Novel band-notch monopole ultra-wideband antenna with external load

A band-notch ultra wideband monopole antenna is presented in this paper. Firstly, an ultra-wideband monopole antenna is designed using a radial patch. The path is fed by using microstrip line. The return loss of the antenna is less than -10dB within the frequency range of UWB system, i.e. from 3.1GHz to 10.6GHz. To restrain the interference between UWB and WLAN a notch band shall be inserted in the UWB passband. Two symmetrical microstrip resonators are externally loaded to the microstrip feed line to form a notch band. The frequency range of notch band can be controlled by adjusting the size and the position of the loaded resonator. A notch band from 5.2GHz to 5.8GHz is achieved. As the experimental results show the proposed antenna has steady characteristics of radiation direction and gain on the whole working frequency range.