Dan wrote:
Now that the various typo mistakes have been corrected, and putting
aside for the moment the name calling and ad hominem arguments, could
it be that _both_ sides in this discussion are correct? Camp 'A' says
that the reflection coefficient is computed the classical way, without
using Zo conjugate, and offers various mathematical proofs and
discussions of infinitely long lines. Camp 'B' says the reflection
coefficient is computed with Zo* (Zo conjugate) in the numerator, and
offers explanations dealing with the conservation of energy and
maximum transfer of power.

Both sides may be correct since they are talking about _two different_
meanings for the term "reflection coefficient." One has to do with
voltage (or current) traveling waves and the other has to do with
power.

If a lossy line is terminated with the complex Z0,
there is no reflection from the load, but the
maximum possible power is not delivered. If the
*load* is made equal to the complex conjugate of
Z0 the maximum *forward power* is delivered but
there is a reflected power (VSWR is not 1:1).

It is difficult to say that the maximum *power* is
delivered without knowing the generator impedance,
since it is involved in any so-called "conjugate
match". For a lossy line, the idea of conjugate
match is, at best, very approximate anyway. And
generator impedance is a mystery in most, but not
all, transmitter PA situations. One possible
exception: a large amount of negative feedback
helps to determine, to some extent, output
impedance, for a signal with time-varying
amplitude (e.g. SSB).

It seems to me to be clear that the use of Z0* in
the reflection coefficient equation has not been
corroborated (see Roy's post), but the use of
ZL=ZO* has been. The two ideas are not equivalent.

After looking at some examples, using the exact
complex hyperbolic equations with Mathcad, it is
obvious that a line must be very lossy to make a
significant difference whether ZL or ZL* is used
to terminate the line. Still, it is important to
understand the basic principles involved, so this
exercise is not foolishness at all.

A word about "credentials". We all respect
established and competent authors. But I have
noticed on several occasions that blind faith has
some exceptions. As an experienced author, I am
personally familiar with this problem.

G. Gonzalez (highly respected) "Microwave
Transistor Amplifiers" second edition, has a good
discussion of Power Waves, based on Kurokawa (I
also have his article). There are no transmission
lines, and the term ZS* (ZS=generator impedance)
is used. In particular, a power wave reflection
coefficient is defined:

Gp = (ZL-ZS*)/(ZL+ZS)

which looks quite familiar, with ZS replacing Z0.
Also, a voltage reflection coefficient:

Gv = [Zs/Zs*] x [(ZL-ZS*)/(ZL+ZS)]

and a current reflection coefficient

Gv = Gp.

The author also defines two-port scattering
parameters in terms of power waves, in which ZS*
and ZL* appear.

For the purposes of the present topic, involving
transmission lines, it seems best to stay away
from power waves, without a lot more studying.

Bill W0IYH