I am using Virtualbox on Windows 7 and the Guest OS is an Ubuntu (live mode). I would like to access my physical (an integrated Intel Centrino Advanced-N 6200 ) wifi card in the Guest OS. I dont have possibility to use an external Wifi dongle. I read many how-to about this subject. The tutorials suggest that using an Bridged connection with my Intel Centrino card can solve my problem, but I was unable to use my real wifi card in this way. Is that possible? I miss something? If it is needed I can switch from Virtualbox to any other virtualization software.
I'm afraid that's not possible, not on Windows 7 hosts.
What you're trying to do is called PCI/PCIe passthrough. VirtualBox supports it to a limited extent when running Linux on the host, but the requirements are very strict:
As it stands, your only option is to disable on-board WiFi and use a USB 2.0 WiFi adapter instead. VirtualBox can pass that through to the guest no problem (well, there shouldn't be problem with that in theory). You mention that this is not possible for you, which means you have no solution to your problem.
Even VMware Workstation, in my opinion the only other suitable alternative VM software, does not support PCI passthrough.