Adding an external antenna jack to a tablet

[KC4YJI]

Has anyone ever tried to add an external wifi antenna jack to a laptop, tablet, or an netbook.  I don't have any problem with a wifi signal and I am not planning to do this, but do find it interesting.  I guess it just comes natural to want to improve your signal.  I thought it would be interesting to do the same thing to a cell phone.  I would love to be able to add a good external antenna to my cell.  How I do miss the old phones that had that feature.  Why is it the best cell signal I ever got was from 18 years ago.  Must be that real antenna.  I have even thought about how you could add an external antenna to a garage door opener to get better range when installed inside a metal building.   

Check out the following videos, this is just one of many that gets the wheels turning.

http://www.youtube.com/watch?v=2lRaXGSjro8&feature=player_embedded

http://www.youtube.com/watch?v=4lmmCctSvb4


Anyway I would love any and all details if you have done this.

[KA1MDA]

I picked up an external USB wifi adapter. It's about the size of a thumb drive and uses an SMA (or reverse SMA, I forget which) connector. Makes it very easy to use an external antenna without having to hack apart the laptop. I just select that device for my network connection instead of the built-in wifi.

[KC4YJI]

That would be fine with a laptop, but what about a tablet.  The smaller the item, the smaller the antenna that it comes with.  There is a big difference in the signal I get on my laptop vs my tablet. 

[LA9XSA]

I've taken apart my MacBook Pro several times, and the AirPort card has two tiny coax connectors on it for the main and auxilliary antenna. The iPad's AirPort card has one coax connector on it. It's easy to disconnect this coax and connect your own, but it's very thin (maybe 1.32mm?) and any substantial length will be very lossy; it's designed for a short run from where the card is placed inside, to an area at the top of the screen near the surface.

[G3RZP]

Depending on the tx power, a gain antenna could actually lead to the device being illegal because of it exceeding the allowed radiated power.

[G8HQP]

Bear in mind that modern devices often have dual or triple-band antennas. Quite difficult to replicate these. I suppose that if you know that in a particular situation the device will only use one band then you can provide an external antenna for that. Also some use diversity reception so two antennas may be needed unless you can guarantee no local variation due to things like people or pets moving around.

[KC4YJI]

I assume you are talking about cell phones.