Can CST model a dielectric material with constant loss tangent?

Modeling the Powerbus with CST

CST has three specification options for user to set material's conductivity property. They are 'Const. Conductivity', 'Const. fit tan delta', and 'Dispersion fit tan delta'. Since CST cannot model materials with constant loss tangent, we select the second option 'Const. fit tan delta'. This specification is based on the model of a first order Debye dispersion, defined by the input of an electric loss tangent value given at the defined frequency. In this model, the material is defined by a loss tangent of 0.015 at 1 GHz. The loss tangent is plotted in Fig.1. The real and imaginary parts of the permittivity are plotted in Fig.2 and Fig.3 respectively. At 1 GHz, the real part of the permittivity equals the epsilon input (4.5).

Fig. 1. Loss tangent based on Debye 1st order model.

Fig. 2. Real part of the permittivity.

Fig. 3. Imaginary part of the permittivity.