HFSS15: De-embedding S-Matrices

To compute a de-embedded S-matrix:

1. If you have already set up the wave port on the desired object face, double-click the wave port’s icon in the project tree.

The Wave Port dialog box appears.

2. Click the Post Processing tab.

3. Select Deembed, and then, either:

• Enter the length to be added in the Distance text box. A positive value de-embeds into the port. A negative value de-embeds out of the port.

You can assign a variable as this value.

• Alternatively, click Get Distance Graphically to draw a line with a length representing the de-embed distance. After you draw the line in the 3D window, the Distance field shows the specified distance. You can edit this value.

After you enter the value, a blue arrow depicts the embedding distance in the model window while the port is selected. After you enter the value, a blue arrow depicts the de-embedding distance in the graphics window while the port is selected.

In cases of a unit cell modelling equivalent screening impedance, the de-embedding distances should point to the nearest surfaces of the substrate even if there is a thickness between these surfaces. Note that a very thick substrate may lead to inaccurate results because HFSS replaces the composite material of the substrate with a sheet.

4. Click OK to assign that length to the selected port.