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

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
If the zero power point is stationary then no energy
can be flowing.

Time for you to review EM waves, Keith. There is a zero
power point in every EM traveling wave every 1/2WL where
the E-field and H-field are both zero at the same time.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
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.

Those "experimental results" paper-only results are a figment
of your imagination. You zero energy level source proved just
the opposite.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 20, 5:34 pm, Cecil Moore wrote:
Jim Kelley wrote:
There is no support for your claim.

There is plenty of support for my claim, Jim, but you
deleted it. I will simply repost it over and over until
you respond.

Given the following experiment with two signal generators
equipped with circulators and load resistors - the generators
are phased-locked to ensure coherency. The two feedlines
are of equal electrical lengths.

SGCL1 is turned on. SGCL2 is turned off.

100W | 25W
50 ohm---50 ohm line---+---291.4 ohm line---291.4 ohm
SGCL1 --Prev1 | SGCL2

What is Pref1 before SGCL2 is turned on? What is Pref1
after SGCL2 is turned on? Did Pref1 change after SGCL2
is turned on?

Since Pref1 *NEVER* encounters the impedance discontinuity
how can it possibly be affected by SGCL2 being turned on?
This is a perfect example of wave interaction.
--
73, Cecil http://www.w5dxp.com

It's not an example of anything other than newsgroup rhetoric, Cecil.
Buy a good RF data acquisition system, all the equipment listed in
your problem, and run the experiment. I'd be happy to discuss the
results with you afterward.

73, Jim AC6XG

Analyzing Stub Matching with Reflection Coefficients
 

Jim Kelley wrote:
It's not an example of anything other than newsgroup rhetoric, Cecil.
Buy a good RF data acquisition system, all the equipment listed in
your problem, and run the experiment. I'd be happy to discuss the
results with you afterward.

Translation: I am clueless to explain one of the most
simple of experiments involving s-parameters.
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Keith Dysart wrote:
If the zero power point is stationary then no energy
can be flowing.

Time for you to review EM waves, Keith. There is a zero
power point in every EM traveling wave every 1/2WL where
the E-field and H-field are both zero at the same time.

Cecil,

Four questions:

* Does your IEEE dictionary have an entry for "stationary"?

* Which part of "every EM traveling wave" is stationary?

* Do you actually read any of the messages to which you respond?

* Do you want to retract your answer?

8-)

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
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?

Cecil,

I did not say the graphic was incorrect, but rather that it is
irrelevant. It correctly shows the addition of two sine waves.

Big deal.

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
* Does your IEEE dictionary have an entry for "stationary"?

I'm afraid you have been taken in by my devil's
advocate argument based on Keith's faulty concepts.
If what he says is true about standing waves, then
the same concepts apply to traveling waves. If there
are no traveling wave energy components being transferred
when two traveling waves are flowing in opposite
directions, then it logically follows that there can
be no traveling wave energy component being transferred
when one traveling wave is flowing in one direction.

The *NET* energy flow is zero in a standing wave.
But the component energy flow in the underlying EM
waves is alive and well and flowing right through
those current and voltage nodes without even knowing
that they are there. The illusion of zero energy flow
in EM traveling waves is one of the problems with
shortcuts. EM waves have a set of boundary conditions
that must be satisfied for them to exist. One of
those conditions is that they must necessarily
travel at c(VF). "Stationary" is not possible for
any single EM wave. Nobody has been able to provide
an example of a standing wave without the underlying
forward and reverse EM traveling wave components
(not even you) :-). Another condition for the existence
of an EM traveling wave is that it has an associated
energy level without which it cannot exist.

A stationary EM wave is a contradiction in terms,
an oxymoron. EM waves cannot stand still
and exist only as a concept in the human mind.
It is an illusionary temporarily superposed profile
of two waves that, in reality, are moving in opposite
directions at c(VF) and have absolutely *NO* effect on
each other. The forward EM wave possesses direction
and momentum that doesn't change until it encounters
a physical impedance discontinuity. The reverse EM
wave possesses direction and momentum that doesn't
change until it encounters a physical impedance
discontinuity. Anything else would violate the laws
of physics.
--
73, Cecil, w5dxp.com



--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
I did not say the graphic was incorrect, but rather that it is
irrelevant. It correctly shows the addition of two sine waves.

OK, if it is irrelevant, why did they publish it?
Why do they talk about "redistribution" of energy
in other directions during a destructive interference
event? Doesn't changing the direction and momentum of
a wave qualify as "interaction"?

And when those two sine waves are coherent, of equal
amplitude, and opposite phase, they permanently *CANCEL*
each other. Doesn't that satisfy the definition of
"interacting"?

I see you have been strangely silent on my example of
s11(a1) originating and flowing away from the impedance
discontinuity only to be canceled by s12(a2) when it
flows through the impedance discontinuity and encounters
the s11(a1) wave flowing away from the impedance
discontinuity. How can the effect of one wave on the
other not be interaction when both are flowing away
from the impedance discontinuity and are *NEVER*
incident upon any impedance discontinuity?
--
73, Cecil http://www.w5dxp.com

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 23, 4:56 am, Cecil Moore wrote:

A stationary EM wave is a contradiction in terms,
an oxymoron.

It sounds just like a standing EM wave. :-)

Anything else would violate the laws
of physics.

The funny thing is, if you knew how to apply that constraint to all of
your claims, you wouldn't find yourself playing newsgroup Whack-a-Mole
day all day.

73, Jim AC6XG

Analyzing Stub Matching with Reflection Coefficients
 

Jim Kelley wrote:
Cecil Moore wrote:
A stationary EM wave is a contradiction in terms,
an oxymoron.

It sounds just like a standing EM wave. :-)

EM waves cannot stand still. They must necessarily move
at the speed of light, c(VF). The illusion of a stationary
EM wave is actually two EM waves moving in opposite directions
at the speed of light. Both waves include all of the boundary
conditions necessary for EM waves to exist.

Again, if you can present an example of an EM standing wave
devoid of the forward and reverse traveling wave components,
now would be a good time.

Anything else would violate the laws of physics.

The funny thing is, if you knew how to apply that constraint to all of
your claims, you wouldn't find yourself playing newsgroup Whack-a-Mole
day all day.

I just love it when you wax technical, Jim.
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
* Does your IEEE dictionary have an entry for "stationary"?

I'm afraid you have been taken in by my devil's
advocate argument based on Keith's faulty concepts.
If what he says is true about standing waves, then
the same concepts apply to traveling waves. If there
are no traveling wave energy components being transferred
when two traveling waves are flowing in opposite
directions, then it logically follows that there can
be no traveling wave energy component being transferred
when one traveling wave is flowing in one direction.

The *NET* energy flow is zero in a standing wave.
But the component energy flow in the underlying EM
waves is alive and well and flowing right through
those current and voltage nodes without even knowing
that they are there. The illusion of zero energy flow
in EM traveling waves is one of the problems with
shortcuts. EM waves have a set of boundary conditions
that must be satisfied for them to exist. One of
those conditions is that they must necessarily
travel at c(VF). "Stationary" is not possible for
any single EM wave. Nobody has been able to provide
an example of a standing wave without the underlying
forward and reverse EM traveling wave components
(not even you) :-). Another condition for the existence
of an EM traveling wave is that it has an associated
energy level without which it cannot exist.

A stationary EM wave is a contradiction in terms,
an oxymoron. EM waves cannot stand still
and exist only as a concept in the human mind.
It is an illusionary temporarily superposed profile
of two waves that, in reality, are moving in opposite
directions at c(VF) and have absolutely *NO* effect on
each other. The forward EM wave possesses direction
and momentum that doesn't change until it encounters
a physical impedance discontinuity. The reverse EM
wave possesses direction and momentum that doesn't
change until it encounters a physical impedance
discontinuity. Anything else would violate the laws
of physics.
--
73, Cecil, w5dxp.com

Cecil,

Nobody said the "wave" was stationary, only the point of zero energy is
stationary. You have again demonstrated that you are not reading and
understanding.

The *NET* paragraph above is simply unmitigated nonsense. It appears
that mistaken notion is one of the root causes of your continuing
confusion. Until you get over this bogus idea of colliding energy flows
there is no hope for further enlightenment.

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
I did not say the graphic was incorrect, but rather that it is
irrelevant. It correctly shows the addition of two sine waves.

OK, if it is irrelevant, why did they publish it?
Why do they talk about "redistribution" of energy
in other directions during a destructive interference
event? Doesn't changing the direction and momentum of
a wave qualify as "interaction"?

And when those two sine waves are coherent, of equal
amplitude, and opposite phase, they permanently *CANCEL*
each other. Doesn't that satisfy the definition of
"interacting"?

I see you have been strangely silent on my example of
s11(a1) originating and flowing away from the impedance
discontinuity only to be canceled by s12(a2) when it
flows through the impedance discontinuity and encounters
the s11(a1) wave flowing away from the impedance
discontinuity. How can the effect of one wave on the
other not be interaction when both are flowing away
from the impedance discontinuity and are *NEVER*
incident upon any impedance discontinuity?


Cecil,

I did respond to your example. I referred you to the message from K7ITM.
The answer is contained in his quote. Since you seemed to have missed
that one, here is the conclusion.

The waves you are trying to create and then quickly cancel, in delta-t,
simply never existed. Problem solved.

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 23, 7:56 am, Cecil Moore wrote:
Gene Fuller wrote:
* Does your IEEE dictionary have an entry for "stationary"?

I'm afraid you have been taken in by my devil's
advocate argument based on Keith's faulty concepts.
If what he says is true about standing waves, then
the same concepts apply to traveling waves.

It becomes clear from your posts that you have a wave
centric view of these behaviours. It is often valuable to
have more than one way to view a situation. Let me offer
you another.

While I will describe this view only for transmission
lines, its equivalent in free space would be the Maxwell
equations, so, knowing your support for Maxwell, you
should find it attractive.

The voltages and currents on a transmission line can
be described with a collection of differential equations.
When these differential eqations are solved for a set of
boundary conditions, the results describe the voltage
and current on the line as a function of time and
location along the line.

Were one to set up an ideal line (for simplicity),
terminated in its characteristic impedance, the functions
that describe the voltage and current on the line can
be derived. Plugging in the time and location one can
determine the voltage at that place and instance. The
curious investigator will be tempted to plot the voltage
for a particular time as a function of location. The
resulting plot will be nicely sinusoidal. Were one to
plot the result for deltaT later, one finds a plot with
exactly the same shape, but slightly shifted. A movie
would show this nice sinusoid shifting its location at
a constant velocity. And our intrepid investigator
names this a travelling wave, a convenient moniker.

Let us consider another line. This one is open circuited.
Solving the diffential equations that describe the line
for these new boundary conditions produces a different
set of functions of time and location. Plotting the
function of voltage with respect to location again
produces a sinusoid, but the amplitude depends on the
selected time. This plot, when played as a movie, shows
no sign of moving and our intrepid investigator names
it a standing wave, another convenient moniker.

But just because they are both called waves does not
make them the same. One always has the same shape and
amplitude and appears to move. The other shares the shape,
does not move and has an amplitude that varies.
Fundamentally, they are both just convenient visualizations
of solutions from the same set of differential equations
with different boundary conditions.

For the standing wave, further arithmetic reveals that the
function that expresses the voltage as a function of time
and location can be simplified and made more useful if
it is expressed in terms of two travelling waves, one
from the left and one from the right. But this is just
an alternate expression of the function that resulted
from the solution of a set of differential equations.

While the initial differential equations express voltage
and current, one could certainly derive equations that
expressed power, or energy storage, or whatever happened
to be of interest. One could then solve these and the
expression that results would be a function of time and
location.

Were one to solve the differential equation for power
on the open circuited line at a location of a voltage
null, the answer would be zero. And all computed without
the need for forward and backward waves.

---

So which is the truth? The differential equations or
the forward and backward waves? Which analysis technique
is more complete? And which is the alternative view that
makes the problems solvable in reasonable time?

It is clear to me that the differential equations rule,
much as Maxwell's equations are considered the root for
electric and magnetic fields.

Travelling and standing waves are mere visualizations,
though that visualization simplifies solving many
problems. But forward and reverse waves are definitely
not the foundation on which all else rests.

....Keith

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 23, 8:54 am, Gene Fuller wrote:
Cecil Moore wrote:
Gene Fuller wrote:
* Does your IEEE dictionary have an entry for "stationary"?

I'm afraid you have been taken in by my devil's
advocate argument based on Keith's faulty concepts.
If what he says is true about standing waves, then
the same concepts apply to traveling waves. If there
are no traveling wave energy components being transferred
when two traveling waves are flowing in opposite
directions, then it logically follows that there can
be no traveling wave energy component being transferred
when one traveling wave is flowing in one direction.

The *NET* energy flow is zero in a standing wave.
But the component energy flow in the underlying EM
waves is alive and well and flowing right through
those current and voltage nodes without even knowing
that they are there. The illusion of zero energy flow
in EM traveling waves is one of the problems with
shortcuts. EM waves have a set of boundary conditions
that must be satisfied for them to exist. One of
those conditions is that they must necessarily
travel at c(VF). "Stationary" is not possible for
any single EM wave. Nobody has been able to provide
an example of a standing wave without the underlying
forward and reverse EM traveling wave components
(not even you) :-). Another condition for the existence
of an EM traveling wave is that it has an associated
energy level without which it cannot exist.

A stationary EM wave is a contradiction in terms,
an oxymoron. EM waves cannot stand still
and exist only as a concept in the human mind.
It is an illusionary temporarily superposed profile
of two waves that, in reality, are moving in opposite
directions at c(VF) and have absolutely *NO* effect on
each other. The forward EM wave possesses direction
and momentum that doesn't change until it encounters
a physical impedance discontinuity. The reverse EM
wave possesses direction and momentum that doesn't
change until it encounters a physical impedance
discontinuity. Anything else would violate the laws
of physics.
--
73, Cecil, w5dxp.com

Cecil,

Nobody said the "wave" was stationary, only the point of zero energy is
stationary. You have again demonstrated that you are not reading and
understanding.

I think he may be too busy having that strange kind of dream he talked
about when he implicitly threw out at least 90% of all S-parameter
analysis by saying that "reality requires complete reflection of the
return wave at the interface between the [matched] source and the
line." Either you believe in the superposition principle in linear
systems, or you don't. He obviously doesn't.

From the lab,
Bunsen

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
The *NET* paragraph above is simply unmitigated nonsense. It appears
that mistaken notion is one of the root causes of your continuing
confusion. Until you get over this bogus idea of colliding energy flows
there is no hope for further enlightenment.

If colliding energy doesn't flow, then waves interact
away from an impedance discontinuity since the colliding
energy components are in separate EM waves traveling in
opposite directions. Which will it be? You cannot have
it both ways.

1. The ExB joules/sec components in the forward wave and the
reflected wave pass through each other with no interaction
such that the *NET* energy flow is zero.

2. The ExB joules/sec components flowing in each direction
cause all energy to stop flowing because of wave interaction.

Please tell us which one is true and which one is false.
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
The waves you are trying to create and then quickly cancel, in delta-t,
simply never existed. Problem solved.

Problem solved by rendering an s-parameter analysis
invalid?

b1 = s11(a1) + s12(a2) = 0

So s11(a1) and s12(a2) in the s-parameter equations don't
exist and never existed. Don't you think you should tell
HP so they can change their Ap Notes?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Keith Dysart wrote:
Were one to solve the differential equation for power
on the open circuited line at a location of a voltage
null, the answer would be zero. And all computed without
the need for forward and backward waves.

The *NET* power at any point on a lossless stub is
zero so that is no big deal. The standing wave
current is always 90 degrees out of phase with
the standing wave current so cos(90) = 0. At a
voltage node, all of the energy has simply moved
into the magnetic field.

Calculate the number of electromagnetic joules in
the line and get back to us on how they are reflected
from your above purely virtual impedance at a
voltage "null" and how they can even exist without
a velocity of c(VF).
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Dr. Honeydew wrote:
Either you believe in the superposition principle in linear
systems, or you don't. He obviously doesn't.

Superposition is known to fail in nonlinear systems.
A source is obviously not linear. The V/I of an active
dynamic source resists any attempt at linear
superposition. How does your superposition work
when you try to spit up a fire hose?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
The *NET* power at any point on a lossless stub is
zero so that is no big deal. The standing wave
current is always 90 degrees out of phase with
the standing wave current so cos(90) = 0. At a
voltage node, all of the energy has simply moved
into the magnetic field.

With 4 amps of RF current at that voltage "null",
how could zero joules/sec possibly exist at that
point? Methinks there are some I^2*Z0 joules/sec
in that 4 amps of RF EM current that necessarily
must be traveling at c(VF).
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Dr. Honeydew wrote:

Either you believe in the superposition principle in linear
systems, or you don't. He obviously doesn't.


Superposition is known to fail in nonlinear systems.
A source is obviously not linear.

Sources are linear. Consider the classic voltage source.. it has zero
impedance. You can stack as many voltage sources as you like, and the
voltage at the top of the stack is the same as the sum of the individual
voltages.



The V/I of an active
dynamic source resists any attempt at linear
superposition.

- a practical RF source, perhaps, might be nonlinear, although it's
pretty easy to come close.. Consider an oscillator isolated by an
isolator or a big pad.

How does your superposition work
when you try to spit up a fire hose?

Just fine. No different than receiving a faint signal superimposed on a
large interfering signal at a different frequency.

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Jim Kelley wrote:

Cecil Moore wrote:

A stationary EM wave is a contradiction in terms,
an oxymoron.


It sounds just like a standing EM wave. :-)

Again, if you can present an example of an EM standing wave
devoid of the forward and reverse traveling wave components,
now would be a good time.

I didn't say anything was devoid of anything, Cecil. I just said your
description of a stationary EM wave sounds just like a standing EM wave.

I don't think you caught my drift (or Gene's), but go ahead and give
it another whack.

73, Jim AC6XG

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
The waves you are trying to create and then quickly cancel, in
delta-t, simply never existed. Problem solved.

Problem solved by rendering an s-parameter analysis
invalid?

b1 = s11(a1) + s12(a2) = 0

So s11(a1) and s12(a2) in the s-parameter equations don't
exist and never existed. Don't you think you should tell
HP so they can change their Ap Notes?

Cecil,

You routinely confuse results and observations with underlying causes.

There is nothing wrong with s-parameter analysis. The problem is that
you keep trying to make s-parameters something they are not. Did you
perhaps notice that word "parameter"? Do you think there might be a
reason that term was chosen rather than, say, "all encompassing
equations describing the entire universe"?

S-parameters work fine for their intended purpose. However, they don't
trump Maxwell's equations or solid state physics, nor do they try to.

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:
Gene Fuller wrote:
The *NET* paragraph above is simply unmitigated nonsense. It appears
that mistaken notion is one of the root causes of your continuing
confusion. Until you get over this bogus idea of colliding energy
flows there is no hope for further enlightenment.

If colliding energy doesn't flow, then waves interact
away from an impedance discontinuity since the colliding
energy components are in separate EM waves traveling in
opposite directions. Which will it be? You cannot have
it both ways.

1. The ExB joules/sec components in the forward wave and the
reflected wave pass through each other with no interaction
such that the *NET* energy flow is zero.

2. The ExB joules/sec components flowing in each direction
cause all energy to stop flowing because of wave interaction.

Please tell us which one is true and which one is false.


Cecil,

You still don't believe in superposition, do you?

I don't need to worry about which of your purported answers is goofier
than the other. Superposition allows me to combine your traveling waves
into a standing wave. The energy analysis then becomes very easy, with
no paradoxes.

73,
Gene
W4SZ

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:

Gene Fuller wrote:

The waves you are trying to create and then quickly cancel, in
delta-t, simply never existed. Problem solved.


Problem solved by rendering an s-parameter analysis
invalid?

b1 = s11(a1) + s12(a2) = 0

So s11(a1) and s12(a2) in the s-parameter equations don't
exist and never existed. Don't you think you should tell
HP so they can change their Ap Notes?

HP would simply observe that what b1 = 0 means is that there is no
energy and there are no waves moving in the direction of b1.

73, Jim AC6XG

Analyzing Stub Matching with Reflection Coefficients
 

Jim Lux wrote:
Sources are linear. Consider the classic voltage source. it has zero
impedance.

You talk about those sources as if they exist in reality.
They only exist in a human mind in a mathematical model.

a practical RF source, perhaps, might be nonlinear, although it's
pretty easy to come close.. Consider an oscillator isolated by an
isolator or a big pad.

I have suggested those configurations myself and those ideas
have been rejected by the other side - which claims that
all one needs to linearize a real-world source is a ten
cent resistor.

How does your superposition work
when you try to spit up a fire hose?

Just fine. No different than receiving a faint signal superimposed on a
large interfering signal at a different frequency.

Do you really think that any of those spit molecules
make it all the way to the source?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
There is nothing wrong with s-parameter analysis.

There is certainly something wrong with it if the terms
in the s-parameter never existed, as you assert.

S-parameters work fine for their intended purpose. However, they don't
trump Maxwell's equations or solid state physics, nor do they try to.

Nobody said they did, Gene, so this is just another one of
your straw men. EM waves canceling each other to zero are
perfectly compatible with Maxwell's equations. When you
use Maxwell's equations on two EM waves of equal amplitude
and opposite phase, do those equations really say that
the two waves, as you assert, never existed in the first
place?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Gene Fuller wrote:
I don't need to worry about which of your purported answers is goofier
than the other. Superposition allows me to combine your traveling waves
into a standing wave. The energy analysis then becomes very easy, with
no paradoxes.

You yourself have said that nothing is lost during superposition.
Presumably that includes energy not being destroyed.

Given that |s11(a1)|^2 = 1 joule/sec

Given that |s12(a2)|^2 = 1 joule/sec

Given that |b1|^2 = 0

What happened to the 2 joules/sec?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Jim Kelley wrote:
HP would simply observe that what b1 = 0 means is that there is no
energy and there are no waves moving in the direction of b1.

Yes, and HF also observes that, e.g.:

|s11(a1)|^2 = 1 joule/sec

|s12(a2)|^2 = 1 joule/sec

Presumably, HP doesn't believe in destruction of
energy. Hecht says those joules existed with a
direction and momentum toward the source. What
happened to those joules to reverse their direction
and momentum?
--
73, Cecil, http://www.qsl.net/w5dxp

Analyzing Stub Matching with Reflection Coefficients
 

Cecil Moore wrote:

Jim Kelley wrote:

HP would simply observe that what b1 = 0 means is that there is no
energy and there are no waves moving in the direction of b1.


Yes, and HF also observes that, e.g.:

|s11(a1)|^2 = 1 joule/sec

|s12(a2)|^2 = 1 joule/sec

I don't think they do.

Presumably, HP doesn't believe in destruction of
energy.

I'm quite sure that's true, which is why they wouldn't agree with your
"e.g." above.

Hecht says those joules existed with a
direction and momentum toward the source.

Actually, he never does say that.

What
happened to those joules to reverse their direction
and momentum?

Clearly, according to everything that is known and is measurable,
those joules are not traveling in the direction you claim.

73, Jim AC6XG

Analyzing Stub Matching with Reflection Coefficients
 

On Apr 23, 10:23 am, Cecil Moore wrote:
Dr. Honeydew wrote:
Either you believe in the superposition principle in linear
systems, or you don't. He obviously doesn't.

Superposition is known to fail in nonlinear systems.
A source is obviously not linear. The V/I of an active
dynamic source resists any attempt at linear
superposition.

So you don't believe in any of the S-parameter analysis done on linear
small-signal amplifiers, then. Might as well just toss HP AN95 in the
trash. Might as well toss the S parameters provided by pretty much
all the RF transistor manufacturers in the trash. And in fact, even
beyond that, you don't believe in any of the S-paramter analysis done
on any system that's propagating power, because that power came from a
source, and if you toss one non-linear element into the system, the
whole system is non-linear and none of this linear systems analysis
would be valid.

Enjoy your dreams, whatever kind they may be. Fortunately, they won't
keep the rest of us from continuing to successfully analyze our
systems, including the sources, with H parameters, Y parameters, S
parameters, or just plain old elemental linear circuit theory.

From the labs,
Bunsen