Time-domain characterization of novel band notched microstrip antennas For UWB application

This paper include time-domain characterization of novel UWB antennas with band notched frequency response. In this paper, three novel ultra wideband (UWB) antenna structures are proposed with band notch characteristics to avoid interference with WLAN//HIPERLAN in 5.15 GHz - 5.85 GHz band. In proposed geometries a wide impedance bandwidth is achieved (3.4 GHz - 12 GHz) to fulfill requirements of UWB for future applications. The proposed antennas are investigated with partial ground plane. All the three antennas have simple stepped rectangular patch shape geometry and by introducing slots of different shape, band rejection characteristics of proposed antennas are achieved. The antenna parameters in frequency domain viz. far-field radiation pattern, S₁₁ and surface current distribution have been investigated to show capability of antennas as effective radiating elements. The measured S₁₁ is well below -10 dB & measured radiation patterns are near Omni-directional. Furthermore, Time-domain transient analysis with Gaussian pulse excitation is also demonstrated. A Gaussian pulse, whose frequency spectrum covers the bandwidth of the antenna, is generated, applied at the antenna input & its radiated pulse is detected. The frequency domain results are first obtained using a wide-band simulation using traditional MoM techniques. Post processing analysis of the frequency domain data is then performed to obtain a time response of each antenna.