Hello, Zhang Kun, Of course the grounds on the outputs on any instrument would be connected. If you do not have a ground plane in your DUT, you can only accurately measure it if you have some sort of virtual ground. Thanks, =================== Dima Smolyansky TDA Systems, Inc. 4000 Kruse Way Place Bldg. 2, Suite 300 Lake Oswego, OR 97035 (503) 246-2272 (503) 246-2282 (fax) TDA's MeasureXtractor is the EDN Product of the Year Finalist! http://www.tdasystems.com/products/measurextractor.shtml ----- Original Message ----- From: "Zhangkun" <zhang_kun@xxxxxxxxxx> To: "si-list" <si-list@xxxxxxxxxxxxx> Sent: Tuesday, May 18, 2004 2:12 AM Subject: [SI-LIST] The Ground of VNA > Dear All > Could you tell me the details about the ground of VNA? From the experiment, I could find out that the ground of two ports of VNA are connected. However, I do not know the detail. > > This is critical for some kind of analysis. For example, there is no ground plane. > > Best Regards > > Zhangkun > 2004.5.18 > > > ------------------------------------------------------------------ > 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 FAQ wiki page is located at: > http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > 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 > > > ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ 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