Dear All: Have anybody studied differential line or single line across perforated reference plane? I use Ansoft to analyze this problem. I find, when there is a slot in the reference plane but and the reference plane is not cut, the S21 is not affectted seriously comparing with the S21 when the reference plane is integral. Could you give me some advice? Best Regards Zhangkun 2003.12.29 ------------------------------------------------------------------ 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.org 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