Kiran: You forgot to scale it: S11DD = 0.5 * { S(1,1)-S(1,3)-S(3,1)+S(3,3) } Sincerely, * Daniel N. de Araujo *Director of Applications, *Nimbic* On Wed, Jun 20, 2012 at 8:27 AM, <kiran.kumar10@xxxxxxxxx> wrote: > Hi All, > Please see the Return Loss plot for the port1 > > [Description: cid:image003.jpg@01CD4EFA.9A043550] > > The plot "red" was obtained by first converting the S-parameter file into > differential and then plotted directly i.e. using Port mapping. You can see > the unnecessary events till 10GHz. > > The "blue" plot was obtained by taking the original single ended > S-parameter file and using formula S11DD=S(1,1)-S(1,3)-S(3,1)+S(3,3) > > Except return loss, all other parameters like insertion loss, FEXT, NEXT > and ICR are giving expected results. > > Best Regards, > Kiran > > > From: Kiran Kumar (WT01 - Manufacturing & Hi Tech) > Sent: Wednesday, June 20, 2012 10:46 AM > To: 'si-list@xxxxxxxxxxxxx' > Subject: RE: [SI-LIST] HSPICE query > > Hi All, > > I think I may not have explained my query clearly. The S-parameter file > from the connector vendor is single-ended and is correct without any > issues. If I plot the differential Return Loss using formula in Synopsis > Custom Waveview, there is no noise and the plot matches the one provided by > the vendor. > > The problem arises when I use HSPICE to generate differential port > S-parameter file from single-ended S-parameter file. Or I should say when I > use P-element like below: > > "P1 1 3 0 Z0P port=1 > P2 2 4 0 Z0P port=2" > > Please let me know if I query is still not clear. > > Thanks in advance. > > Best Regards, > Kiran > > > > From: Kiran Kumar (WT01 - Manufacturing & Hi Tech) > Sent: Tuesday, June 19, 2012 7:10 PM > To: 'bala' > Cc: si-list@xxxxxxxxxxxxx > Subject: RE: [SI-LIST] HSPICE query > > Hi Bala, > > Thanks for your quick response. But your suggestion is not helping. > > Best Regards, > Kiran > > From: bala [mailto:balaseven@xxxxxxxxx] > Sent: Tuesday, June 19, 2012 4:41 PM > To: Kiran Kumar (WT01 - Manufacturing & Hi Tech) > Cc: si-list@xxxxxxxxxxxxx > Subject: Re: [SI-LIST] HSPICE query > > Kiran, > > Generally, P should have N reference for differential parameter,not > node0/gnd.Connect node 1 of 100ohm to P and node 2 to N and try.Since you > are getting issue on return loss alone,this should be the > impedance/termination issue. > > Regards > bala > On Tue, Jun 19, 2012 at 3:26 PM, <kiran.kumar10@xxxxxxxxx<mailto: > kiran.kumar10@xxxxxxxxx>> wrote: > Hi Bala, > > No. I am just using P-element to convert Single ended S-parameter to > differential S-parameter. Moreover only return loss is showing issue; all > other measurements like Insertion loss, NEXT, FEXT etc. remains the same > like vendor provided plots. > > Best Regards, > Kiran > > From: bala [mailto:balaseven@xxxxxxxxx<mailto:balaseven@xxxxxxxxx>] > Sent: Tuesday, June 19, 2012 2:17 PM > To: Kiran Kumar (WT01 - Manufacturing & Hi Tech) > Cc: si-list@xxxxxxxxxxxxx<mailto:si-list@xxxxxxxxxxxxx> > Subject: Re: [SI-LIST] HSPICE query > > Hi Kiran, > > Did you terminate both the port with 100ohm resistor? > > Regards > bala > On Tue, Jun 19, 2012 at 11:37 AM, <kiran.kumar10@xxxxxxxxx<mailto: > kiran.kumar10@xxxxxxxxx>> wrote: > Hi, > > I am working on a project that uses a 6-pair X 4-wafer connector with 24 > differential pairs of 100Ohms differential impedance. Vendor provided a > single ended S-parameter connector model for the same. > > > > When I use HSPICE port element(P-element) and .LIN command to convert the > single ended parameter to differential and plot the Return Loss in Custom > Waveview, I am getting very bad noise in the frequency range up to 10G > (noise frequency of 100MHz). But if I use the original single ended > S-parameter file directly and use port conversion formula (eg. S11DD= > S11-S13+S31+S33 for each port) Then I am getting a clean Return Loss plot > as the plot provided by the vendor. > > The port conversion using P-element is introducing noise in the generated > differential S-parameter model. > > Can someone help me get around this issue? > > Please revert back if the question is not clear. > > Thanks in advance. > > Best Regards, > Kiran > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any attachments > to this message are intended for the exclusive use of the addressee(s) and > may contain proprietary, confidential or privileged information. If you are > not the intended recipient, you should not disseminate, distribute or copy > this e-mail. Please notify the sender immediately and destroy all copies of > this message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient > should check this email and any attachments for the presence of viruses. > The company accepts no liability for any damage caused by any virus > transmitted by this email. > > www.wipro.com<http://www.wipro.com> > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx<mailto: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<mailto:si-list-request@xxxxxxxxxxxxx> with > 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > 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 > > > > -- > bala > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any attachments > to this message are intended for the exclusive use of the addressee(s) and > may contain proprietary, confidential or privileged information. If you are > not the intended recipient, you should not disseminate, distribute or copy > this e-mail. Please notify the sender immediately and destroy all copies of > this message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient > should check this email and any attachments for the presence of viruses. > The company accepts no liability for any damage caused by any virus > transmitted by this email. > > www.wipro.com<http://www.wipro.com> > > > > -- > bala > > Please do not print this email unless it is absolutely necessary. > > The information contained in this electronic message and any attachments > to this message are intended for the exclusive use of the addressee(s) and > may contain proprietary, confidential or privileged information. If you are > not the intended recipient, you should not disseminate, distribute or copy > this e-mail. Please notify the sender immediately and destroy all copies of > this message and any attachments. > > WARNING: Computer viruses can be transmitted via email. The recipient > should check this email and any attachments for the presence of viruses. > The company accepts no liability for any damage caused by any virus > transmitted by this email. > > www.wipro.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 forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > 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 forum is accessible at: http://tech.groups.yahoo.com/group/si-list 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