The purpose for making a parabolic WiFi antenna is to increase the signal strength and improve the link quality. If you’re going to build a parabolic reflector, it would only make sense to at least invest in an 8 dB WiFi antenna. Most WiFi adapters come with a three or 4 dB antenna either built in or removable. In the case of this tutorial the parabolic adapter was made for a wireless laptop that does not have an external antenna option. For this reason I purchased a USB WiFi adapter with a removable antenna, and at the same time purchased an 8 dB antenna to replace the 4 dB antenna that came with the adapter. You could make a small parabolic reflector for the original antenna, but the results would not be as dramatic increasing the signal of the small antenna as it would be for the larger antenna, click here for more info.
To make this parabolic WiFi reflector you will need a piece of craft aluminum either 4 x 10 inches or 8 x 10 inches, and a 4 x 6 inch piece of plexiglass. I used a 4 x 10 inch piece of craft aluminum at a cost of $1.58, and the pieces of plexiglass I got were free scraps. You also need to download and print out the parabolic template located at Binary Wolf.
I placed my craft aluminum lengthwise and parallel on top of a wooden rolling pin. Using the palms of my hands, I gently applied pressure to the aluminum and rolled it back and forth on top of the rolling pin until it began to have the right curve. I matched the curve of the aluminum to the template I had printed out until it lined up correctly.
Next I took my two pieces of plexiglass about 4 inches wide and cut them close to the desired shape, then using a sander I carefully sanded them down until they both met the parabolic curve. Next I drilled a hole for the antenna, the hole in one piece of plexiglass larger than the one in the other, because the WiFi antenna is narrower at the top than it is at the bottom.
Once all the pieces are ready you need an adhesive that will glue the plexiglass to the aluminum. I had some WaterWeld putty laying around so I use that.
In the pictures accompanying this article you can see the signal strength and link quality I had using the original 4 decibel antenna, the 8 dB antenna, in the final signal strength and link quality with the 8 dB antenna mounted in a parabolic reflector. I did all my cutting and standing by hand and had the antenna finished in about one hour’s time.