=== Distributed Sources ===
[[Image:FDTD45.png|thumb|250px300px|[[FDTD Module]]'s Distributed Source dialog]]
Waveguide sources are a special case of distributed sources in EM.Cube's [[FDTD Module]]. A Distributed Source is defined in a rectangular plane of finite extents, parallel to one of the three principal coordinate planes. An impressed electric field component is assumed across the specified rectangular area, which pumps energy into the computational domain. The current version of EM.Cube provides three spatial field profiles for a distributed source: