Hacking The Raspberry Pi WiFi Antenna For More DB

I’ve been testing out the Raspberry Pi 3, and one thing I have found is that the WiFi antenna that was added in this new model is not especially good: the Pi has trouble connecting to my WiFi network in places that other devices have no issues. That’s not surprising, because the antenna on the Pi 3 is tiny: mounted right next to the display connector, it is just a few millimeters wide. [Ward] at DorkbotPDX agrees, so he decided to look into adding a better antenna by adding an external connector.

He tried two approaches: replacing the antenna with a tail connector, and adding a U.FL connector to the unused solder pads on the board. Both require some delicate soldering work, so they aren’t approached lightly. Replacing the antenna with an external connector produced a significant increase in signal output, which should equate with more range for the WiFi connection.

It is also interesting to note that the Pi 3 has solder pads on the board to add an external antenna connector, but that they are not used. Plus, one of the solder pads is covered by solder mask. Using these is the second approach that [Ward] used, soldering on a U.FL connector and connecting that to a small rubber duckie antenna. Again, this proved more efficient, increasing the power output of the antenna significantly.

NOTE: This hack definitely falls into “Don’t try this at home” territory. Messing with antennas voids the warranty and FCC certification for the Pi, and can cause all sorts of signal-related unpleasantness if you aren’t careful.

Simple Directional WiFi Antenna

Back in 2007, [Stathack] rented an apartment in Thailand. This particular apartment didn’t include any Internet access. It turned out that getting a good connection would cost upwards of $100 per month, and also required a Thai identification card. Not wanting to be locked into a 12-month contract, [Stathack] decided to build himself a directional WiFi antenna to get free WiFi from a shop down the street.

The three main components of this build are a USB WiFi dongle, a baby bottle, and a parabolic Asian mesh wire spoon. The spoon is used as a reflector. The parabolic shape means that it will reflect radio signals to a specific focal point. The goal is to get the USB dongle as close to the focal point as possible. [Stathack] did a little bit of math and used a Cartesian equation to figure out the optimal location.

Once the location was determined, [Stathack] cut a hole in the mesh just big enough for the nipple of the small baby bottle. The USB dongle is housed inside of the bottle for weatherproofing. A hole is cut in the nipple for a USB cable. Everything is held together with electrical tape as needed.

[Stathack] leaves this antenna on his balcony aiming down the street. He was glad to find that he is easily able to pick up the WiFi signal from the shop down the street. He was also surprised to see that he can pick up signals from a high-rise building over 1km away. Not bad for an antenna made from a spoon and a baby bottle; plus it looks less threatening than some of the cantenna builds we’ve seen.

Beerquad Wifi Antenna

beerquad

[Coreyfro] recently sent me a thank you note for the biquad wifi antenna article I did for Engadget last fall. He directed me to his monster Beerquad antenna he built based on it. While searching for materials to build his antenna he discovered that flattened Guinness cans are the perfect size for regular antennas and that 25oz Labatt cans make for great double wide versions. He says the reception is great . I’m sure he’ll raise some OpSec eyebrows once he gets the laptop mount done. Most biquad wifi projects on the web are based on Trevor Marshall’s antenna.

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A Better Wifi Antenna

deep dish antenna

here’s a guide for making an antenna for your access point that beats the pringles can on a number of fronts.  it’s easier to assemble, requires no pigtail and no modification to your ap, and it is claimed to have better perfrmance characteristics.

the reflector design was originally intended to increase privacy, but the nice side effect is that it dramatically increases gain in the direction it is facing:

power normally transmitted in that direction is “bounced” forward.  Therefore you have more control of where your signal is going when using this reflector. That feature of this antenna can be used to enhance the privacy of your wireless network and that was my reason for designing it in the first place, the rest is just gravy but it is very real and rather tasty gravy.  :)  Please also note that antenna gain is preferable to amplifier gain because it adds to both transmitted and received power.

the best part is that you can make one basically for free.  grab some aluminum foil, cardboard, and a scissors and get to work.

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Umbrella And Tin Cans Turned Into WiFi Dish Antenna

There’s something iconic about dish antennas. Chances are it’s the antenna that non-antenna people think about when they picture an antenna. And for many applications, the directionality and gain of a dish can really help reach out and touch someone. So if you’re looking to tap into a distant WiFi network, this umbrella-turned-dish antenna might be just the thing to build.

Stretching the limits of WiFi connections seems to be a focus of [andrew mcneil]’s builds, at least to judge by his YouTube channel. This portable, foldable dish is intended to increase the performance of one of his cantennas, a simple home-brew WiFi antenna that uses food cans as directional waveguides. The dish is built from the skeleton of an umbrella-style photographer’s flash reflector; he chose this over a discount-store rain umbrella because the reflector has an actual parabolic shape. The reflective material was stripped off and used as a template to cut new gores of metal window screen material. It’s considerably stiffer than the reflector fabric, but it stretches taut between the ribs and can still fold up, at least sort of. An arm was fashioned from dowels to position the cantenna feed-horn at the focus of the reflector; not much detail is given on the cantenna itself, but we assume it’s similar in design to cantennas we’ve featured before.

[andrew] hasn’t done rigorous testing yet, but a quick 360° scan from inside his shop showed dozens of WiFi signals, most with really good signals. We’ll be interested to see just how much this reflector increases the cantenna’s performance.

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Tactical Wifi Cantenna Needs Picatinny Rails

[Wes] built a cool looking Tactical Wifi Cantenna with some parts from a broken airsoft pistol. The antenna is a cookie can type with an added cone to increase performance, as seen in this tutorial. Once the antenna was built it was time to add some kind of handle, [Wes] just so happened to have such a thing on hand. After epoxy puddying the pistol’s grip to his cookie cantenna he observed that the magazine lock was still functioning. Quick thinking and the application of a  hammer in nut allows the whole rig to quickly attach to the tripod. The antenna also sports a plastic lid and textured paint finish for that ultimate tactical look and feel. A USB Alpha AWUSO36H Wifi dongle even mounts on the back of the rig. We wouldn’t go around outside pointing this at stuff attaching and detaching the tripod but the finish looks great, nicely done!

Check out some other various types of cantennas, even a rifle version if you crave more wifi goodness.

WiFi AP Gets Antenna Augmentation

Feeling bad that his access point was being made fun of by models with beefier external antennas, [Customer Service] decided to do something about it. After cracking open the Asus wl-330ge he found it would be quite easy to add a connector. This access point has two internal antennas that are quite small and use a spring connection to the signal and ground pads on the PCB. Those pads are fairly large and separated, making it easy to solder the connections. Scavenging an antenna connector from an older device, [Customer Service] soldered it in place and drilled a mounting hole in the plastic case. After flashing DD-WRT firmware he’s now got everything he wants from the little guy.