Electrical and Computer Engineering Commons^™

A Physics-Based Pi Pre-Layout Tool For Pcb Pdn Design, Shuang Liang

Masters Theses

"With increasingly stringent requirements for lower voltage supply, and higher density in PCB PDN design, now integrity (PI) is an increasingly important aspect that must be considered. A pre-layout tool based on the Cavity Model and Boundary Element Method is built to automatically achieve a specified target impedance for a multi-layered Printed Circuit Board (PCB) Power Distribution Network (PDN) design with a minimal number of decoupling capacitors.

The pre-work about the post-layout design and analysis is proposed and the guidelines for creating a decoupling capacitors network with better performance has been built. With limit inputs, physical limitations for the minimal …

Passive Harmonic Generation At Spring Contacts, Sen Yang

Doctoral Dissertations

"In the first paper, the RF passive harmonic generation phenomenon on the spring contact is studied. A spring contact harmonic generation measurement system is developed. The factors that may have an impact on the spring contact harmonic generation, such as contact material, contact force, and contact resistance are characterized by the measurement system. The gold-to-gold contact is found to be much superior to the stainless-steel contacts. It is also found that the passive nonlinearity at the spring contact is the semiconductor-like junction formed by the surface oxide film.

In the second paper, we show that the maximum E-field coupling occurs …

Developing A Methodology For Estimating The Growth Of Radiated Emission From Multi-Modular Systems, Kaustav Ghosh

Masters Theses

"The large multiscale problems are commonly faced in real-world applications such as analysis of electromagnetic interference for a printed circuit board installed on a large platform with connected cables, wires and other high speed interfaces. EMI problems are not uncommon in high speed systems which involve multiple modules of complex hardware. As the system clock frequency and data rate increases, so does the challenges in controlling the EMI in such systems. The costs to prototype and to develop networking equipment are growing as a result of increasing complexities and densities. EMC regulations require radiated emission testing to be done in …

Nonlinearity Of Digital I/Os And Its Behaviour Modeling, He Ming Yao, Huan Huan Zhang, Hui Chun Yu, Xing Yun Luo, Bin Li, Hua Sheng Ren, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Due to the rising signal speed in today's integrated circuits (ICs), the digital input/output (I/O) device modeling becomes a very serious challenge. However, its nonlinearity issue was even less addressed. But for accurate EMC and EMI characterizations, the I/O nonlinearity could become a source of unexpected EMC and EMI troubles in the high-speed system. In this paper, we analyze the nonlinearity of high-speed drivers and loads under the influence of various parameters, such as the rising and falling times, data and clock duty cycle distortion (DCD), signal skew, balance of the circuit, etc. Further based on the spectrum property of …

Esd Related Soft Error Detection And Root Cause Analysis, Suyu Yang

Masters Theses

"In this article, several methods are outlined for detecting functional changes in an IC due to external interference such as ESD or EMI. The goal is to provide diagnostic tools for detection of potential soft failure susceptibilities of complex systems during the hardware design stage without the aid of any complex software. After the soft errors are found, circuit modeling techniques are used to characterize the DUT. By running the circuit model, the soft error threshold can be predicted and the circuit model can be used to evaluate the performance of other ESD protection methods. In the end several methods …

The Development Of Near Field Probing Systems For Emc Near Field Visualization And Emi Source Localization, Hui He

Masters Theses

"The objectives of this research are to visualize the frequency dependent electromagnetic field distribution for electromagnetic compatibility (EMC) applications and the radiating source reconstruction on complex shaped electronic systems. This is achieved by combining near field probing with a system for automatically recording the probe position and orientation. Due to the complexity of the shape of the electronic systems of interest, and for utilizing the expertise of the user, the probe will be moved manually not robotically. Concurrently, the local near field will be recorded, associated with the location and displayed at near real time on the captured 3D geometry …

Expert System Algorithms For Identifying Radiated Emission Problems In Printed Circuit Boards, Hwan-Woo Shim, Todd H. Hubing, Thomas Van Doren, Richard E. Dubroff, James L. Drewniak, David Pommerenke, R. Kaires

Electrical and Computer Engineering Faculty Research & Creative Works

Radiated emission algorithms for a printed circuit board EMC expert system are described. The expert system mimics the thinking processes that human EMC engineers would use to analyze circuit boards and make design recommendations. Working with limited information about the enclosure, cables or the exact nature of the signals, the expert system evaluates different structures on the printed circuit board looking for potentially strong radiated emission sources. Results obtained from the analysis of a sample printed circuit board are provided to demonstrate how the expert system quickly identifies problems that would otherwise be difficult to locate.

Comparison Of Via Equivalent Circuit Model Accuracy Using Quasi-Static And Full-Wave Approaches, Bruce Archambeault, Samuel R. Connor, Jianmin Zhang, James L. Drewniak, Mauro Lai, Antonio Orlandi, Giulio Antonini, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The EMC and signal integrity impact of printed circuit board (PCB) trace discontinuities, such as vias, where the signal is transitioned from one layer to another in the PCB stackup, have become significant recently with the use of very high speed signals in today''s systems. If these discontinuities are ignored, significant distortion of the high speed signal can occur, and in many cases, cause data errors. A fast and accurate technique to include the effect of via discontinuities in the typical design process is needed to ensure this distortion is considered if significant. Therefore, a simple equivalent circuit for the …

Mas-Mom Hybrid Method With Wire's Image Using In Excitation Problems, D. G. Kakulia, David Pommerenke, Kai Xiao, D. D. Karkashadze, K. N. Tavzarashvili, G. N. Ghvedashvili, R. S. Zaridze

Electrical and Computer Engineering Faculty Research & Creative Works

An important class of problems is the interaction of an antenna with the cavity of a semi-open metallic structure. In a working environment, an antenna may change its performance due to interactions with its surroundings. This is especially true in automotive applications. Therefore, it is important to consider the interaction of an antenna with possible resonating parts, and to solve these complex electrodynamics problems together. The development of methods for modeling and studying electromagnetic compatibility (EMC) problems has practical value. The method of auxiliary sources (MAS) with the method of moments (MoM) is applied to solve the excitation problem where …

Via Coupling Within Power-Return Plane Structures Considering The Radiation Loss, J. Chen, Todd H. Hubing, Weimin Shi, R. L. Chen

Electrical and Computer Engineering Faculty Research & Creative Works

An accurate analytical model to predict via coupling within rectangular power-return plane structures is developed. Loss mechanisms, including radiation loss, dielectric loss, and conductor loss, are considered. The radiation loss is incorporated into a complex propagating wavenumber as an artificial loss mechanism. The quality factors associated with the three loss mechanisms are calculated and compared. The effects of radiation loss on input impedances and reflection coefficients are investigated for both high-dielectric-loss and low-dielectric-loss PCBs. Measurements are performed to validate the effectiveness of the model.

Radiated Emissions From Populated Printed Circuit Boards Due To Power Bus Noise, Hwan-Woo Shim, Todd H. Hubing, Yan Fu

Electrical and Computer Engineering Faculty Research & Creative Works

Previous studies have demonstrated that power plane pairs in a printed circuit board are capable of generating significant radiated emissions at resonance frequencies if these resonances are not damped by material or component losses. The paper shows that board resonances may be readily damped by component losses. However, radiated emissions from a damped power bus may still exceed FCC or CISPR limits over a broad band of frequencies.

The Development Of A Closed-Form Expression For The Input Impedance Of Power-Return Plane Structures, Minjia Xu, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

In multilayer printed circuit boards, the noise on the power bus is influenced by the impedance between the power and ground planes. Power-bus noise estimates require an accurate estimate of the power-bus input impedance. This paper develops a closed-form estimate of the input impedance for circular power-return plane structures. When the structure is lossy (e.g., boards employing embedded capacitance or densely populated boards), the energy reflected from the board edge does not significantly affect the input impedance. In general, the expressions developed here for circular structures can be used to estimate the impedance of lossy power-return plane structures of any …

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.

Estimating Dc Power Bus Noise, Jingkun Mao, Bruce Archambeault, James L. Drewniak, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Simultaneous switching noise (SSN) resulting from IC devices can result in significant power bus noise, as well as radiation problems. An approach for estimating the power bus noise spectrum is presented in this paper. The power bus noise caused by digital circuits injecting high-frequency noise onto the DC buses feeding digital devices is calculated. The transient current drawn by an IC device is modeled using the load current and the shoot-through current through the power dissipation capacitance. Modeling and experimental results for several digital chips are shown. The modeling agrees well with the experimental results.

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.

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.

An Emi Estimate For Shielding-Enclosure Evaluation, Min Li, James L. Drewniak, S. Radu, Joe Nuebel, Todd H. Hubing, Richard E. Dubroff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

A relatively simple, closed-form expression has been developed to estimate the EMI from shielding enclosures due to coupling from interior sources through slots and apertures at the enclosure cavity modes. A power-balance method, Bethe's (1944) small-hole theory, and empirically developed formulas for the relation between radiation, and slot length and number of slots, were employed to estimate an upper bound on the radiated EMI from shielding enclosures. Comparisons between measurements and estimated field strengths suitably agree within engineering accuracy.

Including Smt Ferrite Beads In Dc Power Bus And High-Speed I/O Line Modeling, Jun Fan, Shaofeng Luan, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Surface mount technology (SMT) ferrite beads are often used in high-speed digital circuit designs to mitigate noise. The common modeling approach is to include SMT ferrite beads as equivalent lumped LCR circuits. The work presented in this paper included SMT ferrite beads as a frequency-dependent impedance in a PEEC-like modeling tool denoted CEMPIE, a circuit extraction approach based on a mixed-potential integral equation formulation. Agreement with measurements demonstrates the approach. The applications shown are segmentation of power areas for noise isolation, and I/O line filtering.

Mitigating Power Bus Noise With Embedded Capacitance In Pcb Designs, Minjia Xu, Todd H. Hubing, Juan Chen, James L. Drewniak, Thomas Van Doren, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the power bus noise and power bus impedance of printed circuit boards with four different kinds of embedded capacitance. These boards have power-ground plane pairs separated by a very thin layer of material with high dielectric permittivity. It is shown that embedded capacitance effectively reduces power bus noise over the entire frequency range evaluated (up to 5 GHz).

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.

20-H Rule Modeling And Measurements, Todd H. Hubing, Hwan-Woo Shim

Electrical and Computer Engineering Faculty Research & Creative Works

The 20-H rule is a printed circuit board layout guideline. On boards with power and ground planes, the fringing field at the edges of the board is contained by backing the edge of the power plane away from the edge of the board by a distance equal to 20 times the separation distance between the planes. In this study, test boards were built and measured with and without implementing the 20-H rule. The measured results are compared to numerical models. The results of this study show that, although the near fields are more contained, the radiation from a board implementing …

Development Of A Closed-Form Expression For The Input Impedance Of Power-Ground Plane Structures, Minjia Xu, Yun Ji, Todd H. Hubing, Thomas Van Doren, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

This paper analyzes the fundamental behavior of PCB power bus structures using the modal expansion method. The results are validated by experiments and full-wave numerical modeling. It is shown that the power bus can be modeled as a series L_eC circuit below the first board resonance frequency. C is the interplane capacitance and L_e is an effective inductance contributed by all the cavity nodes. The effects of the layer thickness, port location, board size and the feeding wire radius on the value of L_e are discussed in this study. L_e can be estimated from the …

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.

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

Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, Min Li, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Subcellular modeling of thin slots in the finite-difference time-domain (FDTD) method is investigated. Two subcellular algorithms for modeling thin slots with the FDTD method are compared for application to shielding end osures in electromagnetic compatibility (EMC). The stability of the algorithms is investigated, and comparisons between the two methods for slots in planes, and slots in loaded cavities are made. Results for scattering from a finite-length slot in an infinite plane employing one of the algorithms are shown to agree well with published experimental results, and power delivered to an enclosure with a slot agree well with results measured for …

Fdtd Modeling Of Common-Mode Radiation From Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Radiation from cables attached to printed circuit boards and shielding enclosures is among the primary concerns in meeting FCC Class A and B limits. The finite-difference time-domain (FDTD) method can be employed to model radiation from printed circuit boards and shielding enclosures with complex geometries, but difficulties in modeling wires and cables of arbitrary radii are encountered. Modeling the wire by setting the axial component of the electric field to zero in the FDTD method results in an effective wire radius that is determined by the mesh discretization. Neglecting the wire radius in applications, such as electromagnetic interference (EMI) or …

Integrating Electromagnetic Compatibility Laboratory Exercises Into Undergraduate Electromagnetics, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha

Electrical and Computer Engineering Faculty Research & Creative Works

A state-of-the art high-frequency laboratory is being developed for pursuing laboratory exercises in EMC. These exercises are being integrated into three undergraduate electromagnetics courses. Two of the courses are a required introductory sequence. The laboratory exercises are designed to stimulate students interest, motivate them to learn concepts, and provide them with exposure to practical EMC applications. Laboratory exercises are also an integral part of an EMC elective course. This paper describes the laboratory development and discusses experiments that can be integrated into these three courses for teaching fundamental electromagnetics as well as EMC.

Fdtd Modeling Of Thin Wires For Simulating Common-Mode Radiation From Structures With Attached Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The analysis of shielding enclosures is complicated by the existence of apertures and cables. The finite-difference time-domain (FDTD) method can model shielding enclosures with complex geometries, but has difficulty modeling wires and cables of arbitrary radii. Modeling the wire by setting the axial component of the electric field to zero in the FDTD results in a wire with a radius determined by the mesh discretisation. Neglecting wire radius in applications such as electromagnetic interference (EMI) or printed circuit board modeling may result in gross errors because near field quantities are typically sensitive to wire thickness. Taflove (1990) developed a wire …

A Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Thin slot modeling for the finite-difference time-domain (PDTD) method is investigated. Two subcellular algorithms for modeling thin slots with the FDTD method are compared for application to shielding enclosures in EMC. The stability of the algorithms is investigated, and comparisons between the two methods for slots in planes, and slots in loaded cavities are also made.

An Algorithm For Automated Printed Circuit Board Layout And Routing Evaluation, Todd H. Hubing, Thomas Van Doren, James L. Drewniak, Puneet Grover, R. Lee Hill

Electrical and Computer Engineering Faculty Research & Creative Works

An algorithm has been developed to evaluate printed circuit boards that are designed using automated board layout and routing software. The algorithm analyzes aspects of component placement and trace routing while searching for violations of basic EMC design principles. The algorithm is implemented in code designed to work with a widely used board layout and routing program. This code can help novice and experienced circuit board designers to avoid mistakes that may result in serious electromagnetic compatibility problems.