On Wed, 02 Jun 2004 16:49:09 GMT, Walter Maxwell wrote:

On Wed, 02 Jun 2004 08:37:30 -0500, Cecil Moore wrote:

Walter Maxwell wrote:

wrote:
Steve at first said the energy in the canceled waves continues to flow toward the
source without a voltage and current and that interference was not involved. He later
changed his mind. All that should be archived on r.r.a.a on Google for the summer
of 2001. Here's an excerpt. Steve said: "The total forward power increases as a direct
result of the vector superposition of forward voltage and current. This DOES NOT
require a corresponding destructive interference process ..." thus contradicting Hecht
in _Optics_ who says any constructive interference process must be accompanied by
an equal magnitude of destructive interference.

Superposition of forward voltage and current?

I'm sure he meant "superposition of forward voltages and superposition of
forward currents."

I don't recall Steve ever mentioning current.

I think you are right re his article. The above quote is from an
r.r.a.a. posting circa Summer 2001.

What Steve apparently doesn't understand is how the
energy direction is reversed when the rearward voltages and currents go to zero.

"How" is not explained in any of the physics references. The closest
physics reference that explains it is _Optics_, by Hecht where he says
something like, at a point some distance from a source, constructive
interference must be balanced by an equal magnitude of destructive interference.
In a matched system, there is "complete destructive interference" toward the
source side of the match point and "complete constructive interference" toward
the load side of the match point. Energy is always displaced from the "complete
destructive interference" event to the "complete constructive interference"
event. (That's what you call a "virtual short" or "virtual open" capable of
re-reflecting the reflected energy.)

Cecil, I explained the 'how', both in Reflections and in QEX. My explantion of
'how' is what Steve is continually stating is incorrect, especially in his last
3-part QEX article. Statements in that article prove he doesn't understand the
wave mechanism that reverses the direction of the reflected energy. Evidence of
this is that by simply saying the voltages cancel is insufficient description of
how the energies reverse direction. In fact, in his Oct 99 ComQuart article he
specifically states that both voltages and power cancel. This tell me that he
doesn't understand the wave action he's attempting to teach.

MIT's Slater and Harvard's Alford both explain it brilliantly, but Steve rejects
those references as 'irrelevant', and says I mistakenly used them as references
in Reflections.

What is really perplexing to me is that several posters on this subject said
that Steve's 3-parter is the best and most illuminating article they ever read
on the subject. How can they have missed some of the most egregious errors
appearing in that paper is unbelievable!

snip

Cecil, the following is a direct quote from Steve's Comm Quart Article, Oct
1999:
"For the impedance matching network to 'work', this analysis must demonstrate
that the steady-state traveling backward power developed at the matching network
input is equal in magnitude but 180 degrees out of phase with the initial power
reflected at the matching network input. For this to occur Vback must be the
negative of VR. In this case ALL POWER TRAVELING BACKWARD TOWARDS THE
TRANSMISTTER WILL BE CANCELED, resulting in the steady-state matched condition."

Emphasis mine.

Walt