Numerical Green's Function (NGF)

In the solution of large electromagnetic problems solved using the method of moments (MoM), sometimes a considerable part of the geometry remains unchanged, while only a small part changes. The unchanged part (static interaction matrix) can be saved to a .ngf file and reused to reduce CPU time.

Tip: To obtain a reduction in CPU time, domain decomposition is recommended for MoM models consisting of a large static part and a smaller dynamic part.
A static part is indicated by the icon in the model tree.
The following restrictions apply with respect to the NGF:
  • The NGF can only be activated on a part. Selecting a sub-part and activating the NGF will activate the NGF for the entire part.
  • The NGF is not supported in conjunction with continuous frequency simulations.
  • When the NGF is activated for a part, the following cannot be modified:
    • geometry
    • the solution method
    • media
    • ports added or deleted
    • loads
    • transmission lines
    • general networks
    The part is essentially “locked”. It is allowed to add or remove sources from the part.