>[Mikon] The guard traces (as well as the ground planes) carry high frequency >return currents (i.e., in the opposite direction) induced by the signals and >help reduce the magnetic loop and the field intensities created thereby. Mike, your's is a good explanation. In my opionion the ground planes carry the same high frequency return currents as the signal traces, but in an opposite direction. Hence the magnetic field created by the ground strips should oppose the magnetic field produced by the signal traces, thereby reducing the degree of coupling. Regards, Ismail ------------------------------------------------------------------ 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