# Substrates

The Substrate definition item in the navigation window allows you to define substrates for use with the Physical Transmission Line model. ViPEC support stripline and microstrip substrates.

To add a new substrate, right click on the Substrate definition item. This will open a dialog which will allow you to define the substrate parameters.

NOTE: The loss tangent parameter must be entered as TAN(rho).

ViPEC Development team (vipec-developers@lists.sourceforge.net)