Gourgen,
Please
define whether you mean a physically realizable channels includes
tolerances for all of the variations discussed before.
John
-----Original
Message-----
From: Oganessyan,
Gourgen [mailto:Gourgen.Oganessyan@MOLEX.COM]
Sent: Wednesday,
January 18, 2006 5:13 PM
To:
STDS-802-3-BLADE@listserv.ieee.org
Subject: Re: [BP]
Interference tolerance test channels
You just did
a mathematical construction, right? Is this channel physically
realizable?
-----Original
Message-----
From: Mellitz, Richard
[mailto:richard.mellitz@INTEL.COM]
Sent: Wednesday,
January 18, 2006 3:09 PM
To:
STDS-802-3-BLADE@listserv.ieee.org
Subject: Re: [BP]
Interference tolerance test channels
Did
it! I built a channel that has 3db less loss at 5GHz with out
impacting the loss at 1GHz. Also I created the AF coefficients to match
this channel. See attached zip file. I also checked the causality of
the s4p as well. J
…Rich
Steve,
But also
realize that the general line also has built in margin for it to
account for temperature, environmental, and material variation as
well. The line as currently proposed has to be examined to look at
from several aspects. For example, the Molex channels are hugging the
new proposed 23 dB line. 5” are on the daughtercard and 35” are on the
backplane, which uses a typical 7 mil line. So we are saying that to
meet the skin effect at the lower frequencies we need a 7 mil wide
line? I think that is too far. Look at the attached figure – 7 mil
wide traces hug that line. I think we have moved it too far upward.
I don’t see
any efforts yet on reducing the problem via the crosstalk aspect of the
problem. Has that been abandoned? I don’t think all of the burden at
this time should be shifted to the channel, but should also be shared
with the total allowable crosstalk. Many of the channels did have
margin. We should look to striking a balance between the two.
John
-----Original
Message-----
From: Steve Anderson
[mailto:steve.anderson@xilinx.com]
Sent: Monday, January
16, 2006 2:52 PM
To: DAmbrosia, John F;
STDS-802-3-BLADE@listserv.ieee.org
Subject: RE: [BP]
Interference tolerance test channels
John, all:
But does a line made with the squared and cubed terms create a
physically realizable channel?
In the real channel I think there may be only two variables to play
with: skin effect and dielectric
absorption.
If we base simulations on something other than this, then I think bad
things can happen like
non-causal
effects.
Steve A.
Guys,
Goergen
asked the magic question. Is it possible? Yes it is. We have a
squared and cubed term to play with. I am hoping Joel has some
suggestions as well. I just had a chance to do a quick scan and saw
this. I will be working on this stuff tonight
John
-----Original
Message-----
From: Oganessyan,
Gourgen [mailto:Gourgen.Oganessyan@MOLEX.COM]
Sent: Monday, January
16, 2006 2:24 PM
To:
STDS-802-3-BLADE@listserv.ieee.org
Subject: Re: [BP]
Interference tolerance test channels
I see now
what you refer too. I am not sure how you physically relaize a channel
you are suggesting, keep low freq the same and come up at 5 GHz? Any
physical channel should result in a tilted line?
-----Original
Message-----
From: Mellitz, Richard
[mailto:richard.mellitz@INTEL.COM]
Sent: Monday, January
16, 2006 1:05 PM
To:
STDS-802-3-BLADE@listserv.ieee.org
Subject: Re: [BP]
Interference tolerance test channels
The
line didn’t only tilt. It also shifted. John D looked at a few channels
as I attached. If we shift, it’s got an impact for KX and KX4.
…Rich
The new channel appears
to be inline with what we stated - a tilt of the line from DC to about
a 3dB drop at 5GHz. Why do you feel the lower frequencies need to stay
fixed?
Thanks, Joe
Joe Abler
abler@us.ibm.com
IBM Systems & Technology Group 919-254-0573
High Speed Serial Link Solutions 919-254-9616 (fax)
3039 Cornwallis Road
Research Triangle Park, NC 27709
Hi Charles,
DC and low freq's went down way to much! Can you create a model with the
same losses at say 1GHz or so and 2 dB less at 5GHz? I thought that's
what we agreed.
... Rich
-----Original Message-----
From: Charles Moore [mailto:charles.moore@avagotech.com]
Sent: Friday, January 13, 2006 8:42 PM
To: STDS-802-3-BLADE@listserv.ieee.org
Subject: [BP] Interference tolerance test channels
guys,
I propose that we use the model ITTC_23.s4p for reduced attenuation
EIT modeling. If it really will not work, ITTC_20.s4p is available as a
bail out channel. If it looks too easy, let me know and i will step it
up just
a tad.
The numbers refer to the fitted attenuation at 5.15...GHz.
charles
--
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| Charles Moore
| Avago Technologies
| Image Solutions Division
| charles.moore@avagotech.com
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