How To Make High Gain Wireless Antenna
What you need: A soup can, copper wire (14 to 18 gauge and 10 cm will do), an insulated antenna wire, an antenna wireless cable (this is a normal wire with two wires inside), SMA connector (this is a normal coaxial TV connector), some tape, piece of wood or plastic (this will be used as support) a solder and a soldering iron.
If you are going to use the improved design at the end of this article, you will also need a wi-fi USB adapter (very cheap to buy). But you can build the High gain antenna without it. Here is how. Read and follow the instructions carefully.
Choosing your can: The can should be like an ordinary soup can. But the height of the can should be longer than the diameter of the can.
Step One: Draw a hole in the side of the can, 2.5 inches from the bottom of the can .
Step two: Strip the insulation of the antenna wire, you will find two cables. One is the shield conductor and the other is the center conductor (in the center of the wire as the name indicates).
Step three: Solder the copper wire to end of the Center conductor of your wire antenna.
Cut the copper wire to 1.25 inches. Make sure it has been soldered firmly to the center conductor of the wire antenna.
Step four: Stick the copper through the hole of the can from the outside. The antenna wire should remain on the outside of the can, while the copper wire should be inserted through the can.
Step five: Solder the shield conductor (the other cable from your wire antenna cable) to the side of the can. Where to solder it? Solder it close to the hole you have made. Yes, the same hole you should have already passed the copper wire through. Any extra length will unbalance the antenna. This particular antenna has a 2.4 gigahertz capability signal. As the wavelength is very small, you don’t want to have any extra length of wire sticking out, get that as close to the hole as possible.
Step Six: Hold the copper wire from inside the can with your support. Use wood or plastic to hold it in place. What you use as support makes no difference, make sure it is non conductive material. The important thing here is that if you look inside the can the only thing you should see is the copper wire that will be held in position by the support. You can make a small hole to the support and then tape the support to the side of the inside of the can.
The copper wire should stay straight, the end of the copper wire inside the antenna should face the opposite side of the can, not the open lid. You can also use epoxy to keep the copper wire straight inside the can, if you don’t have wood or plastic.
Very important: The copper wire inside the can should measure, from the edge of the can to the tip, 1.2 inches. If not, it will not work efficiently, and may not work at all. That is important as it has to match the wave length of your signal.
Tips on using the antenna
The antenna is directional. It should be near the window, to get signal from outside. Screen or metal mesh screens will block the signals entirely. Another tip: get the antenna as high as possible. The closer to the ground, the more objects to block the signal. If you are trying to get signal from 120 feet away, bushes or trees on the path will lower the signal
The antenna wire should not be more than 3 foot long. The high frequency will be attenuated by the length of the cable.
Connect the SMA to a wireless wi-fi or use design improvements below to avoid having to be
working side by side the cable. Signal attenuates when it travels through objects, trees, etc. This is a directional antenna. It will seek out signals in one direction. Point in different directions to get your signal.
You can purchase a wi-fi USB adapter that comes with removable antenna, or purchase a USB SMA Adapter. This is usually worth about 15 USD. Connect the a pig tail SMA to the end of your wi-fi antenna, and then connect the other end to the USB adapter. This way you can boost your internet connection wi-fi if you are working on a laptop.