Planar Green's Functions for Multi-Layered Media

Multi-layered dielectric media can be modelled with Green’s functions. Example of structures that are efficiently modelled with the planar multi-layer substrate method include printed circuit boards (applications using microstrip and stripline structures).

The special Green’s function formulation implements 2D infinite planes with a finite thickness to model each layer of the dielectric and optional conducting layers. Conducting surfaces and wires inside the dielectric layers must be discretised, but not the dielectric layers themselves. Although the layers are infinite in extent, it is often a good approximation to practical antennas as planar structures.

Metallic surfaces and wires can be arbitrarily oriented in the media and can cross multiple layers if they are discretised on layer boundaries (vertices have to coincide with the layer boundaries).

The planar multi-layered media can be defined with in a bounded region, allowing models with many fine layers to be modelled efficiently without requiring the same layers throughout the entire model. Limiting the Green's function to a specific dielectric region would require a region to be defined to encapsulate the layered media, increasing the number of unknowns, but it can be much more efficient when compared to the alternative of modelling each layer individually.

Good performance is achieved since calculations using Green’s functions are accelerated by using interpolation tables.