Dual band-notched ultra-wideband antenna based on U-shaped slit and split ring slot

A novel ultra-wideband antenna (UWB) is designed in this paper, which has the property of simple structure, small size and dual band-notched function. By etching a semicircle-shaped aperture with three notched steps on the ground, additional resonance is excited, and hence much wider impedance bandwidth can be obtained. To generate dual band-notched characteristics, a split ring slot is employed on the radiating element and a U-shaped slit is added on the microstrip line. Simulated and measured results show that the proposed antenna efficiently restrains interference from narrow-band communication system, including WiMax, C-band satellite communication and the wireless local area network (WLAN). In addition, the proposed antenna achieves a good gain and has nearly omnidirectional radiation patterns on the transmission band, which make it a suitable candidate for UWB applications.