You can build a homemade wireless antenna using an inexpensive USB network adaptor and various common household items. Experimenters generally take one of two different paths, depending on their requirements. Reported gains are in the five to 15 decibel range.
Decoding of the wireless signal takes place in the USB adaptor, resulting in a low loss digital output. The digital signal can then be transmitted over USB cable for up to 15 feet, or even farther with active hubs. This method is very efficient, much easier and less expensive than standard do-it-yourself antennas and coax.
This type of wireless antenna is created using assorted sizes of tin cans as waveguides. The USB adaptor is inserted into the can at a carefully calculated spot. These so-called cantennas are fairly directional in nature, making them ideal for point-to-point applications.
A basic parabolic reflector antenna can be made using a variety of objects, from abandoned satellite dishes to cookware such as kitchen strainers or even an old wok. The USB adaptor is placed at the focal point of the parabola. This sort of antenna receives wireless signals from a wider area.