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‘More
like an Ansoft Nexxim EM model based on real material properties. … Rich From: DAmbrosia, John
F [mailto:john.dambrosia@TYCOELECTRONICS.COM] Gourgen, Please define whether you mean a
physically realizable channels includes tolerances for all of the variations
discussed before. John -----Original Message----- Rich, You just did a
mathematical construction, right? Is this channel physically realizable? Gourgen -----Original Message----- 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 From:
DAmbrosia, John F [mailto:john.dambrosia@TYCOELECTRONICS.COM] 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-----
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. From:
DAmbrosia, John F [mailto:john.dambrosia@tycoelectronics.com] 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----- Rich, 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? Gourgen -----Original Message----- 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 From: Joe M
Abler [mailto:abler@US.IBM.COM]
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