Surface Model

The surface conductor model accounts for a very fast drop of the high-frequency electric field as field contacts the surface of the metal. It can be applied only when the conductivity, $\sigma$ , is so high that the dielectric and polarization effects with the material can be neglected. This condition is represented by the equation

where $ϵ$ is the relative permittivity, $\omega$ is the angular frequency, and ${ϵ}_0\approx 8.85\cdot {10}^{-12}F/m$ is the vacuum permittivity.

In this situation it can be demonstrated that the electric fields penetrate the material only in a very tiny layer with a thickness ("skin depth"), $\delta$ defined as

where $\mu$ is the relative permeability and ${\mu }_0=4\pi \cdot {10}^{-7}H/m$ is the vacuum permeability.

The equation above shows that the skin depth effect is most prominent at high frequencies. The higher the frequency, the better the corresponding approximation. If you want to simulate the material behavior at low frequencies, use the Volume Model.

Input Data	Description
Model	Select PEC to select the perfect electric conductor model and ignore other parameters. Select Lossy metal to model an imperfect electric conductor.
Use temperature-dependent data	Specifies material parameters that depend on temperature. A Temperature field appears in the data table. For more information, see Specifying Material Data as a Function of Temperature and Independent Field Variables.
El. conductivity	Electrical conductivity, $\sigma$ .
Rel. Mag. Permeability	Relative magnetic permeability, $ϵ$ .
Surface Roughness	Roughness of the lossy metal surface (root mean square). The surface profile is modeled as a random process with normal distribution. Surface roughness leads to increased total loss and increased inner conductance effects.