When I say impedance, it depends on the capacitance and inductance. So, these two components depend on frequency (wL and 1/wC, where w= 2xpixF). When I say characteristic impedance, it too has capacitance and inductance involved. So when I say I maintain 50 ohm characteristic impedance on my board... there may be lot of frequencies involved in the design resulting in different characteristic impedance? then how the board is said as a 50 ohm impedance controlled..? Thanks and regards, Raj. ____________________________________________________________________________________ The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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