Dear Geoff, My 2-conductor system is placed on a lossy substrate ground plane. But I don't know the typical value of the conductivity of such a substrate. I am following the TSMC0.18 micron technology. Any idea what the substrate is made of and what the typical conductivity of it is?? I couldn't find the details in TSMC0.18 micron technology brochure. Regarding the coupling capacitance and the capacitance to ground I am intending to use FASTCAP. Thanx, Amitava On Fri, 31 Oct 2003, Geoff Stokes wrote: > Dear Amitava and Patrick > > I would be interested in further discussion of this problem. I have a > couple of questions. > > In your 4-terminal metal system, what considerations do you have about the > underlying substrate? At high frequencies, should you consider some kind of > ground plane, or at least, coupling to other conductors? > > Did you obtain your z-parameters from an EM simulator? > > Cheers > Geoff > > > -----Original Message----- > > From: Patrick Zilaro [mailto:pzilaro@xxxxxxxxxxxx] > > Sent: 30 October 2003 22:26 > > To: bhadhua@xxxxxxxxxxxx; si-list@xxxxxxxxxxxxx > > Subject: [SI-LIST] Re: N-port problem in interconnects > > > > > > I think you got it. Cadence Spectre represents each port > > with a positive > > and a negative terminal. This is just like, if you were > > measuring these > > s-parameters using a VNA and microprobes. The microprobes each have a > > positive and a negative terminal. By the way, some circuit > > simulators that > > can handle s-parameters choose to combine all the negative > > terminals into > > one common "reference" terminal. Spectre keeps them separate. > > > > Regards, > > > > Patrick Zilaro > > SI Packaging Engineer > > Broadcom Corporation > > > > -----Original Message----- > > From: si-list-bounce@xxxxxxxxxxxxx > > [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Amitava Bhaduri > > Sent: Thursday, October 30, 2003 2:03 PM > > To: si-list@xxxxxxxxxxxxx > > Subject: [SI-LIST] N-port problem in interconnects > > > > > > > > > > Hi, > > > > I am trying to model the interconnects using the "nport" feature of > > spectre. Take for example I have 2 conductors (A1-B1 and > > A2-B2). A1, B1, > > A2, B2 are connected to other circuit elements, like transistors for > > example. I am trying to model only the interconnect portion. > > _ _ > > B1 | | B2 | | > > | | | | > > | | | |_____________ > > | |_____________ |_____________ | > > |____________ | | | > > | | | | > > | | | | > > | | | | > > | | |_| > > A1 |_| A2 > > > > I am able to obtain a (2 x 2) impedance matrix [Z] for this > > 2-conductor > > system. Using the formula (Z-1)(Z+1)^-1, the impedance > > parameters can be > > converted to s-parameters (as "nport" of spectre operates on > > s-parameters). > > The problem is how do I represent this 2-conductor system > > in spectre "nport" format. If you do "spectre -help nport" > > you will see > > that the instance statement looks like: > > > > Name ( t1 b1 [t2] [b2] ... ) nport <parameter=value> ..., > > > > where the terminals should be given in pairs. Can this > > 2-conductor system > > be realized as 2-port network? What would the common terminals be (-ve > > terminal) in this case? In this 2-port interconnect network can I > > represent the first port as (A1, B1) where A1 is +ve terminal > > and B1 is > > -ve terminal, while the second port being (A2, B2) where A2 is +ve > > terminal and B2 is -ve terminal? > > > > (note: this is only an instance of a 2-conductor system. The > > same problem > > can be extended for any "n-conductor system", where n=1,2,3,4,5...etc) > > > > Would appreciate any help on this. > > Thanks, > > Amit > > > > > > Amitava Bhaduri > > Research Assistant > > 527 ERC > > University of Cincinnati > > OH - 45220 > > ph : 513-556-3025 > > > > ------------------------------------------------------------------ > > 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 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 > > > > > > > > > > > > ------------------------------------------------------------------ > > 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 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 > > > > > > > _________________________________________________________ > > Zetex Semiconductors - Solutions for an analog world > > EID Award Winners for 'Best Use of Technology' 2003 for the > AcoustarTM ZXCW8100 End-to-End Digital Audio Amplifier Controller > > http://www.zetex.com > _________________________________________________________ > > ###################################################################### > E-MAILS are susceptible to interference. You should not assume that > the contents originated from the sender or the Zetex Group or that they > have been accurately reproduced from their original form. > Zetex accepts no responsibility for information, errors or omissions in > this e-mail nor for its use or misuse nor for any act committed or > omitted in connection with this communication. > If in doubt, please verify the authenticity with the sender. > ###################################################################### > > ------------------------------------------------------------------ > 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 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 > > Amitava Bhaduri Research Assistant 527 ERC University of Cincinnati OH - 45220 ph : 513-556-3025 ------------------------------------------------------------------ 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 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