Finite-Volume Time-Domain Modeling of the Mutual Coupling between Dielectric Resonator Antennas in Array Configurations

This paper investigates the potential of the finite-volume time-domain (FVTD) method for the numerical modeling of antennas. The most attractive features of conformal time-domain methods such as FVTD are their geometrical flexibility granted by the spatial discretization using inhomogeneous unstructured polyhedral meshes. Three techniques essential for enhancing the applicability of the FVTD method for practical antenna problems are discussed in this paper: a local time-stepping scheme that increases the simulation efficiency of multi-scale structures, an S-parameter extraction procedure for the modeling of ports, and an efficient domain truncation based on perfectly-matched layers (PML). The simulation of the interaction between two probe-fed cylindrical dielectric resonator antennas (DRAs) in an array configuration is presented as model problem for illustrating these techniques. The mutual coupling coefficient S₂₁ between the two DRAs is computed and compared to measured data for validation.