Check out Eric Bogatin's EDN article on differential line performance testing using CCN's nTegrity. nTegrity provides hands-free circuit board coupon probing and automation of Teledyne LeCroy SPARQ to measure differential line loss, impedance, and delay with ultra-high level of repeatability. Suitable for design and production coupon testing, and quite remarkably -- linking fab results to engineering lab results!
We just added more publications, a set of slides, and a helpful EMI test lab to our resources page. These new additions are mostly focused on signal integrity design and test, and provide valuable information in understanding the links between actual PCB performance and the predictions of design. Let us know how you use these resources in your work. Enjoy!