Isotropic / anisotropic material: linear approximation (without losses)


This model defines a D(E) law of linear behavior for an isotropic or anisotropic material.

Mathematical model

This model is a straight line .

The corresponding mathematical formula is written:

D(E)= ε0εrE


  • ε0 is the permittivity of vacuum; ε0 = 1/(36 π). 10-9 [F/m]
  • εr is the relative permittivity of the material

The shape of D(E) curve is presented in the figure below.

Anisotropic material

For an anisotropic material, this linear model consists of a group of three straight lines.