=== Defining Transmitter Sets ===
[[File:PROP20(1).png|thumb|400px|EM.Terrano's Transmitter dialog with a user defined pattern selected.]]
A transmitter is a point radiator with a fully defined polarimetric radiation pattern over the entire 3D space in the spherical coordinate system. You can model a radiating structure using [[EM.Cube]]'s FDTD, Planar, MoM3D or PO modules and generate a 3D radiation pattern data file for it. These data are stored in a specially formatted file with a "'''.RAD'''" file extension. It contains columns of spherical φ and θ angles as well as the real and imaginary parts of the complex-valued far field components '''E<sub>θ</sub>''' and '''E<sub>φ</sub>'''. The θ- and φ-components of the far-zone electric field determine the polarization of the transmitting radiator.
To define a transmitter source in EM.Terrano, first you need to have at least one base point in your project workspace. In the "Custom Pattern [[Parameters]]", click the '''Import Pattern''' button to set the path for the radiation data file. This opens up the standard [[Windows]] Open dialog, with the default file type or extension set to ".RAD". Browse your folders to find the right data file. A radiation pattern file usually contains the value of "Total Radiated Power" in its file header. This is used by default for power calculations in the SBR simulation. However, you can check the box labeled "'''Custom Power'''" and enter a value for the transmitter power in Watts. [[EM.Cube]] can also rotate the imported radiation pattern arbitrarily. In this case, you need to specify the '''Rotation''' angles in degrees about the X-, Y- and Z-axes. Note that these rotations are performed sequentially and in order: first a rotation about the X-axis, then a rotation about the Y-axis, and finally a rotation about the Z-axis. Â [[File:PROP20(1).png]]Â [[Propagation Module]]'s Transmitter dialog with a user defined radiator selected.
=== Defining Receiver Sets ===