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Missouri University of Science and Technology

Finite Difference Time-Domain Analysis

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Full-Text Articles in Engineering

Modeling Noise Coupling Between Package And Pcb Power/Ground Planes With An Efficient 2-D Fdtd/Lumped Element Method, Ting-Kuang Wang, Sin-Ting Chen, Chi-Wei Tsai, Sung-Mao Wu, James L. Drewniak, Tzong-Lin Wu Nov 2007

Modeling Noise Coupling Between Package And Pcb Power/Ground Planes With An Efficient 2-D Fdtd/Lumped Element Method, Ting-Kuang Wang, Sin-Ting Chen, Chi-Wei Tsai, Sung-Mao Wu, James L. Drewniak, Tzong-Lin Wu

Electrical and Computer Engineering Faculty Research & Creative Works

An efficient numerical approach based on the 2-D finite-difference time-domain (FDTD) method is proposed to model the power/ground plane noise or simultaneously switching noise (SSN), including the interconnect effect between the package and the print circuit board (PCB). The space between the power and ground planes on the package and PCB are meshed with 2-D cells. The equivalent R-L-C circuits of the via and the solder balls connecting the package and PCB can be incorporated into a 2-D Yee cell based on a novel integral formulation in the time domain. An efficient recursive updating algorithm is proposed to fit the …


Numerical Modeling Of Periodic Composite Media For Electromagnetic Shielding Application, Dagang Wu, Rui Qiang, Ji Chen, Ce Liu, Marina Koledintseva, James L. Drewniak, Bruce Archambeault Jul 2007

Numerical Modeling Of Periodic Composite Media For Electromagnetic Shielding Application, Dagang Wu, Rui Qiang, Ji Chen, Ce Liu, Marina Koledintseva, James L. Drewniak, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes a methodology to extract effective electrical properties for periodic composite medium. The extraction algorithm is based on a periodic finite-difference time-domain (FDTD) method. The results are compared with conventional mixing theories and 3D Fourier series expansion methods. Two results show satisfactory agreement. With the extracted effective permittivity and conductivity, one can readily use these parameters to study electrical properties of composite materials with arbitrary micro-geometry and the shielding effects of using composite materials.


An Efficient Implementation Of Parallel Fdtd, Xiaohe Chen, Michael A. Cracraft, Yaojiang Zhang, Jianmin Zhang, James L. Drewniak, Bruce Archambeault, Samuel R. Connor Jul 2007

An Efficient Implementation Of Parallel Fdtd, Xiaohe Chen, Michael A. Cracraft, Yaojiang Zhang, Jianmin Zhang, James L. Drewniak, Bruce Archambeault, Samuel R. Connor

Electrical and Computer Engineering Faculty Research & Creative Works

A parallel FDTD algorithm has been realized based on 1-D domain decomposition. Data communication among different adjacent processors is manipulated by a self-defined C++ class ( MPI_FDTD) in which portable functions of the message passing interface (MPI) library are used. The details of the implementation are discussed. EMC applications of the code such as cross talk of traces, cavity, vias, as well as an IC package are provided to demonstrate the parallel efficiency.


A Three-Dimensional Fdtd Subgridding Algorithm With Separated Temporal And Spatial Interfaces And Related Stability Analysis, Kai Xiao, David Pommerenke, James L. Drewniak Jul 2007

A Three-Dimensional Fdtd Subgridding Algorithm With Separated Temporal And Spatial Interfaces And Related Stability Analysis, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A finite-different time-domain subgrid algorithm locally refines the mesh at regions requiring higher resolution. A novel separation of spatial and temporal subgridding interfaces is presented that allows implementing a novel spatial subgridding method and investigating the stability of each subalgorithm individually. Details are given for a spatial subgridding algorithm having a 1:3 mesh ratio. In the spatial subgridding algorithm, the fine-mesh is constructed with a recessed interface and the interpolation scheme is designed to be symmetric to maintain the stability of the update process. The stability of the spatial subgridding algorithm is analyzed with a matrix method. Numerical examples showing …


A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak Aug 2005

A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

The idea of separating the spatial and temporal subgridding interfaces is introduced in this paper. Based on this idea, the spatial and temporal subgridding algorithms can be developed and analyzed separately. The spatial algorithm was given in the previous paper. In this paper, the temporal subgridding algorithm is described and the stability is illustrated by the analytical formulation of a one-dimensional model. An FDTD code that combines the spatial and temporal subgridding algorithms is implemented. Numerical test models are calculated to show the stability and accuracy of the proposed method.


Coupling Between Differential Signals And The Dc Power-Bus In Multilayer Pcbs, Chen Wang, Marco Leone, James L. Drewniak, Antonio Orlandi May 2005

Coupling Between Differential Signals And The Dc Power-Bus In Multilayer Pcbs, Chen Wang, Marco Leone, James L. Drewniak, Antonio Orlandi

Electrical and Computer Engineering Faculty Research & Creative Works

Differential and common-mode transfer impedances are proposed herein to analyze noise coupled to (from) the dc power-bus from (to) via transitions in differential signals. Expressions for the two transfer impedances in terms of conventional single-ended transfer impedances are derived and verified through measurements, full-wave finite-difference time-domain (FDTD) simulations and an analytical cavity model. Some properties of the differential and common-mode transfer impedances are investigated to facilitate engineering design. The impact of signal current imbalances on power-bus noise and the benefit of differential signals as compared to single-ended signals are quantified.


Static And Quasi-Dynamic Load Balancing In Parallel Fdtd Codes For Signal Integrity, Power Integrity, And Packaging Applications, Sarah A. Seguin, Michael A. Cracraft, James L. Drewniak Aug 2004

Static And Quasi-Dynamic Load Balancing In Parallel Fdtd Codes For Signal Integrity, Power Integrity, And Packaging Applications, Sarah A. Seguin, Michael A. Cracraft, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

The Finite-Difference Time-Domain (FDTD) method is a robust technique for calculating electromagnetic fields, but practical problems, involving complex or large geometries, can require a long time to calculate on any one single-processor computer. One computer with many processors or many single-processor computers can reduce the computation time. However, some FDTD cell types, e.g., PML cells, require more computation time than others. Thus, the size and shape of the individual process allocations can significantly influence the computation time. This paper addresses these load balancing issues with static and quasi-dynamic approaches. The Message-Passing Interface (MPI) library is applied to a three-dimensional (3D) …


A Cn-Fdtd Scheme And Its Application To Vlsi Interconnects/Substrate Modeling, Rui Qiang, Dagang Wu, Ji Chen, Chen Wang, James L. Drewniak Aug 2004

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.


Anticipating Emi And On-Board Interference In Automotive Platforms, Shishuang Sun, Geping Liu, David Pommerenke, James L. Drewniak, Richard W. Kautz, Chingchi Chen Aug 2004

Anticipating Emi And On-Board Interference In Automotive Platforms, Shishuang Sun, Geping Liu, David Pommerenke, James L. Drewniak, Richard W. Kautz, Chingchi Chen

Electrical and Computer Engineering Faculty Research & Creative Works

A dual-step MTL / FDTD strategy is proposed for anticipating full-vehicle level EMI. In the first step, the current distribution along a cable bundle connecting to electronic modules an an automotive platform is calculated using multi-conductor transmission-line (MTL) models. In order to account for common-mode discontinuities on the vehicle chassis, e.g., slots, 3D full-wave modeling (FDTD) is used to determine radiation impedances, which are thereafter incorporated in the MTL models for compensating the radiation power loss. In the second step, the obtained currents are implemented as impressed current sources in full-vehicle full-wave modeling using an FDTD multi-wire subcelluar algorithm. Thus, …


A Three-Dimensional Fdtd Subgridding Algorithm Based On Interpolation Of Current Density, Kai Xiao, David Pommerenke, James L. Drewniak Aug 2004

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.


Representation Of Permittivity For Multiphase Dielectric Mixtures In Fdtd Modeling, Marina Koledintseva, J. Wu, H. Zhang, James L. Drewniak, Konstantin Rozanov Aug 2004

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. …


Using Near-Field Scanning To Predict Radiated Fields, Jin Shi, Michael A. Cracraft, Jianmin Zhang, Richard E. Dubroff, Kevin P. Slattery, Masahiro Yamaguchi Jan 2004

Using Near-Field Scanning To Predict Radiated Fields, Jin Shi, Michael A. Cracraft, Jianmin Zhang, Richard E. Dubroff, Kevin P. Slattery, Masahiro Yamaguchi

Electrical and Computer Engineering Faculty Research & Creative Works

Near-field scanning has often been used to measure and characterize magnetic fields surrounding individual integrated circuits (IC) and high speed digital electronic circuits. The paper describes the use of near-field scanning data, performed in a typical laboratory bench top environment, to predict radiated electromagnetic interference (EMI) in a typical product environment. The product environment may include enclosures and apertures. The approach begins by acquiring sufficient near-field scanning data to allow representation of an unintentional radiating source by an equivalent surface current distribution. The equivalent current distribution is used as a source in numerical full wave modeling. The agreement between direct …


Fdtd Modeling Of Isotropic Dispersive Magnetic Materials, Jing Wu, Marina Koledintseva, James L. Drewniak, David Pommerenke Aug 2003

Fdtd Modeling Of Isotropic Dispersive Magnetic Materials, Jing Wu, Marina Koledintseva, James L. Drewniak, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

Numerical analysis using the finite-difference time-domain (FDTD) algorithm with a piecewise linear recursive convolution (PLRC) procedure for linear isotropic dispersive magnetic materials is presented. The frequency dependence of susceptibility used for this algorithm is represented in Debye, narrowband Lorentzian, and wideband Lorentzian forms, depending on the ratio of the resonance frequency and the resonance line width. Some numerical examples along with measurements are provided.


Anticipating Vehicle-Level Emi Using A Multi-Step Approach, Geping Liu, David Pommerenke, James L. Drewniak, Richard W. Kautz, Chingchi Chen Aug 2003

Anticipating Vehicle-Level Emi Using A Multi-Step Approach, Geping Liu, David Pommerenke, James L. Drewniak, Richard W. Kautz, Chingchi Chen

Electrical and Computer Engineering Faculty Research & Creative Works

A multi-step procedure for anticipating vehicle-level EMI is proposed in this paper. This approach uses multi-conductor transmission line (MTL) modeling to calculate current distributions along the cable bundle. A common-mode circuit is extracted from the MTL modeling, and is employed in full-vehicle full-wave modeling to determine radiation and interference. In this paper, mode-dispersion and mode-conversion phenomena are investigated, and the ambiguous definitions of the common-mode voltage and common-mode impedance are discussed.


Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak Aug 2003

Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A finite-difference time-domain (FDTD) method capable of attaching rectangular computational domains is proposed herein. The aim of this approach is to reduce the size of computational domain according to the geometry of the modeled structure so as to reduce the simulation time with keeping precision of the result in an acceptable range. A multigrid algorithm is applied on the attaching interface between two rectangular domains so that different resolution can be achieved in different domains.


Reconstruction Of The Parameters Of Debye And Lorentzian Dispersive Media Using A Genetic Algorithm, Jianmin Zhang, Marina Koledintseva, Giulio Antonini, James L. Drewniak, Konstantin Rozanov, Antonio Orlandi Aug 2003

Reconstruction Of The Parameters Of Debye And Lorentzian Dispersive Media Using A Genetic Algorithm, Jianmin Zhang, Marina Koledintseva, Giulio Antonini, James L. Drewniak, Konstantin Rozanov, Antonio Orlandi

Electrical and Computer Engineering Faculty Research & Creative Works

A method for reconstruction of the parameters of the Debye or Lorentzian dispersive media is proposed. In this method, S-parameters of a simple parallel-plate fixture filled with the dispersive medium are measured and modeled using the transmission line equations, provided a single TEM mode propagating in this parallel-plate waveguide. The genetic algorithm is used for searching the parameters of the dispersive medium by means of minimizing the discrepancy between the measured and modeled S-parameters. The results are verified using the full-wave FDTD modeling technique.


A Study On Influence Of Guard Band On Common-Mode Current Related To A Microstrip Line, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue May 2003

A Study On Influence Of Guard Band On Common-Mode Current Related To A Microstrip Line, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue

Electrical and Computer Engineering Faculty Research & Creative Works

Influence of guard band on common-mode (CM) current related to a microstrip line (trace) has been studied experimental and FDTD simulation. As the guard band, copper tape is connected along the entire edge of the ground plane. It is cleared that a guard band parallel to and near a trace is most effective in suppressing the CM current. An empirical formula to quantify the relationship between the position of a trace and CM current of the case with a guard band is proposed. Calculated results using the empirical formula and FDTD modeling are in good agreement, which indicates this empirical …


Numerical Modeling Of Electrostatic Discharge Generators, Kai Wang, David Pommerenke, Ramachandran Chundru, Thomas Van Doren, James L. Drewniak, A. Shashindranath May 2003

Numerical Modeling Of Electrostatic Discharge Generators, Kai Wang, David Pommerenke, Ramachandran Chundru, Thomas Van Doren, James L. Drewniak, A. Shashindranath

Electrical and Computer Engineering Faculty Research & Creative Works

The discharge current and the transient fields of an electrostatic discharge (ESD) generator in the contact mode are numerically simulated using the finite-difference time-domain method. At first the static field is established. Then the conductivity of the relay contact is changed, which initiates the discharge process. The simulated data are used to study the effect of design choices on the current and fields. They are compared to measured field and current data using multidecade broadband field and current sensors. The model allows accurate prediction of the fields and currents of ESD generators, thus it can be used to evaluate different …


Fdtd Data Extrapolation Using Multilayer Perceptron (Mlp), H. Goksu, David Pommerenke, Donald C. Wunsch Jan 2003

Fdtd Data Extrapolation Using Multilayer Perceptron (Mlp), H. Goksu, David Pommerenke, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This work compares MLP with the matrix pencil method, a linear eigenanalysis-based extrapolator, in terms of their effectiveness in finite difference time domain (FDTD) data extrapolation. Matrix pencil method considers the signal as superposed complex exponentials while MLP considers each time step to be a nonlinear function of previous time steps.


Fdtd Analysis Of Printed Circuit Boards Containing Wideband Lorentzian Dielectric Dispersive Media, Marina Koledintseva, David Pommerenke, James L. Drewniak Aug 2002

Fdtd Analysis Of Printed Circuit Boards Containing Wideband Lorentzian Dielectric Dispersive Media, Marina Koledintseva, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A Lorentzian model as the general case of a frequency-dependent behavior of a dispersive dielectric material is considered in this paper. Recursive convolution algorithms for the finite-difference time-domain (FDTD) technique for two cases of a Lorentzian medium, narrowband and wideband, depending on the ratio of a resonance line half-width at -3 dB and the resonance frequency of the material, are detailed. It is shown that a wideband Lorentzian model of a dielectric FR-4 used in printed circuit boards is more flexible and gives good agreement with experimental curves, and may be preferable as compared to a Debye model.


Numerical Modeling Of Esd-Simulators, Kai Wang, David Pommerenke, Ramachandran Chundru Aug 2002

Numerical Modeling Of Esd-Simulators, Kai Wang, David Pommerenke, Ramachandran Chundru

Electrical and Computer Engineering Faculty Research & Creative Works

ESD generators are widely used for testing the robustness of electronic equipment against human electrostatic discharge via small metal pieces (e.g. key). Presently the IEC 61000-4-2 ESD standard is hotly discussed to improve test result reproducibility. This paper numerically analyzes an ESD simulator and relates its construction parameters to discharge current and field parameters. It uses FDTD method and models the relay (contact mode discharge) as a material with time dependent conductivity. The process is broken down into a charging phase and a stabilization phase until the electrostatic conditions are reached. Then the conductivity of the relay is changed and …


External Parasitic Inductance In Microstrip And Stripline Geometries Of Finite Size, Marina Koledintseva, James L. Drewniak, Thomas Van Doren, David M. Hockanson Aug 2002

External Parasitic Inductance In Microstrip And Stripline Geometries Of Finite Size, Marina Koledintseva, James L. Drewniak, Thomas Van Doren, David M. Hockanson

Electrical and Computer Engineering Faculty Research & Creative Works

An external parasitic ground (return) plane inductance, or a mutual inductance associated with fringing magnetic fields in planar transmission line structures, is the culprit of common-mode voltage (ground plane noise) that leads to parasitic radiation of the corresponding unintentional "antennas" in high-speed electronic equipment. Mutual inductance of this sort in microstrip and stripline structures is studied here using an analytical quasi- magnetostatic approach and FDTD modeling. Closed-form expressions for mutual inductance in symmetrical and asymmetrical microstrip and stripline structures are presented.


Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak Aug 2002

Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

EMI due to common-mode currents on cables routed in automobiles was studied using a test device designed to mimic a vehicle. Both experimental work and Finite-Difference Time-Domain (FDTD) modeling were employed in this paper. The good agreement between the measurements and modeling results indicates that the numerical tools can be a useful aid in predicting vehicle-level EMI by developing vehicle transfer functions and measuring the module-level EMI characteristics on the bench top.


Fdtd Modeling Of Skin Effect, Chen Wang, James L. Drewniak, Min Li, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, Jingyu Huang May 2002

Fdtd Modeling Of Skin Effect, Chen Wang, James L. Drewniak, Min Li, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, Jingyu Huang

Electrical and Computer Engineering Faculty Research & Creative Works

The data rates and clock speeds of current highspeed signals are increasing rapidly, consequently, not only the lossy nature of FR-4 but also the lossy nature of good conductors, such as copper, need to be taken into account in high-speed signal designs. In order to well predict the loss caused by both dielectric loss and skin effect loss, a suitable simulation tool is needed. A surface impedance boundary condition (SIBC) algorithm was implemented in FDTD modeling herein to accommodate the skin effect loss due to finite conductivity of good conductors. Good agreement between the FDTD result and the measurements as …


Efficient Modeling Of Discontinuities And Dispersive Media In Printed Transmission Lines, R. Araneo, Chen Wang, Xiaoxiong Gu, James L. Drewniak, S. Celozzi Mar 2002

Efficient Modeling Of Discontinuities And Dispersive Media In Printed Transmission Lines, R. Araneo, Chen Wang, Xiaoxiong Gu, James L. Drewniak, S. Celozzi

Electrical and Computer Engineering Faculty Research & Creative Works

The finite-difference time-domain method is applied to the analysis of transmission lines on printed circuit boards. The lossy, dispersive behavior of the dielectric substrate is accurately accounted for by means of several algorithms whose accuracy is discussed and compared. Numerical results are validated by comparisons with measurements and an equivalent circuit of slot in the ground plane is proposed.


High-Performance Inter-Pcb Connectors: Analysis Of Emi Characteristics, Xiaoning Ye, James L. Drewniak, Jim Nadolny, David M. Hockanson Feb 2002

High-Performance Inter-Pcb Connectors: Analysis Of Emi Characteristics, Xiaoning Ye, James L. Drewniak, Jim Nadolny, David M. Hockanson

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) coupling associated with inter-board connection is investigated. Two experimental techniques, based on |S21| measurements, including both common-mode current and near-field measurements, are reported. Both methods, as well as finite difference time domain (FDTD) modeling, were used as experimental and numerical tools for inter-printed-circuit-board (inter-PCB) connector evaluation. The EMI performance of a lab-constructed stacked-card connector, and a commercially available module-on-backplane connector were studied. EMI characteristics of the connectors are demonstrated by investigating a few aspects of the design: type of shield/ground blade for signal return, number and length of ground pins, signal pin designation, etc. Good …


Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff Nov 2001

Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

General methods for reducing printed circuit board (PCB) emissions over a broad band of high frequencies are necessary to meet EMI requirements, as processors become faster and more powerful. One mechanism by which EMI can be coupled off a PCB or multichip module (MCM) structure is from high-frequency fringing electric fields on the dc power and reference planes at the substrate periphery An approach for EMI mitigation by stitching multiple ground planes together along the periphery of multilayer PCB power-bus stacks with closely spaced vias is reported and quantified in this paper. Power-bus noise induced EMI and coupling from the …


The Effects Of Via Transitions On Differential Signals, Chen Wang, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, James L. Drewniak Oct 2001

The Effects Of Via Transitions On Differential Signals, Chen Wang, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Vias in differential transmission lines have been modeled using the finite-difference time-domain (FDTD) method. The velocity that the differential signal propagated through the vias was estimated. Differential S-parameters were calculated up to 50 GHz. Below 10 GHz, the differential signal can propagate through vias without much reflection and distortion. However, as frequency increases, the reflection from the vias and the loss of differential power become significant.


Representation Of Gyromagnetic Composite Media For Fdtd Modeling, Marina Koledintseva, James L. Drewniak, Xiaoning Ye Aug 2001

Representation Of Gyromagnetic Composite Media For Fdtd Modeling, Marina Koledintseva, James L. Drewniak, Xiaoning Ye

Electrical and Computer Engineering Faculty Research & Creative Works

A composite media containing particles with a high internal field of magnetic anisotropy (hexagonal ferrites) useful for numerous EMC applications in a wide frequency band is considered. Effective constitutive parameters of a high-loss composite gyromagnetic media are represented in the Lorentzian form. It is convenient for the numerical analysis using the finite-difference time-domain (FDTD) algorithm with a recursive convolution procedure. The equations for the electric and magnetic field updating in such media are represented.


Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak Aug 2001

Differential Signalling In Pcbs: Modeling And Validation Of Dielectric Losses And Effects Of Discontinuities, R. Araneo, Chen Wang, Xiaoxiong Gu, S. Celozzi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

This paper focuses on differential signal transmission above ground planes with gaps, taking into account the dielectric and conductive losses of the substrate. An equivalent lumped-circuit is proposed and its suitability is investigated by comparing the obtained numerical results with the measured data. Furthermore the differential to common mode conversion of the waves, while crossing the gap, is theoretically analyzed and experimentally verified.