Time-domain performance of printed UWB antennas

Three different printed ultrawideband (UWB) monopole antennas are investigated and their performance compared in terms of bandwidth, radiation pattern stability and fidelity factor. The antennas used are a simple printed rectangular plate monopole, a small spline shaped monopole with shaped groundplane and a smaller spline shaped monopole, where size constraints dominate. The fidelity factor is used to assess the pulse dispersion due to the antenna. It is obtained by transmitting a pulse between a pair of antennas and correlating the received pulse to the input pulse. It is found that the spline shaped monopoles provide an advantage over the rectangular monopole when pulse preserving capability is required.