Reference Plane Options dialog box

The Reference Plane Options dialog box allows you to control the type of reference plane and its orientation. This dialog box is opened when you click on the Change button in the Port Properties dialog box. Note that while these options are defined for all port types, they may only be set by the user for standard box wall ports. For all other port types, these settings are automatically determined by the software.

Shared reference plane length: Select this option if you wish the reference plane for this port to be the same as other box wall ports on the same box wall. This is the default setting for any new port. When a port is shared, then when the port is de-embedded both the port discontinuity and the coupling between the ports and feedlines are removed.

Independent reference plane length: Select this option if you wish to make the reference plane for this port to be independent. When a port is independent, then the reference plane can be a different length than any or all other reference planes in your circuit. When you choose this setting, the coupling between the independent port and other ports in the circuit is not removed by the de-embedding process; additionally, the coupling between the independent port's feedline and all other feedlines is also not removed.

By default, all reference planes are orthogonal, extending along the x or y plane at right angles to the box wall. When you select this radio button, the "Allow this reference plane to be diagonal" checkbox is enabled. Selecting this checkbox directs the reference plane for the port along the direction of the polygon to which the port is attached rather than at a right angle to the box wall. You should also be aware that, although the S-parameter data is accurate, you can not calculate Z0 and Eeff for port.

Examples of all reference plane types and orientations are shown below.

For more details, see the "Diagonal Ports" section in the "Ports" chapter of the Sonnet User's Guide. For a detailed discussion of de-embedding and the use of reference planes, please see the ''De-embedding'' chapter in the Sonnet User's Guide available in PDF format through the Sonnet task bar or by selecting Help => Manuals from the main menu of any Sonnet application.