| style="width:300px;" | Modeling ferrites and magnetoplasmas
| style="width:250px;" | Solid objects
|-
| style="width:30px;" | [[File:Virt_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials, Sources, Devices & Other Physical Object Types#Virtual_Object_Group | Virtual Object]]
| style="width:300px;" | Used for representing non-physical items
| style="width:250px;" | All types of objects
|}
</table>
=== Advanced CMPL CPML Setup ===
In open-boundary electromagnetic modeling problems, you need a boundary condition that simply absorbs all the incoming radiation. For problems of this nature, an absorbing boundary condition (ABC) is often chosen that effectively minimizes wave reflections at the boundary. [[EM.Tempo]] uses Convolutional Perfectly Matched Layers (CPML) for absorbing boundary conditions. Usually two or more ABC layers must be placed at the boundaries of the physical structure to maximize wave absorption. The boundary CPML cells in the project workspace are not visible to the user. But, in effect, multiple rows of CPML cells are placed on the exterior side of each face of the visible domain box.
=== Excitation Waveform & Frequency Domain Computations ===
When an FDTD simulation starts, your project's source starts pumping energy into the computational domain at t > 0. Maxwell's equations are solved in all cells at every time step until the solution converges, or the maximum number of time steps is reached. A physical source has a zero value at t = 0, but it rises from zero at t > 0 according to a specified waveform. [[EM.Tempo]] currently offers four types of temporal waveform:
# Sinusoidal
# Arbitrary User-Defined Function
A sinusoidal waveform is single-tone and periodic. Its spectrum is concentrated around a single frequency, which is equal to your project's center frequency. A Gaussian pulse decays exponentially as t → ∞, but it has a lowpass frequency spectrum which is concentrated around f = 0. A modulated Gaussian pulse decays exponentially as t → ∞, and it has a bandpass frequency spectrum concentrated around your project's center frequency. For most practical problems, a modulated Gaussian pulse waveform with [[EM.Tempo]]'s default parameters provides an adequate performance.
The accuracy of the FDTD simulation results depends on the right choice of temporal waveform. [[EM.Tempo]]'s default waveform choice is a modulated Gaussian pulse. At the end of an FDTD simulation, the time domain field data are transformed into the frequency domain at your specified frequency or bandwidth to produce the desired observables.
{{Note|All of [[EM.Tempo]]'s excitation sources have a default modulated Gaussian pulse waveform unless you change them.}}
[[Image:Info_icon.png|30px]] Click here to learn more about [[EM.Tempo]]'s '''[[Basic_Principles_of_The_Finite_Difference_Time_Domain_Method#The_Relationship_Between_Excitation_Waveform_and_Frequency-Domain_Characteristics | Standard & Custom Waveforms and Discrete Fourier Transforms]]'''.
=== Defining Custom Waveforms in EM.Tempo ===
In some time-domain applications, you may want to simulate the propagation of a certain kind of waveform in a circuit or structure. In addition to the default waveforms, [[EM.Tempo]] allows you to define custom waveforms by either time or frequency specifications for each individual source in your project. If you open up the property dialog of any source type in [[EM.Tempo]], you will see an {{key|Excitation Waveform...}} button located in the "Source Properties" section of the dialog. Clicking this button opens up [[EM.Tempo]]'s Excitation Waveform dialog. From this dialog, you can override [[EM.Tempo]]'s default waveform and customize your own temporal waveform. The Excitation Waveform dialog offers three different options for defining the waveform:
* Automatically Generate Optimal Waveform
| style="width:300px;" | Computing either total electric or total magnetic field distribution on a planar cross section of the computational domain in the time domain
| style="width:250px;" | The field maps are generated at certain specified time intervals
|-
| style="width:30px;" | [[File:farfield_icon.png]]
| style="width:150px;" | Far-Field Radiation Patterns
| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Far-Field_Radiation_Pattern_Observable |Far-Field Radiation Pattern]]
| style="width:300px;" | Computing the 3D radiation pattern in spherical coordinates
| style="width:250px;" | Requires one of these source types: lumped, distributed, microstrip, CPW, coaxial or waveguide port
|-
| style="width:30px;" | [[File:farfield_icon.png]]
| style="width:150px;" | Far-Field Radiation Characteristics
| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Far-Field_Radiation_Pattern_Observable |Far-Field Radiation Pattern]]
| style="width:300px;" | Computing the 3D radiation pattern in spherical coordinates and additional radiation characteristics such as directivity, axial ratio, side lobe levels, etc.
| style="width:250px;" | Requires one of these source types: lumped, distributed, microstrip, CPW, coaxial or waveguide port
|-
| style="width:30px;" | [[File:farfield_icon.png]]
| style="width:150px;" | Far-Field Scattering CharacteristicsPatterns
| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Far-Field_Radiation_Pattern_Observable |Far-Field Radiation Pattern]]
| style="width:300px;" | Computing the 3D scattering pattern in spherical coordinates
| style="width:250px;" | Requires a plane wave or Gaussian beam source
|-
| style="width:30px;" | [[File:rcs_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Radar_Cross_Section_(RCS)_Observable | RCS]]
| style="width:300px;" | Computing the bistatic and monostatic RCS of a target
| style="width:250px;" | Requires a plane wave source
|-
| style="width:30px;" | [[File:rcs_icon.png]]
| style="width:150px;" | Polarimetric Scattering Matrix Data
| style="width:150px;" | [[Glossary of EM.Cube's Simulation Observables & Graph Types#Radar_Cross_Section_(RCS)_Observable | RCS]]
| style="width:300px;" | Computing the scattering matrix of a target for various plane wave source incident angles
| style="width:250px;" | Requires a plane wave source
|-
<table>
<tr>
<td> [[Image:FDTD_FF1.png|thumb|left|770px720px|EM.Tempo's Radiation Pattern dialog.]] </td>
</tr>
<tr>
<td> [[Image:FDTD_FF3.png|thumb|left|480px600px|EM.Tempo's Radar Cross Section dialog.]] </td>
</tr>
</table>
<tr>
<td> [[Image:Period1.png|thumb|350px|Setting periodic scan angles in EM.Tempo's Lumped Source dialog.]] </td>
</tr></tr></table>Â <table><tr><tr><td> [[Image:Period2.png|thumb|350px720px|Setting the array factor in EM.Tempo's Radiation Pattern dialog.]] </td>
</tr>
</table>