[SI-LIST] Re: Fw: Question on Differential S parameters
- From: cf yee <cf_yee@xxxxxxxxx>
- To: Peter.Pupalaikis@xxxxxxxxxx, wolfgang.maichen@xxxxxxxxxxxx
- Date: Tue, 5 Apr 2011 01:32:31 -0700 (PDT)
Hi,
Kindly refer to Agilent's site
http://www.home.agilent.com/agilent/facet.jspx?kå071c&neighborhood=ETM&kt=1&cc=US&lc=eng&homesearch=Search&searchbtn=Search.
You may use VNA model E5071C (4-port, 300kHz-20GHz), you may measure single
ended mode s-param, or there is a feature called "fixture simulator" whereby
the feature will convert single mode to mixed mode s-param (Sdd11,Sdd21...),
then you can save the touchstone data.
I have experience in doing that. If any further info needed, please email me.
rgds,
CF Yee (Agilent)
--- On Tue, 4/5/11, wolfgang.maichen@xxxxxxxxxxxx
<wolfgang.maichen@xxxxxxxxxxxx> wrote:
From: wolfgang.maichen@xxxxxxxxxxxx <wolfgang.maichen@xxxxxxxxxxxx>
Subject: [SI-LIST] Re: Fw: Question on Differential S parameters
To: Peter.Pupalaikis@xxxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx, si-list-bounce@xxxxxxxxxxxxx
Date: Tuesday, April 5, 2011, 8:00 AM
Pete,
actually there _are_ VNAs that can perform truly differential measurements,
but that is indeed a fairly recent development (just about 3 years old).
E.g. Rohde & Schwarz ZVB Vector Network Analyzers which can go up to 20
GHz; they have two independent sources (with calibrated phase of 1%
accuracy - quite a feat at these frequencies). I believe Agilent has
similar offerings. That's still quite a bit less in terms of max frequency
compared to traditional single-source VNAs.
There is nothing inherently wrong with using math to obtain differential
S-parameters from single ended measurements. As long as the system under
test is perfectly linear and time invariant this works beautifully, and
there is little to gain from using a differential stimulus (and it will be
much more expensive for the same maximum test frequency). So it's a good
method e.g. for traces on a printed circuit board, cables, connectors and
similar passive, non-magnetic structures. It starts getting "interesting"
though (read: prone to give completely invalid results) when you apply it
to the analysis of systems that are potentially nonlinear, e.g. an
amplifier or other circuits containing active elements or even just diodes.
Wolfgang
From: Peter.Pupalaikis@xxxxxxxxxx
To: si-list@xxxxxxxxxxxxx
Date: 04/04/2011 04:19 PM
Subject: [SI-LIST] Fw: Question on Differential S parameters
Sent by: si-list-bounce@xxxxxxxxxxxxx
From Pete Pupalaikis's Blackberry
----- Original Message -----
From: Peter J. Pupalaikis
Sent: 04/04/2011 05:54 PM EDT
To: "Grasso, Charles" <Charles.Grasso@xxxxxxxxxxxx>
Subject: Re: [SI-LIST] Question on Differential S parameters
Hi Charles:
Almost all "mixed-mode" measurements are made by almost all pieces of test
equipment as single-ended s-parameters that are converted to mixed-mode in
software. The only piece of equipment I know of that measures by driving
differential or common-mode signals is tektronix TDR and LeCroy WaveExpert
(also TDR). I'm not sure about Agilent TDR and to my knowledge all VNAs
measure single-ended with the mathematical conversion.
There are many ways to do the conversion - one is with formulas - another
is by cascading mixed-mode converter devices. Or they can be converted by
driving pairs of ports of single-ended models in simulation with proper
terminations and extracting components of interest.
Pete
From Pete Pupalaikis's Blackberry
----- Original Message -----
From: "Grasso, Charles" [Charles.Grasso@xxxxxxxxxxxx]
Sent: 04/04/2011 02:20 PM CST
To: "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>
Subject: [SI-LIST] Question on Differential S parameters
Hello all,
I have a question on how the SDD and SCD series of measurements are made.
Never having actually
performed these measurements I did a bit of reading and am unclear on the
process. What I understand is
(at least from one manufacturer of test equipment) that the 4 x 4
single-ended S-parameters (S11 to S44)
are measured. A built-in function then converts them to the mixed mode
S-parameters.
My question: For SDD11 are the trace pairs driven with a differential
signal (in the software?).
By the same token for the SDC measurements are the traces driven with a
common signal?
Thanks!
Best Regards
Charles Grasso
Compliance Engineer
Echostar Communications
(w) 303-706-5467
(c) 303-204-2974
(t) 3032042974@xxxxxxxxx<mailto:3032042974@xxxxxxxxx>
(e) charles.grasso@xxxxxxxxxxxx<mailto:charles.grasso@xxxxxxxxxxxx>
(e2) chasgrasso@xxxxxxxxx<mailto:chasgrasso@xxxxxxxxx>
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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 technical documents are available at:
http://www.si-list.net
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 technical documents are available at:
http://www.si-list.net
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 technical documents are available at:
http://www.si-list.net
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
Other related posts:
