The Boundary Conditions are listed within a group located under the FEEM solver, in the Object Tree. It allows the user to define boundary conditions in the simulation region and assign them to an object or surface.
You can add a new boundary condition by selecting one from the Boundary Condition section of the FEEM tab. Each boundary condition can be edited, renamed, deleted in the same way as any simulation object.
PML
- NAME: Name of the BC
- GENERAL:
- SIGMA: Controls the strength of the absorption inside PML regions. A larger value leads to stronger absorption but too large values can lead to artificial reflections on the inside of the PML regions and therefore decrease the accuracy of the solution.
Perfectly matched layer (PML) boundaries absorb electromagnetic waves incident upon them. They essentially model open (or reflectionless) boundaries. The user can directly specify all the parameters that control their absorption properties. PML boundaries perform best when the surrounding structures extend completely through the boundary condition region. Unlike conventional boundary conditions, PML boundaries have a finite thickness. In other words, they occupy a finite volume that surrounds the simulation region. It is within this volume that the absorption of light happens. The thickness of the PML is defined in the Simulation Region settings as the shell thickness.
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Note: PML settings automatically apply to all simulation region shells. |
PEC
- NAME: Name of the BC
- GEOMETRY: The geometry option defines where the boundary condition can be applied.
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Note: A list of domains will be available under the SIMULATION REGION object once the simulation region is partitioned. A list of solids (primitives) is available under the GEOMETRY Container Group. |
Volume, surface, line, and point in 3D and 2D:
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Volume |
Surface |
Point |
|---|---|---|---|
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3D |
Volume |
Surface or Line |
Point |
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2D |
Surface |
Line |
Point |
Surface Type
- DOMAIN:EXTERIOR : Select the target domain. The reference geometry is the common surface(s) shared by the uttermost surface(s) of the selected domain and the simulation region. The selected domain has to have at least a surface that is shared with one of the simulation region surfaces.
- DOMAIN:DOMAIN : Select the target domains. The reference geometry is the common surface(s) shared by the two selected domains.
- DOMAIN : Select the target domain. The reference geometry is the surfaces of the selected domain.
- SOLID : Select the target solid. The reference geometry is the surfaces that enclose the selected volume if the solid is a 3D shape, or the surface if the solid is a 2D plane.
- SIMULATION REGION : Select one or more simulation region boundaries. The reference geometry is the selected boundaries.
- SOLID:SIMULATION REGION : Select one or more simulation region boundaries and the target solid. The reference geometry is the common surface(s) shared by the simulation region and the target solid.
- MATERIAL:MATERIAL : Select the target materials. The reference geometry is the surface(s) that is shared by the two selected materials. This is only available in some boundary conditions.
- SURFACE : Type the identifier of the partition surface. If the target partition surface is SURFACE 3, type 3. If the target partition surfaces are SURFACE 3 and SURFACE 5, enter 3,5.
The component of the electric field parallel to a Perfect Electric Conductor (PEC) boundary is zero; the component of the magnetic field H perpendicular to a PEC boundary is also zero. PEC boundaries are perfectly reflecting, allowing no energy to escape the simulation volume along that boundary.
PMC
- NAME: Name of the BC
- GEOMETRY: The geometry option defines where the boundary condition can be applied.
|
Note: A list of domains will be available under the SIMULATION REGION object once the simulation region is partitioned. A list of solids (primitives) are available under the GEOMETRY Container Group. |
Volume, surface, line and point in 3D and 2D:
|
|
Volume |
Surface |
Point |
|---|---|---|---|
|
3D |
Volume |
Surface or Line |
Point |
|
2D |
Surface |
Line |
Point |
Surface Type
- DOMAIN:EXTERIOR : Select the target domain. The reference geometry is the common surface(s) shared by the uttermost surface(s) of the selected domain and the simulation region. The selected domain has to have at least a surface that is shared with one of the simulation region surfaces.
- DOMAIN:DOMAIN : Select the target domains. The reference geometry is the common surface(s) shared by the two selected domains.
- DOMAIN : Select the target domain. The reference geometry is the surfaces of the selected domain.
- SOLID : Select the target solid. The reference geometry is the surfaces that enclose the selected volume if the solid is a 3D shape, or the surface if the solid is a 2D plane.
- SIMULATION REGION : Select one or more simulation region boundaries. The reference geometry is the selected boundaries.
- SOLID:SIMULATION REGION : Select one or more simulation region boundaries and the target solid. The reference geometry is the common surface(s) shared by the simulation region and the target solid.
- MATERIAL:MATERIAL : Select the target materials. The reference geometry is the surface(s) that is shared by the two selected materials. This is only available in some boundary conditions.
- SURFACE : Type the identifier of the partition surface. If the target partition surface is SURFACE 3, type 3. If the target partition surfaces are SURFACE 3 and SURFACE 5, enter 3,5.
Perfect Magnetic Conductor (PMC) boundary conditions are the magnetic equivalent of the metal (PEC) boundaries. The component of the magnetic field H parallel to a PMC boundary is zero; the component of the electric field perpendicular to a PMC boundary is also zero.
References
- J. P. Berenger, Perfectly Matched Layer (PML) for Computational Electromagnetics. Morgan & Claypool Publishers, 2007.
- S. D. Gedney and B. Zhao, An Auxiliary Differential Equation Formulation for the Complex-Frequency Shifted PML, IEEE Trans. on Antennas & Propagat., vol. 58, no. 3, 2010.