However, we found http://www.altera.com/literature/cp/cp-ftdsimltn.pdf that with complex and especially 'multi-port' models, simulation becomes quite inefficient. Just parsing of a large equivalent circuit, depending on the simulator, may take from 1 to 10 hours. This is unacceptable, because the pure simulation time is minutes or even seconds. Though a current crutch-like solution, in a long run producing equivalent circuits for S-parameters leads to nowhere. Think of the following: the numerical kernel of any circuit simulator works with matrices and vectors that are tables of numbers. With vector fitting of S-parameters, we convert the sampled data into something very similar, a table of poles and residues. Then, we make something very stupid. We convert these tables into ***huge*** equivalent circuits, with many components and internal nodes, that should be parsed and then again converted by the simulator into matrices, that are much larger than original and more prone to singularity. On the way, we also introduce local truncation error, because equivalent circuits contain L/C components creating differential equation. >Date: Tue, 6 Nov 2007 10:22:21 +0800 >From: "tao xu" <helen.tao.xu@xxxxxxxxx> >Subject: [SI-LIST] Re: Backplane modeling/simulation methodology >Agree with kinger. "Broad Band Spice" can generate Ultra_wide_band circuits >for muti-ports S parameter matrix to keep accuracy and solve convergence >problem of most cases in Hspice. >Thanks and regards >Tao ( Helen ) >On Nov 6, 2007 5:53 AM, Kinger Cai <kinger.cai@xxxxxxxxx> wrote: > Hi Keyvan, > As I mentioned you can use the full-wave field solver, HSS or CST, to > extract the S parameter models (FD). > If you do not feel comfortable to directly use S parameter in your Hspice > simualiton flow, www.Sigrity.com <http://www.sigrity.com/> provides a > tool, "Broad Band Spice", which > can convert a S parameter model to broad band spice after doing sanity and > passivity check. > www.Kingercai.com <http://www.kingercai.com/> provides the same service of > S paramter models to Bradn > band Spice converting as well as S parameter modeling. > > Regards, > Kinger > > High Speed Platform Enabling > Kinger Consultant Advance Inc. > www.kingercai.com > ------------------------------------------------------------------ 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