" wrote:
The shape changes can come from squeezing the balloon (pattern)
horizontally, vertically, or in combination -- which, in antenna hardware
is accomplished by an appropriate array of, and feed system for, its
radiating elements.

Right..... so what creats it, this "squeezing" that you talk about and
from where does this "squeezing force come from in an "appropiate"array?
That's what I was asking not a discussion of what the Yagi array
produces. Why does the lobe narrow?
______________

Narrowing is the natural result of the vector addition of the separate EM
waves radiated from the individual sources comprising the Yagi (or any other
kind of directional array).

RF