In this paper, a multiple loaded monopole with ultrawideband characteristic is presented with loaded resistance, inductance and capacitance are modeled in linear frequency dependent models. To have a fast frequency sweeping process covering ultrawideband, antenna is simulated by the method of moments (MoM) with asymptotic waveform evaluation (AWE). For simulating with AWE process properly, loaded parallel circuit of effectively linear frequency dependent components is derived in AWE model. As an example, a loaded monopole antenna covering 30–900 MHz is simulated from genetic algorithm (GA) optimization process, and measured result have a good coherence with optimized result.