Instructables

Can anyone tell me what's the antenna on this usb wifi adapter?

I want to mod it to improve the reception. What's that metallic plate there? And what should i try modding?

Picture of Can anyone tell me what's the antenna on this usb wifi adapter?
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telis_petsotis (author) 2 years ago
I thought it was a reflector or something and the antenna was somewhere under it.
I've tried a few instructables on usb cantennas but none had the result i was expecting(20 dbi signal boost), only 2-8.
So if i solder a larger aluminum plate on it, would i get better results?
Just try a short piece of wire. Its 2.4Ghz, a 1/4 wave dipole would only be 125 mm long.
telis_petsotis (author)  steveastrouk2 years ago
Where should the wire go and how (by soldering?)? Could you point that out? Is there an instructable on that?
Try tacking a piece on the pad I spotted, in the centre.
telis_petsotis (author)  steveastrouk2 years ago
You mean at the center of the large metallic plate?
No the gold lands on the back I suspect that they might work to A.
On reflection, just push a piece into the hole in the centre and try it.

Steve
If you try to solder anything to the antenna it may not help much at all. That is if you can solder it without killing the dongle. After re-looking at your images i realize the metal piece on the front side is a heat sync and RF shield covering some sensitive electronics. Can't tell is any one component is acting as the antenna or if its using the ground plane or some other trace as an antenna. Chances are you won't be able to make any physical connection to extend the antenna.

A cantenna or dish is going to be your best option. What the cantenna and the dishes do is help focus the signals going to and from the dongle. So they work best when pointed at a known Wi-Fi access point. With a well made set of dishes or cantenna you can create a good point to point Wi-Fi signal over a pretty good distance. But thats typically out in the open with line of sight between the 2 points. If your trying to extend your range then also think about adding a reflector to the antenna on your Wi-Fi router to help direct the signals in the direction of your dongle.

If you are doing this to try and get a better lock on a neighbor's internet then you are breaking the law. When i first built my dish thats what i was trying to do as well.

telis_petsotis (author)  mpilchfamily2 years ago
With the cantennas i've made i was trying to connect to a public hotspot 700 meters away. My laptops wifi card gives me one bar out of four connectivity and with the cantenna on it goes up to only two bars. But with the cantennas i pick up other hotspots in other towns up to 15-20 km away. What i want is a better reception in the one at 700 meters.
Try to find out where the router in the establishment is at. It may be you have several walls between you and it and you won't get a better signal without being on the other side of the building. You can get a very long USB cable and set the cantenna up outside. Just waterproof the dongle and connections that will be out int he elements. I had to run 15 feet of USB cable to get my dish right at the back door of my apartment to get a good signal from the apartment complex behind mine. Anything you can do to reduce the obstacles between you and the hot spot will help allot.
telis_petsotis (author)  mpilchfamily2 years ago
I have a better "view" of the establishment at 15 meters away (45feet). But usb cables don't work when longer than 5 meters.
I think the antenna is inside the board, at the rounded end. The two gold lands on the back are probably antenna connectors.
The large metal piece in the first image. If you want to get a better signal out of it then place the antenna in the focal point of a dish. Be is a vegetable strainer, wok lid, or old satellite dish.

You find the focal point with the formula: f=D²/16*c Take the diameter of the rim of the dish in mm. Square it then divide by 16 and multiply by the distance from the rim to the base of the dish.

Here is a dish i made several years ago.
http://forum.xcpus.com/f152/usb-wifi-adapter-dish-2464.html
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