Time-domain finite-element modeling and simulation of broadband antennas

This paper discusses the numerical issues of applying the TDFEM to the modeling and simulation of broadband antennas and demonstrate its application and capability through several numerical examples. Two critical simulation components, namely the truncation of the open free space and the modeling of antenna feeds, are discussed. The implementation of perfectly matched layers (PML) are briefly described for the truncation of the TDFEM computational domain. An accurate waveguide port boundary condition (WPBC) is employed to model the commonly used coaxial feeds as well as other waveguide feeding structures. In addition, an improvement to the simplified probe feed model is developed. Numerical examples are presented to demonstrate the modeling and simulation of typical broadband antennas, which include a pyramidal horn antenna and a logarithmic spiral antenna