To match a Planar EM design to a similar, but not identical Planar EM design, specify layer associations. The outcome of the matched layers depends upon which layer of a structure (top or bottom) you add the design.
The Top Bottom Association column indicates layer associations. From the Edit Layers window, the Top Bottom Association column is not visible by default. Right-click the grid control column headers and select Top Bottom Association to make the column visible. Alternately, select a row and choose an association on the Top bottom field in the Edit Selected pane. Then choose one of the following on the drop-down menu:
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Item |
Description |
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Top |
The layer is associated with the top surface. For example, if a subcircuit is added to the top layer of a stackup, the subcircuit’s top -associated layers are mapped to the stackup’s top -associated layers. The subcircuit’s neither -associated layers are subsequently mapped to layers of the same type (e.g., signal to signal) beginning at the top and moving downward. If a subcircuit is added to the bottom layer of a stackup, this mapping is reversed; top -associated layers are mapped to bottom -associated layers and neither -associated layers are mapped to like layers, beginning at the bottom and moving upward. |
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Bottom |
The layer is associated with the bottom surface. For example, if a subcircuit is added to the top layer of a stackup, the subcircuit’s bottom -associated layers are mapped to the stackup’s bottom -associated layers. The subcircuit’s neither -associated layers are subsequently mapped to layers of the same type (e.g., signal to signal) beginning at the top and moving downward. If a subcircuit is added to the bottom layer of a stackup, this mapping is reversed; bottom -associated layers are mapped to top -associated layers. The subcircuit’s neither -associated layers are subsequently mapped to layers of the same type, beginning at the bottom and moving upward. |
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Neither |
The layer is not associated with a top or bottom surface. Neither -associated layers are mapped to layers of the same type. For example, if a subcircuit is added to the top layer of a stackup, the subcircuit’s neither -associated layers are mapped to layers of the same type (e.g., signal to signal) beginning at the top and moving downward. If a subcircuit is added to the bottom layer of a stackup, this mapping is reversed; neither -associated layers are mapped to like layers, beginning at the bottom and moving upward. |