WiMAX technology is becoming popular for wireless communications now-a-days. Because of the advantages of U-slot microstrip patch antennas, they are being used for WiMAX applications very often. Hence, in this paper, a wide band U-slot patch antenna has been investigated. Spiral EBG (Electromagnetic Band Gap) structure is used to achieve wide band performance. Rogers RT/duroid 5880with dielectric constant of 2.2 & the thickness of 1.2mm is used for basic U-slot patch antenna design. Four arm spiral EBG structure having 1.2mm as the each arm width is used.