A rubber ball represents the radiation from an antenna. ie perfectly
spherical for an isotropic antenna. You can think of the field strength
of the signal as being proprtional to the ball's radius.

When you put gain into the system you take the same amount of "power"
and "squash" it into specific directions. You take from the direction
you dont want radiation in and put it into the direction you do. You
never get something for nothing and gain always implies directivity,
even if that directivity is undesirable.

Okay?

ml wrote:

what is this theory??