# Dielectric Properties

Specify the dielectric properties of the dielectric medium.

1. Click the Dielectric modelling tab.
2. In the Definition method field, from the drop-down list select Frequency independent.
3. In the Relative permittivity field, enter a value for εr.

Specify the dielectric losses in the dielectric by either specifying the dielectric loss tangent or the conductivity. The two loss terms are related by $\text{tan}\delta =\frac{\sigma }{\omega {\epsilon }_{r}{\epsilon }_{0}}$ .

Note: Low loss dielectric substrates are typically specified in terms of loss tangent, while human tissue (used in SAR1 studies) are specified in terms of conductivity.

1. Select one of the following:
• To specify the dielectric loss tangent, click Dielectric loss tangent.
• In the Dielectric loss tangent field, enter a value for tanδ.
• To specify the conductivity directly, click Conductivity (S/m).
• In the Conductivity (S/m) field, enter a value for σ.
1 specific absorption rate