PO and LE-PO Settings

Optional parameters can be used with the physical optics (PO) or large element physical optics (LE-PO) to save memory and runtime in specific faces.

On the Solve/Run tab, in the Solution Settings group, click the  Solver Settings icon. On the Solver Settings dialog, click the High frequency tab.
Couple PO and MoM/MLFMM solutions (iterative technique, default)
This option uses a hybrid iterative technique to determine the coupling (interaction) between the MoM or MLFMM region and the PO region. As a result, the currents in the PO region will have an effect on the current distribution in the MoM region.
Couple PO and MoM solutions (full coupling)
This option takes into account the coupling between the MoM region and PO regions. This is a non-iterative technique and uses more memory compared to the iterative technique. The currents in the PO region will have an effect on the current distribution in the MoM region.
Decouple PO and MoM solutions
This option ignores the PO regions when calculating the MoM currents. The runtime and memory will be less compared to a fully coupled (default) solution. This option should be used with caution. For example, the input impedance of a dipole antenna in close proximity to a metallic plate, where the dipole is solved using the MoM and the plate using PO, will (incorrectly) be the same as that of the MoM dipole in free space.
Tip: Use this option where the MoM and PO regions are electrically far apart (for example a reflector antenna).
Maximum number of iterations
This option limits the number of iterations for the iterative coupling technique.
Stopping criterion for residuum
This option specifies the termination criterion for the normalised residue when using the iterative method. The iterative solution is terminated when the normalised residue is smaller than this value.
Store / reuse shadowing information
During calculations using the PO formulation, a large amount of the runtime could be spent in determining which surfaces are illuminated from the source(s). This option saves the shadowing information to speed up subsequent runs. Re-use is only possible if the mesh remains unchanged.
Note: Storage of the shadowing information could cause large .sha files on disk.
Use symmetry in ray-tracing (where possible)
This options allows symmetry to be used in full ray tracing when determining the shadowing to reduce runtime. For geometrical symmetry, select this option to utilise symmetry. For electric and magnetic symmetry, this speed up is always used.