"Walter Maxwell" wrote in message
...
On Sat, 17 Jul 2004 18:11:39 -0000, "Dave" wrote:

good idea, they are just another way for lawyers to make money. any new
idea gets ripped off as soon as its out anyway with cheap imitations...
and
then lawyers make more money suing the infringers if they can get a hand
on
them.

wrote in message
news
On Sat, 17 Jul 2004 12:11:22 -0000, "Dave" wrote:


"J. Harvey" wrote in message
. com...

Any comments or technical objections?

if this were that obvious to you, and it would work as described, it
would
already be in wide use.

So let's save some federal money by shutting down the USPTO.
Everything useful that works has already been thought of, so there's
no need for them any more.

i haven't had enough caffeine yet to explain why,
but somehow i think you would get complete cancellation and there
would
be
no propagation at all.

Without giving the problem any serious mathematical or physical thought,
only
knee-jerk intuition, IMO, if a radiator suitable for radiating CP of
either hand
were fed with equal signals leading to both RHCP and LHCP simultaneously,
I
agree with the poster above that complete cancelation would result, and
there
would be no radiation.

This is why a linearly-polarized antenna could not receive any energy.
(har har)

Walt, W2DU

Walter

I'm not bright enough to fully understand all this discussion. But, I
wonder if the appropriate phasing of two circularly polarized waves, one
RHCP and the other LHCP can result in a linearly polarized wave, not zero.
I think I could build an antenna from two crossed dipoles spaced 1/4 wave
apart that porduce either RHCP or LHCP radiation depending on how *one* of
the dipoles is phased with respect to the other. Feed them in phase and get
RHCP. Change the phase of either dipole 180 degrees and get LHCP. The
"unchanged" dipole in both cases has the same polarization and phase.

If (theoretically) two of these antennas were superimposed on each other,
only the phase of *one* dipole of each antenna needs to be 'reversed' to
produce the 'reversed' (RH or LH) polarized wave. The other dipole of each
antenna can be in phase with each other, so the sum is a linear wave.

What am I missing??

Jerry