Seattle Wireless Antenna HowTo

This is the information central for antenna construction. It's here to help you to learn the different types of antennas, and show you how to build them and install them yourself, affordably.

Types of Antennas

There are several kinds of antennas available on the market.

It is best to do some research on what you are trying to cover before you run out and buy an antenna. If you are simply trying to saturate an apartment or house, an omni will do just fine, but over distance you are generally best off getting a directional to cut down on noise and take advantage of AntennaGain. Different types of antennas have different beamspreads and it is good to familiarize yourself with which antenna is the right one for the job.

Build an Antenna Yourself

Here's a list of the homebrew antenna designs on the wiki.
Build a parabolic reflector, below, before replacing any client or AP antenna.

Chinese parabolic cookware! Woks and cheap mesh scoops GREATLY enhance (by ~15dB) USB Wi-Fi adaptor's range--to several Km LOS typical. Construction's a breeze, "dongle" adaptors are cheap, AND just normal loss-free USB cable & connectors are used.
Bonus: Cable runs of ~5m (maybe more) allow "signal sweet spot" locating too. Recommended!
Update: Jan 2005. Check our classy Mk.2 "boutique" version, based on a modified desk lamp base & flexible support stalk + kitchen sieve. When spray painted black this looks most professional and almost invisible beside a laptop. NetStumbler (NS) shows 12+ dB gain over a bare dongle.
Dehandled cookware scoops can also be persuaded, and NS indeed shows slightly higher (~15dB?) gain. HIGHLY recommended.

Ham Radio operators have been designing and building homebrew microwave equipment for years. QSL.net is a storehouse of engineering and practical knowledge: W1GHZ Online Microwave Antenna Book

If you are looking for a way to mount an antenna on the roof without drilling into the roof, one approach is on the WaterProofBoxes page.

Comparision Tests

Gregory Rehm

Gregory Rehm had performed a Homebrew Antenna Shootout (2002.02.14), comparing the following:

Gregory Rehm's test showed that the TinCantenna waveguides variety should be the preferred cantenna design. It consistantly pulled more gain than the PringlesCantenna, and requires very little assembly.

Martybugs

Another Antenna Comparison Testing by martybugs compares the following:

The Conifer dish performed best in this test with the SlottedWaveguides coming in second.
The BiQuads and the TinCantenna performed comparably.

Ever wondered what would happen if you connected up two can antenna in a shotgun arrangement? Ever wondered what a 1 Watt amplifier would do for you?

Other Interesting Links

There are some other interesting ideas for easy ways to build antennas, such as spray-on antennas. Other antenna approaches are at FreeAntennas, which is a great repository of antenna designs.

http://flakey.info/antenna/omni/quarter/wifi_omni.jpg

Quarter-wave "spider omni" (22 December 2005), in Do-It-Yourself Wireless Antenna Update. This is also in Flickenger, Wireless Hacks, 1st ed., 2003, pp.177-8; Flickenger and Weeks, 2nd ed., 2005, pp.331-3.

Forum thread of Antenna Links has best omnindirectional, directional, basic antenna info and calculations links (July '03).

Another SeattleWireless member has provided pictures of high gain antennae he has made. See gallery.tje1 album59 and album62. [21-23 Apr.'06 "can't find the server at gallery.tje1.com."]

Build a Wi-Fi VSWR meter to test and adjust your homebrew Wifi antenna (test equipment).

Lens antennas links? Is there someone who has tried this? Looks like this works in frequencies higher than 2.4 GHz, qsl.net n1bwt chap3.pdf.

Wi-Fi antenna guide to common Wi-Fi antenna types and outdoor wireless network topics.

Geekcorps 21st-c. application of 19th-c. DIY ingenuity thrives around the planet.

Add a parabolic reflector to a standard factory dipole antenna

One of these can provide a quick, easy basis of comparison that any replacement antenna performs well enough.

Erskine reports around 12 dB gain for about $0.10 in materials, cardboard and aluminum foil. Ready templates. Erskine reports these outperform standard cantennas! No pigtail required, no voiding of warranty.
Here are some designs:

Other designs

Here is a nice article on how to build a WiFi Cantenna with an aluminum dryer vent. It gets 17 DBi of gain.

How to build Wi-Fi antennas and use a pistol grip for mobile operations and wardriving.

Looking for extended-range wireless LAN and Wireless Internet systems? This site has tons.

WiFi Antennas,2.4GHz Antennas and GPS antennas Lots of 2.4 GHz and 5.8 GHz antenna designs. The Shortened 3D Corner Reflector Antenna is probably the easiest 18 dBi antenna you can build.


AntennaHowTo (last edited 2010-05-19 20:14:29 by KAB-74-114-141-187)