Al, Thank you for your email my friend! ADS provides multiport de-embedding. Default Symbols are provided till 12 ports and for higher number ports user needs to create symbols locally. Long, I am not sure which version of ADS you tried? ADS2009 or any later release should not have any problem related to multiport de-embedding.. Please send me the data privately and we can sort out any issues. Sanjeev Gupta Applications Engineer Agilent Technologies, EEsof EDA 707-486-8784 (Cell) -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Al Neves Sent: Sunday, August 07, 2011 9:36 AM To: 'Long Yang'; 'Jim Nadolny' Cc: 'Ming Li'; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: De-embed fixture Where do you get the ADS limitation? Agilent ADS has no issues with numerous ports (why aren't the Agilent apps guy chiming in?), I thought it was >224 or some significant number for T-matrix de-embedding for example. I have done multi-port de-embedding with ADS no problem in the past. We easily use Agilent ADS for our 16port BroadSide-Coplanar Coupler ( multiple crosstalk aggressors, resonance) on our Channel Modeling Platform, CMP-08. Scott McMorrow from Teraspeed conceived this structure to mimic backplanes, but maintain flexibility and ability to make meaningful 3D EM analysis -measurement. We co-authored a paper on Jitter Measurement - Simulation Correspondence with LeCroy (it is on our website). Products for the Signal Integrity Practitioner Wild River Technology LLC Alfred P. Neves Founder - Engineer - Business Development (503) 718 7172 Office (503) 679 2429 Mobile 735 South East 16th Ave. Hillsboro, OR 97123 www.wildrivertech.com -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Long Yang Sent: Saturday, August 06, 2011 2:26 AM To: Jim Nadolny Cc: Ming Li; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: De-embed fixture When I worked on my de-embedding project several months ago, I was trying to use ADS because ADS said it can do it. When port number is below 4, such as s4p, s2p, ADS works fine. But when the port number is 6, or 8 or greater, ADS may not work well. I am not sure if ADS is wrong or I am wrong because I am new to ADS, but I am so sure the same method was applied to use ADS for either 4 port S-parameter or 6 or 8 or even 12 port S-parameter. I worked with local ADS application engineer, and they can re-produce the "questionable" results. So I had to write Matlab codes to run de-embedding. Just for reference. Best Regards Long On Fri, Aug 5, 2011 at 00:39, Jim Nadolny <jim.nadolny@xxxxxxxxxx> wrote: > Ming Li, > > I worked with Agilent on this exact problem. > > Agilent developed a method within ADS to perform "S-parameter bi-section". The method is pretty cool, you iterate in frequency to develop 2 mirror images which when combined yield the fixture response. It worked perfectly on simulated data but had a lot of glitches when using real world data. Small things like phase wrap and noise lead to problems with the data. The big killer is that you assume the fixture response is symmetric, but in in all likelihood it's not perfectly symmetric. > > To Agilent's credit, we did get there with this method but at the end > of the day a TRL/M cal method was more robust and quicker for fixture removal. > > Good luck - > jn > > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx > [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Ming Li > Sent: Thursday, August 04, 2011 12:02 PM > To: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] De-embed fixture > > Hi, experts, > I get two identical fixtures on both sides of my DUT. And I got the > s4p data of the fixture itself and s4p data of the DUT cascading with the two fixtures. Could you please kindly let me know how I can de-embed the fixture and get the s4p data for the DUT? I know the math behind it but the data itself is too big to calculate. > > Thanks in advance. > > Regards, > Ming Li > > > ------------------------------------------------------------------ > 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 > > > ------------------------------------------------------------------ > 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 > > > ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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