Standing-Wave Current vs Traveling-Wave Current
 

On Thu, 3 Jan 2008 12:19:32 -0800 (PST), art
wrote:

On 3 Jan, 11:50, Richard Clark wrote:
On Thu, 3 Jan 2008 10:28:07 -0800 (PST), art
wrote:

When current gets to the top of a
fractional
wave antenna it just does not turn back. It has to wait until half a
period time has
elapsed

Guru Prior Art, sir,

Which is more rankling to your celebrity:
1. *being ignored for such stupid remarks;
1. *being criticised for such stupid remarks?

To reduce confusion, select 1 of the above in response.

73's
Richard Clark, KB7QHC

Fortunately idiots such as you are not able to debate civily

My dear Prior Art, sainted Guru of the RF, sir,

By your response, you certainly must admit that your celebrity status
abhors being ignored. After all, who else has responded to your
nonsense?

My idiocy serves yours by keeping your words alive! Who needs civily
when it draws only flies?

73's
Richard Clark, KB7QHC

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
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.

HP would be interested in knowing your theory that the
s-parameter equations cannot be used on a transmission
line. How can you possibly be that ignorant?

Actually, s-parameter equations are an ideal way to
analyze an impedance discontinuity in a transmission
line since the voltages are normalized to SQRT(Z0).
Squaring the normalized voltages yields power.

----50 ohm line--+--1/2WL 300 ohm line--50 ohm load
a1--|--b2
b1--|--a2

b1 = s11*a1 + s12*a2 b2 = s21*a1 + s22*a2

|a1|^2 is forward power, |b1|^2 is reflected power
|b2|^2 is forward power, |a2|^2 is reflected power

Squaring the s-parameter equations yields the power
density (irradiance) equation from the field of optics.
I'm sorry that technical fact upsets you so.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Richard Clark wrote:
Shine the sun on a pie pan. How fast is light moving in getting
through it? How fast is an electron moving in getting through it?
Is light traveling at the speed of light? Would it travel faster than
an electron if we took out the pie? Would it travel faster than an
electron if we kept the pie and took out the pan?

There, there, Richard, everything is going to be OK.
(Somebody get the net!)
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Gene Fuller wrote:
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.

HP would be interested in knowing your theory that the
s-parameter equations cannot be used on a transmission
line. How can you possibly be that ignorant?

Actually, s-parameter equations are an ideal way to
analyze an impedance discontinuity in a transmission
line since the voltages are normalized to SQRT(Z0).
Squaring the normalized voltages yields power.

----50 ohm line--+--1/2WL 300 ohm line--50 ohm load
a1--|--b2
b1--|--a2

b1 = s11*a1 + s12*a2 b2 = s21*a1 + s22*a2

|a1|^2 is forward power, |b1|^2 is reflected power
|b2|^2 is forward power, |a2|^2 is reflected power

Squaring the s-parameter equations yields the power
density (irradiance) equation from the field of optics.
I'm sorry that technical fact upsets you so.

It's a swing and a miss. Strike three! You're out!

The entire point of s-parameter analysis is that the "network" can be
treated as a black box, characterized by the various parameters at the
ports. How does that work to analyze what is happening *inside* the box,
such as somewhere along the transmission line?

73,
Gene
W4SZ

Standing-Wave Current vs Traveling-Wave Current
 

Richard Clark wrote:
There is a vast gulf between seeming and proving.

Richard, you seem to exist. Please prove that you
indeed do exist.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
The entire point of s-parameter analysis is that the "network" can be
treated as a black box, characterized by the various parameters at the
ports. How does that work to analyze what is happening *inside* the box,
such as somewhere along the transmission line?

That's pretty simple to answer, Gene. Simply make
the black box infinitesimally thin so that events
are transparent. Ignorance is immediately alleviated.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Roy Lewallen wrote:
2. I don't understand the mechanism which causes waves to bounce.

I don't understand the mechanism which causes waves to slosh.
Would you mind posting the sloshing equation?

Cecil,

I am not Roy, but I will answer your question.

It is really *very* straightforward. As I hope you will agree, a
standing wave is characterized by voltage and current that are in
quadrature, both in time and in space. In other words, the current loops
are spaced 1/4 wave from the voltage loops, and the current maximum
occurs 1/4 cycle ahead of (or behind) the voltage maximum.

Let's look at conservation of energy, one of your favorite topics.

At some arbitrary starting time, the voltage loop is at a maximum, and
the current is zero. At that time all of the energy in the standing wave
is contained in the capacitive or E^2 term. The physical location of
that energy is centered on the voltage loops.

As the cycle proceeds, the voltage decreases and the current increases.
After 1/4 cycle the current is at a maximum and the voltage is zero.
Now all of the energy in the standing wave is contained in the inductive
or H^2 term. The physical location of that energy is centered on the
current loops.

There are two important observations. First, the location of the
standing wave energy has physically moved by 1/4 wave during the 1/4
cycle. That is the "sloshing" that some of us use as a description. Call
it what you like.

The second observation is that the standing wave is not at all static.
Energy is moving back and forth at the speed of light in the medium.

Some people like to treat standing waves as poor distant cousins to
"real" waves, or perhaps only as "envelopes". It is their option to do
so, but it misses the actual behavior of standing waves and "sloshing"
energy.

The equations can be found in many places, such as Johnson's book on
Transmission Lines and Networks.

73,
Gene
W4SZ

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
The second observation is that the standing wave is not at all static.
Energy is moving back and forth at the speed of light in the medium.

Sorry Gene, The speed of water is "sloshing".
The speed of light is 10^10 faster than "sloshing".
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Gene Fuller wrote:
The entire point of s-parameter analysis is that the "network" can be
treated as a black box, ...

Gene, I cannot find anywhere in the s-parameter information
where some of the network must be hidden inside a black box.
I always thought an s-parameter analysis could be done without
a black box. Could you help us out here and point out exactly
where it says a black box is a requirement. Seems to me the
purpose of an s-parameter analysis is to alleviate ignorance
which obviously doesn't match your agenda.
--
73, Cecil http://www.w5dxp.com

Standing-Wave Current vs Traveling-Wave Current
 

Cecil Moore wrote:
Gene Fuller wrote:
The second observation is that the standing wave is not at all static.
Energy is moving back and forth at the speed of light in the medium.

Sorry Gene, The speed of water is "sloshing".
The speed of light is 10^10 faster than "sloshing".

Cecil,

If your only concern is the definition of "sloshing", then about 100,000
messages have been wasted.

My definition of "sloshing" is as I stated. I believe that Roy would
have the same definition. If your definition involves the speed of
water, then I have no idea why that topic would be relevant here.

73,
Gene
W4SZ