Maloney and Smith [175] optimized a 2-D parallel-plate radiator for pulse radiation using the FDTD method in 1992. A year later they studied the radiation from a Wu-King resistive monopole [176] and used the FDTD method to optimize a conical antenna for pulse radiation [177]. More recently, Shlager and co-workers [162,178] have used the technique to optimize bow-tie and TEM horn antennas for pulse radiation.