This is a good SI-list thread. Our thinking is S-parameters are a sampled
system, and such have issues with DC point, sampling, windowing, etc
Typically we manage the VNA measured S-parameter into a Rational Compact
model (we use Simbeor and ADS) so we can sample it any way we desire, and
continuous functions are easier to deal with than sampled systems, where the
sampling intervals can be different, the samples may not even be equidistant.
We did a DesignCon paper with Heidi Barnes (Keysight) where she used several
different windows on the same S-parameter channel data set and the eye fidelity
changed a LOT.
Saying that, what strengths/weaknesses do you see with our approach? We
ALWAYS do a TDR of the s-parameter and examine both reflected voltage and
impedance profile, as Todd suggested.
- Al
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> On Behalf Of
Westerhoff, Todd
Sent: Thursday, July 11, 2019 6:39 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: AW: extract the channel sparam using Matlab
I have to ask: if you take the two different sets of s-parameters and put a
step or pulse through them in the time-domain, how much difference do you see?
Todd.
Todd Westerhoff
High-Speed Design Product Marketing | Electronic Board Systems
300 Nickerson Rd, Marlboro, MA 01752
todd_westerhoff@xxxxxxxxxx | office: 508-303-5821 | cell: 978-846-0203
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Havermann, Gert
Sent: Thursday, July 11, 2019 2:00 AM
To: farhilltramper@xxxxxxxxx; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] AW: extract the channel sparam using Matlab
Hi Tramp,
Almost all tools have their own way of dealing with S-parameters. There is
passivity or causality enforcement as well as intra and extrapolation if the
frequency points not align with the points given by the S-parameters. For a 1:1
comparison you should use identical frequency steps in simulation and all the
S-Parameter files and switch off all enforcements. Then both tools should give
the same S-parameter result.
If you also convert to time domain, then the differences can be significant
based on the windowing function used by the tool.
Mit freundlichen Grüßen / Kind regards.
Gert Havermann
Signal Integrity Engineer
Dept.: Corporate Technology Services
HARTING Stiftung & Co. KG
Marienwerderstraße 3
D-32339 Espelkamp
Phone +49 (0)5772 47 857
Fax +49 (0)5772 47 90857
mailto:gert.havermann@xxxxxxxxxxx
http://www.HARTING.com
----------------------------------------
HARTING Stiftung & Co. KG | Postfach 11 33, 32325 Espelkamp | www.HARTING.com
Persönlich haftende Gesellschafterin:
HARTING Führungsstiftung | Amtsgericht München | HRA 108479 | München
Vorstand: Dipl.-Kfm. Philip F. W. Harting (Vorsitzender), Dipl.-Kffr. Maresa W.
M. Harting-Hertz, Dipl.-Kfm. Dr.-Ing. E. h. Dietmar Harting, Dipl.-Hdl. Margrit
Harting, Dipl.-Ing. (FH) Dipl.-Wirtsch.-Ing. (FH) Andreas Conrad, Dipl.-Ing.
Uwe Gräff, Dr. iur. Michael Pütz Sitz der Gesellschaft: Espelkamp | Amtsgericht
Bad Oeynhausen | HRA 9021 | UST-ld Nr. DE812136745
-----Ursprüngliche Nachricht-----
Von: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> Im Auftrag von
Tramp
Gesendet: Donnerstag, 11. Juli 2019 06:03
An: si-list@xxxxxxxxxxxxx
Betreff: [SI-LIST] extract the channel sparam using Matlab
Hi experts,
I found that using Matlab RF toolbox cascadesparams, the channel sparam
obtained is slightly different from that obtained with a commercial channel
simulator. Also, different freq points give different sparams. Any comments on
extracting the channel sparam using Matlab?
--
Best Regards,
Tramp
------------------------------------------------------------------
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
------------------------------------------------------------------
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
