Gene Fuller wrote:
Cecil,

I cannot speak directly for Tom Donaly, but you and I are about 99% in
DISagreement over physics.

One more time:

Current, charge, voltage, E-field, and H-field are different physical
entities. They are related, but they are not interchangeable.

No amount of E-field, H-field, or voltage can create or destroy charge.
Current is the movement of charge. At any point in space that charge
must either keep moving (Kirchhoff's current law) or it must be stored
(continuity equation). There is absolutely no other choice, period.

Your traveling wave/standing wave model is intuitive, but otherwise
useless. Many authors reference such a model, but no one seems to use it
for serious calculations.

You have started quoting Balanis:

"The current and voltage distributions on open-ended wire antennas are
similar to the standing wave patterns on open-ended transmission lines ...
Standing wave antennas, such as the dipole, can be analyzed as traveling
wave antennas with waves propagating in opposite directions (forward and
backward) and represented by traveling wave currents If and Ib ..."
_Antenna_Theory_, Balanis, Second Edition, Chapter 10, page 488 & 489


I do not have easy access to the Balanis book at this time. Does he go
on to actually perform antenna calculations such as actual current
distributions and radiated fields? I found the table of contents for
this edition of his book, and it appears that Chapter 10 is a chapter on
traveling wave antennas, not basic dipoles. If so, then it is likely
that Balanis is merely trying to tie the entire world of antennas
together to give a warm and fuzzy feeling to the reader.

Every detailed professional treatment of antenna theory and modeling I
have found starts with Maxwell's equations, and quickly gets immersed in
integral equations, Green's functions, and other messy stuff. Why would
people do this if the mere application of a couple of traveling waves
would provide the correct answers?

Do you have a reference to an analytic treatment using the traveling
wave model that could give results comparable to NEC2? If so, I would
sure like to find that reference.

73,
Gene
W4SZ

Cecil Moore wrote:

Gene Fuller wrote:

Antennas work the same way. Any change in current along the antenna
must be accompanied by a change in stored charge.



The net (total) current on a standing-wave antenna is the phasor sum
of the forward current and reflected current and can change simply
because it is part of a standing wave. The change in net current at
the tip of a standing-wave antenna simply means that the energy has
moved from the H-field into the E-field.



As usual, Cecil is very selective of his quotes. Balanis uses a
highly mathematical approach in most of his book, supplemented by
many graphs and charts. Cecil's quote, like his quote of Tom Rauch
on loading coils is only a very small part of the total.
73,
Tom Donaly, KA6RUH