Amateur radio/Unidirectional propagation antenna
A unidirectional propagation antenna is an antenna that has a propagation pattern in only one direction. Unidirectional propagation antenna are good for communicating with someone or something when you know where the station is. The following are examples of these.
Radar antennas
editRadar antennas are type of unidirectional propagation antenna.
Yagi-Uda antennas
editThis kind of antenna is also a unidirectional propagation antenna.
Satellite dishes
editA satellite dish is a unidirectional propagation antenna that we see a lot. They are usually used to communicate with satellites hence the name "satellite dish"