==Setting Up an Excitation Source==
Before you can run an FDTD simulation, you have to define a source to excite your project’s physical structure. EM.Tempo offers a variety of excitation mechanisms for your physical structure depending on your particular type of modeling problem or application(click on each type to learn more about it):
# '''[[Common_Excitation_Source_Types_in_EM.Cube#Lumped_.26_Gap_Sources|Lumped Source]]''': An ideal source that must be place on a wire (a PEC line object).