A novel compact microstrip-fed planar monopole antenna with quad-notched bands is presented. The proposed antenna is based on one rectangular-stepped-patch. To achieve the higher resonance over the 12 GHz, one lateral L-shaped structure is embedded in the ground. By inserting four U-shaped slots in the radiation patch, quad band-notched properties in the WiMAX (3.3-3.6GHz), INSAT (4.5-4.8GHz), lower WLAN (5.15-5.35GHz) and higher WLAN (5.725-5.825GHz) are obtained. Experimental results indicate that the designed UWB antenna can obtain broadband matched impedance values, good frequency selectivity over the notched bands, relatively flat group delay and nearly omni-directional transmission characteristics across the UWB frequencies.