CST2013: Integral Equation Solver Parameters

Simulation: Solver Start Simulation Integral Equation Solver

Read the Solver Overview or the Integral Equation Solver Overview to understand the basic concepts of the integral equation solver. In this dialog, many important settings for the solver run can be set. Most of them have a strong influence on the calculation time. Also, optimization runs and parameter sweeps can be set up from here.

Solver settings frame

Accuracy: Defines the desired linear equation system solver accuracy in terms of the relative residual norm. This is the termination criterion for each solver run at a single frequency sample.

Store result data in cache: Select this option if you want the solver results to be stored in the result data cache. The efficient usage of the result data cache is explained in the printed documentation "Advanced Topics".

Excitation settings frame

Source type: In this drop-down list you can select the sources for the integral equation solver calculation, ports for S-parameter calculations, a Plane Wave or a List of excitations. The selected sources will be stimulated. In case of S-parameter ports, this defines which row of the S-parameter matrix will be calculated. Select All Ports to calculate the full S-parameter matrix for ports. Choosing the List entry presents a new button offering the possibility to Select... a special combination of port modes or excitations. If current sources or farfield sources are defined they have to be selected in the List.

S-parameter settings frame

Norm to fixed impedance: S-parameters are always normed to a reference impedance. You may either select to norm them to the calculated impedance of the stimulation port or you may specify a number of your choice. Renormalization to a fixed impedance is only possible if all S-parameters are calculated, i.e., whenever all ports and modes are excited.

Frequency samples frame

List of samples: The list of frequency samples allows you to easily define the number, interval, and sampling method of integral equation solver simulation points by entering values in the corresponding columns. Samples may be single frequencies, equidistantly distributed or automatically chosen within the given range. When the number of Samples is not defined (left blank), the solver stops calculating additional samples as soon as the S-parameter sweep convergence criterion is satisfied.

If the upper or lower limit of the frequency range (columns From and To) is omitted (left blank), the global frequency range will be used instead. Please note that the global maximum frequency range is displayed in the first line. To change these values, you may go into the Frequency Range Setting dialog box in the main menu under Solve Frequency....

Invalid settings will be marked by a red background color. Right-click in the highlighted cell and select Help from the context menu to get a hint. Sample definitions (rows of the list) can be deleted using the context menu, or simply by pressing the delete key.

If a broadband frequency sweep is performed with the stopping criterion enabled (default, see Solver Sampling), the number of frequency samples defines the maximum number of integral equation solver runs for a single S-parameter calculation.

Naturally, the simulation time increases with the number of frequency samples. This relationship may be approximately linear.

Use broadband frequency sweep: Calculate broadband S-parameter curves by using as few frequency samples as required for reaching the stop criterion defined in the Solver Sampling dialog. In this frequency sweep mode, the number of frequency samples is an upper limit. At least three samples are required.

Press the Properties... button to configure the convergence criterion of the broadband S-parameter sweep.

Start solver

Starts the integral equation solver calculation.

Optimize...

This button opens a dialog box that allows you to set up and start an optimization run.

Par. sweep...

Opens the parameter sweep dialog.

Acceleration...

Opens the acceleration dialog box to control the high performance options of the simulation run (e.g. GPU acceleration, Distributed Computing, MPI).

Specials...

This button leads to a dialog where further special settings for the solver can be made. The settings are for expert users only and should generally not be changed.

Apply

Store the specified settings without starting the calculation.

Close

Closes this dialog box without performing any further action.

Help

Shows this help text.