Re: Modeling - Fast Tr

Fred (fred@contec.contec.COM)
Thu, 5 Sep 1996 11:38:49 +0800

For information purposes, there is software avaliable that can take in S parameter
tables and produce a working Spice nport circuit for analysis. This has been used
sucessfully, the S parameter curves are faithfully duplicated over a pretty broad
high frequency content where S parameters are most usefull in the first place.

Best Regards,
Fred Balistreri
Applied Simulation Technology
408-434-0967 ext. 102

> From wyip@lsil.com Thu Sep 5 10:41:05 1996
> To: si-list@silab.Eng.Sun.COM
> Subject: Re: Modeling - Fast Tr
> Content-Length: 2969
> X-Lines: 77
>
> Regarding Fabrizio's question on high speed interconnect modeling, I agree with
> Eric that the best solution is to do a S-parameter characterization over the
> frequency range of his application, either via modeling or measurement. One has
> to be careful though that the fixturing closely mimics the actual environment
> in which the connector will reside. One can then build an equivalent RLC
> circuit model based on the physical construction of the connector and run some
> optimization software such as that built into MDS or Hspice to compute the
> model parameters. The optimization goal would be to produce a circuit model withcorresponding S-parameter set matching that of the connector. This would require
> good insight to come up with a circuit model topology which can yield a good
> match.
>
> I think the problem with slicing the connector into smaller sections for direct
> RLC modeling is that, as Eric pointed out, the coupling between sections would
> be ignored. In addition, when it is a true 3D structure, it may not be clear
> how to slice it.
>
> My humble opinion,
> Wai-Yeung
>
> > From Raymond.Anderson@Eng.Sun.COM Wed Sep 4 14:08:10 1996
> > Date: Wed, 4 Sep 1996 12:37:18 -0700
> > From: Raymond.Anderson@Eng.Sun.COM (Ray Anderson)
> > To: si-list@silab.Eng.Sun.COM
> > Subject: Modeling - Fast Tr
> > X-Sun-Charset: US-ASCII
> > Content-Length: 1529
> >
> >
> >
> > I am forwarding this message from Fabrizio Zanella at Teradyne
> > (fab@tcs.teradyne.com). The mail forwarding system choked but I think
> > I have it fixed now.
> >
> > Ray Anderson
> >
> > -----------------------forwarded message starts here------------------------
> >
> >
> > REGARDING Modeling - Fast Tr
> >
> > Hope everyone has had a good summer.
> > I have a generic question regarding creating interconnect models for
> > simulation at extremely fast rise times. The scenario is this: signals with
> > 150ps rise time are being transmitted through an interconnect, like a right
> > angle connector, which is 200ps long. Since the connector is electrically
> > long, what is the best alternative for creating an electromagnetic model that
> > will yield accurate results at 150ps edge rates? My options are, using BEM or
> > FEM analysis:
> > 1) Break connector into seven to ten 2D slices, and create lumped element
> > model subcircuits
> > 2) Break connector into seven to ten 2D slices, and create distributed model
> > subcircuits
> > 3) Draw a one section 3D model of the connector, and create a lumped element
> > subcircuit.
> > 4) Draw a one section 3D model of the connector, and create a distributed
> > model subcircuit.
> > Any feedback or past experiences or mention of other methods would be greatly
> > appreciated.
> > Thanks and regards,
> > Fabrizio Zanella
> > Signal Integrity Engineer
> > Teradyne
> > 44 Simon Street
> > Nashua NH 03060
> > 603-791-3542
> > FAX 603-791-3046
> > fab@tcs.teradyne.com
> >
> > ------------------------end of forwarded message----------------------------
> >
> >
> >
> >
> > ----- End Included Message -----
> >
> >
> >
>