Interfacing heterogeneous structured FDTD mesh components

A new approach to combine heterogeneous, structured FDTD mesh components with different orientations and discretization sizes is discussed. In order to alleviate the aliasing problem at the mesh interfaces, we use both analytical interpolators and analytical filters at overlapped subdomains. We show that improvements of around 20 dB can be obtained by analytical filters that are good approximations to an ideal low-pass filter. Furthermore, in order to alleviate numerical impedance mismatches, a phase compensation method can be used. In this way, spurious reflections at the mesh interfaces can be reduced by 5 to 20 dB, for the discretization scales considered.