Rolled monopole with bandstop function for UWB applications

In this paper, the rolled fat monopole antenna with bandstop function for UWB systems is proposed. The proposed antenna has the omnidirectional patterns in azimuth and very small size. It covers 3.1~10.6 GHz band for VSWR < 2, using the rolled monopole structure. The proposed antenna has wide bandwidth and bandstop function of 5 GHz WLAN band limited by IEEE802.11a and HIPERLAN/2. To achieve these two characteristics of wide bandwidth and bandstop, the fat monopole and lambda/4 slits are used, respectively. From the measured results, it is observed that wide bandwidth from 3.1 to 10.6 GHz for the VSWR<2 is achieved, while 5 ~ 6 GHz WLAN band is band-notched.