De-embedding Without Reference Planes

Reference planes are optional for co-calibrated, and orthogonal box-wall ports but are required for diagonal boxwall ports. If you do not specify a reference plane for a particular port in the project editor, em will assume a zero-length reference plane for that port. This means that de-embedding will remove the discontinuity associated with that particular port, but will not shift the reference plane for it.

As discussed in the next section, em may generate bad de-embedded results if you attempt to remove a very short (but greater than zero) reference plane for a boxwall port. However, if you de-embed without a reference plane, em will not attempt to negate any length of transmission line at all. As a result, de-embedding without a reference plane does not lead to any error. Therefore, we recommend that you de-embed without reference planes rather than specify very short, non-zero, reference plane lengths for orthogonal boxwall ports.