Limitations of the Singulariy Expansion Method in the characterization of antennas

This paper reports on a technique based on the Singularity Expansion Method (SEM) to completely characterize antennas. This technique provides a full model of the Antenna Transfer Function (ATF) in the frequency domain or the Antenna Impulse Response (AIR) in the time domain based on a set of few parameters. However, some limitations are noted in the physical interpretation of these results. Performance and limitations of this approach are examined for two different antennas: a monopole and an Ultra-Wide Band (UWB) antenna.