Preface - High-Speed Signal Propagation

Welcome, and thank you for your interest in High-Speed Signal Propagation: Advanced Black Magic. This is an advanced-level reference text for experienced digital designers who want to press their designs to the upper limits of speed and distance.

If you need to transmit faster and further than ever before, this book is here to help. You’ll find it packed with practical advice.

The material in this book has been honed during my many years of work as chief technical editor of standards for both Fast Ethernet and Gigabit Ethernet—projects which, I hope, have touched your life in a favorable way. During those and many other projects, the models and concepts described here have been of invaluable service to me. Now I’d like to pass them on to you.

When you are done reading, share your knowledge with those around you as my technical mentor, Martin Graham, has done with me. Educate your coworkers. Educate your management. Above all, continue to educate yourself. If this book inspires you to advance your understanding with even one laboratory measurement, then I will know you are on the right track.

I would also like to say it has been a great pleasure teaching and working with many of you through my classes and lectures. Above all, I appreciate those who take the time to share with me their thoughts, their concerns, their dreams, and their problems. It always interests me to hear about real experiences from real engineers.

Printed circuit traces	Limits to attainable speed and distance RC and LC mode propagation Skin effect and dielectric loss design charts and equations Proximity effect Surface roughness Non-TEM mode of propagation Step response Effect of vias
Differential signaling	Edge-coupled and broadside-coupled differential pairs Effect of bends Intrapair skew Differential trace geometry impedance Crosstalk Radiation
Inter-cabinet connections	Coaxial cables Twisted-pair cables Fiber optics Equalizers General building wiring for LAN applications
Clock distribution	Special requirements for clocks Clock repeaters Multidrop clock distribution Clock jitter Power filtering for clock sources
Simulation	Frequency-domain simulation method Applicability of Spice and IBIS

Each chapter in this book treats a specialized topic having to do with high-speed signal propagation. They may be studied in any order.

Chapters 1 and 2 present the underlying physical theory of various transmission-line parameters, including the skin effect, proximity effect, dielectric loss, and surface roughness.

Chapter 3 develops a generalized frequency-response model common to all conductive media.

Chapter 4 outlines the calculation of time-domain waveforms from frequency-domain transfer functions.

Chapters 5 through 11 discuss specific transmission media, including single-ended pcb traces, differential media, general building wiring standards, unshielded twisted-pair wiring, 150-W shielded twisted-pair wiring, coaxial cables, and fiber.

A basic understanding of the frequency domain representation of linear systems is assumed. Readers without the benefit of formal training in analog circuit theory can use and apply the formulas and examples in this book. Readers who have completed a first-year class in introductory linear circuit theory will comprehend the material at a deeper level.

This book is a companion to the original book by Johnson and Graham, High-Speed Digital Design: A Handbook of Black Magic, Prentice-Hall, 1993. The two books may be used separately or together. They cover different material.

The original book deals with a broad spectrum of high-speed phenomena. It builds a solid understanding of ringing, crosstalk, ground bounce, and power supply noise as they exist on printed circuit boards. It emphasizes basic circuit configurations where these effects may be easily understood and learned. It treats supplementary subjects including chip packages, oscilloscope probe, and power systems for high-speed digital products.

This High-Speed Signal Propagation book is more highly specialized, delving into issues relevant to transmission at the upper limits of speed and distance. If you need to transmit faster and further than ever before, this book shows you how.

High-Speed Digital Design and High-Speed Signal Propagation together comprise a good reference set for persons working with high-speed digital technology.

Those of you familiar with my other books will recognize similarities in style. Notably, I’ve tried to impart, as best I can, the same sense of realism born of long experience.