A novel compact ultrawideband (UWB) microstrip monopole antenna with enhanced bandwidth by use of slots and parasitic strips is presented. The proposed antenna consists of a semicircular shaped patch with a U-slot and two rectangular slots, a semi ellipse shaped ground plane, and two parasitic radial strips. The designed antenna has a small size of 20 x 22 x 0.8 mm 3 and operates over the frequency band between 3.76 and 11.84 GHz for 20log |S11| < -10dB.