To accommodate more channels for many wireless applications, it  requires more bandwidths that can easily be obtained by using microstrip patch antennas. A special type of patch antenna having a U-shaped slot is proposed in this paper that can be used for wideband operation. All simulation work is carried out by using ADS (Advanced Design System) simulation tool. A high gain has been realized wideband X-band antenna on it. The designed antenna is square shaped having sides 29.2mm. As a substrate layer alumina dielectric is used having thickness of 1.6mm and dielectric constant of 4.6. This designed antenna works efficiently from 7.9GHz to 11.9GHz frequency range with 4GHz bandwidth at −10dB return loss.