Independent Reference Planes and Diagonal Ports
Reference planes may share their length with other reference planes or be independent of other reference planes. By default, all reference planes on a box side are shared and the same reference plane length is used for all ports on that side. When independent reference planes are used, The reference planes can be a different length but any coupling between feedlines is not removed.
For some designs, feedlines do not lie in either the x or y axis, but extend diagonally from the port. In this case, if the port is orthogonal, the reference plane does not extend along the feedline, so that the feedline effects are not removed correctly in the de-embedding process. An example is shown below.
The solution to this problem is to apply the diagonal port feature to your port. A reference plane must be defined as independent in order to use the diagonal feature. The diagonal feature may be applied to box-wall ports, co-calibrated ports and components. This feature is not available for delta gap ports or via ports. Once a port is designated as diagonal, the reference plane will extend along the polygon to which the port is attached as shown below.
