Aluminum foil can increase the range and security of your Wi-Fi router

Cal Jeffrey

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If you are old enough, you might remember your dad balling up tinfoil on the rabbit ears to bring in channel four a little bit clearer. Results of this little trick were negligible at best and usually required multiple applications of foil until it looked like the TV was ready to go bowling. Now it appears that your dad may have been onto something.

Researchers at Dartmouth University have discovered that not only will aluminum foil increase the range, reception and speed of WiFi signals, it can also shape them in ways that make your router more secure. However, the method described in their paper differs considerably from your dad’s.

Instead of putting foil directly on the router’s antenna, they instead used a 3D-printed shape wrapped in aluminum and placed it around or behind the antenna.

The 3D reflector can be custom-formed to fit any router design to shape its signal to precise specifications. For example, you can print one that blocks the signal from going out the window but increases the range, speed and reliability within a specific room in the house. Best of all, it’s cheap and effective.

“With a simple investment of about $35 and specifying coverage requirements, a wireless reflector can be custom-built to outperform antennae that cost thousands of dollars,” Dartmouth professor and project lead Xia Zhou told EurekaAlert.

To create the antenna aides, Zhou and his colleagues developed a software program called WiPrint. By inputting the desired signal shape requirements, the app creates a 3D-printable image. Once printed, you only need to wrap it up in foil.

They have not released the software yet and have not announced a date when it will be available (if at all). However, the team is presenting its research and the software at ACM's BuildSys 2017 in Delft, Netherlands on November 8.

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Take (2) 8x11 cardboard backings and cover with Al foil. Place together at right-angles and experiment with the distance to the router antennas.

This forms a directional reflector straight between the two antennae away from the reflector and at the right distance, the waves interact in a 3rd harmonic, additive fashion. This is '30-40's short wave radio technology :grin:

A MIMO router with both IN & OUT antennas will not do well with this.
 
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And let's not forget that it's great for blocking those pesky radio waves from Mars that my neighbor is constantly raving about while he covers his latest football helmet with Reynolds best!
 
How is this news? I remember doing this with my Linksys 802.11b router 15y ago.

You are right. I remember an article to a linksys wrt about this before. Just make sure there are no plants along that direction beam or it will slowly die.
 
I figured if aluminum foil can help to focus the wifi beams, if I cover the wifi modem router with aluminum foil it will cause a decrease in the spread of the wifi beams. So I covered my wifi modem router with the foil and see if it decreased the reception on my laptop.

So I covered my wifi modem router and checked my laptop to see if there was any decrease in the bars; there was NO (zero) decrease in reception.

So if the aluminum foil can not block the wifi beams, it certainly can not reflect them to increase the distance.

Easy for you to try. See if I was correct. The aluminum foil is a joke/scam.....
 
I figured if aluminum foil can help to focus the wifi beams, if I cover the wifi modem router with aluminum foil it will cause a decrease in the spread of the wifi beams. So I covered my wifi modem router with the foil and see if it decreased the reception on my laptop.

So I covered my wifi modem router and checked my laptop to see if there was any decrease in the bars; there was NO (zero) decrease in reception.

So if the aluminum foil can not block the wifi beams, it certainly can not reflect them to increase the distance.

Easy for you to try. See if I was correct. The aluminum foil is a joke/scam.....

Your knowledge of electromagnetism is lacking. Transmission is not a binary function; yes/no. Frequencies transmit through a conducter based on frequency, conductivity, and thickness. Skin depth.

It's like covering a light bulb with clingfilm and claiming its a bad insulator. For example, reflection depends on polarization, the angle which the light hits the material, the colour of the light, and refractive index of the material. Life is not that simple.

Put a laser beam of the right colour, at the right angle (Brewster), and you will have zero transmission on cling film.
 
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