Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
Cecil Moore wrote:
This is steady-state after the wave interaction. What
you guys don't seem to realize is that s11(a1) and
s12(a2) are continually changing, continually
interacting, and a1 & a2 are rotating phasors
changing with time.

Utter nonsense. Any setup that includes t0 or t=0 is not steady state.

Gene, you obviously misunderstood what I said. There is
no t0 or t=0 in my above statement. It is just that the
delta-t doesn't change from the transient state to the
steady-state.

In an s-parameter analysis:
The normalized voltage, a1, equals Vi1/SQRT(Z0) where
'i' stands for incident voltage. a2 equals Vi2/SQRT(Z0).
These voltages are normally represented in phasor
notation but they can just as easily be represented
in exponential notation where a1 = Vi1*e^jwt+X and
a2 = Vi2*e^jwt+Y, where X and Y are constant phase
angles. Thus, the s-parameter equation becomes:

b1 = Vi1[cos(wt+X)]/SQRT(Z0) + Vi2[cos(wt+Y)]/SQRT(Z0) = 0

adding the delta-t "tick" gives:

b1 = Vi1{cos[w(t+delta-t)+X]}/SQRT(Z0) +
Vi2{cos[w(t+delta-t)+Y]}/SQRT(Z0) = 0

Vi1 obviously has to be an equal magnitude to Vi2 and
X and Y obviously have to be 180 degrees apart. Given
that, for every delta-t "tick" of time, the two real
normalized voltages sum to zero. The square of the
normalized RMS value gives average power in each
wave. The equation can be turned into a differential
equation by having delta-t approach zero in the limit.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
You really do need
to realize that there is no need for a circulator.

So Tektronix can just abandon its circulator business
and kiss their circulator profits goodbye? When are
you going to patent your idea and get rich?

There you go. Still stuck. You really should crack the books in search
of a reference to support your contention. You won't find one.

And that is exactly why the argument has been raging for decades.
Humans have not yet acquired 100% of all knowledge. You seem to
claim that you have mastered that task but I seriously doubt it.

And the relevence of the conjugate match is that the conjugate
is the generator source impedance and it is the impedance that
the wave incident upon the generator sees.

I see you have not yet read Walter Maxwell's article. The
generator source impedance is not what is seen by the reflected
waves.

I have certainly never said that. If you could point me to the words
that misled you into thinking that, I will attempt to clarify your
misunderstanding.

Correct me if I'm wrong. I understood you to say that energy
cannot flow past an instantaneous zero energy point yet there
is an instantaneous zero energy point every 1/2WL in an EM
traveling wave.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
On Apr 20, 12:46 pm, Cecil Moore wrote:
I already did - Bruene's early 1990's QST article.

Sorry. Not a good enough description for any kind of analysis.

Ignore it if you choose. That's when the present hoopla
began, at least in the amateur radio community. You can
follow the thread from that point to the present to see
what is happening in the present.

Nothing to sweep under the rug, I am afraid. It is key that the
dissipation depends on the design of the generator. Some
times those 'reverse watts' cause the dissipation to drop
to 0, sometimes they cause it to increase by a factor of 4,
sometimes they cause it to increase by the numerical value
of the 'reverse watts'. Pretty much hard to argue that those
'reverse watts' are real when their heating effect is so
variable.

Not at all. The heating effect depends upon how much of
the reverse joules/sec are re-reflected. If the dissipation
drops to 0, that is prima facie evidence that all the
reflected joules/sec have been re-reflected. If the
dissipation increases by a factor of 4, that is prima facie
evidence that all of the reflected joules/sec are being
dissipated in the source along with all of the joules/sec
available from the source into a matched load. Anything
else would violate the conservation of energy principle.

I'd suggest you think of power as a quantity not a situation.
Superposition works for linear, time invariant circuits with
multiple sources. Check any text book. The generators and
lines under discussion meet these requirements.

But superposition obviously doesn't work at the source
*point*. One possible technical conclusion may be that
the dynamic active source is constant, fixed, and refuses
to be superposed (for any constant, fixed load). If that
is true, it would certainly stop the present raging debate
in its tracks.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
Cecil Moore wrote:
This is steady-state after the wave interaction. What
you guys don't seem to realize is that s11(a1) and
s12(a2) are continually changing, continually
interacting, and a1 & a2 are rotating phasors
changing with time.

Utter nonsense. Any setup that includes t0 or t=0 is not steady state.

Gene, you obviously misunderstood what I said. There is
no t0 or t=0 in my above statement. It is just that the
delta-t doesn't change from the transient state to the
steady-state.

In an s-parameter analysis:
The normalized voltage, a1, equals Vi1/SQRT(Z0) where
'i' stands for incident voltage. a2 equals Vi2/SQRT(Z0).
These voltages are normally represented in phasor
notation but they can just as easily be represented
in exponential notation where a1 = Vi1*e^jwt+X and
a2 = Vi2*e^jwt+Y, where X and Y are constant phase
angles. Thus, the s-parameter equation becomes:

b1 = Vi1[cos(wt+X)]/SQRT(Z0) + Vi2[cos(wt+Y)]/SQRT(Z0) = 0

adding the delta-t "tick" gives:

b1 = Vi1{cos[w(t+delta-t)+X]}/SQRT(Z0) +
Vi2{cos[w(t+delta-t)+Y]}/SQRT(Z0) = 0

Vi1 obviously has to be an equal magnitude to Vi2 and
X and Y obviously have to be 180 degrees apart. Given
that, for every delta-t "tick" of time, the two real
normalized voltages sum to zero. The square of the
normalized RMS value gives average power in each
wave. The equation can be turned into a differential
equation by having delta-t approach zero in the limit.

Cecil,

I should have know better than to read this with a cup of coffee in my
hand. I just snorted coffee all over my keyboard.

8-)

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
I should have know better than to read this with a cup of coffee in my
hand. I just snorted coffee all over my keyboard.

Your highly technical rebuttal of my posting is noted.
Have you ever seen the equation?

The integral of e to the x = function of u to the n
__
|_
__|e^x = F(u^n)
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
I should have know better than to read this with a cup of coffee in my
hand. I just snorted coffee all over my keyboard.

Gene, I've got an experiment for you. Go to:

http://micro.magnet.fsu.edu/primer/j...ons/index.html

and set one phase to 0 and the other phase to 180 degrees.
Then get an index card and cover up everything to the
left except one point on each wave. All you see is those
two single points moving up and down. That gives you a
visual idea of how s11(a1) and s12(a2) originate and are
canceled at a Z0-match *point*. Plot those points back
in time and you will have a history of the canceled waves
from which you can compute average power density as
|s11(a1)|^2 and |s12(a2|^2.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
I should have know better than to read this with a cup of coffee in my
hand. I just snorted coffee all over my keyboard.

Gene, I've got an experiment for you. Go to:

http://micro.magnet.fsu.edu/primer/j...ons/index.html


and set one phase to 0 and the other phase to 180 degrees.
Then get an index card and cover up everything to the
left except one point on each wave. All you see is those
two single points moving up and down. That gives you a
visual idea of how s11(a1) and s12(a2) originate and are
canceled at a Z0-match *point*. Plot those points back
in time and you will have a history of the canceled waves
from which you can compute average power density as
|s11(a1)|^2 and |s12(a2|^2.

Cecil,

You are going to pull a brain muscle by stretching so much. Are you
suggesting that two wiggling points on a web page are the key to
understanding the universe?

Here's a thought experiment for you. Read the message by Tom, K7ITM,
where he copied a quote from physicsforums.com. See if you can figure
out how those waves you insist are created and then quickly canceled
(delta-t later) might have never existed in the first place. Hint: waves
don't interact with each other, but they do interact with materials
containing electrons. (I believe that covers quite a few materials.)

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 21, 8:35 am, Cecil Moore wrote:
Keith Dysart wrote:
I have certainly never said that. If you could point me to the words
that misled you into thinking that, I will attempt to clarify your
misunderstanding.

Correct me if I'm wrong. I understood you to say that energy
cannot flow past an instantaneous zero energy point yet there
is an instantaneous zero energy point every 1/2WL in an EM
traveling wave.

Actually I said a zero power point, but you are essentially
correct. If the zero power point is stationary then no energy
can be flowing. When energy is flowing, either there is no
zero power point, or the zero power point is moving as well.

At a given point on the line, when the voltage or current is
always zero then no energy is flowing. When energy is
flowing, the voltage and current will not always be zero at
that point.

There can also be a voltage and current but they can be
90 degrees out of phase so no net energy flows. In this
case, energy will flow first forward then backwards with
an average of zero.

....Keith

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 21, 8:47 am, Cecil Moore wrote:
Keith Dysart wrote:
Nothing to sweep under the rug, I am afraid. It is key that the
dissipation depends on the design of the generator. Some
times those 'reverse watts' cause the dissipation to drop
to 0, sometimes they cause it to increase by a factor of 4,
sometimes they cause it to increase by the numerical value
of the 'reverse watts'. Pretty much hard to argue that those
'reverse watts' are real when their heating effect is so
variable.

Not at all. The heating effect depends upon how much of
the reverse joules/sec are re-reflected. If the dissipation
drops to 0, that is prima facie evidence that all the
reflected joules/sec have been re-reflected. If the
dissipation increases by a factor of 4, that is prima facie
evidence that all of the reflected joules/sec are being
dissipated in the source along with all of the joules/sec
available from the source into a matched load. Anything
else would violate the conservation of energy principle.

So you expect that some of the reverse wave is reflected at the
generator and yet experiment has shown that none of the
reverse wave is reflected at the generator when the generator]
source impedance is the same as the line characteristic
impedance. I am curious as to why you ignore these
experimental results.

I'd suggest you think of power as a quantity not a situation.
Superposition works for linear, time invariant circuits with
multiple sources. Check any text book. The generators and
lines under discussion meet these requirements.

But superposition obviously doesn't work at the source
*point*. One possible technical conclusion may be that
the dynamic active source is constant, fixed, and refuses
to be superposed (for any constant, fixed load). If that
is true, it would certainly stop the present raging debate
in its tracks.

As you noted previously, it does not matter whether the
reverse wave is created by a reflection or another generator.
So the experiment has been done with a generator at both
ends of the line and the results are entirely consistent with
the results predicted using the generator source impedance
to compute the amount of reflection. I am curious as to
why you ignore these results.

And, of course, there results are consistent with the analysis
described in any basic text book on transmission lines.

....Keith

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
You are going to pull a brain muscle by stretching so much. Are you
suggesting that two wiggling points on a web page are the key to
understanding the universe?

No, just wave cancellation. If the graphic is completely
incorrect, as you say, why did they publish it?
--
73, Cecil http://www.w5dxp.com