User Defined Surface Impedance

This option allows the definition of a complex user defined surface impedance, Z_s.

Note: The surface impedance (real and imaginary parts) are defined with the DI card. The SK card then uses the label defined at the DI card.

Parameters:

Material label: Label of the material which will be used as the defined surface impedance (as specified in the DI card).

For example, to model a solid dielectric object with relative permittivity $ε_{r}$ and with conductivity $σ$ at a specific angular frequency $ω = 2 π f$ , the following surface impedance expression will be used:

(1)

Z_{s} = \sqrt{\frac{μ_{0}}{ϵ_{0} ε_{r} - j \frac{σ}{ω}}}

The user defined complex surface impedance Z_s relates to the surface current J_s and the E-field by $E_{t a n} = Z_{s} J_{s}$ where $E_{t a n}$ is the tangential E-field and $J_{s}$ is the surface current density.