Hi All,
When I talked to Charles I said this seemed
to have promise because the
Goergen line has as strong sqrt(f) dependence and low frequencies. It
has basis
in the skin loss physics. This would mostly affect KX which we really
didn't
spend much time on. After all we just changed the ICR fit line.
However, I made
these comments without really taking a close look at our data. Isn't
theory grand...
J
Since then I did look at the data. I had
Steve Krooswyk alter the
spreadsheet s-parameter analysis tool (SCAT) to look at this new fit.
What I discovered
was that it actually makes many channels appear much worse. After
further
review of the data I think we could do much better by just changing the
confidence region lines for KX only. However, I think the data needs to
be
presented and then we, as working group, can determine a plan of action.
…Rich Mellitz, Intel Corporation
803-216-2160 (o)
803-873-7343 (m)
-----Original Message-----
From: Charles Moore [mailto:charles_moore@agilent.com]
Sent: Tuesday, November 29, 2005 1:11 PM
To: STDS-802-3-BLADE@listserv.ieee.org
Subject: [BP] proposed channel model change
guys,
Rich Mellitz and i have been discussing
changing the
channel model,
to use a fit to Amax, as we are now doing for
the interference
tolerance
test channel (see moore_03_1105.pdf), instead
of a fit to a straight
line.
This would have several advantages:
1. It would use a common method for both
the test
channel and the
working channel
2. It would allow us to replace three
graphical
tests:
i. That the linear fit
is better than Amax
ii. That the insertion loss
is always better than Amax + something
iii. That the ripple is better
than something
with one numeric test, that mc
< 1.0, and the graphical ripple
test. We may need an
additional limit on bc.
3. Since the fit to Amax will be
substantially
better than the fit
to a straight line, the ripple
will be smaller and more meaningful.
This will reduce the number of
false fails. We should be able
to shrink the ripple bounds
(Rich: will you figure out by how
much?) which may also reduce
false passes.
4. Since the fit will be especially
improved at low
frequency, we
will be able to reduce f1,
especially for 10GBASE-KR, which
actually uses low frequencies more
than either 1000BASE-KX or
10GBASE-KX4.
Does anyone see any problems with this
proposal?
charles
--
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| Charles Moore
| Agilent Technologies
| ASIC Products Division
| charles_moore@agilent.com
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