Hi Zhiping, Yes, I think you are right. It just like to build a RLGC models from S-parameter matrix. There are a lot of values for R,L,G,C. However, If not try to construct a complete S2P matrix, but only use S11 measurement to prove correct S21 simulation result. It may be OK, right? Thanks, John -----Original Message----- From: Zhiping Yang (zhiping) [mailto:zhiping@xxxxxxxxx] Sent: Tuesday, May 17, 2005 1:14 PM To: scott@xxxxxxxxxxxxx; John Lin (ªL´Â·×) Cc: steve weir; si-list@xxxxxxxxxxxxx Subject: RE: [SI-LIST] Re: Estimate ISI with S parameters -- Using TDR to do SDD21 correlation? Hi Scott, I can not agree with your statement that S11 contains all the information that you need to characterize a channel. In order to completely characterize a two-port channel, the complete S2P matrix is required. In the real application, it is OK to use TDR (S11) to construct a channel model, but this model may not be unique and you may have different S21 for different models. It is not difficult to find a simple example to prove it. Thanks. Best regards, Zhiping ------------------------------------------------------------------ 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