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Old December 23rd 07, 07:39 AM posted to rec.radio.amateur.antenna
Cecil Moore[_2_] Cecil Moore[_2_] is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 3,521
Default Standing-Wave Current vs Traveling-Wave Current

Denny wrote:
Nice graphic, Cecil.. But the thread has drifted beyond recognition..
Part of the original dispute across a couple of threads as I
remember it, was the contention that there is no energy contained
within the reflected wave and therefore no energy contained within the
standing wave, i.e. a mere artifact...


Unfortunately, that goes against the distributed network
reflection model that I learned at Texas A&M during the 50s.
The joules/sec in any EM wave are ExB. The total joules
stored in the transmission line are exactly the number of
joules necessary to support the forward energy and reflected
energy.

I simply wanted to point out that the standing wave on a line does
contain energy and it is a childishly simple exercise to prove it,
therefore the reflected wave must contain energy...
As far as the questioner, where does the energy go between the
standing wave peaks - oy vey....
If it is a real question - as opposed to a rhetorical device which I
hope was the intent - then the profound ignorance of basic physics is
vastly beyond the limited space I have to go over it... See ANY
introductory level, physics textbook for details...


The standing wave current is the phasor sum of the forward
current and reflected current. The standing wave voltage is
the phasor sum of the forward voltage and reflected voltage.

At the point where the standing wave current is equal to zero,
the standing wave voltage is at a maximum indicating that all
of the EM energy at that point is contained in the E-field.

At the point where the standing wave voltage is equal to zero,
the standing wave current is at a maximum indicating that all
of the EM energy at that point is contained in the H-field.

Standing waves are an artifact of the superposition of forward
and reflected waves. Where the two E-fields cancel, the total
H-field will at a maximum. Where the two H-fields cancel, the
total E-field will be at a maximum.
--
73, Cecil http://www.w5dxp.com