What is that round thing on the back of the phone?

[BadCash]

Hey, just got a S3 mini and when I inserted the battery I noticed a small round thing on the back of the phone, just below the battery (see attached photo). What could this be? There is no hole on the back cover for it. It almost looks like an antenna connector, like the one I used to have on my Sony Ericsson K800i for connecting an external antenna! Could it have anything to do with the NFC-chip which is not present in my phone but I have seen that there is a NFC version of the S3 mini coming...? Just curious.

 

[Jonatas Loureiro]

Damn it, I wanna know too, but one thing is for sure it's not for nfc, almost every phone has it even the ones from the 90's, but sure it is for something to connect to

So, after a while I searched for external antenna on phone's back, and here are the results:
And here's a quote: "EDIT: It turns out they are antenna connectors."