A directional antenna has a higher gain than an omnidirectional antenna as they focus the radio frequency energy in a particular direction.
A typical use for a directional antenna is down long highways or in the aisle of a warehouse.
Directional antennas can be used outdoors for areas away from a building or to cover a long distance between buildings.
If mounted on a ceiling, a directional antenna can point down to a floor to cover a small floor area.
Path antennas produce an egg shaped pattern away from it’s flat surface. They provide a broad directional pattern with a gain of around +6 to 8 dBi in the 2.4Ghz band and 7 to 10 dBi in the 5Ghz band
The Yagi-Uda antenna has an outer case shaped like a thick cylinder, but inside the antenna has a wire with several parallel elements that increase in length.
The Yagi-Uda antenna produces a more focused egg shape pattern that extends along the length of the antenna. It can result in a gain of around 10 to 14 dBi
Line of Sight Antennas
Where there is a line of sight between two antennas, a highly focused narrow beam can be used to focus the energy over a long distance.
Parabolic dish antennas can focus these signals onto a central antenna mounted in the centre of the dish. The shape of the antenna helps focus the received signals onto the centre of the dish.