On Tue, 11 Oct 2005 16:57:51 GMT, Cecil Moore wrote:


****Quote****
Newsgroups: sci.physics.electromag
From: "Kevin G. Rhoads"
Date: Tue, 07 Oct 2003 12:49:14 -0400
Subject: Transmission Line Question
....
So unless almost all the power diverts into an undesireable
mode (by a factor of more than a million to one), one foot
of cable should see pure TEM at the end.
***End Quote***

But Cecil, nowhere in the analysis you quoted does it estimate how
much power is diverted from the dominant mode at the discontinuity.

If the explanation of the discontinuity is that some power is
converted from dominant propagation mode to another mode, and that
those other modes are evanescent, it seems that this analysis of the
impact of the discontinuity considers only estimating the decay rate
of the evanescent modes without estimation of the relative magnitude
of the power diverted to those modes in the first place.

Owen
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