Improving WiFi reception

ubuysa

The BSOD Doctor
With everyone stuck at home at this time I know that good Internet access is essential. I also know from past experience myself that getting a good WiFi signal from any distance can be a bit hit and miss, and that's really down to your antenna. Hopefully my long experience in networking can help improve your signal quality by maximising your antenna performance.

The best directional wireless antenna you can have is a yagi array, the same technology used by TV antennas. A yagi array consists of a receiver element and several director elements placed strategically in front of it to tune the incoming signals.

You can improve the performance of most existing external WiFi antennas by adding a series of director elements in front of it to create a simple yagi array and similarly tune the signals your antenna receives. Note that because WiFi uses microwave wavelengths a WiFi yagi antenna is very small compared to a TV antenna (see the photo of a commercial WiFi yagi array below).

Converting an existing external WiFi antenna to a yagi array is not that expensive nor difficult, you can make the director elements from aluminium foil stuck to a card with sticky tape (non-metallic). For the best performance you want to use heavy-duty polar foil (0.05mm) from aluminium food containers, but standard food-grade kitchen foil (0.02mm) also gives good results.

See the drawing below for the size of the three foil strip directors (in yellow), their relative positions, and the rough size of the mounting card. The card needs to be stiff enough not to fold or bend when mounted vertically. These dimentions are critical and the more accurate you can be the better the array will perform.

WiFi signals are vertically polarised so you have to mount the card so that the foil director strips are vertical (as in the drawing). They must be on the imaginary line between your external antenna and the hotspot so that the director array is pointing towards the hotspot and in front of your external antenna.

You may need to move the card slightly in a longitidinal direction to 'tune' the antenna until you get the strongest signal. Elevating the front of the card might also be necessary to keep the directors on the line of sight to the hotspot (but try to keep the external antenna and the directors parallel). In the past I've used plasticine to hold the card and allow for a bit of tuning adjustment. Some Blu-Tak might work just as well though.

Most people should find some improvement in signal strength and in stability, though this will work better for some than others. Add a comment below to let me know how well this works for you. Some photos of your yagi arrays would be welcome too.
 

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ubuysa

The BSOD Doctor
I hope my little April Fool above gave you a few minutes of mirth yesterday? There were lots of clues in there; 14mm (1st April) 41mm (1st April for Americans) and of course 'polar foil' is an anagram of April Fool.

Yagi WiFi antennas are a real thing and you can make your own, just not with kitchen foil and card..... :cool:
 

SpyderTracks

We love you Ukraine
I hope my little April Fool above gave you a few minutes of mirth yesterday? There were lots of clues in there; 14mm (1st April) 41mm (1st April for Americans) and of course 'polar foil' is an anagram of April Fool.

Yagi WiFi antennas are a real thing and you can make your own, just not with kitchen foil and card..... :cool:
Ha ha, I did wonder, now it makes absolute sense! That’s brilliant!
 

ubuysa

The BSOD Doctor
Ha ha, I did wonder, now it makes absolute sense! That’s brilliant!
Thanks. I actually created it for the marina here, we lived on our yacht in there every winter for 12 years (cruising in the summer) and I know how awful WiFi reception is there. WiFi is entirely the wrong technology for a marina in any case because of all those moving yacht masts, but it's cheap and convenient.

I posted that on the the marina client's Facebook page and got some interesting comments. Two boats apparently started to make it!

It went down much better there where there are few IT techies. I didn't expect it to do well on here because everyone knows too much, but I figured I might as well try it... :)
 
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