Joel Koltner wrote:
Hi Richard,

Thanks for your help...

"Richard Clark" wrote in message
...
Because they look cool?

More because they don't take up a lot of space. I realize that any
reasonably small antenna for 2m (meaning: "fits in the palm of your
hand") is going to be a compromise anyway, but if you can have a
nice-looking antenna that performs as well as a rubber ducky, heck, I'll
have it look nice too...


Stated that way, it should be possible to create a patch antenna that
has comparable performance.

Or a "patch looking" antenna.

There's a couple ways to go about it, none of which involve starting
with a 2.4 GHz patch operated at 1/20th the design frequency.

1) use something as a dielectric that has a high epsilon, so the
wavelength is shorter. For cellphones and the like, various ceramics
like alumina are used. It's pretty easy to get to epsilon=10, but that
only gets you to 1/3 the size.

2) build something like a meander line on a suitable substrate. This is
sort of the squashed flat version of a rubber ducky loaded vertical.
Rather than making a 3d spiral which is a "radiating inductor" you do it
on a flat surface. It's a bit tricky because a simple back and forth in
a single plane won't radiate very well (the field from one meander
cancels the adjacent one). But a spiral might work.

3) low loss lumped loading components.

But, to return to your original 2.4GHz patch.. it's going to look like a
capacitor of some sort at 144 MHz. The feedline would probably do most
of the radiation.