# '''PEC Traces:''' These represent perfect conductor objects that have zero thickness and no editable material properties.
# '''Conductive Sheet Traces:''' These represent imperfect metal objects. They have a very small finite thickness t and a finite conductivity s.
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{{Note|Two or more PEC and conductive sheet traces can coexist at the same Z-coordinate. In this case, the Layer Stack-up Settings dialog shows these trace rows stacked up on top of each other between their common top and bottom substrate layers.}}
Slots and apertures are cut-out and removed metal in an infinite perfectly conducting (PEC) ground plane. When a slot is excited, tangential electric fields are formed on the aperture, which can be modeled as finite magnetic surface currents confined to the area of the slot. Therefore, instead of modeling the electric surface currents on the PEC ground around the slot, one can alternatively model the finite-extent magnetic surface currents on PMC traces. In [[EM.Cube]]'s [[Planar Module]], you define slot objects under PMC traces. A PMC trace at a certain Z-plane implies the presence of an infinite PEC plane at that Z-coordinate. Therefore, you do not need to define an additional PEC plane at that location on the layer stack-up. The slot (PMC) objects provide the electromagnetic coupling between the two sides of this infinite ground plane. By the same token, you cannot place a PEC trace and a PMC trace at the same Z-level, as the latter's ground will short the former. However, you can define two or more PMC traces at the same Z-plane. In this case, all the slot objects lie on the same infinite PEC ground plane. <br />
Every time you define a new trace, it is also added under the respective category in the Navigation Tree. Alternatively, you can define a new trace from the Navigation Tree by right clicking on one of the trace type names and selecting '''Insert New PEC Trace...'''or '''Insert New PMC Trace...'''or '''Insert New Conductive Sheet Trace...'''A respective dialog opens up for setting the trace properties. Once you close this dialog, it takes you directly to the Layer Stack-up Settings dialog so that you can set the right position of the trace on the stack-up.
=== Defining Embedded Object Sets === Embedded object sets represent short material insertions inside substrate layers. They can be metal or dielectric. Metallic embedded objects can be used to model vias, plated-through holes, shorting pins and interconnects. These are called PEC via sets. Embedded dielectric objects can be used to model air voids, thin films and material inserts in metamaterial structures. Embedded magnetic object are not currently supported by [[EM.Cube]]âs [[Planar Module]]. Embedded objects can be defined either from the Layer Stack-up Settings dialog or directly from the Navigation Tree. In the former case, open the "Embedded Sets" tab of the stack-up dialog. This tab has a table that lists all the embedded object sets along with their material type, the host substrate layer, the host material and their height.  {{Note|Two The height of an embedded object is always identical to the thickness of its host substrate layer.}} [[File:PMOM23.png]] Figure 1: [[Planar Module]]'s Layer Stack-up dialog showing the Embedded Sets tab. To add a new object set, click the arrow symbol on the '''Insert''' button of the dialog and select one of the two options, '''PEC Via Set''' or more '''Embedded Dielectric Set''', from the dropdown list. This opens up a new dialog where first you have to set the host layer of the new object set. A dropdown list labeled "'''Host Layer'''" gives a list of all the available finite substrate layers. You can also set the properties of the embedded object set, including its label, color and material properties. Keep in mind that you cannot control the height of embedded objects. Moreover, you cannot assign material properties to PEC via sets, while you can set values for the '''Permittivity'''(ε<sub>r</sub>) and conductive sheet traces '''Electric Conductivity'''(σ) of embedded dielectric sets. Vacuum is the default material choice. You may use [[EM.Cube]]'s Material List for this purpose, which can coexist be opened up by clicking the '''Material''' button. Once embedded object sets are added to the Embedded Sets table, you can edit their properties at any time by selecting their row and clicking the same Z-coordinate'''Edit''' button. In  [[File:PMOM21.png]] [[File:PMOM22.png]] Figure 2: The [[Planar Module]]'s PEC Via Set and Embedded Dielectric Set dialogs. To define an embedded set from the Navigation Tree, right click on the '''Embedded Object Sets''' item in the '''Physical Structure''' section of the Navigation Tree and select either '''Insert New PEC Via Set...''' or '''Insert New Embedded Dielectric Set...''' The respective New Embedded Object Set dialog opens up, where you set the properties of the new object set. As soon as you close this casedialog, it takes you to the Layer Stack-up Settings dialog shows these trace rows stacked up , where you can examine the location of the new object set on top the layer hierarchy. After a new embedded object set has been defined and added to the Navigation Tree, it becomes the active trace. You are now ready to create geometrical objects in the new active trace. Remember that [[Planar Module]] does not allow you to draw 3D objects. The solid object buttons in the '''Object Toolbar''' are disabled to prevent you from doing so. Instead, you draw planar [[Surface Objects|surface objects]] as the cross section of each other between embedded sets. [[EM.Cube]] extends these planar objects across their common top host layer automatically and bottom substrate layersdisplays them as wire-frame, 3D extruded objects. Extrusion of embedded object sets happen after meshing and before every simulation. You can enforce this extrusion manually by right clicking the '''Layer Stack-up''' item in the '''Computational Domain''' section of the Navigation Tree and selecting '''Update Planar Structure...''' from the contextual menu. [[Image:MORE.png|40px]] Click here to learn more about '''[[Defining Materials in EM.Cube]]'''.}}
=== Drawing & Managing Planar Objects ===