[SI-LIST] Re: Regarding understanding of mixed mode S-parameters
- From: Peter.Pupalaikis@xxxxxxxxxxxxxxxxxx
- To: malli.1729@xxxxxxxxx
- Date: Wed, 21 Aug 2013 10:36:54 -0400
I took a look at this document. I'm not sure exactly what the author is
trying to say and I'm not sure exactly how to interpret it (which is a bad
thing about slides in general - you have to be at the presentation of the
slides to really know what was being conveyed).
But, with my interpretation of what the author is trying to say, I think he
may have a misunderstanding about SDD11, SDD22 and these paths he is
referring to.
Here is my attempt to explain this suspected misunderstanding:
First, consider a differential line with no mode conversion at all. This
would mean that the system could be viewed as a two-port with the four SDD
parameters defining the differential-mode transmission. Also, consider that
we drive the line with a voltage source with some source reflection
coefficient and some load reflection coefficient. We know that when we
launch this signal, depending on mismatches, the signal will bounce back and
forth between the load and source. I believe that is what he is trying to
indicate with these so-called paths - that the signal at the load will be
thelaunched signal plus some portion of the signal that reflects from the
load back to the source and back to the load again and that this portion
represents this nuisance signal. We all know that that can certainly be a
problem. If the source and load are matched to the reference impedance and
the line is mismatched to the reference impedance, we know that we will
certainly get this effect, but many would be surprised to know that under
this condition, this bouncing around of the signal is entirely found in the
SDD21 term. In other words, the output waveform with respect to the voltage
source depends only on SDD21, in this case. In other words, all of these
reflections would be built into SDD21 already and the transfer function does
not depend on SDD11 or SDD22. Of course with mismatched source and load,
theequations are much more complicated and SDD11 and SDD22 do get into the
picture, but I'd have to know those mismatches to determine the effect on
thetransfer function.
I guess what I'm saying is that the s-parameters are not "paths" per se, but
define frequency domain port-port relationships with no concept of time and
distance.
In the end, I guess you'd have to talk to the author to find out what he
really means by these slides.
Pete
mallikarjun K ---08/21/2013 08:43:37 AM---Hi, I am referring to the
document
[IMG]
From:
[IMG]
mallikarjun K <malli.1729@xxxxxxxxx> [IMG]
To:
[IMG]
"si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>, [IMG]
Date:
[IMG]
08/21/2013 08:43 AM [IMG]
Subject:
[IMG]
[SI-LIST] Regarding understanding of mixed mode S-parameters [IMG]
Sent by:
[IMG]
si-list-bounce@xxxxxxxxxxxxx
----------------------------------------------------------------------------
Hi,
I am referring to the document
http://www.t11.org/ftp/t11/pub/fc/msqs/10-518v0.pdf[1]
in this document, i am referring to sections paths to degredad signals.
they are showing paths like this
[image: Inline image 1]
i didn't understand how they are saying wanted signal became Nuisance
signal after SDD11 and SDD22 .
any help to understand this.
Malli
------------------------------------------------------------------
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[2]
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[3]
List archives are viewable at:
//www.freelists.org/archives/si-list[4]
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu[5]
--- Links ---
1 http://www.t11.org/ftp/t11/pub/fc/msqs/10-518v0.pdf
2 //www.freelists.org/webpage/si-list
3 http://tech.groups.yahoo.com/group/si-list
4 //www.freelists.org/archives/si-list
5 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
Other related posts:
