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Sparky[_3_] February 16th 14 07:36 AM

Fractal antennae?
 
I've seen some videos about the work done by Fractal Antenna (fractenna.com).
Looks to be very exciting.

Has anyone done any development work on an amateur antenna using fractals?

Thanks.


Phi February 16th 14 10:34 AM

Fractal antennae?
 
I assume you have read this:


''A fractal antenna's response differs markedly from traditional antenna
designs, in that it is capable of operating with good-to-excellent
performance at many different frequencies simultaneously. Normally standard
antennas have to be "cut" for the frequency for which they are to be
used-and thus the standard antennas only work well at that frequency.

This makes the fractal antenna an excellent design for wideband and
multiband applications. In addition the fractal nature of the antenna
shrinks its size, without the use of any components, such as inductors or
capacitors.''

http://en.wikipedia.org/wiki/Fractal_antenna


dave February 16th 14 01:59 PM

Fractal antennae?
 
On 02/15/2014 11:36 PM, Sparky wrote:
I've seen some videos about the work done by Fractal Antenna (fractenna.com).
Looks to be very exciting.

Has anyone done any development work on an amateur antenna using fractals?

Thanks.


I have seen and used them at 500 MHz, they work no better than any other
Circular Polarized antenna, might have a slight size advantage in some
uses, nothing revolutionary.

dave February 16th 14 02:00 PM

Fractal antennae?
 
On 02/16/2014 02:34 AM, Phi wrote:
I assume you have read this:


''A fractal antenna's response differs markedly from traditional antenna
designs, in that it is capable of operating with good-to-excellent
performance at many different frequencies simultaneously. Normally
standard antennas have to be "cut" for the frequency for which they are
to be used-and thus the standard antennas only work well at that frequency.

This makes the fractal antenna an excellent design for wideband and
multiband applications. In addition the fractal nature of the antenna
shrinks its size, without the use of any components, such as inductors
or capacitors.''

http://en.wikipedia.org/wiki/Fractal_antenna


Look up "log periodic" antenna.

gareth February 16th 14 11:59 PM

Fractal antennae?
 
"Sparky" wrote in message
...
I've seen some videos about the work done by Fractal Antenna
(fractenna.com).
Looks to be very exciting.

Has anyone done any development work on an amateur antenna using fractals?


The April and June 1998 Technical Topics column has a couple of pages on
fractal antennae.



Sparky[_3_] February 17th 14 01:05 AM

Fractal antennae?
 
The April and June 1998 Technical Topics column has a couple of pages on
fractal antennae.


A link to the archive?

Thanks.


somebody February 17th 14 01:22 AM

Fractal antennae?
 
On Sun, 16 Feb 2014 10:34:29 -0000, "Phi" wrote:

I assume you have read this:


''A fractal antenna's response differs markedly from traditional antenna
designs, in that it is capable of operating with good-to-excellent
performance at many different frequencies simultaneously. Normally standard
antennas have to be "cut" for the frequency for which they are to be
used-and thus the standard antennas only work well at that frequency.

This makes the fractal antenna an excellent design for wideband and
multiband applications. In addition the fractal nature of the antenna
shrinks its size, without the use of any components, such as inductors or
capacitors.''

http://en.wikipedia.org/wiki/Fractal_antenna


There used to be a 'fractenna' whack job lurking on the newsgroups.
What ever happened to him?

Michael Black[_2_] February 17th 14 02:36 AM

Fractal antennae?
 
On Sun, 16 Feb 2014, Sparky wrote:

The April and June 1998 Technical Topics column has a couple of pages on
fractal antennae.


A link to the archive?

Thanks.


Those tended to be collected in books, at least the useful bits.

And I thought there was One Big Collection when the column finally ended.
I think the ARRL carries them, if not it was the CQ Bookshop where I
noticed, and I seem to recall the One Big Collection was cheaper than the
individual collections. That said, I have no idea if the referenced
article is there, but it was a really good column so likely lots of other
interesting things.

Michael


Sparky[_3_] February 17th 14 05:53 AM

Fractal antennae?
 
For simple antennas, I suspect you are correct.

However, I think it when more complex antennas with complex radiation
patterns that fractal design becomes useful.

You find this type of antenna used at microwave frequencies, which was why
I suggested you try the microwave groups. In one of those you may well find
someone who has designed a fractal antenna.


Microwaves and HF:

http://www.youtube.com/watch?v=3Xq6h31UCKQ [starting at time 1:10]

ham antennas too, apparently.


Wymsey February 17th 14 08:17 AM

Fractal antennae?
 
On Sun, 16 Feb 2014 21:36:58 -0500, Michael Black wrote:

Those tended to be collected in books, at least the useful bits.


There are a number of pieces in Antenna Topics, by Pat Hawker, published
by the RSGB, 2002.


Charlie.



--
M0WYM
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