MLFMM Settings

A number of optional settings are available when using multilevel fast multipole method (MLFMM) to solve a model.

Note: It is recommended to use the default settings. Modifying the advanced settings can impact accuracy and/or run time.

Activate additional stabilisation for the MLFMM

Select this option to activate additional stabilisation for a model with severe convergence problems.

Field calculation methods

Near-field: The MLFMM uses a fast near field calculation method (default), but in some cases the traditional integration method could be used.
Far field: The MLFMM method uses a fast far field calculation method (default), but in some cases the traditional integration method could be used.

Box size at finest level

The MLFMM is based on a hierarchical tree-based grouping algorithm and depending on the frequency and the model dimensions, the Solver automatically determines the number of levels in this tree and the size of the boxes at the finest level. This option allows you to adjust the box size. Adjusting the box size can improve convergence in some cases. The box size is specified in terms of the wavelength. The default is 0.23 and the minimum value should be larger than 0.2. Increasing the box size increases the memory requirement.

Tip: Make incremental changes of 0.03 at a time.