Slotted Waveguide Antenna
For detailed descriptions of what a slotted waveguide is, please see Trevor Marshall's website at: http://trevormarshall.com/waveguides.htm (Spanish translation - Traducción al español )
Download the solid model files if you want to mill your own or try tweaking the design. 
You will need PTC's Pro/DESKTOP Express to work with the solid model files in the zip file. You can download it for free here: http://www.ptc.com/products/desktop/express/download.htm
March 21, 2004: Looks like PTC is no longer offering free downloads of Pro/DESKTOP as of December 2003. What's more, it seems that any downloads before that date needed to extend their licenses. Does anyone have any other suggestions for free/cheap ways of reading these files? [BensonMiller]
Take a look at the NovemberMeeting2002 page for details on the informal testing we did.
Buy one
If you'd like to buy a slotted waveguide antenna based on Trevor's plans, please goto my online store: http://www.jefflaplante.com/catalog/index.php/cPath/22
Special! Now through July 30th, buy a 16 slot sector waveguide form my store and get it for $150! That's $50 off folks! Limited to stock on hand. Once they're gone, the discount is over. These antennas will come unassembled. You get to solder the solid copper feedcone to the N connector and mount the end plates yourselves. Yippee!
Get one here: http://www.jefflaplante.com/catalog/product_info.php/products_id/50
Just Parts
If you're just looking to buy parts, Online Metals in Seattle sells 2" x 4" x 0.125" rectangular aluminium tubing with no minimum lengths and will also cut custom dimensions. A five foot section (suitable for the 16-slot waveguide) costs around $32.11. If you're local, you can order online and pickup in person near the Ballard bridge. http://www.onlinemetals.com/merchant.cfm?pid=1208&step=4&showunits=inches. Of course, you still have to cut the slots.
Intro
I have been collaborating with Trevor to produce solid model files for his slotted waveguide antenna designs. He does the engineering, I do the solid modeling and other drafting tasks.
Virtues:
- simple construction
- strong
- horizontal polarization (perfect for laptop pc card antennas)
- great gain - 16dBi
- 360 degree omni or 180 degree sector, take your pick.
- relatively unobtrusive (32 slot omni is 2x4x60 inches)
- free design (Trevor Marshall has graciously given us his design for free)
- inexpensive
- Way Cool!
Photos:
Resources:
- Trevor Marshall has created an excellent design for a 16 or 32 slot waveguide antenna
- Perth Wireless in Australia has a member who has also created a slotted waveguide antenna. It's a big success.
- Rob Clark from Perth Wireless has been making slotted waveguides using cheap downpipe, with extremely good results.
- Rob's downpipe antennas designs have also been implemented and documented at:
Other People using this design:
I did some kismet testing with my zaurus. I'm seeing about a 16dBi gain with this antenna compared to the rubber ducky OEM antennas on the WAP11! The antenna performs quite well when you have line of sight to it. The large trees to the south of my house really kill the signal. If you live north or due west of me on the west side of the street you can pick up a very nice signal.
My installation is a tad crooked because I overtightened the mounting U bolt on the bottom. (Don't do this if you get one from me. I didn't want that bugger to move!) Now I'm thinking of modifying my wap11 with POE so it can go up on the top of the roof instead of on the side like it is now. That would give me much better line of sight all around. Maybe next month.
Benjamin's waveguide
Benjamin Henrion WaveGuide Antenna: I've tested my antenna over 16km (LLN-Waterloo, BE), works very well. Trying also TetraPak antennas.
More pics: http://www.ffii.org/~zoobab/bh.udev.org/filez/photos/waveguide/
More details: http://reseaucitoyen.be/index.php?SlottedWaveGuide2
My TetraPak antennas: http://www.ffii.org/~zoobab/bh.udev.org/filez/photos/tetrapak/
Longshot test: http://www.ffii.org/~zoobab/bh.udev.org/filez/photos/lln-waterloo/
