# Problem Solving 101 with Eric Bogatin – Engineering Principles With an Emphasis on Understanding The Math

At Artech House, we ask our authors what problems their books can help readers solve. In this series, we share what our authors aim to do in their writing. Read on to find out what Eric Bogatin, who wrote Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Applications, had to say:

• Never be intimidated again by the technical jargon associate with transmission lines, impedance, and reflections.
• Identify the important design features that most affect the characteristic impedance or differential impedance of transmission lines.
• Use a 2D field solver to optimize a circuit board stack-up design and make the cost-performance tradeoffs.
• Interpret TDR measurements to identify what might be artifacts and what is a real feature.
• Interpret differential TDR measurements to extract the differential impedance of interconnects.
• Extract a high bandwidth model of an interconnect from TDR measurements by matching parameter values of a simulation to the measurement.

#### What are the features of your book and the specific benefits a reader can expect to derive from those features?

• Feature: Engineering principles, without the math.
• Benefit: Build intuition, not be intimidated by the jargon.
• Feature: How to use a 2D field solver to explore design space.
• Benefit: Quickly optimize a circuit board stack up for single-ended and differential transmission lines.
• Feature: How to interpret TDR measurements Gain the most value out of a TDR measurement.
• Benefit: Verify if the product meets spec and is acceptable.
• Feature: Eliminate artifacts in TDR measurements.
• Benefit: Improve the quality of your TDR measurements.
• Feature: Understand how a differential pair works.
• Benefit: Critically evaluate the popular literature about differential pair design to make your own judgement of the right and wrong approaches.
• Feature: Simulate transmission line circuits to compare with TDR measurements.
• Benefit: Extract high bandwidth circuit models of interconnects from measurements to use in your system simulations.

#### Please name the audiences at which this book is aimed. How will this audience use your book?

Audience: Hardware engineer, PCB layout engineer, technician, PCB fab engineer, PCB commodity manager, circuit board design engineer, test engineer Learn the principles of transmission lines to better communication with other engineers

• Design the stack up of a board for a target impedance using a 2D field solver
• Interpret the measurements from a TDR to characterize their interconnects
• Know when a measurement or simulation may have an artifact and is not realistic
• Simulate their TDR measurements to extract accurate circuit models of their transmission lines and discontinuities.

#### This book offers seven important features that differentiate it from any other book out there:

1. Each chapter contains a few short relevant videos that show practical applications of the principles, the simulation tools or the measurements tools and how to used these to solve actual design or characterization problems.

2. The engineering principles are presented with an emphasis on understanding, not hidden by the math.

3. The design of transmission lines is illustrated using rules of thumb, approximations and 2D field solvers. The details of how to use 2D field solvers to explore design space and gain insight into how physical design influences design is clearly presented.

4. The principles behind the TDR instrument is presented without a lot of math and with many examples of both simulations and measurements of real interconnect structures to illustrate how to interpret the measurements.

5. The properties of differential pairs are introduced in a simple way to highlight how the coupling between traces affects the odd mode impedance and the differential impedance. Simulation tools are used to show how differential pairs can be designed and how a differential TDR measures the properties of differential pairs.

6. A free, open source animation tool is provided for download to illustrate how signals dynamically propagate on transmission lines and reflect from impedance changes.

7. A free, open source simulation tool is provided with many completed circuit files which can be downloaded along with measurements, which can be used to simulate the TDR response of transmission line circuits and discontinuities.