To get the most bang out of your WiFi buck, you need the right antenna for the job. There are two prominent types of wifi antenna: Directional and Omni-directional. We’ll just talk about the directional antennas in this post.
When your talking about an antenna for a wireless network, it’s all about the “gain”. Gain measures how well the antenna increases effective signal power. Directional antennas are primarily used for Point-to-Point applications and occasionally for Multi-Point systems. There are three basic types of directional antennas:
- Backfires — The Backfire is a small directional antenna with excellent gain. They look similar to a parabolic dish, but the gain isn’t as high. Backfire antennas are recommended for point to point or point to multi-point systems because of the excellent gain and the good noise figures. Some backfire antennas can achieve 15 dBi of gain which is excellent considering the antenna is only 10 inches diameter.
- Yagi — Yagi antennas were the design of two Japanese people, Hidetsugu Yagi and Shintaro Uda, and are sometimes referred to as Yagi-Uda antennas. They were originally designed for radio, but are now also used for 802.11 systems. These antennas are typically very directional and are used for point to point, or to extend the range of a point to multi-point system. Yagi’s have excellent signal strength and in the right circumstances can communicate for miles!
- Parabolic Dish — Now we’re talking power. Parabolic dish antennas put out tremendous gain. No pain, no gain — they are a little hard to point and make a connection with. Dish antennas are almost always used for a point to point system for long haul systems. These antennas are highly focused and are the perfect tool if you want to send your signal a very long distance.
Keep your antenna up for a post on Omni-Directional Antenna.