By using PVC, all-thread, washers, some cheap copper tubing, a Pringles can, and some scrap cardboard, we were able to make a prototype shotgun yagi in a matter of hours. In about 45 minutes, we had the collector rod built, the locknuts on, and the whole thing in place. The result is a Pringles can that pulls about 12db!
http://www.oreillynet.com/cs/weblog/view/wlg/448
This article will describe how to make a cheap, portable, high performance (15-18 db) directional antenna out of commonly available parts that can be purchased in most grocery and hardware stores. Unlike these other designs, the CookieCantenna aims to let you have your cookies and eat them too!
http://www.seattlewireless.net/CookieCantenna
One of my latest obsessions is building homebrew WiFi antennae. This is the first antenna I built. It is the ubiquitous circular waveguide cantenna. The probe should be 30.8mm (1.21 inch) long, and should be set 63mm (2.5 inch) from the inside of the back lid of the can.
http://www.lincomatic.com/wireless/homebrewant.html
The biquad antenna is easy to build, and provides a reliable 11dBi gain, with a fairly wide beamwidth. Some very rough initial testing using the biquad as a feed on a 24dBi Conifer dish looks very promising. I also managed to get a marginal link to a 180 degree waveguide on an access point 10km away, using only the biquad by itself, connected to a 30mW RoamAbout wireless card.
http://martybugs.net/wireless/biquad/
Hee is the details on building a double biquad antenna with approx 13dBi gain. The test results indicate that the gain of the double biquad is approx 2dBi higher than that of the biquad, which is a significant improvement as 3dBi is a doubling of signal.
http://martybugs.net/wireless/biquad/double.cgi
This page details the construction of an easy-to-make collinear 360 degrees omni-directional, vertically polarised, antenna for 802.11b g wireless networking. The antenna is very robust and compact, and has a gain of approximately 5 to 6dBi.
http://martybugs.net/wireless/collinear.cgi
Here is how to build a high gain antenna for 2.4 gHz wireless networks. A customized classic cantenna using 4 inch diameter aluminum dryer vent pipe, and a 4 to 6 inch pipe adapter. Although the basic design is the same as other cantenna type antennas, the materials are a bit different. Preliminary results show a gain of 15 DBi. Not bad for less than $10 worth of materials.
http://www.wb8erj.com/wirelessCantenna.html
Got no dough for a commercial WiFi antenna? Looking for an inexpensive way to increase the range of your wireless network? A tin can waveguide antenna, or Cantenna, may be just the ticket. This design can be built for under $5 U.S. and reuses a food, juice, or other tin can.
http://www.turnpoint.net/wireless/cantennahowto.html
Describes a simple way to determine the main RF characteristics of a Wifi (IEEE802.11b/g wireless LAN) antenna. Although this procedure is written specifically with Wifi antennas in mind, it can also be used on other antennas.
http://pe2er.nl/antennetesten/antennameasurement.htm
A prototype 2.45Ghz antenna for mobile use. Can be used this antenna for surveying signal strength using a variety of free wlan tools. Very simple to construct, requiring just a piece of wire, an N socket and a 100mm diameter (approx) tin lid.
http://www.frars.org.uk/cgi-bin/render.pl?pageid=1071