Fractal 10m Antenna
 

In article , Roy Lewallen
wrote:
Meander line antennas, including "fractals", share the same properties
as other electrically short antennas: narrow bandwidth and high
conductor current. The latter can result in poor efficiency due to I^2 *
R loss. Meander lines are better than some other methods of loading and
worse than others, depending on how the meander and other methods are
implemented. It's just one of the techniques which antenna designers
have in their bag of techniques to use.

Roy Lewallen, W7EL

Hello, and you make some good points, Roy. (I always pay close attention
to many of Steve Best's IEEE papers on antennas). While I've not analyzed
or experimented with antennas based upon fractal patterns I have always
wondered whether broadband performance could be achieved since fractal
patterns would repeat with electrical (frequency) scaling. Granted, these
patterns unlike, say a logarithmic spiral, would only repeat at discrete
values. Your comment above indicates this is not the case, however.
Sincerely, and 73s from N4GGO,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337

Fractal 10m Antenna
 

John Doe wrote:
"I have a lot of time on my hands."

I recall the Fractenna man, Dr. Chip Cohen, used to define fractals as
self similar elements assembled to cover a wide range of frequencies.

That roughly conforms to Kraus, "structures that preserve their shapes
at different scales."

Kraus` conical spiral and log periodic antennas in Figure 310 on page 68
of the 3rd edition of "Antennas" also seem to fit the repeating
structures of different scales designed to produce very broad bandwidth
with moderate gain and might be called fractals.

Best regards, Richard Harrison, KB5WZI