An internal ultra-wideband monopole antenna for use in the portable wireless communication applications is presented. The proposed antenna has compact dimensions of 12 mm ?e 16 mm ?e 4.5 mm. It consists of a radiating patch, a matching stub, and a ground plane. The designed antenna fabricated with a case and has a wide bandwidth of more than 8.7 GHz (2.3− 11 GHz) for a return loss less than 10 dB. With this ultra-wideband capability, the antenna can cover the WiBro (2.3− 2.39 GHz), Bluetooth (2.4− 2.4835 GHz), S-DMB (2.605− 2.655 GHz), and UWB (3.1− 10.6 GHz) bands. The performances of the proposed antenna as installed on a laptop computer were investigated and discussed.