I built a simple RF communication system with a 433MHz transmitter and a receiver. The transmitter needs to transmit in a 180º range (I mean in one half of a sphere, I don't know how to say that in English), the receiver must be omnidiectional.
I was told that a good antenna for small 433MHz modules is a one quarter wave lenght wire, and also that the shape is important, but I didn't found on google what are the best shapes.
What are the possible shapes for auch an antenna? What are the pros and cons of each of them?