Michael J. Coslo wrote:
On Mar 4, 7:01 am, wrote:
Michael J. Coslo wrote:

snippage

Anyhow, if they have managed to make this antenna extremely efficient,
what they must have done is make the RF resistance not become much
lower as the physical size goes down. Some other possibilities are
that they somehow managed to make the Velocity factor really low,
maybe 25 percent.
That's exactly what is being experimented with; materials that make the
velocity factor low.

Now how you do this without getting big losses in that material, I haven'
t
a clue, but evidently some people think they can do it.

I looked a little at metamaterials on Wikipedia, and it is some
interesting (read mind boggling) stuff.

That to me is the issue, just how they can get a velocity factor low
and maintain efficiency at the same time. Certainly in regular
materials, where people have tried doing things like insulation
adjustments, they have succeeded in shortening the antenna, but
eventually run up against the no free lunch doctrine.

Probably everyone already knows this, but in case anyone doesn't, an
example of this is a wire dipole. If you use insulated wire, the
antenna will be a little shorter than a bare wire antenna when tuned
for a given frequency. The insulation changes the Velocity Factor.
I'll not call shenanigans just yet. I've seen a lot of wonder antennas
come and go in the short time I've been a Ham.

- 73 de Mike N3LI -


I will say this about the research.

It is one thign to make a tiny antenna that works at micro-watts

Quite another to make the wire not melt at kilowatts

--
John in Detroit E-Dress is smoked, Invalid equals NET.