**From:** Jian Zheng (*[email protected]*)

**Date:** Wed Dec 22 1999 - 18:37:02 PST

**Next message:**Qu Pingyu: "RE: [SI-LIST] : Frequency dependence and all that jazz"**Previous message:**Chris Cheng: "RE: [SI-LIST] : Clean sheet of paper"**In reply to:**Ron Miller: "Re: [SI-LIST] : Frequency dependence and all that jazz"**Next in thread:**Erik Daniel: "Re: [SI-LIST] : Frequency dependence and all that jazz"

Hi, Ron:

You can also try our MDSPICE simulator which basically accept the SPICE

netlist (limited to R, L, C, K) and s-parameter files compatible with the HP

measurement results in files. We also offer accurate and efficient full wave

simulators. Thanks!

Best regards,

----------------------------------------------------------------------------

------------

Jian-X. Zheng, Ph.D

Zeland Software, Inc., 39676 Mission Blvd., Fremont, CA 94539, U.S.A.

Tel: 510-797-8109, Fax: 510-797-8241, Web: http://www.zeland.com

----------------------------------------------------------------------------

------------

-----Original Message-----

From: [email protected]

[mailto:[email protected]]On Behalf Of Ron Miller

Sent: Wednesday, December 22, 1999 4:23 PM

To: [email protected]

Subject: Re: [SI-LIST] : Frequency dependence and all that jazz

Nilesh

Please contact Art Frasier at Intel, Santa Clara. He has HP MDS/ADS

which

can used measured S-parameters together with other frequency dependent

elements

and transfer them back into the time domain.

Ron Miller

Steve Corey wrote:

Nilesh -- SPICE-like simulators doing time-domain analyses solve

their differential equations in the time domain, based on the charge/flux

stored in

capacitors/inductors and the derivatives of the voltage/current

variables at each node/branch. A time-domain simulator has no concept of

frequency.

It is quite possible to get frequency dependence included in a model

for a time-domain simulator, since L's and C's are frequency-dependent

impedances/admittances and can be shown, when used in conjunction

with R's (and inductance coupling coeffficients) to accurately represent any

well-behaved

function if used in the correct topology and with the correct

values. However, for certain structures (e.g., long cables used at high

frequencies) a large

number of lumped elements is required to represent the delay.

A full wave solver is one of many approaches to getting a frequency

dependent model. Other approaches, such as 2-D solvers, may be quite

sufficient

without going to such great lengths -- you have to evaluate what

frequency-dependent effects you are trying to model. /* begin brazen

advertising */ We

offer a tool which extracts models from measured data and handles

some effects, such as non-uniform impedance and next-door coupling, quite

well. /* end

brazen advertising */ General full-wave modeling from measurement is

on the horizon, and is a current research topic in academia, but we do not

offer it at

this time.

Hope this helps,

-- Steve

-------------------------------------------

Steven D. Corey, Ph.D.

Time Domain Analysis Systems, Inc.

"The Interconnect Modeling Company."

http://www.tdasystems.com

email: [email protected]

phone/fax: (206) 417-3439

-------------------------------------------

"Shah, Nilesh N" wrote:

* > Hi:
*

* > I have a question:
*

* > It's all well and fine to build frequency dependent MODELS,
*

* > but what about the simulator(ex Hspice) itself?
*

* > For example, if I feed the output of a simple inverter to an
*

* > L,C, R network, (and I'm doing a simple time domain transient
*

analysis)

* >
*

* > INVERTER------LRC NETWORK----OUTPUT
*

* >
*

* > does the simulator decompose the output waveform of the inverter
*

* > into it's frequency components before feeding it into the LC
*

network?(i

* > don't think so)
*

* > For example, if the output of my buffer looks like a repeating
*

square pulse

* > running at 400Mhz 50% duty cycle with a finite rise time, does the
*

LRC

* > network "see"
*

* > the input wave as
*

* > Asin(w1t)+Bsin(w2t)+..... etc
*

* > where w1=400Mhz and w2,w3 etc are the harmonics?Or does one have
*

to

* > explicitly
*

* > take the output of the waveform, decompose it and then feed it
*

artificially

* > to the LRC network?
*

* >
*

* > or does the LRC network "see" as it's input,a bunch of dc points
*

for

* > which the simulator solves the nodal matrix using difference or
*

differential

* > equations? i.e. does the LRC network "see" only 1 frequency coming
*

in which

* > is the fundamental?
*

* >
*

* > How does this work?How is the frequency content of the output
*

waveform of

* > the buffer conveyed to the LCR network?
*

* > I was planning to investigate this but I thought some of
*

* > you experts out there might have the answer at the top of your
*

head...

* >
*

* > Also, tools like Ansoft Q3d extract models only at 1 frequency(I
*

think), so

* > unless you use HFSS, how do you get a true frequency dependent
*

model?

* > I've generated R,L versus frequency and other parameter versus
*

frequency

* > curves, but this is with 2 d models using TEM assumptions.what
*

about 3-d

* > models?
*

* > is ther ANY way at all except for using a full wave solver like
*

HFSS to

* > generate true frequency
*

* > dependent models and simulate in the time domain?
*

* >
*

* > Thanks for your ideas in advance.
*

* > Nilesh
*

* >
*

* >
*

* > Nilesh N Shah,
*

* > Package Electrical Design Engineer,
*

* > PCG, Folsom, CA.
*

* > Intel Corporation.
*

* > tel:916-356 1129.
*

* >
*

* > **** To unsubscribe from si-list: send e-mail to
*

[email protected] In the BODY of message put: UNSUBSCRIBE

si-list, for more help, put HELP.

* > si-list archives are accessible at
*

http://www.qsl.net/wb6tpu/si-list

* > ****
*

**** To unsubscribe from si-list: send e-mail to

[email protected] In the BODY of message put: UNSUBSCRIBE

si-list, for more help, put HELP.

si-list archives are accessible at

http://www.qsl.net/wb6tpu/si-list

****

-- Ronald B. Miller _\\|//_ Signal Integrity Engineer (408)487-8017 (' 0-0 ') fax(408)487-8017 ==========0000-(_)0000=========== Brocade Communications Systems, 1901 Guadalupe Parkway, San Jose, CA 95131 [email protected], [email protected]**** To unsubscribe from si-list: send e-mail to [email protected] In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****

**Next message:**Qu Pingyu: "RE: [SI-LIST] : Frequency dependence and all that jazz"**Previous message:**Chris Cheng: "RE: [SI-LIST] : Clean sheet of paper"**In reply to:**Ron Miller: "Re: [SI-LIST] : Frequency dependence and all that jazz"**Next in thread:**Erik Daniel: "Re: [SI-LIST] : Frequency dependence and all that jazz"

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