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I have been doing some research on directional antennas and I have found people are able to build a directional antenna using a Wi-Fi dongle and some cheap parts. My purpose is to build a directional antenna and mount it on my Raspberry Pi. Does anyone any better suggestions on how I could approach this task?

Examples on YouTube:

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  • Pringles can is amazing.
    – Daniel
    Mar 25 '16 at 3:46
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As Daniel pointed out - True directional antennas need to be build to specification the same way as omnidirectional antennas. Real directional antennas can achieve kilometres of WiFi link at the same power as omnidirectional.

First problem with directional antennas is that you need them on both sides to work properly.

Second issue is that the antenna you trying to convert to direction antenna was built specifically to be Omnidirectional (send data all around it)

By putting a beer can or pringles tin over it all you are doing is blocking 90% of the WiFi while letting the rest go in one direction. You CANNOT achieve amplification like this regardless what people say. You just this illusion of better range but its nothing like a few kilometres is it?

The only reason you may think you get better WiFi signal is because you blocking out WiFi noise by putting a can over it.

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  • "First problem with directional antennas is that you need them on both sides to work properly." - no, you don't. You get twice the gain with one on both ends, but you can use it on one end just fine.
    – psusi
    Sep 27 '18 at 17:51
  • It is difficult to follow what you mean. Could you explain a little bit please
    – Piotr Kula
    Sep 27 '18 at 19:42
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Pringles cans work amazingly, but here's what you really want: High Power USB-Yagi Plug and Play directional WiFi Antenna 802.11n 2200mW.

Products like these are professionally made to the correct standards. I'm an Amateur Radio operator, so I'm familiar with the ins and out and difficulties of antenna building, and it is especially difficult at 2.4 GHz. Even a 2mm difference can hurt performance noticeably. Get something professionally built, or use a Cat7 cable.

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  • if i use a Pringle can , how much gain can I achieve? and also does it cost alot? Mar 25 '16 at 4:02
  • What distance are you looking to have between the RPi and the Access point?
    – Daniel
    Mar 25 '16 at 15:53
  • You can easily get about 10dBish of gain, but in practice it get much farther than you would think. It is extremely directional, so it not only increases signal strength, but also your signal-to-noise ratio. The pringles can is the best. You can get about double the distance.
    – Daniel
    Mar 25 '16 at 16:15

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