Characterization And Reduction Of Line To Line Crosstalk On Printed Circuit Boards

An important concern for high speed circuit designs is that of crosstalk and electromagnetic interference. In PCB board-level designs, crosstalk at microwave frequencies may result from imperfections in shielding of PCB interconnects or more generally transmission lines. Several studies have been done to characterize and improve the isolation between PCB transmission lines for both digital and RF circuits. For example, previous studies in the microwave region have examined the effect that line type, line length, and separation have on crosstalk and suggest that without full shielding, the upper limit of isolation is on the order of 60dB for traditional board-level lines [1]. In order to more fully characterize crosstalk and improve isolation above 60 dB, this thesis studies signal-to-ground-plane separation, considers advanced line types, and examines the effect of 3D shielding. Results are presented from 100MHz to 30GHz for the traditional transmission line structures of microstrip, CPW, differential pair and CPW differential pair. This study shows that with a halving of distance between signal and ground planes, isolation between transmission lines can be reduced by as much as 20dB, making this one of the best ways to improve performance. Advanced methods of shielding are then presented. Direct launch stripline and single-sided CPW improve upon existing crosstalk reduction techniques, while split shielding and ablation of dielectric PCB material are also proposed. The data and additional crosstalk reduction techniques discussed in this thesis serve two purposes. One: with a more complete understanding of the effects that transmission line types and parameters have on crosstalk, engineers can quickly identify potential crosstalk issues and resolve them before manufacturing. Second, this thesis presents the engineer with four new additional techniques that may become available in advanced manufacturing environments. Such techniques can further reduce crosstalk and may allow for isolation values to approach 100 dB at the PC board level.

The high reliability and operating speed (high clock frequencies) are essential elements for electronic equipment. With the increase in the speed of operation of the circuits on printed circuit boards (PCB), the wavelength becomes comparable to the length of interconnections. This implies in the circuit analysis being then made in terms of transmission line. From this fact, undesirable effects such as failure to signal integrity (SI) may occur, for example, the crosstalk noise. This problem of signal integrity can bring serious harm to the functioning of a printed circuit board. It is important that such failure is remediated in the initial phase of the project, since the correction becomes even simpler and less costly. In fact, some computational tricks were used to try to measure integrity issues of crosstalk-type signal, because without such tools, advanced calculations, which would cause delays in the process, would be needed.

This thoroughly updated leading-edge circuit design resource offers the knowledge needed to quickly pinpoint transmission problems that can compromise the entire circuit design. This new edition demonstrates how to apply EM theory to solve signal integrity problems with a practical application-oriented approach. Discussing both design and debug issues at gigabit per second data rates, the book serves as a practical reference for projects involving high-speed serial signaling on printed wiring boards. Step-by-step, this book goes from reviewing the essentials of linear circuit theory, to examining practical issues of pulse propagation along lossless and lossy transmission lines. It provides detailed guidelines for crosstalk, attenuation, power supply decoupling, and layer stackup tradeoffs (including pad/antipad tradeoffs). Other key topics include the construction of etched conductors, analysis of return paths and split planes, microstrip and stripline characteristics, and SMT capacitors. Filled with on-the-job-proven examples, this hands-on reference is the book that engineers can turn to time and again to design out and troubleshoot circuit signal loss and impedance problems.

"This dissertation explores two topics pertinent to electromagnetic compatibility research: maximum crosstalk estimation in weakly coupled transmission lines and modeling of electromagnetic radiation resulting from printed circuit board/high-density connector interfaces. Despite an ample supply of literature devoted to the study of crosstalk, little research has been performed to formulate maximum crosstalk estimates when signal lines are electrically long. Paper one illustrates a new maximum crosstalk estimate that is based on a mathematically rigorous, integral formulation, where the transmission lines can be lossy and in an inhomogeneous media. Paper two provides a thorough comparison and analysis of the newly derived maximum crosstalk estimates with an estimate derived by another author. In paper two the newly derived estimates in paper one are shown to be more robust because they can estimate the maximum crosstalk with fewer and less restrictive assumptions. One current industry challenge is the lack of robust printed circuit board connector models and methods to quantify radiation from these connectors. To address this challenge, a method is presented in paper three to quantify electromagnetic radiation using network parameters and power conservation, assuming the only losses at a printed circuit board/connector interface are due to radiation. Some of the radiating structures are identified and the radiation physics explored for the studied connector in paper three. Paper four expands upon the radiation modeling concepts in paper three by extending radiation characterization when material losses and multiple signals may be present at the printed circuit board/connector interface. The resulting radiated power characterization method enables robust deterministic and statistical analyses of the radiated power from printed circuit board connectors. Paper five shows the development of a statistical radiated power estimate based on the radiation characterization method presented in paper four. Maximum radiated power estimates are shown using the Markov and Chebyshev inequalities to predict a radiated power limit. A few maximum radiated power limits are proposed that depend on the amount of known information about the radiation characteristics of a printed circuit board connector"--Abstract, page iv.

This leading-edge circuit design resource offers the knowledge needed to quickly pinpoint transmission problems that can compromise circuit design. Discusses both design and debug issues at gigabit per second data rates.

This book presents selected papers from the International Conference on Computing, Communication, Electrical and Biomedical Systems (ICCCEBS 2021), held in March 2021 at KPR College of Engineering and Technology, Coimbatore, Tamil Nadu, India. The conference explores the interface between industry and real-time environments with newly developed techniques in computing and communications engineering. The papers describe results of conceptual, constructive, empirical, experimental, and theoretical work in areas of computing, communication, electrical, and biomedical systems. Contributors include academic scientists, researchers, industry representatives, postdoctoral fellows, and research scholars from around the world.

Cogently addressing the future of signal integrity and the effect it will have on the data transmission industry as a whole, this all-inclusive guide addresses a wide array of technologies, from traditional digital data transmission to microwave measurements, and accessibly examines the gap between the two. Focusing on real world applications and providing a wide array of case studies that show how each technology can be used—from backplane design challenges to advanced error correction techniques—this guide addresses many of today’s high-speed technologies while also providing excellent insight into their future direction. With numerous valuable lessons pertaining to the signal integrity industry, this resource is the ultimate must-read guide for any specialist in the design engineering field.

Substrate Integrated Suspended Line Circuits and Systems provides a systematic overview of the new transmission line - the substrate-integrated suspension line (SISL). It details the fundamentals and classical application examples of the SISL. The basic SISL concept and structure, various passive circuits and active circuits, and front-end sub-systems are systematically introduced. Featuring research on topics such as high-performance RF/microwave/mm-wave circuits and system, this book is ideal for researchers, engineers, scientists, scholars, educators, and students. Since transmission line is a fundamental component of microwave and mm-wave circuits, the properties of a transmission line, such as losses, size, and dispersion, are vital to the performance of the whole system. Suspended line has been proved to be an excellent transmission line, as it has attractive features such as low loss, weak dispersion, high power capacity, and low effective dielectric constant. However, Conventional waveguide suspended line circuits require metal housing to form air cavities which is Substrate Integrated Suspended Line Circuits and Systems essential to the operation of suspended lines circuits. Also, the metal shell should provide mechanical support and shielding, which contribute to large size and heavy weight. Meanwhile, precise mechanical fabrication and assembling are strongly required, which brings difficulties to the design and fabrication of conventional suspended line circuits, and the manufacturing cost of suspended line circuits increases correspondingly. In this book, we will introduce a new platform of high-performance transmission line, i.e. substrate integrated suspended line (SISL). SISL keeps all the merits of the suspended line while overcomes the drawbacks of conventional waveguide suspended line circuits. Moreover, it is self-packaged and highly integrated. The basic SISL concept and structure, various passive circuits and active circuits, and front-end sub-systems will be systematically introduced. Featuring research on topics such as high-performance RF/microwave/mm-wave circuits and system, this book is ideally designed for researchers, engineers, scientists, scholars, educators, and students.

The theory of transmission lines is a classical topic of electrical engineering. Recently this topic has received renewed attention and has been a focus of considerable research. This is because the transmisson line theory has found new and important applications in the area of high-speed VLSI interconnects, while it has retained its significance in the area of power transmission. In many applications, transmission lines are connected to nonlinear circuits. For instance, interconnects of high-speed VLSI chips can be modelled as transmission lines loaded with nonlinear elements. These nonlinearities may lead to many new effects such as instability, chaos, generation of higher order harmonics, etc. The mathematical models of transmission lines with nonlinear loads consist of the linear partial differential equations describing the current and voltage dynamics along the lines together with the nonlinear boundary conditions imposed by the nonlinear loads connected to the lines. These nonlinear boundary conditions make the mathematical treatment very difficult. For this reason, the analysis of transmission lines with nonlinear loads has not been addressed adequately in the existing literature. The unique and distinct feature of the proposed book is that it will present systematic, comprehensive, and in-depth analysis of transmission lines with nonlinear loads. A unified approach for the analysis of networks composed of distributed and lumped circuits A simple, concise and completely general way to present the wave propagation on transmission lines, including a thorough study of the line equations in characteristic form Frequency and time domain multiport representations of any linear transmission line A detailed analysis of the influence on the line characterization of the frequency and space dependence of the line parameters A rigorous study of the properties of the analytical and numerical solutions of the network equations The associated discrete circuits and the associated resisitive circuits of transmission lines Periodic solutions, bifurcations and chaos in transmission lines connected to noninear lumped circuits

This unique book provides you with practical guidance on understanding and interpreting signal integrity (SI) performance to help you with your challenging circuit board design projects. You find high-level discussions of important SI concepts presented in a clear and easily accessible format, including question and answer sections and bulleted lists. This valuable resource features rules of thumb and simple equations to help you make estimates of critical signal integrity parameters without using circuit simulators of CAD (computer-aided design). The book is supported with over 120 illustrations, nearly 100 equations, and detailed reference lists at the end of each chapter.