A simple and compact circular microstrip antenna with tuning stub above wide-slot ground plane for band-notched ultra wide-band (UWB) using inverted-U slot is presented. The proposed antenna is easy to be integrated with microwave circuitry for low manufacturing cost. The antenna is successfully designed, simulated and measured including SWR, radiation patterns and gain. The antenna can operate in the 2.8-12.8 GHz frequency range and cover the UWB operating bandwidth of 3.1-10.6 GHz with a notched frequency band of 5.06-5.96 GHz. The antenna gain varies from -4.1 dBi to 7.1 dBi and yields bidirectional pattern.
