"Jimmy" wrote in message .com...
"Jan Van Belle" wrote in message
...
Hello all,

The last days I was searching for more info o how to build fratal
antennas on the web. But besides lots of links to fractenna.com and a few
powerpoint slides I found nothing.

Has anyone sucessfully build such an antenna for HF? Is anyone using it?

Kind regards,

Jan, ON5DOA

A fractal antenna is just another antenna that uses lumped inductance to
shrink the size of the antenna along with destroying the radiation pattern.
The arrl has a nice explantion of why antennas radiate on their web site.
Aplly this info to fractals and small coils and it is easy to see why they
dont work worth a hoot.

An 18 page paper entitled

FRACTAL ANTENNAS
Introduction to fractal technology and presentation of a fractal
antenna adaptable to anytransmitting frequency - The "FRACTENT"
By Werner Hödlmayr, DL6NDJ
January 2004

Can be downloaded at www.antenneX.com

His conclusion:

"The attentive reader will note that the spacing of resonant
frequencies in a fractal structure is logarithmic, whereas most of the
HF amateur bands follow a linear sequence. This means that the antenna
structure has to have a scaling which follows the same logarithmic
law. To build such an antenna is a challenge asking for a professional
simulation program (which allows more than 10,000 segments) and very
much perseverance."

Interesting references:

[2] Jaggard, D.L. (1990): On Fractal Electrodynamics. In Recent
Advances in
Electromagnetic Theory, H.N. Kritikos and D.L. Jaggard, editors,
Springer-Verlag, New York.
[3] Jaggard, D.L. (1991): Fractal Electrodynamics and Modeling. In
Directions in Electromagnetic Wave Modeling. Plenum Publishing Co.,
New York, 435-446