Hybrid method for time-domain analysis of wire antennas embedded in a scattering dielectric medium

A hybrid time domain method for the analysis of embedded wire antennas is presented. The radiation from wire antennas placed within a heterogeneous dielectric medium is strongly dependent on near-field coupling effects and backscatter from material discontinuities. A time-domain MoM solution for the embedded wire antenna is combined with an FDTD model of the surrounding dielectric structure. The induction theorem is used to interface the sub-domains and establish equivalent current sources while also allowing scattered fields to re-enter the MoM (source antenna) domain. The technique is validated by comparing the hybrid model with a standard MoM solution for an 8-mm loop antenna with wire radius of 0.2 mm. The loop antenna was centred within a 30×30×30 cell FDTD domain composed of 5-mm voxels