Applying a Characterised Surface to a Face
Apply a characterised surface to a face bordering free space or dielectric regions.
When a characterised surface definition is applied to a face, you must specify a vector to ensure the correct surface orientation. The U-Vector should be set to point into the direction of the U-Vector (or X vector in global coordinates) of the original characterised surface. This characterisation is performed either through solving with periodic boundary conditions, an infinite ground plane or measurements. The projection of the U-Vector onto the face correspond to the U-Vector (or principal direction) of the original characterised surface.
- For flat faces, the normal is the same everywhere on the face.
- For curved faces, the normal changes as a function of the position on the face.
Curved surfaces such as radomes have to be split into smaller faces so that a valid U-Vector can be defined for each surface. As an illustration, consider a sphere. There is no single vector that has a valid projection onto the surface of a sphere, since at two points, the vector points in the direction of the face normal.
- Select a face to apply a characterised surface.
- From the right-click context menu, select Properties.
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On the Modify Face dialog, click the
Properties tab.
- In the Medium drop-down list, select the characterised surface to apply to the face.
- In the Thickness field, specify the thickness of the characterised surface (only supported for MoM/MLFMM).
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Under U-Vector, specify the start
point and end point for the U-Vector. The vector is not
required to be exactly in the plane of the face, since it is projected onto the
face, but it should be approximately parallel to the face.
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Click OK to apply the characterised surface and to
close the dialog.
The U-Vector can be displayed in POSTFEKO to verify that all faces have the correct settings and U-Vector orientations applied.