Jennifer -- Do you have ADS? It might help you. Here is some material on recent advances in their transient simulator. The 1st link is for a paper we (GigaTest) did for the SI Seminar Series last year. The 2nd is a webinar on the same topic ( I think delivered by Sanjeev Gupta of Agilent). Good luck. -- Gary Otonari http://www.home.agilent.com/upload/cmc_upload/All/Meas_Based_Transient_Simul ation_Gigatest.pdf http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=1454262 &nid=-34511.0.00&id=1454262 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Jennifer Maharani Sent: Thursday, May 14, 2009 12:49 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Causality Dear all, I have non-passive non-causal S-parameter. I can use some commercial tools that can generate broadband spice with passivity enforcement. Not with causality enforcement, though. In transient simulation it clearly shows non-causal response. Does anybody know how to resolve this issue? Quick and dirty solution will also be appreciated. Many thanks. ------------------------------------------------------------------ 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.net 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 technical documents are available at: http://www.si-list.net 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