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.
Coffee Can TinCantenna (waveguide) ***recommended***
CookieCantenna (waveguide with funnel)
Note: please update this list often with new local pages, add offsite links to the end of this page
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.
Gregory Rehm had performed a Homebrew Antenna Shootout (2002.02.14), comparing the following:
- Lucent "range extender" omni directional
Flickenger design PringlesCantenna Yagi
Rehm's modified design PringlesCantenna
Flickenger design coffee can waveguide TinCantenna
Coffee can TinCantenna waveguide with corrected radiator placement by Rehm
A Hunts 26.5 oz. pasta sauce can waveguide TinCantenna that fell in the optimum size range
A Nalley's 40 oz. "Big Chunk" beef stew can Waveguide TinCantenna
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.
Another Antenna Comparison Testing by martybugs compares the following:
Modified 24dBi Conifer (ex-Galaxy) dish.
Cantenna (similar to TinCantenna)
Two 8-slot 180-degree downpipe SlottedWaveguides
- 8-element Collinear Omni Antenna
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?
Take a look at the testing using Netstumbler: http://windsurf.mediaforte.com/wifi/wifi_antenna.html
Other Interesting Links
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).
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:
Deep Dish Cylindrical Parabolic Template includes more images, so this page takes a bit to load. Links to ready templates.
This is also in Flickenger, Wireless Hacks, 1st ed., pp.174-6; Flickenger and Weeks, 2nd ed., pp.328-331.
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.