Before you can run an FDTD simulation, you have to define a source to excite your projectâs 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_EMGlossary of EM.Cube's Excitation Sources#Lumped_.26_Gap_Sources|Lumped Source|Lumped Sources]]''': An ideal source that must be place on a wire (a PEC line object).# '''[[Common_Excitation_Source_Types_in_EMGlossary of EM.Cube's Excitation Sources#Distributed_Sources Distributed Source |Distributed Sources]]''': A source with a prescribed impressed field component that is defined on a rectangular region # '''[[Glossary of space parallel to a principal planeEM.Cube's Excitation Sources#Microstrip Port |Microstrip Port Sources]]'''# '''[[Common_Excitation_Source_Types_in_EMGlossary of EM.Cube's Excitation Sources#Waveguide_Sources Coplanar Waveguide (CPW) Port |Coplanar Waveguide (CPW) Port Sources]]''': A distributed source that must be placed across a hollow PEC box object# '''[[Glossary of EM.Cube's Excitation Sources#Coaxial Port |Coaxial Port Sources]]'''# '''[[Common_Excitation_Source_Types_in_EMGlossary of EM.Cube's Excitation Sources#Plane_Wave_Sources Waveguide Port |Waveguide Port Sources]]'''# '''[[Glossary of EM.Cube's Excitation Sources#Plane Wave |Plane Wave Source]]''': A distributed source with a plane wave profile defined using a virtual box object enclosing the entire physical structure. # '''[[Common_Excitation_Source_Types_in_EMGlossary of EM.Cube's Excitation Sources#Gaussian_Beam_Sources Gaussian Beam |Gaussian Beam Source]]''': A distributed source with a complex-valued focused Gaussian beam profile defined using a virtual box object enclosing the entire physical structure.
[[Image:FDTD_FF4.png|thumb|400px|A lumped source defined on a vertical PEC line object and a waveguide source defined across a hollow PEC box.]]