Omnidirectional Antenna

An omni directional antenna is considerably more difficult to build than a directional "cantenna" type of antenna. However if you are wish to experiment here are some designs:

• To see what is inside the standard "rubber ducky" antennas that come with most APs or routers, check out the Anatomy of a Rubber Ducky Antenna page

• SlottedWaveguides seem to give good results.

• discones are not too difficult to build : by example here or here. (or in French, in German). images.google('discone'). The gain is probably low (yet better than with quarter-waves which are already much better than the built-in antennae). They are easy to build.

• Two designs from the folks at Guerilla.net

  • http://www.guerrilla.net/reference/antennas/2ghz_collinear_omni_lowpwr/ (DOWN 03/09)

  • http://www.guerrilla.net/reference/antennas/2ghz_collinear_omni/ (link DOWN 03/09)

• For a much simpler collinear, check out the Home-brew Compact Collinear Antenna

• TerrySchmidt's maxrad pictures

  • http://www.nycwireless.net/Images/maxrad/ (broken? 2002/08/16)

• There are also kits available for 5($28), 8($35) and 12($45) dBi gain omnidirectional antennas from Aerialix:

  • http://www.aerialix.com/

• How to make a Weatherproof Vertically Polarised Omnidirectional Aerial (Not 2.4ghz, but a start.)

  • http://www.irational.org/sic/radio/omni-aerial.html

• Another Omni-Directional aerial, 2.4ghz and made using only coax cable, nice if your locale is a bit sparse with brass tubing etc.

  • http://wireless.gumph.org/articles/homemadeomni.html

Where to Buy

http://www.moonblinkwifi.com - Wide selection of equipment. Willing to help you design your wireless network!

http://www.jefatech.com - Has excellent prices on antennas. Low Shipping.

http://www.hdcom.com/2.4ghzantennas.html

http://www.superpass.com (located in canada)

http://www.timesantenna.com/products/Omnidirectional-Antenna.asp (Base in China)

http://www.wlanmall.com (Located in Southern California)

http://www.cmpter.com (Located in China)

http://www.hyperlinktech.com (minimum order $100, will customize any antenna connector - no pigtail needed)

Diswire (Europe based with some nice 5 GHz antennas)

http://www.demarctech.com/ (good selection, a little more expensive than average)

http://www.wirelesslan-italia.com - a good site, optimal for people in italy (cause it's difficult and expensive to import from outside)

SenaoCard -- if you have a card with mc or mmcx connectors, see here for antenna source/prices.

ITMM 8dBi rubber duck omni with rp-sma for common AP's and Outdoor AP/Antennas

• CategoryHowTo