Compact band-notched UWB printed square-ring monopole antenna

A simple and compact ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed in this paper. The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded at the centre of the square ring radiator and the impedance bandwidth of the antenna overlapped with IEEE 802.11a is rejected consequently. The measured bandwidth of the proposed antenna occupies about 7.69GHz covering from 3.11GHz to 10.8GHz with expected notched band from 5.12GHz to 5.87GHz. The geometry parameters of the antenna are investigated and optimized with HFSS. A quasi-omnidirectional and quasi-symmetrical radiation pattern in the whole band is also obtained. As a result, this kind of band-notched UWB antenna requires no external filters and thus greatly simplifies the system design of UWB wireless communication.