Adding Variables

Define variables to create a parametric model.

A model is parametric when it is created using variable expressions. When a variable expression is modified, any items dependent on that variable are re-evaluated and automatically updated. It is the recommended construction method when creating a model, but not compulsory.

Defined variables are stored as part of the model in the .cfx file.

  1. Open the Create Variable dialog using one of the following workflows:
    • On the Construct tab, in the Define group, click the  Add Variable icon.
    • On the model tree, a right-click context menu is available on Variables. From the list, select Add Variable.
      Figure 1. The model tree (Construction tab).


    • On the model tree, click the icon. From the drop-down list, select Add Variable.
      Figure 2. The drop-down list available in the model tree.


    • Press # to use the keyboard shortcut.
  2. Create the following variables:
    1. Optional: Add the variable comments.
    Name Expression Comment
    freq 9e9 The operating frequency.
    lambda c0/freq*1000 Free space wavelength.
    pin_r 1 Pin radius.
    wg_h 10 Waveguide height.
    wg_w 20 Waveguide width.
    Tip:
    • Click Add to keep the Create Variable dialog open and add more variables.
    • Click Create to add a variable and close the Create Variable dialog.