ThinkPad 11b/g/n Wireless LAN Mini-PCI Express Adapter II
This chip is currently not supported by any in-kernel driver. There are two options available, a Linux driver available for download from Realtek, or ndiswrapper.
The Realtek Linux driver for this chip can be downloaded from the Realtek website
More information about using the Realtek native driver in Ubuntu: 
64bit-linux-driver-deb(only test on kernel 2.6.31-20):main
More information on using the Windows drivers with Ndiswrapper can be found here:.