Shape/Layer Modifiers in AWRDE

Shape modifiers are layout objects that can manipulate shapes by various methods such as edge length, spacing, and Boolean operations. A shape modifier applies to one or more shapes in a layout. A layer modifier applies to all shapes on the selected layers. Typical applications of these modifiers include:

• You can parameterize an EM layout so that the geometry can be swept to create a parameterized EM model or a parameterized EM layout. When this is used in a subcircuit, it gets the EM simulation for the geometries requested. In this mode, these modifiers are used in an EM layout.
• You can change all shapes on specific layers that can be used with extraction and yield analysis to study the effects of layer shifting or resizing during the manufacturing processes. In this mode, these modifiers are used in a schematic layout.
• You can align or space out shapes in a schematic layout when using layout items not associated with schematic models, which cannot snap together like layouts with schematic models.

• The available shape modifiers include:

  • Edge
  • Point Stretch
  • Width
  • Radius
  • Ellipse Size
  • Array Modifiers
  • Spacing Modifiers
  • Polar Spacing Modifiers
  • Stretch Area Modifiers
  • Control Point Modifiers

  The available layer modifiers include:

  • Layer Offset
  • Layer Resize
  • Layer Boolean
  • Layer Corner
  • Shape Pre-processing

Modifiers in EM Layout

The AWR Design Environment software has powerful techniques to parameterize EM structures that enable the following capabilities:

1. Generating an EM-based model by sweeping many geometries of an EM structure
2. Generating an EM-based model by simulating only the geometries needed in the design
3. Optimization of an EM structure without using the extraction flow
4. Yield analysis of an EM structure without using the extraction flow

There are three different techniques available to fully parameterize an EM document:

1. Defining variables in a STACKUP and using equations to parameterize any of the dielectrics or materials used in the EM structure
2. Using shape modifiers to parameterize the layout geometry in the EM structure
3. Using Pcells to parameterize the layout geometry in the EM structure

Parameterization is only available for AXIEM and Analyst software EM structures.

Modifiers in Schematic Layout

Shape and layer modifiers allow additional manipulation of layout shapes outside of layouts snapping together from schematic elements. When using either the Stretch Area shape modifier or any of the layout modifiers, changes to the modifier do not change the schematic layout. When you generate the EM document from extraction, however, the shapes are changed.

The following layout shows a simple transmission line, 20um wide and 100um long. A Layer Resize modifier is set to oversize the shape by 20um.

When the EM document is created, the line is oversized in each direction by 20um; so, the total size is 60um wide and 140um long. The following figure shows the extracted AXIEM document.

Now that you have learnt about modifiers, just think about these:

•  Why do you need modifiers?
•  What are the different types of modifiers and which one should you use in a design?

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Team SimTech