On 6 Dec 2003 12:27:00 -0800, (emma) wrote:

Hi Richard,

I tried it. I considered my Hentenna as a transmission line and I
applied the standing wave theory according to "THE ARRL ANTENNA BOOK
18th Ed 1997, Fig 65".
The currents flow the antenna as shown below:

http://antennas.ee.duth.gr/recradioa...ndingwaves.htm


Obviously, the currents of the 3 parallel horizontal branches are
flowing in the same direction. Their sum gives the total field. On the
other hand, we have 3 antiparallel pairs of currents flowing through
the vertical branches. Therefore the field becomes equal to zero.
As a result, the arrangement radiates and it can not be considered as
a transmission line.

Emma.

Hi Emma,

You are arguing from a forced analysis not from transmission line
theory. The flaw is that the current defines a transmission line.
The current flow defines the results, the transmission line structure
imposes the laws they must operate within.

The structure is a transmission line shorted at both ends and fed at
an opportunistic point for the purpose of matching to the source. It
is a classic, skeletal cavity resonator that leaks. Efficiency is in
the eye of the beholder.

More the question is: "What does it matter?" There is no gain
obtained from a design's name redefined away from transmission line to
the term Hentenna. Further, given the japanese expression of Hen to
denote strange (strange antenna), this naming only seeks to mystify
what is quite ordinary (even if it is uncommon).

73's
Richard Clark, KB7QHC

Dear Mr. Richard Clark,

I would like to much appreciate your comments
which guided Miss Emma and the rest of us, TheDAG members,
to consider the Hentenna as a parallel combination
of two shorted transmission line segments,
a fact which definitely lacked our attention!

Now, it is interesting to note that
this two Transmission Line pieces in parallel
present a theoretical SWR = oo,
independently of any parameter.
This result embarrasses somewhat the view of the Hentenna

| ...
| fed at an opportunistic point for the purpose of matching to the source
| ...

Besides that, a Richwire-MoM simulated Hentenna model
gives a computed directivity of ~3dBd,
which obviously is rather something more than

| ...
| a classic, skeletal cavity resonator that leaks
| ...

After these,
it seems more appropriate to ascribe "Hen"
to the fact that a rather slim Hentenna,
externally looked almost as a lambda/2 dipole,
gives a computed directivity twice as much as of its dipole counterpart
with a surprising 90 degrees rotated Linearly Polarized Pattern
in the direction of its maximum,
relatively to the well known polarization of its counterpart,
for the same orientation of both.

But enough with the theory.
Practical conclusions are expected to result
from the comparison of the measurements between
the two, under construction, models:
the initially given and the -hopefully- improved one.

Once again, thank you very much for your time and help.

Sincerely yours,

pez
SV7BAX
TheDAG

A Study of Hentenna : Analysis, Simulation, Construction and Antenna
 

FunkTechnikPlus # Journal
Théorie-Expérimentation-Métrologie-Logiciel-Applications
open transactions on independent scientific engineering research

Issue 12 - Year 4
A Study of Hentenna : Analysis, Simulation, Construction and Antenna
Pattern Measurements
E. A. Babli, N. I. Yannopoulou, P. E. Zimourtopoulos
https://www.otoiser.org/index.php/ftpj/article/view/64

Paper 26 Download
https://www.otoiser.org/index.php/ft...download/64/56

Current Issue 17 - Year 6 - Sunday 30 September 2018
https://www.otoiser.org/index.php/ft...iew/2018.09.30

Next Issue 18 - Year 6 - Thursday 31 January 2019
https://www.otoiser.org