I am interested in some feedback regarding routing 100 ohm differential GHz signals on thin vs wide trace widths. I am currently looking using 8 mil traces with a 12 mil gap between the +/- pair. The routing is fairly open and does not require very tightly coupled traces. I understand that the tighter the traces are as a pair the common noise is improved. The board material is FR408. A proposed core would use a dual-stripline with a 7 mil dielectric between the planes (gnds) and routing layers and a 7 mil (or higher) dielectric between the routing layers. The routing is orthogonal and tandem crosstalk is controlled. A stripline approach is also an option if needed.=20 Doug Hopperstad ------------------------------------------------------------------ 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 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