It does not impede the signal while tremendously reducing the weight.
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However, producers try to make them pretty light, since they are not full like the TV parabolas, that's why they have the denomination of grid. so it's not a good choice when traveling. Moreover, it is cumbersome: an antenna of 24dbi has a 1 meter diameter. It is very difficult to point on the emitter (they are different techniques though), but once you get it, it's just awesome the SNR you get ! Sadly, this kind of antenna has only an efficiency of around 50% :(. Typically, this is the antenna I prefer, when you don't have to move it. The higher the gain, the more peaks you'll have, the thinner will be the forward radiation pattern, the more difficult it will be to point on the desired direction. Note that the radiation pattern has a sort of unwanted "flower" radiating backward. Moreover, the gain is directly linearly proportional to the area of your antenna, meaning that the biggest is your antenna, the more gain it will have.Īs an analogy, we can see the parabolic antenna as a laser: it is difficult to point on the right place, but when it is pointed right, you get the maximum SNR. What is cool about parabolic antenna, is that they are universal: one antenna working for Wifi can work for other purpose. so maybe the solution for cellphone to have a longer battery life is simply to add them an antenna ? Yes, probably, but it wouldn't fit into your pocket anymore. This also explain why the car antennas were so big few years ago, now electronic tries to replace them, but usually an inadequate antenna requires a damn lot of power.
Suppose you fix it on your balcony, do you really care about the backward radiation ? We want then a more directive antenna to maximize the gain.įinally, it is nice to notice that an omnidirectional antenna does depend on the wavelength (and obviously on the frequency), thus an antenna used for FM radio (100MHz) will be much bigger than an omnidirectional antenna used for Wifi (2.4 GHz). Typically, this kind of antenna is cool when wardriving, but for everyday, especially if you stay at the same point (ie at home), it's not very useful.
If you increase the size of your antenna, people from the ground floor won't be able to capt it anymore (and vice-versa), but it will reach more people horizontally. If you've a small omnidirectional antenna, people from the ground floor will be able to catch your signal. To give an example, imagine that you are living at the 3rd floor of a building. When increasing the size of your antenna, the azimuth goes smoother.
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