On Thu, 02 Dec 2004 11:47:36 -0600, Cecil Moore
wrote:
If I had used 10 dBm, I would have lost most of the readers.
You lost them at 100W

On Thu, 02 Dec 2004 12:14:58 -0600, Cecil Moore
wrote:
Betcha can't name the model number or maker.
Hint: If it's not obvious
I Win! You can't name them at Intel OR ARRL! :-)
Another violation of Initial Conditions

Wes Stewart wrote:
All of the S-parameters I've ever measured were referenced to the ends
of the cables used to connect the DUT to the test equipment.

Where the signal generator was connected?

b1 = s11*a1 + s12*a2

The HP S-parameter Ap Note 95-1 sez:

|a1|^2 = Power incident on the input of the network
= Power available from a source impedance Z0

What was |a1|^2 referenced to?
--
73, Cecil http://www.qsl.net/w5dxp

On Thu, 02 Dec 2004 12:55:58 -0600, Cecil Moore
wrote:
Apparently two separate concepts in the same sentence
are just too much for you to comprehend.
Which:
1. You can't name the model/maker of this supposed Intel source
or
2. You can't name the model/maker of this supposed ARRL source
?

Suppositions and guessing are hallmarks of Initial Conditions
violation.

Richard Clark wrote:
I Win! You can't name them at Intel OR ARRL! :-)
Another violation of Initial Conditions

Apparently two separate concepts in the same sentence
are just too much for you to comprehend.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,

It's a slow day, so I thought I might take some time to help you out of
your dilemma.

Q: Where are the missing joules?

A: They are associated with the large standing wave supported by the
mismatched terminations of your transmission line.

As I have pointed out previously, standing waves are not inert. The
shape of the wave does not travel down the line, but the fields are
changing, and the charges are moving. Within each loop of the standing
wave the stored energy simply oscillates between magnetic energy when
the current is high and electrostatic energy when the voltage is high.
Very basic stuff.

The problem in your analysis is the initial axiom that RF waves always
move. This is simply incorrect, and it leads to the dilemma you face.
Traveling waves are fine if you do the math correctly, but the physical
situation is in the form of a standing wave. The model results need to
agree or there is a math error.

And as many people have pointed out, always add the voltages and
currents first and only consider power at the very end of the analysis.

Since you are also an optics guru you might want to check into the
details of laser cavity operation or Fabry-Perot etalon operation. These
are highly mismatched systems with very strong standing wave components
along with a little bit of net traveling wave. Definitely related to the
problem you posed.

73,
Gene
W4SZ


Cecil Moore wrote:

[snip]

After steady-state has been reached, the XMTR has output 300 more
joules than the load has accepted. A smaller real-world experiment
will easily verify that it is a fact that all energy sourced that
has not reached the load must necessarily be confined to circulating
energy or losses in the transmission line.

Question: In the above example, where are those 300 joules of energy
located and what is happening to them?

We know that 300 joules is wave energy and RF waves always move
at the speed of light, i.e. they cannot stand still. So please
determine how much energy is moving and in which of only two
possible directions.

Richard Clark wrote:

On Wed, 01 Dec 2004 21:27:25 -0800, Jim Kelley
wrote:


The confusion I think stems from the contention that any 'reflected
power' (unfortunate nomenclature IMO) is first sourced and then after
reflection returned back into the source, or to a circulator load as the
case may be. The latter case is certainly correct. The former is
phenomenologically problematic.


Hi Jim,

By that same logic it follows that the power "into" the transmission
line was in fact never "into" the line at all but into the circulator
input, and any power finding its way into the circulator load also
never found its way into the line, but was merely reflected at the
circulator/line interface.

A circulator, being in general a three (or four) port directional
device, might have some trouble buying into that logic. ;-) The crux of
the phenomenological problem is that power does not flow or move, nor is
it something that is reflected. Hence Roy's (and Reg's) suggestion that
the voltages and currents resulting from the fields which propagate must
be analyzed. From that analysis (which involves the fields, or V and I,
propagating, reflecting, and interfering in both directions) one can
determine the quantities of energy being absorbed by the effected
dissipative loads in the circuit.

A transmission line circuit which includes a circulator w/load does
indeed provide a mechanism by which a portion of the energy produced by
a source can effectively be reflected from a mismatched load back toward
the generator. On encountering the circulator in the reverse direction,
it is then directed to the circulator load where it can be dissipated.
In a lossey transmission line, that reflected signal will be attenuated
and would in fact increase the total amount of energy the transmission
line dissipates. The amount of energy produced by the generator
increases by the amount lost to the circulator load and the transmission
line. **Absent the circulator, those energy losses would not be
realized - nor sourced.**

The argument that fields "have" or "contain" energy is misdirected and
misapplied. Obviously one can measure a field at each of the electrical
outlets in his house even when nothing is drawing energy from those
outlets. The potential to create a transfer of energy does not
necessarily equate with a transfer of energy. A mechanism must exist
which provides the conduit for a transfer of energy. It is that
mechanism, and the nature of the source and the load which determine the
amount of power being generated and transferred to the dissipating load.

73, Jim AC6XG

Richard Clark wrote:
Which:

One last time:
The 100 watts came from a MENTAL signal generator existing ONLY in
my IMAGINATION for the propose of discussing a HYPOTHETICAL example
on r.r.a.a. I'm sorry you are having difficulty understanding that
concept. Perhaps English lessons would help?
--
73, Cecil http://www.qsl.net/w5dxp

On Thu, 02 Dec 2004 13:38:05 -0600, Cecil Moore
wrote:
One last time:
Actually there is no last time unless:
1. You can't name the model/maker of this supposed Intel source
or
2. You can't name the model/maker of this supposed ARRL source
?
Choose one or both.
Suppositions and guessing are hallmarks of Initial Conditions
violation.

Cecil,

Radio amateurs and "magic antenna" charlatans love to abuse Poynting
vectors and the Poynting theorem.

The basic answer is no, it is not correct to say, "the power in an EM
wave was [is] defined as ExH."

The Poynting vector, generally described as ExH, is the energy flow
density. It has units of energy/area/time. While this may seem to be
nitpicking it is essential to note that this vector is defined at a
point, not for a "wave", and an integration (or summation) over the
surface of a closed volume must be performed before one can say anything
about power or conservation of energy.

In practical terms the Poynting vector ExH and the Poynting theorem have
little utility for radio amateurs.

73,
Gene
W4SZ

Cecil Moore wrote:

Roy Lewallen wrote:

I strongly suggest forgetting completely about "forward" and "reverse"
power. If you must deal with directional waves, look at forward and
reverse voltage and current waves.


Say Roy, exactly how many of those EM voltage and current waves
have you encountered that didn't possess any energy? I always
thought the power in an EM wave was defined as ExH. :-)
--
73, Cecil http://www.qsl.net/w5dxp