On 20 Oct, 14:41, Roy Lewallen wrote:
Mike Kaliski wrote:

As others have mentioned, several articles appeared in various magazines
about the design of fractal antennas. The basic idea is to fold a
standard length of wire using a fractal pattern so that it fits into a
smaller space. One solution I saw was to wind a wire back and forth
across and along a plank of wood using pins or slots cut in the wood to
support the turns. Taking a four inch wide piece of wood around eight
feet long and winding equispaced turns you could easily fit 24 feet of
wire along the plank.
__ __ __
|__| |__| |__| | Using a pattern like this.

Other more complex or even three dimensional designs can fit more wire
into a given space. . .

This general category of antenna is often known as a "meander line", a
technique used for making electrically short antennas which has been
known and used for a very long time. "Fractal" antennas are a more
recent idea. They're a class of meander lines using particular
algorithms to do the meandering in a particular irregular way. Among the
interesting properties of some of these antennas is the presence of
non-harmonically related multiple resonances.
Snip

The non- harmonically related multiple resonance is quite important
now that all ham freqencies are not harmonically related.
I have found that it is possible for a single Gaussian antenna to
be resonant on many frequencies that are not related purely by
balancing the LC ratio at a given radiator length of choice
without reliance on traps or harmonics. These are contained
in there own band pass circuit and which can be moved at will.
The importance being that there is less interference between
band users as well as ambidextry and a constant impedance.
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.

Art KB9MZ



snip

Roy Lewallen, W7EL