# Triangles as Thin Anisotropic Dielectric Sheet

This option defines a thin anisotropic dielectric sheet. The definition is similar to the isotropic dielectric sheet, except that the layers are anisotropic.

Note: The material parameters for the anisotropic dielectric sheet are defined with the DI and DL cards. The SK card then uses the label defined at the DL card.
The principal direction in each layer is defined by the angle $\alpha$ (see Angle in the dialog image) relative to the projection of the vector $\zeta$ (Reference direction group) onto the plane of the triangle (in the DI card). Here $\alpha$ is measured in the mathematically positive sense with respect to the normal vector of the triangle.
Tip: POSTFEKO can be used to display the fibre direction and to check visually that the input file is correct.
In this case the card line is followed by an additional line for each layer. The medium properties in the principle direction is different from those in the orthogonal direction which lies in the plane of the triangle and orthogonal to the principal direction.

## Parameters:

Reference direction
The X, Y and Z components of the vector $\zeta$ (used to define the principal direction, see image on the dialog).
Layered dielectric label
Label of the layered dielectric medium which will be used (as specified in the DL card).