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Old September 2nd 03, 01:07 PM
 
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"Peter O. Brackett" wrote:
On another whole level it simply DOES NOT MATER which defiinition
of the reflection coefficient one uses to make design calculations though,
as long as the definition is used consistently throughout any calculations.

One can convert any results based on the non-conjugate version of rho to
results based on the conjugate version of rho and vice versa.

In other words, neither version is "RIGHT" or "WRONG" as long
as the results from using that particular definition are interperted
correctly in terms of the original definition.


While true, this is not what is occuring in the 'revised rho' debate.

Their claim is simply that 'classical rho' has been mis-calculated all
these years and we should start using the 'proper' calculation. There
is no acknowledgement that 'revised rho' will have different properties
than 'classical rho' and that, therefore, they are introdcing a new
entity.

Their claim of incorrectness derives from the fact that 'classical rho'
can have a magnitude greater than 1 and a belief that this means
reflected power is greater than incident. This belief is inconsistent
with generally accepted knowledge, so rather than modifying the belief,
the derivation of 'classical rho' is rejected.

Their second difficulty derives from not being able to separate
the behaviour at a particular interface from the system behaviour.
They do not recognize that a reflection at a particular interface
(which would reduce energy transfer at that interface), can
improve overall system energy transfer by improving the energy
transfer at another interface. This being what a transmission line
transformer does, for example.

Once they overcome these two hurdles, they will have no problems
with the classical definition of rho.

So... who gives a damm about the defintion of rho as long as you are
consistent in it's use. It simply doesn't matter! [Unless you choose
M to be singular. ;-) ]


There is no problem if this is what the 'revised rho' crowd really is
attempting to do, but they should clearly state this and have the
courtesy to pick a new name (despite Humpty-Dumpty's assertions) to
facilitate clear communication.

Really though, you are thinking several levels above them when you
hypothesize the existence of other, self-consistent, definitions of
rho.

They are still at the 'classical rho computation is just plain wrong'
level.

....Keith