Scott, For what you say: ¡°In the same project I also was successfully able to extract with a 2D field solver, simulate with Hspice and correlate to measurements, the crosstalk isolation between two traces seperated by a 1/2 oz copper plane. Through simulation we were able to determine that by using 1 oz copper we could increase the crosstalk isolation by 10 dB.¡± you have mentioned the crosstalk between two traces seperated by a plane, can you make a more detail description? I am very interested in it. Best regards, Yun Nan Senior Engineer Wuhan Fiberhome Networks yunnan@xxxxxxxxxx ------------------------------------------------------------------------------- I've been able to successifully achieve better than -70 dB of crosstalk isolation between multiple analog video signals using guard traces for over 60 inches of total trace length. They do work quite nicely if vias are used to ground the trace over regular intervals. Not only did I have these results in Spice simulations. But also they were subsequently confirmed by VNA measurements on the traces, within 1 dB of the simulated results. Without the guard traces, the crosstalk was greater than 6 dB worse. In the same project I also was successfully able to extract with a 2D field solver, simulate with Hspice and correlate to measurements, the crosstalk isolation between two traces seperated by a 1/2 oz copper plane. Through simulation we were able to determine that by using 1 oz copper we could increase the crosstalk isolation by 10 dB. We utilized guard traces for several hundred single-ended and several hundred differential traces on an analog video crosspoint switch. Without the guard traces and stitch vias, we would not have been able to meet our end-to-end crosstalk isolation requirement of -60 dB. Best regards, Scott -- Scott McMorrow Teraspeed Consulting Group LLC 2926 SE Yamhill St. Portland, OR 97214 (503) 239-5536 http://www.teraspeed.com ------------------------------------------------------------------ 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: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //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