On Sep 24, 5:45*am, "Richard Fry" wrote:
"Art Unwin" wrote Presumably the nulls between lobes on a radiation pattern
are a result of radiation cancellation. IF this is true then it means
we have not harnessed *all the radiation available.

__________

It is true, but that doesn't mean or prove that any of the TOTAL radiation
has been "lost." * It has merely been re-directed to produce some maximum
value in one or more directions, and some minimum value in others.

Think of squeezing an inflated balloon. *No matter what is its final shape,
the volume of air inside the balloon remains constant.

Below is a link showing this, as applies to an antenna. *The area within the
directional pattern is the same as if the pattern was omnidirectional.

http://i62.photobucket.com/albums/h8...atternGain.gif

RF

All quite true ,But my reasoning on harvesting is to provide for
maximum return or use.
For a Yagi the radio amateur is interested in the main lobe and it's
xyz coverage.
All the rest is considered "wasted" or providing unwanted interference
If I did not create the nulls between lobes my time of use is then
doubled instead of wasted.
The beam that I am interested in is one that has a single lobe which
I can control in
terms of elevation and beam depth where I am not knocked out because
of radiation
nulls, which is the case for all planar arrays.
Just another reason to focus on equilibrium for radiation formation.
where one can obtain
gain with a single lobe but with a usable lobe width and depth and
uninterupted propagation..
But then, all is known about antennas and if it were possible as the
experts state or
we would have been using such antennas years ago !!!!!
Or as another person stated we don't need a different
type of beam radiation as we already have one!!!!
So by all means crush any and all ideas of change