3D finite-difference time-domain modeling and a simple perfect mirror model analysis were carried out for different Si post heights in the photonic crystal region. Results show that the bend efficiency increases rapidly with Si post height. For a post height of 6.5 µm, this structure yields a bend efficiency of 97.3% at a wavelength of 1.55 µm for 90° bends in 2 µm X 2 µm …

Cavity Enhancement Of The Magneto-Optic Kerr Effect For Optical Studies Of Magnetic Nanostructures, Aaron R. Hawkins, N. Qureshi, Holger Schmidt

Faculty Publications

We present a study of cavity enhancement of the magneto-optic Kerr effect using dielectric multilayers in order to facilitate optical studies of individual single-domain nanomagnets. We develop a transfer matrix theory to analyze Kerr rotation from an arbitrary number of possibly lossy dielectric layers. The combination of one lossless and one thin metallic layer is found to be most favorable for studying individual nanomagnets, providing the best tradeoff between signal enhancement and spatial resolution. Accounting for the microscopic surface structure, we find good agreement between theory and experiment. Using this technique, we demonstrate Kerr enhancements by a factor of more …

Unitary Space-Time Transmit Diversity For Multiple Antenna Self-Interference Suppression, Adam Lane Anderson

Theses and Dissertations

A common practice for government defense agencies and commercial aeronautical companies is to use dual antennas on test flight air vehicles in order to overcome occlusion issues during high-speed telemetric maneuvers. The dual antennas, though never being masked at the same time, unfortunately lead to a drastic increase in nulls in the signal pattern. The result of this interference pattern can be compared to the effect of fading in a multiple-input multiple-output (MIMO) multi-path scattering environment. Confidence in this comparison leads to the use of unitary space-time MIMO codes to overcome the signal self-interference. The possibility and performance of several …

A Ray-Based Investigation Of The Statistical Characteristics And Efficient Representation Of Multi-Antenna Communication Channels, Gus Ryan German

Theses and Dissertations

Multi-antenna communication systems are attracting research interest as a means to increase the information capacity, reliability, and spectral efficiency of wireless information transfer. Ray-tracing methods predict the behavior of wireless channels using a model of the propagation environment and are a low-cost alternative to direct measurements. We use ray tracing simulations to validate the statistical time and angle of arrival characteristics of an indoor multipath channel and compare model parameter estimates with estimates derived from channel sounding measurements. Ray tracing predicts the time and angle clustering of multipaths observed in the measurements and provides model parameter estimates which are closely …

Architectures For Symbol Timing Synchronization In Mimo Communications, Kejing Liu

Theses and Dissertations

Maximum likelihood symbol timing estimation for communication over a frequency non-selective MIMO fading channel is developed. The cases of known data (data-aided estimation) and unknown data (non-data-aided estimation) together with known channel and unknown channel are considered. The analysis shows that the log-likelihood functions and their approximations can be interpreted as SISO log-likelihood functions operating on each of the receive antennas. Previously published symbol timing estimators are shown to be special cases of the more general framework presented. Architectures based on both block processing and sequential processing using a discrete-time phase-locked loop are summarized. Performance examples over a MIMO channel …

Incentive Auctions And Stable Marriages Problems Solved With Bn=2c-Privacy Of Human Preferences, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Incentive auctions let several participants to cooperate for clearing a set of offers and requests, ensuring that each participant cannot do better than by inputting his true utility. This increases the social welfare by efficient allocations, and is proven to have similar outcomes as the tradition English Auctions. The desk-mates (stable matchings) problem comes from the need of placing students in pairs of two for working in projects or seating in two-seats desks. The stable marriages problem consists of finding matches of a man and a woman out of two sets of men, respectively women. Each of the persons in …

Wideband Channel Characterization For Mimo Scenario, Justin T. Holzer

Theses and Dissertations

Because broadband wireless systems benefit from accurate channel characterization, there is growing interest in broadband wireless multiple-input multiple-output (MIMO) channel models. This thesis verifies the suitability of the Saleh Valenzuela with Angle (SVA) model for wideband MIMO communication models. While recent wideband MIMO measurements have been obtained by switching a single transmit/receive pair over all possible antenna pair combinations, a simultaneous probing system is superior because of the time required for the antenna-switching channel measurements. This work provides two different wideband channel estimation algorithms based on simultaneous transmission from and reception on all antennas. Simulated data from an electromagnetic ray …

Consensus Seeking, Formation Keeping, And Trajectory Tracking In Multiple Vehicle Cooperative Control, Wei Ren

Theses and Dissertations

Cooperative control problems for multiple vehicle systems can be categorized as either formation control problems with applications to mobile robots, unmanned air vehicles, autonomous underwater vehicles, satellites, aircraft, spacecraft, and automated highway systems, or non-formation control problems such as task assignment, cooperative transport, cooperative role assignment, air traffic control, cooperative timing, and cooperative search. The cooperative control of multiple vehicle systems poses significant theoretical and practical challenges. For cooperative control strategies to be successful, numerous issues must be addressed. We consider three important and correlated issues: consensus seeking, formation keeping, and trajectory tracking. For consensus seeking, we investigate algorithms and …

Motion Compensation Of Interferometric Synthetic Aperture Radar, David P. Duncan

Theses and Dissertations

Deviations from a nominal, straight-line flight path of a synthetic aperture radar (SAR) lead to inaccurate and defocused radar images. This thesis is an investigation into the improvement of the motion compensation algorithm created for the BYU inteferometric synthetic aperture radar, YINSAR. The existing BYU SAR processing algorithm produces improved radar imagery but does not fully account for variations in attitude (roll, pitch, yaw) and does not function well with large position deviations. Results in this thesis demonstrate that a higher order motion compensation algorithm is not as effective as using a segmented reference track, coupled with the current lower-order …

A Framework For Trajectory Based Visual Event Retrieval, Ilker Ersoy, Filiz Bunyak, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a framework of a system for the query and retrieval of video data based on video events in huge video repositories. the events are formulated using domain-independent event primitives which are represented by spatio-temporal relationships between objects in the video scenes. Complex events are expressible as combinations of simpler events. This facilitates support of event queries from a variety of points of view. in addition, the framework is expected to provide adaptability of the framework to multiple domains.

Performance Evaluation Of Block-Based Motion Estimation Algorithms And Distortion Measures, S. R. Subramanya, Hiral Patel, Ilker Ersoy

Electrical and Computer Engineering Faculty Research & Creative Works

Motion estimation is an important component in video compression schemes which impacts the encoder performance and the quality of the reconstructed video sequence. Block-Based techniques are the most popular among the several motion estimation techniques used in practice due to their simplicity allowing efficient hardware implementations. the quality of motion predicted frame and the speed of motion vector computation are the primary measures of performance of motion estimation schemes. the video compression standards only specify the syntax of the bitstream and not any specifics of the motion estimation techniques. Thus, the knowledge of the workings and performance of commonly used …

A Suite Of Secure Multi-Party Computation Algorithms For Solving Distributed Constraint Satisfaction And Optimization Problems, Marius C. Silaghi

Electrical Engineering and Computer Science Faculty Publications

Privacy requirements can be modeled within the distributed constraint satisfaction framework, where the constraints are secrets of the participants. In [20] we introduced a first technique allowing agents to solve distributed constraint problems (DisCSPs), without revealing anything and without trusting each other or some server. The first technique we propose now, MPC-DisCSP2, is a dm times improvement for m variables of domain size d. A second technique we propose, MPC-DisCSP3, has a similar complexity as MPD-DisCSP2, a little slower in the worst case, but guarantees that the returned solutions are picked according to a uniform distribution over the total set …

Fabrication, Characterization, And Modeling Of Organic Capacitors, Schottky Diodes, And Field Effect Transistors, Mo Zhu

Doctoral Dissertations

The objectives of this project are to fabricate, characterize, and model organic microelectronic devices by traditional lithography techniques and Technology Computer Aided Design (TCAD).

Organic microelectronics is becoming a promising field due to its number of advantages in low-cost fabrication for large area substrates. There have been growing studies in organic electronics and optoelectronics. In this project, several organic microelectronic devices are studied with the aid of experimentation and numerical modeling.

Organic metal-insulator-metal (MIM) and metal-insulator-semiconductor (MIS) capacitors consisting of insulating polymer poly(4-vinylphenol) (PVP) have been fabricated by spin-coating, photo lithography, and reactive ion etching techniques. Based on the fabricated …

Robust Image Transmission Based On Wavelet Tree Coding, Error Resilient Entropy Coding, And Error Concealment, Lei Cao, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

A scheme with three key components including wavelet tree coding, error resilient entropy coding (EREC), and error concealment is proposed for robust image coding and transmission over noisy channels. First, we individually encode the spatial-orientation trees in the wavelet domain using the algorithm of set partitioning in hierarchical trees (SPIHT). Error propagation is thus limited because multiple independent bit streams are generated. Meanwhile, a high source coding efficiency is also preserved because the self-similarity property in each wavelet tree remains intact. Next, we use EREC to reorganize these variable-length bit streams into fixed-length data slots before multiplexing and transmission. Therefore, …

Time Blanking For Gbt Data With Radar Rfi, Weizhen Dong

Theses and Dissertations

The 1215 MHz to 1400 MHz band is important for radio astronomers to observe redshifted extragalactic hydrogen ionic (HI). Observations at these frequencies are complicated by radio frequency interference (RFI) from strong man-made transmissions such as the ARSR-3 Air Surveillance Radar. In this thesis, we characterize some data files recorded at the National Radio Astronomy Observatory (NRAO) at Green Bank, West Virginia, USA, where this RADAR system causes significant data corruption. Using this data, we present a blanking technique to separate RFI from cosmic signal. There are generally two blanking approaches, time window blanking and detected pulse blanking. Compared with …