Sorry for any inconvenience I might have caused, but upon further
review, I mis-referenced the wrong paper. Although the Wheeler
paper is a "definite-read" to SI engineers, the paper I meant to
reference was:
TI Effect of Surface Roughness on Eddy Current Losses at
Microwave Frequencies
AU Samuel P. Morgan, Jr.
SOURCE Journal of Applied Physics
VOLUME 20
DATE April, 1949
PP 352-362
Pat
P.S. If you haven't noticed, my personal library of journal papers
dates back a bit. It's amazing how much of this was done in the
40's & 50's, yet we continue to re-invent the stuff.
On Apr 7, 2:04pm, Pat Zabinski wrote:
> Subject: Re: [SI-LIST] : Q: HSPICE w-elements' RLCGs - conversion coeffici
> Vadim,
>
> Back in 1942, Harold Wheeler went through the analytics to derive
> the equivalent to "lambda" for various forms of surface roughness
> (e.g., rectangular, triangular, etc). In his paper referenced
> below, lambda varies depending up several factors, primarily
> the RMS surface roughness and skin depth (i.e., frequency and
> material properties). He was able to show how lambda could
> reach 2.
>
> TI Formulas for the Skin Effect
> AU Harold A. Wheeler
> SOURCE Proceedings of the IRE
> DATE September, 1942
> PP 412-424
>
> Obtaining a copy of this paper would be an excellent start in understanding
> the skin effect on effective resistance.
>
> Pat Zabinski
>
>
> >
> > Another issue... XFX provides an optional fudge factor "lambda" that
> > effectively accounts for copper plane/trace surface roughness. This fudge
> > factor effectively scales the default copper resistivity in the skin layer.
> > The default value of "lambda" is 1.
> >
> > Has anyone of you done any study as to what this Lambda should be? How does
> > this value vary (if at all) from one board vendor to another ? Is there any
> > particular value for Lambda if one is going to use XFX' data with Hspice
> > W-elements?
>
> --
> Pat Zabinski ph: 507-284-5936
> Mayo Foundation fx: 507-284-9171
> 200 First Street SW [email protected]
> Rochester, MN 55905 www.mayo.edu/sppdg/sppdg_home_page.html
>
>
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>
>-- End of excerpt from Pat Zabinski
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