Thanks for your feedback. Sometimes, living in the simulation world, you forget the real-world effects of boards. Lee: Is there any way to predict this frequency dependency of er? Fred: Is the frequency dependence of R and G caused by the same issues Lee is discussing (dielectric constant over frequency)? Are there any other causes of this? (As a side note, the equation suggests R and G to be fixed in frequency, while L and C are the frequency dependent values. I guess that's why the lumped element model breaks down and models are more accurately viewed as distributed full-wave EM models) Thanks again for the comments. Ryan ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: http://www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: http://www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu