Abstract— In this paper, the design and analysis of a compact size microstrip ultra-wideband (UWB) antenna is considered. The antenna is mounted on a 38 mm× 25 mm cheap FR4 substrate of dielectric constant εr= 4.4 and thickness of 1.6 mm. The original shape of the patch is circular; and a hexagonal notch is removed (making it a spanner-shaped antenna) to achieve ultra-wideband characteristics. To cover the Bluetooth and the GSM 1800 bands, a meandered strip is integrated with the spanner-shaped antenna. Also, the antenna has super-wideband characteristics with an upper frequency edge of 50 GHz. To reject the interference from WiMAX (3.5 GHz) and WLAN (5.5 GHz), two slots are etched from the radiating patch. The antenna has a stable Omni-directional radiation pattern and a peak gain that increases in the UWB range from 2 dBi to 10 dBi, while it is almost 0.7 dBi at the GSM 1800 center frequency and 1.65 dBi at the Bluetooth center frequency. Measurements show a good agreement with the simulated results which are obtained using HFSS simulator.