I guess we are not doing a good job of letting people know about our tools: TDA Systems's MeasureXtractor is among the tools that check passivity and causality, and we happen to think that our tools does the best and most thorough passivity enforcement. I can corroborate this assertion by the fact that MeasureXtractor was in the finals of the EDN Product of the Year Award for 2003, which nomination is reviewed both by the industry and academia people. Our R&D guys have been doing research in the area since early 1990's. For more info: http://www.tdasystems.com/products/measurextractor.shtml 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) ----- Original Message ----- From: "Ray Anderson" <reanderson@xxxxxxxxxxxxx> To: <si-list@xxxxxxxxxxxxx> Cc: <Zhichao.Deng@xxxxxxxxxx> Sent: Monday, September 20, 2004 8:17 AM Subject: [SI-LIST] Re: Rational Approximation with passivity enforcement > > At present there are at least 2 commercial tools that that I am aware of > thatstate they enforce passivity in the models they generate. Those > tools are: Sigrity's BroadBand Spice (latest version), EMWonders's > EMtoSPICE. There are several other companies providing tools to > generate spice models via the rational approximation approach from > measured or simulated S and/or Y parameters, but I'm not aware that they > have implemented passivity enforcement.. I'm sure someone will chime in > if there other tools that enforce passivity that I'm not aware of. > > If you haven't examined the work of Dr. Gustavsen at SINTEF, I suggest > you visit his Vector Fitting web site at > http://www.energy.sintef.no/Produkt/VECTFIT/index.asp . You will find > his papers and further info on vector fitting in general and passivity > enforcement in particular including downloadable Matlab code which > implements those concepts. In addition to the commercial tools available > you may want to check out the work done at Georgia Tech by Dr. > Swaminathan and his students on a tool called BEMP. The tool enforces > passivity and is extensively discussed in several of the papers they > have published. > > Most of the passivity enforcment work that I am aware of deals with the > problem of S-parameters at DC by > extrapolating the s-parameter data from the lowest frequency data points > available down to DC if a value at DC is not provided in the data set. > > Deng, Zhichao wrote: > >>I am a PhD student and I am doing literature research on the topic of >>rational approximation with passivity enforcement. >> >>It seems that the passivity enforcement are almost based on the state >>space form with LMI or Hamiltonian matrices for the passivity of either >>Y or S parameters. >> >>1) Is there any commercial tool available has passivity enforcement >>capability? >> >>2) What is the latest trend on passivity enforcement? >> >>3) How to fix DC value of S parameter during vector fitting process? >> >>Thank you. >> >> >> > > ------------------------------------------------------------------ > 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