Ubuntu provides support for proprietary drivers like ATI,NVIDIA and Broadcom.To install these first enable the repositories for closed source packages.
Enabling repositories to install proprietary software
Go to System--> Administration-->Software sources
Select the highlighted options as shown in the below given figure
Configuring proprietary drivers in Linux(Ubuntu)
Ubuntu provides an optional installation package to enable/activate Broadcom based systems.
To install the drivers go to system-->Administration-->Hardware drivers.A window as shown below will appear with a list of available proprietary drivers