"Dr. Slick" wrote in message
om...
"David Robbins" wrote in message
...
From 'Fields and Waves in Communications Electronics' by Ramo Whinnery
and
Van Duzer. section 1.16 and 1.23

start with positive moving wave plus negative moving wave = total to
load
for both voltage and current, simple kirchoff's law summations at the
junction of the coax and load.
Vp+Vn=Vload (1)
Ip-In=Iload (2)
note that their convention is that current moving to the 'right' is
positive
so the reflected 'negative' current wave is moving left which gives the
negative sign on the second term.

now use ohm's law to rewrite (2)

Vp/Zo - Vn/Zo = Vload/Zload (3)



I believe this line (3) is only true if Zo is purely real.

If Zo is complex, i don't think you can apply
this.


yes you can. in sinusoidal steady state analysis as discussed in 'Basic
Circuit Theory' by Desoer and Kuh. in chapter 7 and specifically section 5
of that chapter they show the kirchoff current and voltage laws and ohms law
generalized for phasor representations of voltage and current and complex
impedances and admittances. those representations are perfectly valid in
that type of analysis.