Causal Excitation in Antenna Simulations

The critical relevance of ensuring the excitation’s causality in electromagnetic (EM) simulations is validated via theoretical arguments and simulation results. Two families of model pulses with an implicitly causal behavior, namely the windowed-power (WP) and the power-exponential (PE) ones, are elaborately discussed. After introducing their unipolar prototypes, the relevant families are supplemented with monocycle and ringing variants, and are used for building signatures with almost rectangular spectral contents. Their utility is evidenced by contrasting their performance with that of other types of excitations that are habitually employed in antenna simulations. The WP pulse is also shown to be an almost exact replica of signatures generated by physical circuitry and to be singularly expedient for improving the effectiveness of EM computational packages