Guys This is 200 MHz SSTL. Correct or incorrect frequency dependent dielectric and/or copper surface roughness modeling are insignificant when compared to all of the other channel impairments in a poorly terminated system at these data rates. The proper tools for these sorts of systems look like hammers and chisels vs. laser scalpels. scott colin_warwick@xxxxxxxxxxx wrote: > Hi Marc, > > > Further to Istvan's comment "ideally you need to do the frequency dependent > simulation over the entire frequency range of interest," > frequency-independent loss violates the Kramers-Kronig relation and is > therefore non-causal. > > > > Here are a couple of papers about one way of modeling frequency-dependent > loss ("Svensson-Djordjevic" model) in such a way that the model is causal: > > * C. Svensson and G. Dermer, "Time domain modeling of lossy interconnects," > IEEE Trans. Adv. Packaging, vol. 24, no. 2, pp. 191-196, May 2001. > > * T. Arabi, A. Murphy, T. Sarkar, R. Harrington, and A. Djordjevic, "On the > modeling of conductor and substrate losses in multiconductor, multidielectric > transmission line systems," IEEE Trans. Microwave Theory Tech., vol. 39, no. > 7, pp.1090-1097, Jul. 1991. > > > > Also, if you happen to be going to IEEE MMT-S IMS 2009 in Boston in June, you > can check out our paper about Svensson-Djordjevic implementation: > > * Radoslaw M. Biernacki, Yunhui Chu, Fangyi Rao, and Yutao Hu "Causality > Enforcement in Fast EM-based Simulation of Multilayer Transmission Lines" > > > > hth > > -- Colin Warwick, Agilent EEsof EDA > > http://signal-integrity-tips.com > > > > > > -----Original Message----- > > From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On > Behalf Of Marc Battyani > > Sent: Thursday, May 21, 2009 9:13 AM > > To: si-list > > Subject: [SI-LIST] Prepreg dielectric constant and thickness: what actual > values to use? > > > > > > Hi, > > When you specify a stackup the thicknesses of the cores are well defined but > > the for the prepreg layers it's less obvious. So when using one or several > > prepreg sheets do you just use and add the basic thicknesses or is there a > > correction to make? > > > > For the dielectric constant of those materials, when you have 4.3-4.5 @ 1MHz > > and 3.8-4.0 @ 1GHz what value should we use as a basis for the simulations > > for 125MHz HSTL or 200MHz SSTL for instance? > > > > Thanks, > > > > Marc > > > ------------------------------------------------------------------ > 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 > > > -- Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC ------------------------------------------------------------------ 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