Posted by Admin on Mar 28, 2017
Cell phone signal boosters either come with external Omni Antenna or Directional Antenna. Learn the differences between exterior building or vehicle omni-directional and building uni-directional cell phone signal booster antennas. Then select the best one for your needs.
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We're going to try to explain to you the difference between an omni-directional antenna and a uni-directional antenna (commonly referred to, as simply "directional antenna"). See the video above because it contains animation. A directional antenna primarily transmits and receives energy from one direction. Whereas an omnidirectional antenna receives and transmits energy 360 degrees.
An omnidirectional antenna means that the energy radiates all the way around an antenna. Remember that most antennas act just like a dipole. Therefore, this antenna requires a magnetic plane like the roof of your car to act as the bottom part of the dipole. Remember that a dipole looks like this but you can also turn it sideways so it can look like this (see the video). An omnidirectional antenna radiates all the way around and the actual radiation pattern kind of looks like a donut. There're different types of energy. Remember that we're showing you a slice of their energy. If you take this and make it 360 degrees, you can see it is the shape of a donut. You have some dead areas and you have radiated power on both sides which radiates 360 degrees. That is an omnidirectional antenna.
Marine antenna is another example of an omni-directional antenna. It is also a dipole. However, this is a marine antenna and it is designed to mount onto a fiberglass boat. Therefore, we don't have a bunch of metal for the bottom plane. If you recall, an omnidirectional antenna, a dipole looks like this and this is your feed point. We have put this ground plane right here. These radials and they are tuned to 800 megahertz and 1900 megahertz. Because they radiate a certain way, they fool this antenna into thinking that this is ground. There is a whip inside that is about 12 inches long. It acts just like the antenna designed to go on top of a car. But this one goes on a boat. It is waterproof and it works very well.
A yagi antenna is pretty simple. It works very similar to an omnidirectional antenna. It uses directors and a reflector to make the power radiated energy go out only in the direction we want. These directors make this energy want to go a certain way. The energy wants to go in a particular direction, hits this and then bounces back. This is the driving element and this is the grounding element. Just like in the omnidirectional antenna. That is the driving element and this is the grounding element. The energy will go that way. Then we put this large reflector out here which makes the energy want to go that way. We could have a directional antenna without these elements but it just wouldn't be as directional or as powerful.
Therefore, you put these out here, slightly smaller. Notice they are all the same size. What they do is encourage that energy to come in or go out. They give this antenna some gain. Gain is basically taking power and increasing that power or that radiated energy. The pattern for this antenna looks like this. And you will get a little spike. Then you get a little bit off the end. The antenna itself is here and it is mounted to a tree or pole. The energy is primarily going in this direction. You do get a little bit off the backside but not much. This antenna will not work as an omnidirectional antenna. Basically, find the cell tower that you want to use, and point it at it.
An omnidirectional antenna is great for a vehicle. That is because the vehicle is moving through space. So, it is bouncing off different cell towers. Whereas if you were to put a directional antenna on your car and then point it at a cell tower - You would lose connection when it turns to go other direction. For example, as soon as you go into a grocery store parking lot, that cell tower still stays in the same place. But you have now moved somewhere else and lost the signal. Therefore, a directional antenna won't work for a vehicle. A directional antenna is really good for a home or business installation. This is because you can tune your system for optimal coverage on the inside using a directional antenna.
If you would like to see the demonstration and animations, please see the actual video for more information to help answer your questions. Thank you!