Gene Fuller wrote:
Do you see the common factor in your response about "wave interaction"?
In all of your examples there is an interface or some sort of
discontinuity. Nobody argues that waves are forever unchanging. However,
those changes take place only through interaction with interfaces or
other discontinuities.

I don't disagree and I have gone on record as saying that
reflections only occur at physical impedance discontinuities.
The interaction of s11(a1) and s12(a2) is caused by the
interaction of a1 and a2 with the impedance discontinuity.
There's no doubt about that.

a1 interacts with the impedance discontinuity to cause
s11(a1) and s21(a1). a2 interacts with the impedance
discontinuity to cause s12(a2) and s22(a2). s11(a1),
s12(a2), s21(a1), and s22(a2) are created as a result
(an effect) of the interaction of a1 and a2 with the
impedance discontinuity. I have *NEVER* said that
waves interact with each other in the absence of
an impedance discontinuity. Assertions to that effect
are obfuscations of what I have said.

But even you must realize that the wave component, s11(a1),
*originates* traveling *away from* the impedance discontinuity
as an *EFFECT* of the forward wave, a1, being incident upon
the impedance discontinuity. It is a1 that is incident upon
the impedance discontinuity, not s11(a1). s11(a1) *originates*
at the impedance discontinuity traveling *away from* it and is
*never incident* upon the impedance discontinuity. All s11(a1)
ever encounters is s12(a2) and is canceled on the spot if
s12(a2) is of equal magnitude and opposite phase.

The wave component, s12(a2), *originates* at the impedance
discontinuity traveling *away from* the impedance discontinuity
as an *EFFECT* of the reflected wave, a2, being incident upon
the impedance discontinuity. It is a2 that is incident upon
the impedance discontinuity, not s12(a2). s12(a2) *originates*
at the impedance discontinuity traveling *away from* it and
is *never* incident upon the impedance discontinuity. All it
ever encounters is s11(a1) and is canceled on the spot if
s11(a1) is of equal magnitude and opposite phase.

Arguing that s11(a1) and s12(a2) are incident upon the
impedance discontinuity is obviously false since they
originate traveling *away from* the impedance discontinuity.
It is impossible for signals that originate traveling away
from the impedance discontinuity, to ever be incident upon
the impedance discontinuity. The confusing of cause and effect
is obvious.

So how do you think that signals that originate traveling
*away from* the impedance discontinuity ever can be incident
upon the impedance discontinuity?
--
73, Cecil, w5dxp.com