Analysis using FDTD of ultra-wideband dipole antennas

When a dipole antenna is excited by an ultra-wideband (UWB) pulse, the antenna rings at its resonant frequency, thus stretching out the waveform in time. The impedance characteristics of ultra-wideband dipole antennas are analyzed using the FDTD method. The results of the FDTD analysis of the antennas present a measured bandwidth suitable for ultra-wideband antenna use. Results for the Sierpinski diamond dipole antenna are similar to those obtained for the diamond dipole antenna (Schantz, H.G. and Fullerton, L., Proc. IEEE Antennas and Propag. Soc. Int. Symp., vol.4, p.100-3, 2001; Siwiak, K. et al., IEEE Radio and Wireless Conf. - RAWCON, 2001), with a very small improvement in bandwidth - approximately 110 MHz increase of usable bandwidth. The bow-tie dipole antenna, on the other hand, offers a much wider bandwidth compared to both the diamond dipole and Sierpinski diamond dipole antennas.