"Owen" wrote in message
...

Apparently, Michaels described in "Technical Correspondence" in QST
NOV 1997 a method for calculating loss on a mismatched line.

I don't have the article, and haven't been able to find it on the net,
so I am working from references to it that I have seen, mainly in
Usenet.

Apparently, the method involves calculation of a factor (let's call it
MR) as MR=|(Zl-Zo*)/(Zl+Zo)|, and the line loss between two points is
given by 10*log((1-MR1**2)/(1-MR2**2)) where MR1 and MR2 are the
values for MR at points 1 and 2.

I have compared the results of this on lines with Xo0 and high VSWR,
and the results are identical to calcuating the loss by subtraction of
Real(VI*) at point 1 from Real(VI*) at point 2.

Has anyone a link to, or a reference to the derivation of the formula?

Owen

In my first edition of "Paul and Nasar", p 335, dealing with lossy
transmission lines; there is a footnote as follows:

For the interested reader, a very thorough discussion of the derivation the
transmission-line equations is given in R. B. Adler, L. J. Chu, and R. M.
Fano , "Electromagnetic Energy Transmission and Radiation", Wiley, New York,
1960, chap. 9.

I have never seen the reference, so cannot comment, but may be available in
a university library. Wonder if that is the Fano in "Fano's limit".

73,

Frank