This past May I had the fortunate experience of riding with Kent Britain, WA5VJB to the Dayton Hamvention in Ohio (he may tell you otherwise). Among other things, Kent is an exceptional antenna designer, with projects on his resume that include antennas that were conceived to reside in the second stomach of a cow (Try to figure out THAT dielectric constant!). You may have read his articles in CQ and CQ VHF magazines. He kind of knows a thing or two. I crap you negative.
Anyway, what I came to tell you about are a unique design approach Kent has for low cost antennas. Before Dayton, a group that I do some hobby work with was looking for a directional WiFi antenna to interface with a Linksys WRT-54G router that was powered by PoE (power over ethernet) and mounted to the side of a piece of antenna mast. The project was created out of necessity to reach a ranger station that was just out of reach for our stock omnidirectional antennas. We ordered some of these from Kent:
What you see are two high gain antennas for 2.4 GHz designed onto printed circuit boards! Here are the datasheets:
Quad Patch antenna datasheet (sadly, this antenna has been discontinued)
We ended up using the Quad Patch for a few reasons. First, we could easily mount it to the side of the weatherproof telecom box we strapped to the tower (the router was mounted inside). The polarization needed by the Yagi to work did not line up with the tower leg we were using. Second, according to the datasheet, ir provides 11 dBi gain, which, in retrospect, was overkill, but who cares.
They work GREAT and do a lot better than a “cantenna”, (Which, if you model it with antenna software, has some serious flaws).
So, if you are on a budget, or just want a great antenna for your project, I highly recommend you check out Kent’s website over at http://www.wa5vjb.com. More on our WiFi project in a later article…..for now, go build your own!