Cecil Moore wrote:
Gene Fuller wrote:
Cecil Moore wrote:
As you well know, the convention is to apply a negative
sign to positive energy flowing in the opposite direction
from the "forward" energy which is arbitrarily assigned
a plus sign.

Let's see even one reference that mentions explicitly the concept of
applying a negative sign to positive energy. Not power, not voltage,
not current, not waves, but energy.

If you keep feigning ignorance like that Gene, you are
going to lose all respect. If the Poynting vector has
a negative sign, as used by Ramo & Whinnery, that sign
is an indication of the *direction of energy flow*,
see quote below.

From Ramo & Whinnery:

The Poynting vector is "the vector giving *direction* and
magnitude of *energy flow*". When Ramo & Whinnery hang a
sign on a Poynting vector in a transmission line, it is
an indication of the direction of energy flow.

For pure standing waves,
"The average [NET] value of Poynting vector is zero
at every cross-sectional plane; this emphasizes the
fact that on the average as much energy is carried
away by the reflected wave as is brought by the
incident wave."

What? Reflected waves "carrying" energy? Shame on
Ramo & Whinnery for contradicting the rraa gurus.

It is impossible to satisfy you, Gene. When I quote
reference after reference about reflected power, you
say power doesn't reflect. When I change it to reflected
energy, you ask for a reference.


Cecil,

Still up to your tricks? I ask for reference on a scalar quantity, and
you respond with some stuff about vectors.

If you want to continue to misinterpret the experts and believe that
power, energy, or whatever flows in opposite directions at a single
point at the same time, go right ahead. I suppose such beliefs expounded
on RRAA are quite harmless in the grand scheme of world affairs.

For future reference, however, just remember: Fields first, then power
or energy. That's the way superposition really works.

(By the way, I am not the one who made the point about power vs. energy.
That must have been someone else.)

73,
Gene
W4SZ

Gene Fuller wrote:
For future reference, however, just remember: Fields first, then power
or energy. That's the way superposition really works.

Way back before optical physicists could measure light
wave fields, they were dealing with reflectance,
transmittance, and irradiance - all involving power
or energy. They are still using those concepts today
proven valid over the past centuries. Optical physicists
calculate the fields *AFTER* measuring the power density
and they get correct consistent answers.

Use whatever method works for you but don't try to change
or replace the body of the laws of physics that was in place
before your grandfather was born. Your rejection of those
laws of physics from the past centuries is why you are so
confused today by your steady-state short cuts. It's why
Keith doesn't recognize a 1.0 reflection coefficient when
it is staring him in the face. It's why Roy rejects energy
in reflected waves. Optical physicists have known for
centuries where the energy goes. That RF engineers are
incapable of performing an energy analysis is sad.

Irradiance (intensity) is a power density. Many problems
in physics can be solved without even knowing or caring
about the strength of the fields. Here is one such lossless
line problem for you.

100w--50 ohm line--+--1/2WL 300 ohm line--50 ohm load
Pfor1--|--Pfor2
Pref1--|--Pref2

Without using fields, voltages, or currents: Calculate
the magnitudes of the four P terms above. Using the RF
power reflection-transmission coefficients, please explain
the magnitude of Pref1. If you cannot do that, you really
need to broaden your horizons and alleviate your ignorance.

Quoting HP AN 95-1: "The previous four equations show that
s-parameters are simply related to power gain and mismatch
loss, quantities which are often of more interest than the
corresponding voltage functions."
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
For future reference, however, just remember: Fields first, then power
or energy. That's the way superposition really works.

Way back before optical physicists could measure light
wave fields, they were dealing with reflectance,
transmittance, and irradiance - all involving power
or energy. They are still using those concepts today
proven valid over the past centuries. Optical physicists
calculate the fields *AFTER* measuring the power density
and they get correct consistent answers.

"Way back" is irrelevant. One only needs to open a serious text book on
Optics, such as Born and Wolf, to see how optical physicists perform
analysis today.


Quoting HP AN 95-1: "The previous four equations show that
s-parameters are simply related to power gain and mismatch
loss, quantities which are often of more interest than the
corresponding voltage functions."

I agree with this statement completely (surprised??). S-parameter
analysis is very useful. However, the "corresponding voltage functions"
are equally valid, even if not as "interesting". What you might also
notice in AN 95-1 is that there is no mention of incident and reflected
waves on a transmission line, each carrying energy (or power or whatever
you prefer), and passing like ships in the night.

You like to talk about conservation of energy, implying that your
"powerful" reflected wave model is essential to meeting the conservation
of energy requirement. In fact, your model is a poster child for the
violation of energy conservation. Electromagnetic energy, like any
energy, is a scalar quantity, and it is only positive. It is not
possible to "net" the non-zero energy contributed from your
counter-traveling waves to zero. The direction of the wave propagation
does not change the sign of the energy. Be careful here; energy is *not*
the same as the energy flux or Poynting vector. Don't mix terms that
have totally different units. What *can* be assigned negative values are
the fields. (Voltage and current are not exactly "fields", but they will
work for these transmission line examples.) A "net" of zero volts or
current is exactly what happens at the standing wave nodes resulting
from the counter-traveling waves. After you have done the superposition
correctly, using fields, not energy or power, then you can easily
determine the energy and power state as needed. Conservation of energy
will be automatically satisfied, assuming no mathematical blunders. The
Maxwell equations would be pretty useless if they did not provide
conservation of energy.

For future reference, just remember: Fields first, then power
or energy. That's the way superposition really works.

73,
Gene
W4SZ

Gene Fuller wrote:
"Way back" is irrelevant. One only needs to open a serious text book on
Optics, such as Born and Wolf, to see how optical physicists perform
analysis today.

The readers may be interested in how it is done today.
Please tell us how the phase of light is measured today.

What you might also notice in AN 95-1 is that there
is no mention of incident and reflected ...

Sorry Gene, I'm tired of wasting my time proving that you
are lying. Anyone who wants to prove how unethical you are
can do so by accessing:

http://www.ecs.umass.edu/ece/labs/an...parameters.pdf

and searching for "incident" and "reflected".
Lots of unethical BS deleted after that.
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:

What you might also notice in AN 95-1 is that there is no mention of
incident and reflected ...

Sorry Gene, I'm tired of wasting my time proving that you
are lying. Anyone who wants to prove how unethical you are
can do so by accessing:

http://www.ecs.umass.edu/ece/labs/an...parameters.pdf

and searching for "incident" and "reflected".
Lots of unethical BS deleted after that.

I guess I must be hitting close to target. You always get nasty when I
create problems for your pet theories.

Thanks for the reference to AN 95-1, even though I have several copies
already. Your directed search terms prove my point exactly. I suppose
puncturing your balloon is "unethical", but that is your problem, not mine.

I challenged you to find any case in AN 95-1 that supports your claim of
counter-traveling waves in a transmission line, with each wave carrying
its own energy that somehow nets out to zero. You came up with exactly
nothing, which is not surprising.

Ranting and raving does not have any impact on the correct physical
reality.

Oh, by the way, my full comment was, ". . . there is no mention of
incident and reflected waves on a transmission line, each carrying
energy (or power or whatever you prefer), and passing like ships in the
night."

Your careful trimming is noted.

73,
Gene
W4SZ

Gene Fuller wrote:
I challenged you to find any case in AN 95-1 that supports your claim of
counter-traveling waves in a transmission line, with each wave carrying
its own energy that somehow nets out to zero.

I did exactly that earlier and you didn't comprehend
it then - but here it is again.

(b1)^2 = (s11*a1 + s12*a2)^2 = 0

(b1)^2 is reflected power. It is only zero when
(s11*a1 + s12*a2)^2 = 0

(b1)^2 = (s11*a1)^2 + (s12*a2)^2 + 2(s11*a1)(s12*a2)

Since a1 and a2 are phasors, their multiplication
involves cos(A) of the Angle between them.

Pref1 = P1 + P2 + 2*SQRT(P1*P2)cos(A)

Does that equation look familiar? Please reference the
s-parameter ap note, pages 16 & 17, for the meaning of
those squared terms. The power density equation can be
derived from the s-parameter equation.

http://www.ecs.umass.edu/ece/labs/an...parameters.pdf
--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
Gene Fuller wrote:
I challenged you to find any case in AN 95-1 that supports your claim
of counter-traveling waves in a transmission line, with each wave
carrying its own energy that somehow nets out to zero.

I did exactly that earlier and you didn't comprehend
it then - but here it is again.

(b1)^2 = (s11*a1 + s12*a2)^2 = 0

(b1)^2 is reflected power. It is only zero when
(s11*a1 + s12*a2)^2 = 0

(b1)^2 = (s11*a1)^2 + (s12*a2)^2 + 2(s11*a1)(s12*a2)

Since a1 and a2 are phasors, their multiplication
involves cos(A) of the Angle between them.

Pref1 = P1 + P2 + 2*SQRT(P1*P2)cos(A)

Does that equation look familiar? Please reference the
s-parameter ap note, pages 16 & 17, for the meaning of
those squared terms. The power density equation can be
derived from the s-parameter equation.

http://www.ecs.umass.edu/ece/labs/an...parameters.pdf

Wow! You missed again! And I thought that you actually understood what
s-parameters are all about.

Get a clue. None of your rantings say anything about the behavior of
waves on the transmission line. As usual you keep ducking the question
by answering a different one.

73,
Gene
W4SZ