Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
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Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
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Re: Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
#2Antenna design seems like an obvious target for 4D-printing.
Re: Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
#3The link should change to https://roelof.info/projects/(2014)Pretty_Fly_For_A_Wifi/Pre...
Also a question to the community: which is the most bang-for-the-buck DIY antenna: does not need millimeter accurate measurements, increases signal by ~2x, and ideally small and stow-able.
Most common usecases are extending signal on 3g/4g USB dongles, and extending wifi signals at home (to one side at the expense of the other).
Re: Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
#4Unfortunately, there's no real testing. Just pictures.
Antenna testing is usually done in a big open flat space, with gear that can measure field strength. Do this some place where you can't pick up any other WiFi signals. Some WiFi gear lets you read signal strength from software, and you need something that can do that. There are some videos online of people measuring antenna patterns at ranges of a few feet, but that gets you strange near-field results. You need distance for this, like a hundred feet or so. The antenna is usually placed on a nonmetallic turntable that can be rotated, and the idea is to generate a chart of signal strength vs. angle.
Here's an test of a "cantenna" in a real antenna testing facility.[1] He also builds one with the same dimensions out of copper sheet, for comparison, and also compares with simulated results. Antenna design used to be a black art, but now there are software tools to help with design and evaluation.
The ARRL Antenna Book has good advice on how to build antennas cheaply.
[1] http://www.antennamagus.com/blog/593/pringles-cantenna-measu...
Re: Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
#5hi,
I'm the author of the project. To answer questions about testing and which design is 'the best': The project was produced in a cultural context so I had no access to specialized measuring equipment or techniques. What I've done is to run side by side comparisons, so I only have circumstantial evidence.The method was to compare the antenna or reflector against the stock antenna on the same dongle and seeing which one resulted in most SSIDs showing up in wavemon. That being said, the big difference between most diy antennas vs the stock antenna is that the diy antennas basically work on the principle of directionality, meaning increased gain in a narrow cone. So you have to point your antenna at the signal source for a higher gain.
Which one is the best really depends on the use case, materials available and time you want to invest. I've found the biquad in the sardine tin[1] to be the handiest for all-round situations and use it frequently. It is directional, but has a wider field of view than other directional antennas. Compact design, sturdy build quality. Not too difficult to produce and sardines combine great with pizza or pasta. Here is some more info on that type of design[2]. If you only have access to dongles without a detachable antenna I'd recommend using a wok or some other parabolic reflector.
[1]http://roelof.info/projects/(2014)Pretty_Fly_For_A_Wifi/IMG_...
Pretty_Fly_For_A_Wifi/IMG_0963.png){kind=link}
Re: Rebuilding, Testing and Documenting Self-Made Wi-Fi Antennas
#6hi, I'm the author of the project. To answer questions about testing and which design is 'the best': The project was produced in a cultural context so I had no access to specialized measuring equipment or techniques. What I've done is to run side by side comparisons, so I only have circumstantial evidence.The method was to compare the antenna or reflector against the stock antenna on the same dongle and seeing which…
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