Where does it go? (mismatched power)
 

On 18 jun, 07:55, K1TTT wrote:
On Jun 17, 10:55*pm, Cecil Moore wrote:

On Jun 17, 5:08*pm, K1TTT wrote:

but you have already admitted that it is the only mechanism... though
you will now undoubtedly argue against yourself. * em wave reflection
IS the only mechanism for redistributing rf energy, you admitted that
when you agreed that superposition of the waves is the mechanism that
causes the interference in the first place.

Superposition and reflection are NOT the same mechanism. You are

i didn't say they were

totally confused about what I have said. Wave REFLECTION (of one wave)
is not caused by SUPERPOSITION (of two waves) and vice versa. Wave
reflection happens to a single wave when it encounters an impedance
discontinuity. Superposition requires two or more waves. They are
clearly two completely different mechanisms. So I will repeat what I
said befo

There are two mechanisms for redistributing the reflected energy back
toward the load.

1. The re-reflection of the SINGLE reflected wave from the load at an
impedance discontinuity associated with the power reflection

its really the voltage and current reflection coefficient.

coefficient, e.g. 0.5 in my earlier example. Thus in that earlier
example, 1/2 of the reflected energy from the load is re-reflected
back toward the load and joins the forward wave toward the load. That
leaves 1/2 of the reflected energy that is transmitted through the
impedance discontinuity toward the source without being reflected.

The second energy redistribution mechanism occurs associated with
superposition of MULTIPLE WAVES.

that is what i said, and what you agreed to earlier.



2. The percentage of the reflected energy from the load that is
transmitted through the impedance discontinuity toward the source
superposes with the reflection of the source forward wave from the
impedance discontinuity. In my earlier example, the following two
wavefronts superpose in the direction of the source.

Pfor1(rho^2) = 50w and Pref2(1-rho^2) = 50w

Pref1 = 50w + 50w - 2*SQRT(50w*50w) = 0

This is the second mechanism (wave cancellation) that redistributes

but that is NOT a "second' mechanism. *it IS superposition, which is
what you agreed to earlier, maybe in a different thread. *the
mechanism is superposition, the observation is that the waves
interfere either constructively or destructively.

the energy in the canceled wavefronts back toward the load. This step
2 is technically NOT a reflection since it involves two waves. This is
the step that the RF gurus are missing.

no we are not, we understand superposition which is the underlying
basic mechanism of your optical interference terms.







I really wish you understood the s-parameter equations which are
easier to discuss than the above RF equations.

In the s-parameter equation:

b2 = s21*a1 + s22*a2

the term, s22*a2, is the SINGLE WAVE re-reflection term, i.e. a2 is
the reflected voltage from the load.

In the other s-parameter equation:

b1 = s11*a1 + s12*a2 = 0

s11*a1 and s12*a2 are the TWO WAVEFRONTS that superpose to zero, i.e.

stop there and you are perfectly correct.



engage in wave cancellation.
--
73, Cecil, w5dxp.com- Ocultar texto de la cita -

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the mechanism is superposition, the observation is that
the waves interfere either constructively or destructively.

In the end you will see you basically agree and 90% of this issue it
is the Babel curse :)

Where does it go? (mismatched power)
 

On Jun 18, 5:55*am, K1TTT wrote:
1. The re-reflection of the SINGLE reflected wave from the load at an
impedance discontinuity associated with the power reflection

its really the voltage and current reflection coefficient.

It's really an electromagnetic wave obeying all the laws of physics
for an electromagnetic wave INCLUDING ENERGY CONTENT. ExH is the power
density of the wave and the voltage coefficient squared is the power
reflection coefficient. All of the power/energy math used on a Z0-
match gives identical answers as using the voltages PLUS it answers
the original question asked by the first poster to this thread about
what happens to reflected energy. The answer is that reflected energy,
like any other energy, is conserved traveling at the speed of light in
the medium, until it is dissipated or radiated.

Try measuring the voltage and current content of a laser beam and you
will realize why optical physicists are decades ahead of RF engineers
in understanding where EM wave energy goes.

This [superposition] is the second mechanism (wave cancellation) that redistributes

but that is NOT a "second' mechanism. *it IS superposition, which is
what you agreed to earlier, maybe in a different thread.

In my statement above "This" refers to "superposition" which is the
second mechanism after reflection, the first mechanism. ***I REPEAT!
(1) REFLECTION IS NOT THE SAME AS (2) SUPERPOSITION!!!*** You are now
just engaging in obfuscation of what I have said. I expect such shabby
behavior from others on this newsgroup, but not from you.

Wave cancellation is just a special case of superposition, i.e. wave
cancellation is superposition.

(2nd mechanism) Superposition == Interference == Wave Cancellation,
which is ***NOT*** the same as
(1st mechanism) Reflection. I cannot say it any plainer than that.
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On Jun 18, 5:57*am, K1TTT wrote:
you edited too much out of context... it doesn't matter which method
you use to calculate where it goes as long as you know the limitations
of your method.

Exactly! The method that most RF engineers use does not tell how the
energy flows. Witness the posters who are implying that a reflected
wave contains no energy because they cannot figure out where that
energy goes or how it gets there. In his food-for-thought example,
w7el completely ignores the role of superposition/interference in
redistributing the energy, a phenomenon known and understood in the
field of optical physics for at least a century.
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On Jun 18, 8:43*am, lu6etj wrote:
In the end you will see you basically agree and 90% of this issue it
is the Babel curse :)

Don't forget the 10% of misquotes.
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On Jun 18, 10:28*am, Cecil Moore wrote:

In my statement above "This" refers to "superposition" which is the
second mechanism after reflection, the first mechanism. ***I REPEAT!
(1) REFLECTION IS NOT THE SAME AS (2) SUPERPOSITION!!!*** You are now
just engaging in obfuscation of what I have said. I expect such shabby
behavior from others on this newsgroup, but not from you.

NOW ITS MY TURN TO YELL! I NEVER SAID THAT REFLECTION WAS THE SAME AS
SUPERPOSITION, I HAVE BEEN SAYING THAT YOUR 'WAVE CANCELLATION' AND
'INTERFERENCE' ARE SUPERPOSITION! JUST WHAT YOU ADMIT BELOW:


Wave cancellation is just a special case of superposition, i.e. wave
cancellation is superposition.

Where does it go? (mismatched power)
 

On Jun 18, 10:35*am, Cecil Moore wrote:
On Jun 18, 5:57*am, K1TTT wrote:

you edited too much out of context... it doesn't matter which method
you use to calculate where it goes as long as you know the limitations
of your method.

Exactly! The method that most RF engineers use does not tell how the
energy flows. Witness the posters who are implying that a reflected
wave contains no energy because they cannot figure out where that
energy goes or how it gets there. In his food-for-thought example,
w7el completely ignores the role of superposition/interference in
redistributing the energy, a phenomenon known and understood in the
field of optical physics for at least a century.
--
73, Cecil, w5dxp.com

because, at least when i do circuit design, i NEVER calculate energy,
and only at the end calculate power if i really need to. voltage and
current or E and H are the simpler things to handle and totally
sufficient for all circuit analysis, either lumped or distributed.

Where does it go? (mismatched power)
 

On Jun 18, 11:48*am, K1TTT wrote:
NOW ITS MY TURN TO YELL! *I NEVER SAID THAT REFLECTION WAS THE SAME AS
SUPERPOSITION, I HAVE BEEN SAYING THAT YOUR 'WAVE CANCELLATION' AND
'INTERFERENCE' ARE SUPERPOSITION! *JUST WHAT YOU ADMIT BELOW:

When I said reflection is the first mechanism and superposition is the
second mechanism, you said: "... but that [referring to superposition]
is NOT a "second' mechanism." The implication seemed clear to me.

Good grief, everyone is free to review what I said and what you said
in disagreement. I said reflection is the first mechanism and
superposition is the second mechanism. You said superposition is NOT a
second mechanism, clearly implying that superposition is the same as
the first mechanism which was already defined by me as reflection.
Your implication was clearly that reflection and superposition are the
same mechanism.

Do you agree that wave reflection can cause a redistribution of wave
energy?

Do you agree that superposition can cause a redistribution of wave
energy?

Do you agree that wave reflection and wave superposition are two
different mechanisms?

If so, you agree with everything I have previously said and are now
just blowing smoke. If you misspoke, just admit it. If you
misunderstood what I said, just admit it. If you have changed your
mind, just admit it. If you still disagree with any of those three
statements, please continue the argument that you started in response
to my assertion that there exists two mechanisms that can redistribute
energy in a transmission line, (1) reflection and (2) superposition.
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On Jun 18, 11:51*am, K1TTT wrote:
because, at least when i do circuit design, i NEVER calculate energy,
and only at the end calculate power if i really need to. *voltage and
current or E and H are the simpler things to handle and totally
sufficient for all circuit analysis, either lumped or distributed.

The subject of this thread is "Where does it go? (mismatched power)",
not "How do I do circuit design?"
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On Jun 18, 5:39 pm, Cecil Moore wrote:
On Jun 18, 11:48 am, K1TTT wrote:

NOW ITS MY TURN TO YELL! I NEVER SAID THAT REFLECTION WAS THE SAME AS
SUPERPOSITION, I HAVE BEEN SAYING THAT YOUR 'WAVE CANCELLATION' AND
'INTERFERENCE' ARE SUPERPOSITION! JUST WHAT YOU ADMIT BELOW:

When I said reflection is the first mechanism and superposition is the
second mechanism, you said: "... but that [referring to superposition]
is NOT a "second' mechanism." The implication seemed clear to me.

Good grief, everyone is free to review what I said and what you said
in disagreement. I said reflection is the first mechanism and
superposition is the second mechanism. You said superposition is NOT a
second mechanism, clearly implying that superposition is the same as
the first mechanism which was already defined by me as reflection.
Your implication was clearly that reflection and superposition are the
same mechanism.

Do you agree that wave reflection can cause a redistribution of wave
energy?

no. wave reflection causes current and voltage waves to change
direction, magnitude, and phase.


Do you agree that superposition can cause a redistribution of wave
energy?

your observed 'redistribution of wave energy' is a results of
superposition of current and voltage waves and then another
calculation to convert the sum to power and another calculation to
integrate the energy.


Do you agree that wave reflection and wave superposition are two
different mechanisms?

of course, i've never said otherwise.


If so, you agree with everything I have previously said and are now
just blowing smoke. If you misspoke, just admit it. If you
misunderstood what I said, just admit it. If you have changed your
mind, just admit it. If you still disagree with any of those three
statements, please continue the argument that you started in response
to my assertion that there exists two mechanisms that can redistribute
energy in a transmission line, (1) reflection and (2) superposition.
--

Where does it go? (mismatched power)
 

On Jun 18, 5:41*pm, Cecil Moore wrote:
On Jun 18, 11:51*am, K1TTT wrote:

because, at least when i do circuit design, i NEVER calculate energy,
and only at the end calculate power if i really need to. *voltage and
current or E and H are the simpler things to handle and totally
sufficient for all circuit analysis, either lumped or distributed.

The subject of this thread is "Where does it go? (mismatched power)",
not "How do I do circuit design?"
--
73, Cecil, w5dxp.com

since when did any thread like this stay on topic for more than a
couple messages?

Where does it go? (mismatched power)
 

On Jun 18, 1:28*pm, K1TTT wrote:
Do you agree that wave reflection can cause a redistribution of wave
energy?

no. *wave reflection causes current and voltage waves to change
direction, magnitude, and phase.

The question asked by the original poster is, exactly what happens to
the reflected energy? Optical physicists know that a reversal of
energy flow direction accompanies the change in direction of the E-
field and the B-field which changes the direction of the ExB Poynting
vector, i.e. changes the "direction and momentum" of the EM wave
according to Eugene Hecht. How can you not know that a voltage/current
wave requires energy? How can the voltage and current change direction
without the energy changing direction? Does supernatural intervention
separate the voltage and current from the ExH energy?

Maybe you should reference, "Fields and Waves ...", by Ramo and
Whinnery where they describe the forward and reflected power-density
Poynting vectors.

Do you agree that superposition can cause a redistribution of wave
energy?

your observed 'redistribution of wave energy' is a results of
superposition of current and voltage waves and then another
calculation to convert the sum to power and another calculation to
integrate the energy.

Is that a yes or no answer? The same thing happens with light waves in
free space where voltage and current are completely irrelevant.

Do you agree that wave reflection and wave superposition are two
different mechanisms?

of course, i've never said otherwise.

You sure implied otherwise. Why did you argue with me when I said they
are two different mechanisms in action to redistribute energy, (1)
reflection and (2) superposition? You said superposition is not the
second mechanism.
--
73, Cecil, w5dxp.com

Where does it go? (mismatched power)
 

On 18 jun, 16:02, Cecil Moore wrote:
On Jun 18, 1:28*pm, K1TTT wrote:

Do you agree that wave reflection can cause a redistribution of wave
energy?

no. *wave reflection causes current and voltage waves to change
direction, magnitude, and phase.

The question asked by the original poster is, exactly what happens to
the reflected energy? Optical physicists know that a reversal of
energy flow direction accompanies the change in direction of the E-
field and the B-field which changes the direction of the ExB Poynting
vector, i.e. changes the "direction and momentum" of the EM wave
according to Eugene Hecht. How can you not know that a voltage/current
wave requires energy? How can the voltage and current change direction
without the energy changing direction? Does supernatural intervention
separate the voltage and current from the ExH energy?

Maybe you should reference, "Fields and Waves ...", by Ramo and
Whinnery where they describe the forward and reflected power-density
Poynting vectors.

Do you agree that superposition can cause a redistribution of wave
energy?

your observed 'redistribution of wave energy' is a results of
superposition of current and voltage waves and then another
calculation to convert the sum to power and another calculation to
integrate the energy.

Is that a yes or no answer? The same thing happens with light waves in
free space where voltage and current are completely irrelevant.

Do you agree that wave reflection and wave superposition are two
different mechanisms?

of course, i've never said otherwise.

You sure implied otherwise. Why did you argue with me when I said they
are two different mechanisms in action to redistribute energy, (1)
reflection and (2) superposition? You said superposition is not the
second mechanism.
--
73, Cecil, w5dxp.com

"-Do you agree that wave reflection can cause a redistribution of
wave
energy?-"
"-No. wave reflection causes current and voltage waves to change
direction, magnitude, and phase.-"

You see? Babel curse...! One ask about energy other answer with
current, voltage, etc. (same thing divided in pieces).

Do you agree cars have engines?, ¡Of course not! ¡cars have
crankshaft, cylinder, piston, rods...!
Thus you are never going to reach an agreement :D :D

Where does it go? (mismatched power)
 

On Jun 18, 8:23*pm, lu6etj wrote:
On 18 jun, 16:02, Cecil Moore wrote:





On Jun 18, 1:28*pm, K1TTT wrote:

Do you agree that wave reflection can cause a redistribution of wave
energy?

no. *wave reflection causes current and voltage waves to change
direction, magnitude, and phase.

The question asked by the original poster is, exactly what happens to
the reflected energy? Optical physicists know that a reversal of
energy flow direction accompanies the change in direction of the E-
field and the B-field which changes the direction of the ExB Poynting
vector, i.e. changes the "direction and momentum" of the EM wave
according to Eugene Hecht. How can you not know that a voltage/current
wave requires energy? How can the voltage and current change direction
without the energy changing direction? Does supernatural intervention
separate the voltage and current from the ExH energy?

Maybe you should reference, "Fields and Waves ...", by Ramo and
Whinnery where they describe the forward and reflected power-density
Poynting vectors.

Do you agree that superposition can cause a redistribution of wave
energy?

your observed 'redistribution of wave energy' is a results of
superposition of current and voltage waves and then another
calculation to convert the sum to power and another calculation to
integrate the energy.

Is that a yes or no answer? The same thing happens with light waves in
free space where voltage and current are completely irrelevant.

Do you agree that wave reflection and wave superposition are two
different mechanisms?

of course, i've never said otherwise.

You sure implied otherwise. Why did you argue with me when I said they
are two different mechanisms in action to redistribute energy, (1)
reflection and (2) superposition? You said superposition is not the
second mechanism.
--
73, Cecil, w5dxp.com

"-Do you agree that wave reflection can cause a redistribution of
wave
energy?-"
"-No. *wave reflection causes current and voltage waves to change
direction, magnitude, and phase.-"

You see? Babel curse...! One ask about energy other answer with
current, voltage, etc. (same thing divided in pieces).

Do you agree cars have engines?, ¡Of course not! ¡cars have
crankshaft, cylinder, piston, rods...!
Thus you are never going to reach an agreement :D :D- Hide quoted text -

- Show quoted text -

it wouldn't be any fun if we agreed on everything!

Where does it go? (mismatched power)
 

On Jun 18, 3:23*pm, lu6etj wrote:
Do you agree cars have engines?

Some cars have engines but some cars have motors. :-)
--
73, Cecil, w5dxp.com