Homemade receivers can boost your Wi-Fi signal reception with the application of a little science. Radio waves, like those used in Wi-Fi, degrade over distance and when passing through obstacles; they also reflect off of metal. A Wi-Fi signal receiver can be any kind of metal surrounding your Wi-Fi antenna to help bounce the radio waves toward it. You can use a metal food can or a foil-lined chip canister to make your signal receiver.
Thoroughly clean out your metal object. For example, wash a food can and let it dry completely.
Measure the diameter of the opening for your metal receiver. The larger the diameter of the can, the closer to the unopened base you want the antenna to be. A 3-inch diameter can should have the antenna 3.75 inches from the bottom. A 4-inch diameter can should have the antenna only 1.75 inches from the bottom. Most food cans are in that range. Mark the spot on the can where the antenna will go.
Hold the USB adapter against the can with the connector side away from the can and trace the outline at the mark you made. Drill a hole or otherwise cut out the place needed to insert the antenna. Tape the edges of the hole to prevent cuts to you or the antenna. Insert the antenna in the can and tape it in place.
Connect the USB extension cord to the USB adapter and then plug the cord into your computer. Point the can at the Wi-Fi hotspot, and the signal will be much stronger. Note that if you aren't pointed at the hotspot, your signal strength will decrease significantly, as the metal deflects anything not entering the mouth of the can.
Things You'll Need
USB Wi-Fi adapter
USB extension cord
Metal receiver -- food can, etc.
Saw, drill or scissors
Tape or file the edges of a food can to prevent accidental cuts.
Attach the can to a tripod for better stability and more accurate aim.