HFSS and HFSS 3D Layout support finite dielectrics. Dielectric layers are always truncated according to the HFSS Model Extents. Using the extents settings, define how the polygon dielectric and negative signal layers are generated relative to the base polygon. By default, the HFSS Model Extents setting for “Honor primitives on dielectric layers” is selected, but when the check box is unselected, dielectric layers use the extents settings regardless of whether or not drawn polygons on them. For more information, see HFSS 3D Model Extents.
In contrast, Signal layers can be made of either dielectric or conducting materials and can have internal, user-drawn shapes to create what are sometimes called "dielectric bricks" or "dielectric inclusions”. While sometimes called "bricks", there are no limitations on the dielectric shapes. Signal layers assigned a dielectric material creates objects corresponding to whatever shapes exist on the layer. Signal layers may overlap other Signal layers in elevation, and this provides a great deal of flexibility for representing dielectric object.
From the event that dielectrics on different Signal layers overlap, the Precedence Value on the EM Modeling Properties can be used to resolve ambiguities with lower values having priority. If EM Modeling Properties have not been added or cannot be used to resolve overlaps, precedence is assigned according to material properties.