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Rich,
You
just did a mathematical construction, right? Is this channel physically
realizable?
Gourgen
-----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 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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