CST2013: Special Solver Parameters - Solver

Simulation: SolverStart SimulationSpecialsSolver

Special settings frame

Normalize to reference signal [always normalized if default signal is used]: In case of the default Gaussian excitation signal, which is predefined in CST MICROWAVE STUDIO, all frequency results of the transient solver are automatically normalized to the spectrum of this default signal in order to provide consistent broadband results, independent of the transient excitation signal. This allows convenient comparisons to e.g. frequency domain solver results.

However, selecting other signals for excitation, e.g. a rectangular pulse or an imported signal, this normalization step is not done by default. This means that in these cases all frequency results are purely represented by the unnormalized discrete Fourier transformation of the correspondent transient data. In any case, you can still apply a normalization step to the selected reference signal in CST MICROWAVE STUDIO by enabling this check button, independent whether this signal is actually used or not. As mentioned above, changing this button has no influence when the default Gaussian excitation signal is used.

In case of a transient co-simulation run, usually the excitation is driven from within CST DESIGN STUDIO. Consequently also the result normalization can be controlled here, either normalizing to a Gaussian reference signal or not. This can be defined for each task separately and consistently effects both, the frequency domain results in CST  MICROWAVE STUDIO as well as in CST DESIGN STUDIO.

Please find further information in this context on the Reference Value and Normalization page.

Automatic S-parameter adjustment: Disable this check button to receive pure S-parameter results without any passivity adjustment.

Prepare Farfields: All farfield results are automatically precalculated to speed up the postprocessing.

Open boundary settings frame

PML Type: Here, you may specify the PML formulation. Allowed options are ConvPML for the Convolution PML or GTPML for the Generalized PML theory.

The default value is the Convolution PML which provides a material independent absorbing boundary condition. In addition to electric and magnetic material properties also conducting materials are considered for this absorbing boundary.

The Generalized PML theory provides a basic absorbing boundary condition, considering only electric and magnetic materials.

Variable PML layer mesh steps: The mesh steps inside the PML are increased towards the outer PML boundary to allow a maximal possible PML depth. The number of used layers is defined in the Settings for PML Boundary  dialog.

Keep PML depth during adaptive mesh refinement: The initial PML depth is maintained during adaptive mesh refinement passes. Consequently the number of PML layers increases with subsequent passes, however, the total number of PML layers is kept as small as possible by applying variable PML layer mesh steps.

Time integrator settings frame

In this dialog box, some special settings concerning the PBA model in connection with the time step calculation can be made. Note that these parameters are sensitive regarding the stability of the time domain calculation, so be careful when changing them.

Subcycling: Choosing the Activate selection will always check for the possibility to use them in the calculation whereas the button Deactivate prevents this procedure. The Automatic detection will instead come to this decision by an internal procedure.

Subgrid specific cycling: In case that the Multilevel Subgridding Scheme is activated for a given simulation structure, the different grid levels can be calculated with different timesteps. Then the basic timestep presented in the solver information window or in the solver result file corresponds to the finest mesh level, each coarser mesh level is updated with the twofold timestep, fourfold timestep and so on. Consequently, the time step factor defined in the Special Solver Parameters - General dialog page is multiplied to the timesteps of all levels.

In addition to the reduced mesh cells of a subgridding model, this functionality might lead to yet another improvement of the simulation time.

The subgrid specific cycling behavior can be switched on and off by choosing the Activate or Deactivate selection. In addition and similar to the subcycling procedure described above this decision can be made automatically by selecting  the Automatic detection.

OK

Accepts the input and closes the dialog.

Cancel

Closes this dialog box without performing any further action.

Help

Shows this help text.

Special Solver Parameters: Waveguide, Steady State, AR-Filter, Material, General