Monday, December 24, 2012

Omni Antenna vs. Directional Antenna


A common question we hear from customers looking at all our antenna options is, “do I need an omnidirectional or a directional antenna?”

First, remember that before buying any antenna for a fixed location (home, office, etc), we recommend doing a site survey first so you can get an idea of whether an antenna will help you, if you need an amplifier as well, and what kind of improvement you can expect to see from your signal boosting equipment. Click here for site survey instructions: 3gstore.com/rssi

Once you’ve determined that an antenna will indeed help you, it’s time to decide which one is going to be best for your needs. There are two basic classifications of antennas: directional antennas, which must be aimed towards the cell tower you’re using, and omnidirectional antennas, which pick up signal from 360 degrees around and don’t need to be aimed.

Directional antennas are higher gain than omnidirectional antennas, but only if they’re aimed properly — if a directional antenna isn’t aimed at the tower, it won’t be very effective at all. A directional antenna is great when you know there’s only one tower serving you, or when there are multiple towers in the area and your device is bouncing between towers, because you can aim the antenna right towards the tower you want to use.

3Gstore carries two kinds of directional antenna, Yagi and Panel. A Yagi antenna is the hardest to install and isn’t appropriate for most users. Yagis are made to be installed at a fixed location with direct line of sight to the cell tower and are obviously NOT a good choice portable use. Yagi antennas are recommended only if you have line of sight to the cell tower (i.e. no obstructions in the way) and can be very effective in situations where the signal is extremely weak at the location but better signal is available within a mile or so.

If a customer doesn’t have line of sight to the tower but does know where the tower is (or doesn’t mind doing some trial-and-error while installing to find the optimum direction to aim it), then we recommend the panel antenna. Panel antennas are directional but they are more forgiving than Yagis, they just need to be aimed in the general direction of the tower. Panel antennas are also not recommended for portable use, since you would have to locate the new tower and re-aim it every time you got to a new location.

If you want to use a directional antenna but don’t know where your tower is located, check out this tip of the week: www.evdoinfo.com/tip75

Omni antennas are used more frequently, because they are easier to set up and you can use them in both fixed and traveling applications. When installing an omni antenna in a fixed location, you don’t need to worry about aiming it, although we do recommend installing it on the side of the building where signal is best if possible. Omni antennas aren’t as high-gain as directional antennas, BUT an omnidirectional antenna will actually be MORE effective than a directional antenna if you aren’t able to aim a directional antenna properly — so don’t discount an omni antenna simply because you see that the directional antennas have “better specs”!