Dear all experts, I have a question that why the return current will return back underneath the trace line? I realize the equation of this by using mathematical formula, but not for its Electromagnetic phenomenon? Because I've studied from some articles of return Current or Current Loop...etc, but all those topic said that " It'll reinforce a electromagnetic field to make return current as close as possible to the trace of forward signal. I'm confused that why electromagnetic field make forward and return current closer, but not further ? Whether I can suppose it as a Differential Signal Piar similarly of its electromagnetic field? Regards, Binchuan.Wang ------------------------------------------------------------------ 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