Hi Steve -- Multiple lines, not multiple widths on the same line -- sorry if that was not clear. That was to eliminate etching variations and weave effects through averaging of different traces on the same glass weave. The various line widths won't throw off the VNA... so with that clearer, does my method work before getting into the resonator method you suggest? (Removal of copper loss from insertion loss) Bill --- On Tue, 2/16/10, steve weir <weirsi@xxxxxxxxxx> wrote: From: steve weir <weirsi@xxxxxxxxxx> Subject: Re: [SI-LIST] Re: DesignCon presentations posted To: "Bill Dempsey" <cadcocat@xxxxxxxxx> Cc: si-list@xxxxxxxxxxxxx, Istvan.Novak@xxxxxxx Date: Tuesday, February 16, 2010, 9:04 PM Bill, varying line widths will throw the line impedance off and make VNA operation problematic. I think a better answer is to build a resonator structure and derive the loss from Q. Steve. Bill Dempsey wrote: > <second posting...apologies> > Hi Istvan, > I just read the DesignCon paper on the loss tangent measurement and had a > question with regards to other possible techniques to measure Df (and > similarly Dk). > Previously you built a stripline test board for measuring glass weave > effect.Ã? The cool thing about this board was that you launched from > "inside" the board and minimized the effects of the launch structure.Ã? Ã? > Couldn't you build a similar test board with various copper line widths and > measure insertion loss on a VNA?Ã? Once you have the insertion loss, > couldn't you then subtract out the Rdc+Rac component from the overall > insertion loss to give you a loss curve from which you could derive Df?Ã? > Use the various line widths to minimize any weave effect. > > Using this same board, can you not look at group delay to also measure the Dk > over frequency? > > I know your paper talks about cured and uncured resin variations but in the > end, isn't it just the cured value we need?Ã? Most tools don't address a > frequency dependent Df/Dk at this time so what do we do once we get a > frequency dependent Dk/Df anyway? I'm curious to see how others are > addressing this issue and how much their lab measurements have been off from > simulations. > > And I'd like to see some posts from tool vendors who are addressing the > frequency dependence of these values. > > Regards, > Bill > From: istvan Novak <Istvan.Novak@xxxxxxx> > To: SI-List > <si-list@xxxxxxxxxxxxx> > Sent: Mon, February 15, 2010 10:52:42 PM > Subject: [SI-LIST] DesignCon presentations posted > > > FYI: > > For those of you who could not make it to DesignCon, the Oracle-SUN > presentations are posted at http://www.electrical-integrity.com/ > > For the three Best Paper Award winner presentations, both the written > materials and the slides are posted: > ââ?¬Å?Introduction and Comparison of an Alternate Methodology for Measuring > Loss Tangent of PCB Laminatesââ?¬ï¿½ > ââ?¬Å?Additional Trace Losses due to Glass-Weave Periodic Loadingââ?¬ï¿½ > ââ?¬Å?Accuracy Improvements of PDN Impedance Measurements in the Low to > Middle Frequency Rangeââ?¬ï¿½ > > Also posted are the slides for the panel discussion "Making Sense out of > Dielectric Loss Numbers, Specifications and Test Methods" > > Regards, > > Istvan Novak > Oracle-SUN > > > ------------------------------------------------------------------ > 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: > Ã? Ã? Ã? Ã? Ã? Ã? Ã? Ã? http://www.si-list.net > > List archives are viewable at:Ã? Ã?   Ã? Ã? Ã? Ã? Ã? Ã? > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > Ã? Ã? Ã? Ã? Ã? Ã? http://www.qsl.net/wb6tpu > Ã? > > > > >     > >     ------------------------------------------------------------------ > 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 > Old (prior to June 6, 2001) list archives are viewable at: >       http://www.qsl.net/wb6tpu >   > >   -- Steve Weir IPBLOX, LLC 150 N. Center St. #211 Reno, NV 89501 www.ipblox.com (775) 299-4236 Business (866) 675-4630 Toll-free (707) 780-1951 Fax ------------------------------------------------------------------ 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 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu