On Oct 20, 4:57 pm, art wrote:
....
The case for Fractals is somewhat different to ham use in that for an
encapsulated
high frequency SYSTEM it matters not if what some would call the feed
line radiated
since usually power is not a main consideration making it ideal for
stealth purposes
since the fractal meanderings can be made to conform to any shape
structure while
maintaining a desirable LC ratio which with the use of laminated
circuitry is
becoming more available.

It appears that the above MAY actually be a sentence. However, with
74 words in it, I get completely lost before I get to the end of it.
Would you be so kind as to diagram it for us, Art, or at least divide
it up into something a little more manageable?

Thanks.

Cheers,
Tom

On 20 Oct, 17:41, K7ITM wrote:
On Oct 20, 4:57 pm, art wrote:
...

The case for Fractals is somewhat different to ham use in that for an
encapsulated
high frequency SYSTEM. It matters not if what some would call the feed
line radiated
since usually power is not a main consideration making it ideal for
stealth purposes.
Fractal meanderings can be made to conform to any shape
structure while
maintaining a desirable LC ratio which with the use of laminated
circuitry is
becoming more available.

It appears that the above MAY actually be a sentence. However, with
74 words in it, I get completely lost before I get to the end of it.
Would you be so kind as to diagram it for us, Art, or at least divide
it up into something a little more manageable?

Thanks.

Cheers,
Tom

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

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

Kraus calls fractal antennas "artistic antennas". Kraus says: "Fractals
are structures that preserve their shape at different scales."

In Figure 21-50 of page 774 of the 3rd edition of "antennas" (If you
don`t have it, you need it), Kraus writes:
"Note the impedance fluctuations of the fractal antennas compared with
the plate and square loop."

Not a ringing endorsement but there may have been progress since the
book was published in 2003.

Best regards, Richard Harrison, KB5WZI

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