DIY Directional Wifi Antenna Booster

While living in Thailand, I rented an apartment where the internet wasn’t provided thinking it would be easy to get on my own.  Boy was I wrong.  Internet was around $150 to start, $100 a month, required a 12 month contract, and you needed a Thai ID (back in 2007), so I went looking for other options. I came across this site and decided to build my own wifi antenna booster out of a chinese spoon, so I could then get wifi from the bigmac shop down the street for free.

The parts were relatively cheap ($50 in all), and most of that expense was in the usb dongle.  My parts list included:

usb dongle

baby bottle (it rains HARD in the tropics)

usb cable (with amplifier if over three feet)

wire cutters (any will do)

Electrical Tape

Silicone Waterproof Sealant

craft plastic mesh(to center in the baby bottle)

Asian wire spoon


The hardest part of the build is figuring the out the exact the placement of the antena in the spoon.  First you need to find the exact spot of the antenna in the dongle so you can place it right at the focal point of the spoon( I think I actually took off the plastic case to solve this mystery.)  Next you need to find the focal point of the spoon by using Cartesian equation (f=D^2/(16c)) or the square of the diameter divided by 16 times the depth of the spoon. The rest is easy, cut a hole the size of the bottle, put the usb cable through the nipple of the bottle till the distance is right at the focal point and tape the nipple to the wire, and put it all together.  I ended up taping it to my mop handle and leaving it on my balcony railing.


and the finished product:


It worked amazingly, I was able to not only get Wifi from the burger spot down the road, but I was also able to get signals from the high rise 1km away.  Here is a pic from in front of my building to illustrate how far it was to the end of the street where the signal was coming from:

Screen Shot 2013-02-01 at 7.17.13 PM

28 thoughts on “DIY Directional Wifi Antenna Booster

  1. Hey, great instructions, but I had some questions, sorry I am just really ignorant of this kind of thing. What is the white block attached to the USB cable that you show in the picture with the little bonsai plant in the background? Is that the USB amplifier? Also, what did you do with the other end of the USB cable? I assume the USB dongle goes into your computer right?

  2. Good result and full marks for your innovation. I would suggest a solid spoon would do even better Dependent on frequency some signal will pass through from the front and others from the back . Yours is a satelite dish with the USB dongle as the signal receiver.

    1. No, it won’t in the same way no signal from a microwave oven gets through the holes in the window in the door. The holes are much smaller than the wavelength of the signal. 1/4 wave at 2.4 gHz is around 1.2″.

  3. I would think it would be easier to run some sort of signal strength software (if there is such a thing) and then move the receiver in or out for best signal.

  4. I’m a little confused. I could see how this would increase your signal strength sending to the burger shack (ie. upload) but if the burger shack is not putting out a strong enough signal to reach your unit this is nothing you can do to boost that signal.

    1. It amplifies both ways because it aggregates the the surface area of the spoon (~2*pi*r^2) directly at/from the router vs. the tiny (1/4″ maybe) omnidirectional antenna in the usb.

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