> No, both EZNEC and elementary physics show that an E-W
> dipole
> sloped 45 degrees radiates exactly equal amounts of both
> vertical and horizontal polarization in N and S directions
> with zero elevation, in free space.
The reason you see that display is the program only tells
you level in two planes, perfectly vertical and perfectly
horizontal. The reason you visualize it is you are
visualizing wrong.
The fact the display shows only two planes and must display
a tilted field as a combination of the two when it really
isn't leads people to erroneously believe they have the best
of both worlds, an antenna that radiates both vertical and
horizontal. In fact true at all.
The field actually is a single polarization that is neither
vertical or horizontal, but some angle between. Exactly 90
degrees from that polarization alignment is a null, so we
have a single tilted polarization NOT a combination of both.
For example as we are broadside to a perfect dipole the
field is perfectly horizontal. As we move off towards the
ends the field tilts, with maximum tilt towards vertical
near the ends. But at EVERY point it is a single
polarization that simply is tilted.
The only way we can have both polarizations present in a
single direction is by having a field that rotates with
time.
Eznec+ 4 allows you to go into a menu that gives field
strength in tabular form. From that menu you can see exactly
how much rotation the field has. You will see a bent dipole,
unless very specific conditions are met with length and
angles, simply generates a single polarization that has
various tilts in various directions. It dispels the myth
that we can "mix" two polarizations without a quadrature or
near quadrature phase relationship (so the wave rotates) and
have both polarizations. Unless we change the polarization
with time, it can only be a single polarization in a single
direction.
73 Tom
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