On Sep 13, 11:29*am, Richard Clark wrote:
On Sun, 13 Sep 2009 12:46:30 +0100, "christofire"

wrote:
Does one wave has many polarizations, or one antenna has many
polarizations? Which one: transmitter or receiver? Could you teach me?
A*

You appear to have changed your identity from S* to A* !

The answers according to the physics that real-life radio communication
depends upon, and was designed by, a

A much simpler, and compelling explanation:
* * * * *what you see is what you get.

If it looks vertical, the polarization is vertical;
If it looks horizontal, the polarization is horizontal.

It thus stands to reason that if the radiator is U shaped you see both
horizontal and vertical - hence the full sphere filled with radiation.

This closes the simple answer, which of course drives a very lengthy
explanation - there is no such thing as a free lunch:

Now, I can well anticipate some wag pointing out that they are
standing, looking at these "goal posts" edge on and see only the
vertical supports. *"There is no horizontal view - no horizontal
polarization. *It can't be isotropic!"

Of course it can't; and yet the vertical radiation fills the null of
the horizontal (and likewise, the horizontal fills the null of the
vertical). *Total field is spherical.

What does this make of a tilted radiator? *What you see is what you
get. *At some perspectives it looks goofy horizontal AND it looks
goofy vertical. *In other perspectives it just looks vertical. *As Art
might protest: *"Never mind goofy, how much horizontal?" *If we reduce
this to a number of goofiness, a trig function would serve quite well.
Most students who were trained in mechanics would recognize the method
to deconstruct an angle into its two, XY, components. *If the tilt
were 45 degrees, in full view of that angle you must experience the
single antenna as having two equal vertical and horizontal
contributions to radiation. *If it were tilted 30 degrees, obviously
one polarization would dominate over the other. *Ground would compound
the issue, but would not negate the general principle.

This last part returns us to the discussion of isotropism which
encompasses the topic of Lambert's Law which is generally confined to
a black body radiator (or the sun from a great distance as it fails to
be isotropic in the near view, such as we have here on earth). *Few
here need concern themselves with this unless they are making patch
antennas. *However, within the discussion above, the topic of view,
angle, and radiation contribution are wrapped up in Lambert and
cosine.

73's
Richard Clark, KB7QHC

Richard cannot read this. However I find his posting to be rewarding .
The present aproach to radiation is that a free electron is torn away
from the nucleous of an atom which creates uncertaincy. Such an action
is that of the strong force which is akin the the splitting of an atom
where such an action would release electrons such that they would
bombard electrical networks such as in Hawaii. When one uses Maxwells
equations
it becomes very obvious that with decreasing impeadance radiation
increases until we get to the point of zero impedance where reality is
forced to be reviewed.
Since we now recognize that radiation is not created by the radiator
itself as it is only a carrier of a radiator, the model used must be
of cylinder type of homogeonos free electrons
where removal of the free electrons/particles is by a "weak force" and
not a strong force.
Thus in reality the model to be used is that of a cylinder where the
"stiction" of each electron,(I should really keep to the term particle
so one does not automatically insert neutrinos or a subset of
leptons) to a diamagnetic material is effectively replaced by a hoop
stress which first showed up in the boundary of the "Big Bang".
Now we have something that meets reality, where increase in current
applied creates an increase in radiation and where the model is seen
to be a boundary consisting of particles bound to each other! This is
basically implied by Maxwell's equations as illustrated by the
computer programs where radiation increase is proportional to the
decrease of impedance
of the energy robbing metallic radiator and where cylindrical boundary
model increases it's share of the current applied for continued
radiation and still is in concert with known laws
without resorting to extreme low temperature to attain "zero
impedance" which lacks reality.
As a side note. It is the arbitrary boundary in shear (spin) which
provides the Weak Force of the Standard Model as foreseen by Einstein
when he took on his fruitless search. And it would appear that the
reversal of the positive sign of the shown "Radio World" material is
somewhat supporting of this posting but that should be the subject of
a separate thread.
Art Unwin