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
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| Image Solutions Division
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charles.moore@avagotech.com
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