Sizes

The entries in this section define the area of the box, and include Cell Size, Box Size and Num Cells. The Box Size remains fixed, but you may change either the Cell Size or the Number of Cells. You choose which you wish to change by selecting the Cell Size or Num Cells radio button. After changing one of the entries, click on the Calculate button or hit the Enter key to update the other factor. These three values are related in the following manner:

Num Cells * Cell Size = Box Size

where Num Cells must be an integer.

Cell Size: This entry row defines the size of a single cell of the box area. The Sonnet electromagnetic analysis starts by automatically subdividing your circuit into small rectangular subsections. Em uses variable size subsections. Small subsections are used where needed and larger subsections are used where the analysis does not need small subsections.

A Sonnet “cell” is the basic building block of all subsections, and each subsection is “built” from one or more cells. Thus the “dimensions” of a cell determine the minimum subsection size. You enter an X dimension (width) and a Y dimension (height). If you wish to change the cell size, click on the Cell Size radio button just above the entry boxes.

Selecting cell size is important. The EM analysis automatically subsections the circuit based on the cell size. Small cells result in slower but more accurate analyses. For a detailed discussion of subsectioning, see Subsectioning in the Sonnet User’s Guide.

Box Size: This entry row displays the size of the box area. Initially, this box area is defined by the bounding box of the circuit elements being translated to Sonnet. The size is displayed in this dialog box but you may not directly edit the dimensions. If you need to increase the size of your box, use the margins to increase box size. For more details, see Margins. You may also specify a Sonnet custom box, for details, see Sonnet Custom Box. If you change the box size, the presently selected dimension, cells or num. of cells, stays the same and the other value is updated.

Num Cells: This entry row defines the number of cells in the box area. You enter an X dimension (width) and a Y dimension (height). If you wish to change the number of cells, click on the Num Cells radio button just above the entry boxes. The number of cells must be an integer number in both dimensions.

Note that the cell size is updated to the closest allowed cell size which allows for an integer number of cells to fit in the box area.