== EM.Libera's Excitation Sources ==
[[Image:MOM6B.png|thumb|320px|EM.Libera's Strip Gap Source dialog.]]
Your 3D physical structure must be excited by some sort of signal source that induces electric linear currents on thin wires, electric surface currents on metal surface and both electric magnetic surface currents on the surface of dielectric objects. The excitation source you choose depends on the observables you seek in your project. EM.Libera provides the following source types for exciting your physical structure: