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Full-Text Articles in Engineering
A Three-Dimensional Fdtd Subgridding Algorithm With Separated Temporal And Spatial Interfaces And Related Stability Analysis, Kai Xiao, David Pommerenke, James L. Drewniak
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 …
Influence Of An Extended Stub At Connector Ports On Signal Launches And Trl De-Embedding, Jianmin Zhang, James L. Drewniak, David Pommerenke, Bruce Archambeault, Zhiping Yang, Wheling Cheng, John Fisher, Sergio Camerlo
Influence Of An Extended Stub At Connector Ports On Signal Launches And Trl De-Embedding, Jianmin Zhang, James L. Drewniak, David Pommerenke, Bruce Archambeault, Zhiping Yang, Wheling Cheng, John Fisher, Sergio Camerlo
Electrical and Computer Engineering Faculty Research & Creative Works
Characterization of PCBs (Printed Circuit Boards) is usually associated with measurement using a VNA (Vector Network Analyzer) in the frequency-domain or a TDR (Time Domain Reflectometer) in the time-domain. The often used signal launch techniques on PCBs based on the VNA or TDR measurement in the microwave frequency range use SMA or 3.5 mm connectors, in edge-launch or vertical-launch fashions. The signal transition between the launch port and the DUT (Device Under Test) introduces errors in the measurement, which is dominant when compared with a transmission line itself on the PCB as the technologies of PCB manufacturing well developed today. …
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
Electrical and Computer Engineering Faculty Research & Creative Works
A novel approach of equivalent circuit model extraction is developed for modeling of integrated package and PCB power distribution networks (PDN). The integrated PDNs are formulated from a full-wave finite-difference algorithm, and the resulting matrix equations are converted to equivalent circuits. The equivalent circuits, as well as the decoupling capacitors and the attached circuit components, can be analyzed with a SPICE-like solver in both the time and frequency domains. The modeling of dielectric loss is also addressed. The method is used to model three PDN problems including a simple power bus, a BGA package mounting on a PCB, and a …
Complex Power Distribution Network Investigation Using Spice Based Extraction From First Principle Formulations, Giuseppe Selli, James L. Drewniak, Richard E. Dubroff, Jun Fan, James L. Knighten, Norman W. Smith, Dean Mccoy, Bruce Archambeault, Stefano Grivet-Talocia, Flavio G. Canavero
Complex Power Distribution Network Investigation Using Spice Based Extraction From First Principle Formulations, Giuseppe Selli, James L. Drewniak, Richard E. Dubroff, Jun Fan, James L. Knighten, Norman W. Smith, Dean Mccoy, Bruce Archambeault, Stefano Grivet-Talocia, Flavio G. Canavero
Electrical and Computer Engineering Faculty Research & Creative Works
The modeling and the analysis of the power distribution networks (PDN) within multi-layer printed circuit board is crucial for the investigation of the performance of PCB systems. Carrying out such analyses in SPICE based tools has the advantage of being faster than the corresponding full-wave modeling and it allows obtaining both frequency and time domain results.
Validation Of Circuit Extraction Procedure By Means Of Frequency And Time Domain Measurement, Giulio Antonini, Antonio Ciccomancini Scogna, Antonio Orlandi, Vittorio Ricchiuti, Giuseppe Selli, Shaofeng Luan, James L. Drewniak
Validation Of Circuit Extraction Procedure By Means Of Frequency And Time Domain Measurement, Giulio Antonini, Antonio Ciccomancini Scogna, Antonio Orlandi, Vittorio Ricchiuti, Giuseppe Selli, Shaofeng Luan, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Aim of this paper is the validation in both frequency and time domain of the procedure to extract fully H-Spice compatible equivalent circuits of structures on printed circuit boards. The procedure is initiated by standard measurement of scattering parameters between 40MHz to 20GH. After the extraction of the equivalent circuit, the computed scattering parameters are compared with those measured. The same equivalent circuit is also used for transient analysis in order to compare TDR measurement and eye-pattern to a pseudo-random bit sequence with those coming from the simulations.
A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak
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.
Wide-Band Lorentzian Media In The Fdtd Algorithm, Marina Koledintseva, James L. Drewniak, David Pommerenke, Giulio Antonini, Antonio Orlandi, Konstantin Rozanov
Wide-Band Lorentzian Media In The Fdtd Algorithm, Marina Koledintseva, James L. Drewniak, David Pommerenke, Giulio Antonini, Antonio Orlandi, Konstantin Rozanov
Electrical and Computer Engineering Faculty Research & Creative Works
This paper considers the case of a wide-band Lorentzian (WBL) algorithm in the finite-difference time-domain (FDTD) modeling of dispersive media. It is shown herein that the WBL model is a physically meaningful and practically useful case of the frequency behavior of materials along with the Debye and narrow-band Lorentzian (NBL). The recursive convolution algorithms for the finite-difference time-domain technique for NBL and WBL models differ. The Debye model, which is suitable for comparatively low-frequency dispersive materials, may not have sufficient number of parameters for describing the wide-band material, especially if this material exhibits pronounced absorption at higher frequencies. It is …
Electrical Material Property Measurements Using A Free-Field, Ultra-Wideband System [Dielectric Measurements], C. A. Grosvenor, R. Johnk, D. Novotny, S. Canales, J. Baker-Jarvis, M. Janezic, James L. Drewniak, Marina Koledintseva, Jianmin Zhang, Poorna Chander Ravva
Electrical Material Property Measurements Using A Free-Field, Ultra-Wideband System [Dielectric Measurements], C. A. Grosvenor, R. Johnk, D. Novotny, S. Canales, J. Baker-Jarvis, M. Janezic, James L. Drewniak, Marina Koledintseva, Jianmin Zhang, Poorna Chander Ravva
Electrical and Computer Engineering Faculty Research & Creative Works
We present nondestructive measurements of material properties using TEM horn antennas and an ultra-wideband measurement system. Time-domain gating and genetic algorithms are used to process the data and extract the dielectric properties of the material under test.
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
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 Three-Dimensional Fdtd Subgridding Algorithm Based On Interpolation Of Current Density, Kai Xiao, David Pommerenke, James L. Drewniak
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.
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
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.
A Cn-Fdtd Scheme And Its Application To Vlsi Interconnects/Substrate Modeling, Rui Qiang, Dagang Wu, Ji Chen, Chen Wang, James L. Drewniak
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.
Representation Of Permittivity For Multiphase Dielectric Mixtures In Fdtd Modeling, Marina Koledintseva, J. Wu, H. Zhang, James L. Drewniak, Konstantin Rozanov
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. …
Susceptibility Characterization Of A Cavity With An Aperture By Using Slowly Rotating Em Fields: Fdtd Analysis And Measurements, Kimitoshi Murano, Takeshi Sanpei, Fengchao Xiao, Chen Wang, Yoshio Kami, James L. Drewniak
Susceptibility Characterization Of A Cavity With An Aperture By Using Slowly Rotating Em Fields: Fdtd Analysis And Measurements, Kimitoshi Murano, Takeshi Sanpei, Fengchao Xiao, Chen Wang, Yoshio Kami, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
This paper describes the evaluation of the susceptibility of a cavity with an aperture using the finite-difference time-domain (FDTD) method and experimentally. To reduce the computing time, the FDTD method is used for the radiation from the cavity and the susceptibility is obtained by using the reciprocity theorem. The cavity used here is modeled after a full-tower desktop enclosure with a 3.5-in bay. The susceptibility characteristics are evaluated by measuring outputs of a monopole antenna and transmission lines installed in the cavity. The susceptibility characteristics, using a three-dimensional (3-D) map, are studied from the computed and the measured results by …
Common-Mode Current Due To A Trace Near A Pcb Edge And Its Suppression By A Guard Band, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue
Common-Mode Current Due To A Trace Near A Pcb Edge And Its Suppression By A Guard Band, Yoshiki Kayano, Motoshi Tanaka, James L. Drewniak, Hiroshi Inoue
Electrical and Computer Engineering Faculty Research & Creative Works
The common-mode (CM) current due to a trace near a printed circuit board (PCB) edge, and its suppression by a guard band have been studied experimentally and with finite-difference time-domain (FDTD) modeling. As the guard band, copper tape is connected along the entire edge of the ground plane. First, a PCB electromagnetic interference (EMI) coupling path that results from the nonzero impedance of the PCB ground plane is discussed. As the trace is moved closer to the PCB edge, the CM current increases. Then, the effect of the guard band on the CM current is detailed. A guard band parallel …
Fdtd Method Capable Of Attaching Rectangular Domains, Kai Xiao, David Pommerenke, James L. Drewniak
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.
Modeling Issues For Full-Wave Numerical Emi Simulation, Michael A. Cracraft, Xiaoning Ye, Chen Wang, Sandeep K. R. Chandra, James L. Drewniak
Modeling Issues For Full-Wave Numerical Emi Simulation, Michael A. Cracraft, Xiaoning Ye, Chen Wang, Sandeep K. R. Chandra, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
In electromagnetic modeling, agreement between modeling and measurements is a common goal. There are questions that define every model. What is to be modeled? How is it going to be modeled? At what scale is it to be modeled? Through sample results and discussion, this paper addresses some general and some specific elements of model veracity. Through determination, numerical models can certainly be pushed to match any measured results. However, in the end the question that this paper addresses is not necessarily "How good can this model be?" as it is "Is this model good enough?".
Application Of Higher-Order Fem Elements To The Analysis Of Microstrip Structures, H. Wang, C. L. Guo, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Application Of Higher-Order Fem Elements To The Analysis Of Microstrip Structures, H. Wang, C. L. Guo, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
Microstrip structures, formed by metal traces printed on a dielectric substrate above a reference plane, are frequently the object of electromagnetic modeling. In this paper, hybrid FEM/MoM formulations employing conventional Whitney elements and newly developed linear-tangent/linear-normal (LT/LN) tangential vector finite elements (TVFEs) are applied to the analysis of microstrip structures with thin traces. This paper shows that the variation of the electric field below the trace is a significant issue to be addressed in microstrip structure modeling. Different mesh methods are investigated and the advantages of the LT/LN TVFEs are discussed.
Anticipating Full Vehicle Radiated Emi From Module-Level Testing In Automobiles, Geping Liu, Chingchi Chen, Yuhua Tu, James L. Drewniak
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.
Transmission Line Modeling Of Vias In Differential Signals, Chen Wang, James L. Drewniak, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander
Transmission Line Modeling Of Vias In Differential Signals, Chen Wang, James L. Drewniak, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander
Electrical and Computer Engineering Faculty Research & Creative Works
Signal layer transitions in differential lines are modeled using both FDTD and equivalent circuit methods. The equivalent circuit is developed based on transmission-line reasoning regarding via behavior. Parameters of each transmission-line segment are obtained based on its corresponding physical geometry. The mixed-mode S-parameters from the equivalent circuit and the FDTD modeling are compared. Good agreement is demonstrated in the frequency range from 1 GHz to 20 GHz. The results indicate that vias in differential lines can be modeled as a transmission line for a quick and easy engineering estimation of the differential signal behavior in an environment of signal layer …
Efficient Modeling Of Discontinuities And Dispersive Media In Printed Transmission Lines, R. Araneo, Chen Wang, Xiaoxiong Gu, James L. Drewniak, S. Celozzi
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.
Dc Power-Bus Design Using Fdtd Modeling With Dispersive Media And Surface Mount Technology Components, Xiaoning Ye, Marina Koledintseva, Min Li, James L. Drewniak
Dc Power-Bus Design Using Fdtd Modeling With Dispersive Media And Surface Mount Technology Components, Xiaoning Ye, Marina Koledintseva, Min Li, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
DC power-bus modeling in high-speed digital design using the finite-difference time-domain (FDTD) method is demonstrated herein. The dispersive character of the dielectric layers used in printed circuit board substrates is taken into account in this study. In particular, FR-4 is considered. The complex permittivity of the dielectric is approximated by a Debye model. A wide-band frequency response (100 MHz-5 GHz) is obtained through a single FDTD simulation. Good agreement is achieved between the modeled and measured results for a typical dc power-bus structure with multiple surface mount technology (SMT) decoupling capacitors placed on the printed circuit board (PCB). The FDTD …
The Effects Of Via Transitions On Differential Signals, Chen Wang, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, James L. Drewniak
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.
Grounding Of Heatpipe/Heatspreader And Heatsink Structures For Emi Mitigation, Chen Wang, James L. Drewniak, D. Wang, Ray Alexander, James L. Knighten, David M. Hockanson
Grounding Of Heatpipe/Heatspreader And Heatsink Structures For Emi Mitigation, Chen Wang, James L. Drewniak, D. Wang, Ray Alexander, James L. Knighten, David M. Hockanson
Electrical and Computer Engineering Faculty Research & Creative Works
EMI problems caused by the presence of heatpipe/heatspreader and heatsink structures in a high-speed design are well known in engineering practice. High-frequency noise can be coupled from IC packages to an electrically conductive heatsink or heatspreader attached to the IC, which then is radiated, or the energy coupled to an enclosure cavity mode. This EMI coupling path was modeled with the finite-difference time-domain (FDTD) method, and a mitigation approach was investigated. Good agreement between measurements and FDTD modeling is demonstrated, indicating FDTD is a suitable tool for analysis and design. Then, several grounding schemes suitable for a heatsink or heatspreader …
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Investigation Of Pcb Layout Parasitics In Emi Filtering Of I/O Lines, Xiaoning Ye, Geping Liu, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
EMI filters are often utilized on I/O lines to reduce high-frequency noise from being conducted or coupled off the PCB and resulting in an EMI problem. However, layout parasitics are usually inevitable in practical circuit design, and the filtering performance may vary. In this study, the impact of the board layout on the filtering performance is investigated by |S21| measurements of sample PCB boards with different filter layouts. The finite-difference time-domain method is applied to model the boards, support the experimental work, and can be used to provide a means for conducting "what-if" engineering studies.
Dc Power Bus Design With Fdtd Modeling Including A Dispersive Media, Xiaoning Ye, Jun Fan, Marina Koledintseva, James L. Drewniak
Dc Power Bus Design With Fdtd Modeling Including A Dispersive Media, Xiaoning Ye, Jun Fan, Marina Koledintseva, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
DC power-bus modeling in high-speed digital design using the FDTD method is reported here. The dispersive medium is approximated by a Debye model to account for the loss. A wide band frequency response (100 MHz-5 GHz) is obtained through a single FDTD simulation. Favorable agreement is achieved between the modeled and measured results for a typical DC power-bus structure with multiple SMT decoupling capacitors mounted on the board. The FDTD tool is then applied to investigate the effects of local decoupling on a DC power-bus. The modeled results agree with the results from another modeling tool, the CEMPIE (a circuit …
Experimental And Fdtd Study Of The Emi Performance Of An Open-Pin-Field Connector For Modules-On-Backplanes, Xiaoning Ye, Jim Nadolny, James L. Drewniak, Richard E. Dubroff, Thomas Van Doren, Todd H. Hubing
Experimental And Fdtd Study Of The Emi Performance Of An Open-Pin-Field Connector For Modules-On-Backplanes, Xiaoning Ye, Jim Nadolny, James L. Drewniak, Richard E. Dubroff, Thomas Van Doren, Todd H. Hubing
Electrical and Computer Engineering Faculty Research & Creative Works
Experimental measurements and numerical modeling were used to study the EMI performance of a module-on-backplane connector for various configurations of signal-return pin-outs. A commercially available open-pin-field connector was used in these results to connect between the mother-board and the daughter-card. The experimental techniques, based on measuring |S21|, included both common-mode current measurements and monopole near-field probe measurements. The FDTD method was used to provide numerical support of the near-field measurements and generally agreed with the measured results for frequencies up to 3 GHz. The FDTD method was also used to investigate the relationship between the radiated EMI at …
Experimental And Numerical Study Of The Radiation From Microstrip Bends, H. Wang, Yun Ji, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Experimental And Numerical Study Of The Radiation From Microstrip Bends, H. Wang, Yun Ji, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
This paper investigates the radiation from microstrip lines with 90-degree bends. A 1-GHz TEM cell is used to measure the radiation from microstrip lines with different kinds of bends. A full wave hybrid FEM/MoM code is used to compute the radiation. Both experimental and numerical results show that there is no significant difference between the radiation from right angle bends and bends with two 45-degree corners at frequencies and trace dimensions that are likely to be found on printed circuit boards.
Emi Resulting From A Signal Via Transition Through Dc Power Bus-Effectiveness Of Focal Smt Decoupling, Wei Cui, Xiaoning Ye, Bruce Archambeault, Doug White, Min Li, James L. Drewniak
Emi Resulting From A Signal Via Transition Through Dc Power Bus-Effectiveness Of Focal Smt Decoupling, Wei Cui, Xiaoning Ye, Bruce Archambeault, Doug White, Min Li, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Signal vias are commonly used in multilayer printed circuit board (PCB) design. For a signal via transitioning through the internal power and ground planes, the return current has to jump from one reference plane to another reference plane. The discontinuity of the return current at the via excites the power and ground planes, and results in power bus noise, and can produce an EMI problem as well. Numerical methods, such as finite-difference time-domain (FDTD), moment methods (MoM), and partial element equivalent circuit (PEEC), were employed herein to study this problem. The modeled results were supported by the measurements. In addition, …
Fdtd Modeling Of Lumped Ferrites, Min Li, Xiao Luo, James L. Drewniak
Fdtd Modeling Of Lumped Ferrites, Min Li, Xiao Luo, James L. Drewniak
Electrical and Computer Engineering Faculty Research & Creative Works
Implementing ferrites in finite-difference time-domain (FDTD) modeling requires special care because of the complex nature of the ferrite impedance. Considerable computational resources and time are required to directly implement a ferrite in the FDTD method. Fitting the ferrite impedance to an exponential series with the generalized-pencil-of-function (GPOF) method and using recursive convolution is an approach that minimizes the additional computational burden. An FDTD algorithm for a lumped ferrite using GPOF and recursive convolution is presented herein. Two different ferrite impedances in a test enclosure were studied experimentally to demonstrate the FDTD modeling approach. The agreement is generally good.