So another way for the lurkers to check all this: assume a line Zo =
50-j5, and a load Zload = 1+j100. Assume some convenient Vf at the
load. Calculate rho = Vr/Vf from the equation quoted below. Now find
Vr, and from the line impedance and Vf and Vr, find If and Ir. Add
the V terms and I terms to get the net line voltage and current at the
load. Does that correspond to the expected load current for the given
Zload? If so, fine; if not, where does the difference in current come
from? If you assume the line current is correct from your If and Ir
calcs, and the load current is correct as the net line voltage = net
load voltage, and use Zload to get Iload, does the line power
dissipation plus the load power dissipation equal the power fed in
from a generator? Try all those calcs after revising the Vr/Vf
formula to match what Besser is now teaching, and see if things line
up a bit better.

The truth is all there to be seen with just a bit of work.

Cheers,
Tom

(yeah, I've done it, as you might guess. And so have a lot of
others.)

(Dr. Slick) wrote in message . com...
Actually, my first posting was right all along, if Zo is always real.

From Les Besser's Applied RF Techniques:

"For passive circuits, 0=[rho]=1,

And strictly speaking: Reflection Coefficient =
(Zload-Zo*)/(Zload-Zo)

Where * indicates
conjugate.

But most of the literature assumes that Zo is real, therefore
Zo*=Zo."


And then i looked at the trusty ARRL handbook, 1993, page 16-2,
and lo and behold, the reflection coefficient equation doesn't have a
term for line reactance, so both this book and Pozar have indeed
assumed that the Zo will be purely real.

That doesn't mean Zload cannot have reactance (be complex).

Try your calculation again, and you will see that you can never
have a [rho] (magnitude of R.C.)greater than 1 for a passive network.

How could you get more power reflected than what you put in (do
you believe in conservation of energy, or do you think you can make
energy out of nothing)? If you guys can tell us, we could fix our
power problems in CA!

But thanks for checking my work, and this is a subtle detail that
is good to know.


Slick