The Printed Circuit Designer's Guide to... ™
Secrets of High-Speed PCBs, Part 2

by: Martyn Gaudion, Polar Instruments

If you’re a PCB designer or design engineer, chances are you’re probably dealing with high-speed PCBs and their attendant issues. This book, The Printed Circuit Designer’s Guide to…Secrets of High-Speed PCBs: Part 2, is a must-read, not just for designers, but for anyone involved with, or confused by, high-speed PCBs: purchasing agents, salespeople, marketing professionals, recent graduates, etc.

This micro eBook, the second in a series published by I-Connect007, is a compilation of columns written by Martyn Gaudion, CEO of Polar Instruments, for The PCB Design Magazine over several years. In this edition, Martyn examines issues such as laminate loss, differential insertion loss, impedance control, modelled vs. measured results, and much more.

ISBN: 978-0-9796189-9-4

Martyn Gaudion
Martyn Gaudion is the managing director of Polar Instruments Ltd. He began his career in the early 1980s at Tektronix, where he was responsible for test engineering on high-bandwidth portable oscilloscopes. During his time at Tektronix, he gained widespread experience in PCB assembly and was extensively involved with the introduction of surface mount technology. In 1990, Gaudion joined Polar, where he was responsible for the design and development of the Toneohm 950, Polar’s multilayer PCB short circuit locator. He became marketing manager at Polar during 1997 as the market for controlled impedance test became a major section of Polar’s product range. He was appointed sales and marketing director in 2001 and CEO in 2010. Gaudion also writes occasional articles for a number of PCB industry publications, and regularly contributes to IPC’s High-Speed High-Frequency standards development activities. Gaudion is a chartered company director and a fellow of the London-based IoD (Institute of Directors). In 2016, he was appointed vice chairman of the European Institute of Printed Circuits (EIPC).

Polar Instruments specializes in designing EDA and measurement tools which simplify the design, fabrication, testing and specification of high-speed printed circuit boards (PCBs). Polar’s innovative product line includes the industry standard Controlled Impedance Test System (CITS), which provides the global PCB industry with an easy-to- use test system for high-speed digital and RF boards, as well as class-leading tools for fast and accurate design and testing of impedance and insertion loss controlled PCBs. Polar Speedstack is the layer stack-up design and documentation tool of choice for many designers, fabricators and PCB technologists. Established in 1976, Polar Instruments now has operations and long term channel partners in the US, UK, Europe and Asia Pacific.

This book has been technically reviewed by the following experts:

Rick Hartley

Eric Bogatin Dean, Signal Integrity Academy

Chapter Summaries

  • Chapter 1

    Chapter 1

    Chapter 1 focuses on S-parameters, surface roughness, and skin effect—what these terms describe, and how they interact with each other.
  • Chapter 2

    Chapter 2

    Chapter 2 considers the relationship between laminate losses and line length, and ways to accurately model line length and dielectric loss.
  • Chapter 3

    Chapter 3

    Chapter 3 is the conclusion of the previous chapter, adding copper and copper losses into the equation and covering various ways to model surface roughness.
  • Chapter 4

    Chapter 4

    Chapter 4 focuses on methods for measuring insertion loss, for single-ended traces and differential traces as well. This includes several new methods for using TDR to measure loss.
  • Chapter 5

    Chapter 5

    Chapter 5 discusses how to design vias for the greatest signal integrity benefit, including information on via stubs and backdrilling, and why “Good modelling can’t fix a bad design.”
  • Chapter 6

    Chapter 6

    Chapter 6 takes the reader through repeatability, reproducibility, and rising frequency, and how they relate to high-frequency measurements.
  • Chapter 7

    Chapter 7

    Chapter 7 explains why engineers sometimes get startlingly different results for measured trace impedance and calculated/modelled trace impedance, and what this means to your design.
  • Chapter 8

    Chapter 8

    Chapter 8 focuses on some of the challenges related to measuring thin copper and narrow traces at low GHz operating speeds, where impedance rises over time, with a cumulative build-up of resistive effects.
  • Chapter 9

    Chapter 9

    Chapter 9 investigates impedance control, and how reference impedance standards, field solvers, and proper test coupon design can help engineers optimise their designs.

Print-on-demand paperbacks are available for this title. Click below to order from our distributor.

What Our Readers Are Saying

I particularly like Martyn's writing style. He uses personal experiences as metaphors for what he is teaching in a non-threatening way. The book is aimed at a semi-technical audience, but if you are a new board designer, or even a seasoned veteran, these two books will certainly uncover little nuggets to make you realize what you didn't know you didn't know, or what you may have even forgotten.

-Bert Simonovich, Consultant & Founder, LAMSIM Enterprises Inc.
Full Review

Contact the Author

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Book Recommendation -- By Bert Simonovich, Consultant & Founder, LAMSIM Enterprises Inc.

I recently checked out two, little e-books from Martyn Gaudion titled, Secrets of High Speed PCBs Part 1 and Secrets of High Speed PCBs Part 2.

Part 1 is a high-level introduction that takes us on a journey through material properties, measuring, modelling and specifying high-speed PCBs. Gaudion briefly touches on transmission line theory and factors affecting insertion loss, as well as why characteristic impedance changes over frequency. He closes off with a discussion about flexible PCB issues and putting tolerance of measurements into perspective.

In Part 2, Gaudion takes some of the topics discussed in Part 1, like factors affecting insertion loss, and expands on them in greater detail. He also discusses measuring techniques for insertion loss and impedance, then shares his experience with pitfalls you can encounter when interpreting measurements. At the end of the e-book, there is a nice glossary of terms not typically found in the PCB industry, which is quite useful.

I particularly like Martyn's writing style. He uses personal experiences as metaphors for what he is teaching in a non-threatening way. The book is aimed at a semi-technical audience, but if you are a new board designer, or even a seasoned veteran, these two books will certainly uncover little nuggets to make you realize what you didn't know you didn't know, or what you may have even forgotten. Afterward, you can then reach out to find the answers while trying to design your PCB with your favorite PCB fabricator. I wish I had them when I was starting out in my career

Rick Hartley Rick Hartley is the principal of RHartley Enterprises, through which he consults and teaches internationally to resolve noise, signal integrity and EMI problems. Hartley’s focus is on the correct design of PC boards to prevent and solve problems. His design career has focused on circuits and PC boards for computers, aircraft avionics and telecommunications. His consulting efforts have also focused on the automotive and appliance spaces. Hartley has a degree in engineering from Ohio Technical Institute and 51 years of experience. He has dedicated the past 40 years to PC board and circuit development with emphasis on control of noise, in digital, analog and RF circuits. Rick is a member of the IPC Designers Council executive board, and past national chairman of the Designers Council. Rick has written numerous technical papers and articles on methods to control noise, EMI and signal integrity.

Eric Bogatin Eric Bogatin is currently the dean of the Teledyne LeCroy Signal Integrity Academy. Additionally, he is an adjunct professor at the University of Colorado – Boulder in the ECEE department, where he teaches a graduate class in signal integrity and is also the editor of the new journal Signal Integrity Journal. Bogatin received his BS in physics from MIT, and MS and PhD in physics from the University of Arizona in Tucson. He has held senior engineering and management positions at Bell Labs, Raychem, Sun Microsystems, Ansoft and Interconnect Devices. Bogatin has written six technical books in the field, and presented classes and lectures on signal integrity worldwide.