If you've ever taken the back panel off of a laptop you'll see a small square with two wires coming out of it labeled WLAN. That would be your wireless adapter. One wire runs to the motherboard and the other up and around the display panel as an antenna.
Phones have the same basic concept, and if the wire going to the circuit board itself were to be unhooked - it would obviously not work.
If I were you, I would take it to the Apple store and have them test it.
If you're still under warranty you should be able to claim defective hardware and get them to flash all your contacts and data to a new phone and just take the new one home with you.