Stap 17 vertalen
The iPad 3G has a black plastic strip along the top edge of the rear case for transmission of signals. The large black plastic piece at the top of this picture is the 3G antenna assembly.
The odd looking structure boxed in red is what the 3G chip and possibly the logic board are fastened to. It is resistance welded to the rear case and probably serves as a ground point for the boards attached to it.