Total Loss: How to Qualify Circuit Boards

We clarify the role of signal loss measurements, aka Total Loss, in specifying and qualifying circuit board materials for high-speed electronic design. We then demonstrate the NIST Multiline measurement technique in particular by characterizing test lines fabricated in conventional PCB materials. The paper describes and demonstrates this technique, and shows how to accurately report signal propagation loss as a function of frequency, even when using TDR-based systems. The paper also reveals how impedance mismatch and differential delay variance contribute to the reported loss for various test methods in practice today.
DesignCon 2011




Total Loss:
How to Qualify Circuit Boards


Don DeGroot, CCNi
don.degroot@PCBmeasuements.com

Peter Pupalaikis, LeCroy
peter.pupalaikis@lecroy.com

Brian Shumaker, DVT Solutions, LLC
sales@gigaprobes.com
Abstract
We clarify the role of signal loss measurements, aka Total Loss, in specifying and
qualifying circuit board materials for high-speed electronic design. We then demonstrate
the NIST Multiline measurement technique in particular by characterizing test lines
fabricated in conventional PCB materials. The paper describes and demonstrates this
technique, and shows how to accurately report signal propagation loss as a function of
frequency, even when using TDR-based systems. The paper also reveals how impedance
mismatch and differential delay variance contribute to th