===Running A Wideband FDTD Simulation===
Once you build your physical structure in the project workspace and define an excitation source, you are ready to run an FDTD simulation. The simulation engine will run even if you have not defined any observables. Obviously, no simulation data will be generated in that case. [[EM.Cube]]'s [[FDTD Module]] Tempo currently offers several different simulation modes as follows:
# Wideband Analysis
# HDMR
Analysis is the EM.Tempo's simplest and most straightforward simulation mode of the [[FDTD Module]]. It runs the FDTD time marching loop once. At the end of the simulation, the time-domain field data are transformed into the frequency domain using a discrete Fourier transform (DFT). As a result, you can generate wideband frequency data from a single time-domain simulation run. The other simulation modes will be explained later in this manual.
To open the Simulation Run Dialog, click the '''Run''' [[Image:run_icon.png]] button of the '''Simulate Toolbar''' or select '''Menu > Simulate > Run...''' from the menu bar or use the keyboard shortcut '''Ctrl+R'''.