On Sun, 18 Jul 2004 15:44:09 GMT, "Jerry Martes" wrote:


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

Well, Jerry, your last statements is correct. Apparently you missed Roy's post,
where he explained that two equal harmonically related RHCP and LHCP signals
reduce to a linearly-polarized wave. I was out of my tree when I came up with
the knee-jerk response of no signal. I knew better, but I spoke without having
my brain in motion. Happens too often when one gets to my age.

Walt