Antenna Types

Omni-directional Antennas:

The most common type of antenna for a WLAN is an omni-directional antenna, also known as a dipole antenna. An omni-directional antenna radiates its signal out in all directions equally. Omni directional antennas are most commonly are used to create hot spots by transmitting a signal over a large area in all directions or receiving signals in all directions when the transmit location is unknown or close by. Omni WiFi antennas do not need to be pointed since their radiation cone is 360 degrees, working in all directions. Each specific antenna has a gain rating or dBi number which coincides with the performance. The higher the dBi rating the larger the area the signal covers. Keeping that in mind and thinking about what your specific needs are you can begin to narrow down what antenna is best for you. A 14 dBi antenna has been rated to cover almost half a mile in distance.

Semi-directional Antennas:

Semi-directional antennas direct an RF signal in a specific direction, typically in short- to medium-distance communications, up to about two miles. Instead of sending and receiving signals from all directions, they focus their strength in one direction, and are blind to the other. For example, your semi-directional antenna is facing East, it will not see or receive the signals coming from west of it. Because it’s more focused than the omni antenna, it can be used to increase signal distance. Semi-directional antennas are primarily used for short and medium range remote wireless bridge networks. Two office buildings that are across the street from one another and need to share a wireless network connection would use semi-directional antennas. They are not commonly used for WLANs.

Highly-directional Antennas:

Highly-directional antennas, like parabolic dish and grid antennas, are strictly used for point-to-point communications, like providing network bridging between two points far away from each other. They provide the most focused,...