Gene Fuller wrote:
Never is a long time.

Waves never interact *is* a long time.

I agree with Jim and Roy, and most of the rest of the world.
Electromagnetic waves, or photons if you prefer, simply do not interact
without the assistance of interfaces, discontinuities, or a non-linear
medium. Interference is a result from linear superposition. No waves are
harmed in the process.

"No waves are harmed in the process" implies that waves can
never be canceled. Yet, all the textbooks and all the web
pages say that when two coherent collinear waves of equal
magnitudes and opposite phases meet, they only appear to
be destroyed but their energy components are actually
"redistributed" in different directions.

That's exactly what happens to reflected waves toward the
source when a Z0-match is achieved. The energy components
in the reflected waves, s11(a1) and s12(a2), are redistributed
back toward the load. How does b1 ever go permanently to
zero without s11(a1) and s12(a2) canceling each other?

There is also no law that says all
of the individual component waves you may choose to create need to have
some sort of detailed energy balance.

Yes, there is, Gene. It is called the conservation of
energy principle. You cannot create energy in one place,
have it destroyed in another place, and then argue that
everything is all right because the net energy balance
remains the same.

"If other independent and dependent variables had been chosen, the
network would have been described, as before, by two linear equations
similar to equations 1 and 2, except that the variables and the
parameters describing their relationships would be different. However,
all parameter sets contain the same information about a network, and it
is always possible to calculate any set in terms of any other set."

The other variables described earlier in the note include voltage and
current. Again, we come to my old standby, mathematical convenience.
S-parameters are very useful, but they bring nothing new to the physical
reality.

Then why are you so afraid to discuss an s-parameter
analysis? Please respond to my example posting. How
does s11(a1) go from 5 to 0 without interacting with
something?
--
73, Cecil http://www.w5dxp.com