Hi From the telegraphic equations on Transmision lines it seems the impedance of the Trace varies with frequency. In my design specifications it is specified that my trace should be on (25 +/- 10%) Ohms. How will I do it ? How will I do these kind of analysis? The frequency of the signal is high and also the rise time is significantly low. Will FFT be of some help here ? Regards Karan. --------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software ------------------------------------------------------------------ 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