Peter O. Brackett wrote:
Jerry:

[snip]
"Jerry" wrote in message
...
.
.
.
I thought the FF Tab data in EZNEC was very informative for analyzing
the circularity of the antennas i tried to analyze with EZNEC.
Perhaps you know of some additional data that would assist me in
better understanding the polarization of these antennas. Tell me
what is left out of Roy's data in EZNEC.

Jerry KD6JDJ
[snip]

Apparently nothing!

Jerry it seems that I have an older version of EZNEC, a version that did
not support CP outputs.

I just contacted Roy todayh and ordered the latest upgrade to EZNEC +
version 5 which
Roy tells me supports CP outputs.

But... one thing about NEC is that it does not support antennas in
motion. NEC and all of the commercial
software that is derived from this (US Taxpayer supported code, God
Bless the US Taxpayer!) do not
support antennas in motion. Rather NEC supports only static antennas in
steady state excitation.

And, why would this be "important"... it doesn't support arbitrary
terrain surfaces either, nor non-uniform soil properties.

Since the vast majority of "amateur radio" antennas (this is r.r.a.a,
after all) can be modeled adequately by NEC.

If you need more, fork out the bucks for a FEM code that does what you need.




There may be some "multi-physics" programs/software out there that can
calculate radiated fields
for antennas in motion, but I am not aware of them. Of course I'm not
an expert and I have not done any
research on this topic and so I don't personally know of any programs
that can produce
CP outputs for antennas that are in motion, specifically symmetric
antennas that are rotating
at some arbitrary angular rotation velocity with respect to their axis
of symmetry.


As you say, you've not researched it.

I would suggest that the need for such a thing is fairly small, but I'll
bet someone somewhere has done it, just not as a "end user" software
product.




Certainly, there IS a lot of modeling of EM waves from moving objects
(radar reflections being of particular interest).

Depends on the relative scales, too. If you're talking waves from a
meter scale object viewed from kilometers away, then using a point
source approximation for the object will work nicely, and then it's just
simple geometry.