There is a lot of good information available on the internet for homebuilt 2.4 GHz WLAN antennas for 802.11. Here is one that will outperform most of those antennas and most commercial ones as well. It’s called a Curtain Quad. It is cheap and simple and has a gain of about 17 dBi.
The following describes a version of this antenna that I built and tested.
23, 13, WLAN Helix antenna design
How to design and build helix antennas is described here. Also some of the theory behind it. There are tree radiation modes of helical antennas. The most used mode is the axial mode, it provides maximum radiation along the helix axis. For axial mode, the circumference of one helix-turn is in the order of one wavelength. In normal mode, radiation goes broadside to the helix axis. It occurs when helix diameter is small in respect to the wavelength. If wavelength is small compared to the helix diameter, in conical mode, radiation will go into multiple lobes.
Sardine Can Antenna a BiQuad or Bi circle
Need a quickee antenna ? Got 10 minutes & simple tools ? You won't get a simpler cheaper or more compact design. The unit can be neatly hidden in a pencil case or plastic bag beside your road warrior notebook so it's not intimidating for field use. It's directional enough to even pin point the signal location (using NetStumbler etc ) in a multilevel building. RECOMMENDED !
Easy Homemade 2.4 Ghz Omni Antenna
An easy stepbystep guide go making a homemade wireless antenna for a fraction of the cost of commercial antenna. Uses readily available parts and requires no specialist tools or knowledge. Or in geek speak a diy homebrew omnidirectional colinear dipole design suitable for 802.11 wifi compatible hardware with external antenna connector.
Helix Calculator
Javascript for calculating the dimensions of a helix antenna at the frequency of your choice.
Ez-10 10 dBi Corner Reflector
Template for a corner reflector addition to your WiFi router to improve range.
Ez-12 Parabolic Reflector
Knock up this tinfoil and cardboard reflector to add to the WiFi antenna on your router for increased range.
Deep Dish Cylindrical Parabolic Template
The original stickyback tape and tinfoil reflector design for improved WiFi range
