Choose the material tab on the left window, and then choose new material. You can define a new material and input the parameters you want. You can use er and tan delta, as well as other ways of describing the material, or even use parameters for these values so that you can easily vary them if you want to.
THERE ARE TWO MAIN WAYS TO CREATE MATERIAL IN CST STUDIO:
Using the Material Library: CST Studio offers an in-built library of resources with pre-defined properties. You can surf the library and pick the material that best suits your needs.
Defining a New Material: If the material you need isn't available in the library, you can define a new one. This involves specifying the material properties like permittivity, permeability, and conductivity. You can define these properties in various ways, including:
Entering fixed values
Using formulas to denote frequency-dependent properties
Here are some resources that can help you create materials in CST Studio:
CST Help Documentation: The official CST Studio documentation likely has a detailed definition of materials. You can find it by searching the software or the CST website.
YouTube Tutorials: Several YouTube tutorials demonstrate how to create materials in CST Studio. Searching for "create material in CST" or "define new material in CST" should provide you with some helpful video guides