Is there an antennae can send waves out different distances/strengths for each angle?

Question

Let's use a flash light to demonstrate since it all acts the same no matter what the spectrum. So to do what I wanted in the above question, I would put a piece of paper in the bottom half of the flashlight's light to block out it's strength. So across in the dark room, I'll see the top half is bright and the bottom half of the light circle is more dark. Can I do this with radio waves? Can you slightly block out radio waves?

Answer 1

Radio signal propagation can be controlled by the size and shape of the antenna ie., microwave dishes for communications every dish has a beam width and has 3 gain section top mid and bottom gain. You can sheild the signals depending on what frequency will determine what material you would need to do such a thing.

Answer 2

Every antenna is directional. Even a simple TV antenna has gain preferentially in one direction. Here's a nice writeup

http://en.wikipedia.org/wiki/Antenna_(radio)

Answer 3

pondering the right attitude whose hypotenuse is the dimensions of the cord, the gap to the attachment factor is the area opposite necessary for the definition of sine of the given attitude. sin55 = 3.seventy one/length of cord. length of cord = 3.seventy one/sin55 = 4.5 m i'm assuming the cord does not sag. i'm assuming the antenna is vertical from the attachment factor to the floor - not a gin pole or some thing that tapers.