# Multiport Post-Processing Limitations

The Multiport post-processing application macro has several limitations.

The following options are not supported by the Multiport post-processing application macro:
• The application macro requires a specific label for the ports and loads when using the Feko model as input. The label mapping should be consistent between ports and loads. The recommended naming convention for the loads and ports are <label>_x, where x is the port number.
• The directivity factor for far fields is not calculated (the gain factor is calculated). Any directivity that would be calculated would have to make several assumptions, and you could easily obtain incorrect results. If directivity had to be calculated, it could be done in one of the following ways:
• The power lost in the loads, added by the post-processing can be taken into account to approximate the directivity. The approximation is only valid as long as the model contains no other loads, and the model consists of lossless materials.
• The far field can be integrated, but this requires a sufficiently fine sampled far field for the results to be accurate.
• The application macro assumes that the power settings were not changed from the default (PW 0).
• Current sources are not supported for field calculations. S-parameters are only calculated where there were changes in the load values.
• Exporting current data are not supported since the data is associated with a mesh.