Hi Emma,

I don't have many comments, only that the increased bandwidth you see
in your model with the larger wire is consistent with what I'd expect,
and that it surprises me a little that the resistive part of the
feedpoint impedance is monotonic with "d" in the thin-wire case but
not in the thicker-wire case.

Also, I see antenna design as a series of tradeoffs which can be
divided into a few areas: arrange conductors so that you can get
current distributions give you the directional pattern you want and
also in an arrangement that you can build with sufficient mechanical
ruggedness and in a suitable mechanical configuration for your
application. Arrange a feed and matching system so you can get the
desired current distribution on the conductors. Decouple your
feedline and any other conductors in the area from the antenna
structure. The tradeoffs come when you find there is no practical way
to feed your ideal antenna, or when you find it's too big to mount on
your car, or whatever. The antenna you've modeled doesn't seem very
difficult to build, so I would suggest actually building one and
testing it to see if it works like you expect, and if it's
mechanically practical for you. These are pretty generic comments,
but I'm honestly not very clear on just what you wish to
accomplish--what problem you are trying to solve.

Cheers,
Tom


"Emma" wrote in message ...
Yes,"a" in the diagram below is the wire radius.


http://antennas.ee.duth.gr/recradioa...ntennaGeometry
/Hentenna%20Geometry.htm

My design results, for two different radius values,
of R, X, Z, Rho, SWR and Directivity, as they vary with the driving element
position,
are shown at

http://antennas.ee.duth.gr/recradioa...ntennaA/Henten
naA.htm

and

http://antennas.ee.duth.gr/recradioa...ntennaB/Henten
naB.htm

I would be most grateful if you could have a look at these results and make
any comments.

I would also appreciate any reference you may point at, in addition to those
I collected at

http://antennas.ee.duth.gr/recradioa...ferences/refer
ences.htm

Thank you in advance for your time,

Emma