The following is a list of different characteristics of media with respect to the propagation of electromagnetic waves:
- Linear
- Isotropic : similar properties in any direction of travel for waves through that medium.
- Homogenious: all properties (e.g. $\varepsilon_r$) is independent of position
- Conductive: $\sigma > 0$
- Source free: $\vec{J} = 0$
Combinations:
- Simple: linear + homogenious + isotropic