Of EM.Tempo's source types, lumped sources, waveguide sources and distributed sources let you define one or more ports for your physical structure and compute its port characteristics. To do so, first you need a "Port Definition" observable in the navigation tree. One of EM.Tempo's real advantages over frequency-domain solvers is its ability of generate wideband S/Z/Y parameter data in a single simulation run.
[[Image:Info_icon.png|40px]] Click here to learn more about '''[[Data_Visualization_and_Processing#Graphing_Port_Characteristics Computing_and_Graphing_Port_Characteristics | Computing and Graphing Port Characteristics]]'''.
[[Image:FDTD77.png|thumb|400px|Time-domain evolution of the electric field at a given point.]]