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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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