buy the book ,
make the movie...
So once again let us go back to school...
Imagine a point (RF) source.
This source is located within a sphere at its center.
The surface of the sphere is defined as unity gain.
This sphere is all the gain you have.
There is no more.
To get any gain in any direction other that unity it has to come from within the volume of the sphere.
So any "gain" that you get was already there.
It is just being taken form the volume of the sphere and reapplied elsewhere.
Hopefully in a useful direction.
Myself , I am more concerned with nulls.
If I'm taking gain away from an elevation or direction I want to make sure it isn't from somewhere I want or need it .
It's called the Antenna Handbook. You need a copy.
School's out ...
ad nausea
The feed point impedance of either of these examples will be on the order of several thousand ohms. You will need to investigate a "stub match" at the feed point to get it to a reasonable level for ladder or window line. Coax feed is not recommended.