"Richard Clark" wrote in message
...
On Thu, 15 Nov 2007 22:54:14 -0000, "Mike Kaliski"
wrote:

I guess you are skeptical that there might be a specific point on an
antenna
that matches the impedence of free space and thus radiates energy more
strongly than the rest of the antenna.

Hi Mike,

When your energy is frequency based, and your interface is large in
terms of wavelength (and anything over 1/10th wave is still large);
then trying to home in on a "specific" point is not very specific at
all.

This is the subject that interests me
and I intend to try and establish to my own satisfaction whether this is
or
is not the case.

You will probably be able to approach it by degrees, but as you get
closer focus has to be abandoned (classic wavelength vs. physical
length diffraction limitation).

If this can be established in a scientifically robust
manner, then I will present my experimental method, measurements and
conclusions for critical examination. I am unfamiliar with work that has
been carried out in this field, so I will carry out further searches and
reading before embarking on reinventing the wheel. Thanks for the link and
the suggestion about plasmonics and fields, I will follow up on that.

More towards the RF end of the scale, diffraction limits (being
broken) and your interest, consider:
http://physicsworld.com/cws/article/print/17398

You can listen to others crow about how "someday" science will catch
up, or you can simply see that science has already left that crowd in
the dust. The article above (and others found by googling "Boeing,
and "negative refractance") will give you an RF material that turns
beams in the opposite direction of what would be expected.

Our crowing buddies would shrug this off (lack of experience in this
matter) because they don't realize that it solves the diffraction
limitation. Build your own model and throw RF against it yourself to
discover a lens with absolute (not fuzzy) focus.

73's
Richard Clark, KB7QHC

Thank you Richard. I was aware of negative index refraction materials. Now
to make them sufficiently broadband and work at optical frequencies...

Cheers
Mike G0ULI