AsymptoticSolver Object

This object controls the asymptotic high frequency solver. Use the 'Start' command to run the solver.

Asymptotic Solver Settings

• General

• Detailed solver control options (SBR)

• Detailed solver control options (SBR_RAYTUBES)

Asymptotic Solver General

SetSolverType ( enum{"SBR", "SBR_RAYTUBES"} type )

This selection specifies whether the solver should use independent rays (SBR) or raytubes (SBR_RAYTUBES). Independent rays are generally more robust for complex geometries, but the performance of the raytube solver is better at higher frequencies for large and relatively smooth objects.

SetSolverMode ( enum{"MONOSTATIC_SCATTERING", "BISTATIC_SCATTERING","FIELD_SOURCES","RANGE_PROFILES"} type )

This selection specifies whether the solver should run in Monostatic or Bistatic Scattering, Field source or Range profile mode. For monostatic calculations, the observation angles are identical to the excitation angles. Therefore, for this mode the specification of an observation angle sweep is required only. For bistatic calculations, the excitation and observation angles do not need to be the same. As a consequence, an additional excitation angle sweep needs to be defined when the solver is used in bistatic mode. For field source calculations, no incident plane wave is required, therefore the definition of an observation angle sweep is sufficient. The range profile mode uses similar observation angle definitions as the monostatic mode, but only either single point or single angle sweeps are supported. In case of a single observation point definition, a one dimensional range profile is calculated whereas for two dimensional sweep definitions, a sinogram (range vs. angle) will be generated.

SetAccuracyLevel ( enum{"LOW", "MEDIUM", "HIGH", "CUSTOM"} type )

This setting allows you to choose from one of the predefined accuracy configurations such as Low,  Medium or High. Low accuracy means that the simulation settings will be optimized for fast simulations whereas High accuracy implies settings optimized for obtaining very accurate results. Typically the Medium accuracy default provides a good compromise between accuracy and simulation speed. In addition to these default configurations, you may also choose Custom which allows specifying more detailed solver options by using the detailed solver control options.

ResetPolarizations

Resets the current excitation polarization list

AddHorizontalPolarization ( double value )

This method allows you to add a new horizontal plane wave polarization to the list of excitations. The amplitude of the plane wave electric field vector in V/m is given as an argument.

AddVerticalPolarization ( double value )

This method allows you to add a new vertical plane wave polarization to the list of excitations. The amplitude of the plane wave electric field vector in V/m is given as an argument.

AddLHCPolarization ( double value )

This method allows you to add a new left hand side circular plane wave polarization to the list of excitations. The amplitude of the plane wave electric field vector in V/m is given as an argument.

AddRHCPolarization ( double value )

This method allows you to add a new right hand side circular plane wave polarization to the list of excitations. The amplitude of the plane wave electric field vector in V/m is given as an argument.

AddCustomPolarization( double ethetare, double ethetaim, double ephire, double ephiim)

This method allows you to add a new custom polarization to the list of excitations. The complex amplitudes of the plane wave electric field vector components in V/m are given as arguments.

SetSolverMaximumNumberOfReflections ( int value )

This parameter specifies the maximum number of ray reflections which will be taken into account for the ray tracing computation.

StorePOResults ( bool flag )

This option controls whether the first order PO farfields are calculated in addition to the total farfields including all multiple reflection and diffraction effects. Comparing the two sets of results can be used for checking the influence of the higher order effects on the solution. This option is only available for the Monostatic and Bistatic scattering modes.

SetSolverRangeProfilesCenterFrequency ( double value )

This method allows you to specify the center frequency for the range profile and sinogram calculation. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesAutomatic ( bool flag )

This method allows you to specify if the range extend or bandwidth settings will be determined automatically or whether the values set by the respective methods will be taken. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesNumberOfSamples (  int value )

This method allows you to specify the number of spectral samples for the range profile or sinogram computation. This value needs to be a power of two larger or equal 16. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesWindowFunction (  enum{"RECTANGULAR", "HANNING", "HAMMING", "BLACKMAN"} type )

This method allows you to specify the spectral window function being used for calculating range profiles or sinograms. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesSpecMode (  enum{"RANGE_EXTEND", "BANDWIDTH"} type )

This method allows you to specify whether the resolution of the range profile or sinogram calculation shall be specified by either specifying the maximum range extend or by setting the calculation bandwidth around the center frequency. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesRangeExtend ( double value )

This method allows you to specify the maximum range extend for the range profile and sinogram calculation if the specification mode is set to RANGE_EXTEND. Please note that this setting is only effective for the Range profile computation mode.

SetSolverRangeProfilesBandwidth ( double value )

This method allows you to specify the bandwidth for the range profile and sinogram calculation if the specification mode is set to BANDWIDTH. Please note that this setting is only effective for the Range profile computation mode.

ResetFrequencyList

Resets the current frequency sweep list.

AddFrequencySweep ( double fmin, double fmax, double fstep)

This method allows you to add a new frequency sweep definition to the list of frequency sweeps. Each sweep is defined by its lower and upper bounds as well as a step width. You can specify a single frequency point by setting the lower and upper bounds to the same value. Please note that the step width must match with the frequency range such that an integer number of frequency points will be defined.

ResetExcitationAngleList

Resets the current excitation angle sweep list.

AddExcitationAngleSweep ( enum{"POINT", "THETA", "PHI", "BOTH"} type, double thetamin, double thetamax, double thetastep, double phimin, double phimax, double phistep)

This method allows you to add a new angular sweep definition to the list of excitation angle sweeps. The meaning of the angular parameters depends on the type setting:

AddExcitationAngleSweepWithRays ( enum{"POINT", "THETA", "PHI", "BOTH"} type, double thetamin, double thetamax, double thetastep, double phimin, double phimax, double phistep)

This method has the same effect as AddExcitationAngleSweep, but in addition the solver will store the rays for each excitation direction for visualization. Please refer to the description of the AddExcitationAngleSweep method for more information. For more information on ray storage, please refer to the asymptotic solver control dialog box description in the online documentation.

ResetFieldSources

Resets the current field source excitation list.

SetFieldSourcePhasor ( string fieldsourcename, double amplitude, double phase)

This method allows you to define the amplitude and phase shift which should be applied to a previously defined field source.

SetFieldSourceRays ( string fieldsourcename,  bool flag)

This method allows you to specify whether the rays should be stored for a previously defined field source. For more information on ray storage, please refer to the asymptotic solver control dialog box description in the online documentation.

SimultaneousFieldSourceExcitation( bool flag)

If this flag is set to True, all field sources are excited simultaneously. In this case only one farfield result will be calculated which contains the superposition of all field sources. If this flag is set to False, a sequence of calculations will be performed where only one field source is active for each run. The default setting is to perform a simultaneous excitation.

ResetObservationAngleList

Resets the current observation angle sweep list.

AddObservationAngleSweep ( enum{"POINT", "THETA", "PHI", "BOTH"} type, double thetamin, double thetamax, double thetastep, double phimin, double phimax, double phistep)

This method allows you to add a new angular sweep definition to the list of observation angle sweeps. The meaning of the angular parameters depends on the type setting:

AddObservationAngleSweepWithRays ( enum{"POINT", "THETA", "PHI", "BOTH"} type, double thetamin, double thetamax, double thetastep, double phimin, double phimax, double phistep)

This method has the same effect as AddObservationAngleSweep, but in addition the solver will store the rays for each excitation direction for visualization. Please refer to the description of the AddObservationAngleSweep method for more information. For more information on ray storage, please refer to the asymptotic solver control dialog box description in the online documentation.

UseParallelization  ( bool flag )

Enable or disable parallelization (multithreading) for the asymptotic solver.  

MaximumNumberOfThreads ( int number )

Define the maximum number of parallel threads to be used for the asymptotic solver run.

RemoteCalculation  ( bool  flag )

Enable or disable remote calculation for the asymptotic solver. When enabled, an asymptotic solver run is submitted to the network instead of performing the calculation locally. Please note that activating remote calculation turns off other distributed computing options. The setting does not influence parameter sweeps and optimizer runs with distributed computing.

DistributedComputing( bool  flag )

Enable or disable distributed computing for the asymptotic solver. When enabled, an asymptotic solver run will be subdivided into a number of distributed computing jobs as specified by the DistributedComputingNodes setting. Each job will then handle a certain subset of excitation directions.  Please note that activating distributed computing turns off other remote calculation options. The setting does not influence parameter sweeps and optimizer runs with distributed computing.

DistributedComputingNodes( int number )

Define the maximum number of computing nodes to be used for distributed computing of excitation directions. This setting will also determine the number of jobs to be submitted for a single asymptotic solver run.

StoreResultsInCache ( bool flag )

Stores results of the asymptotic solver in the result cache.

Start int

Starts the solver with the current settings and returns 1 if the calculation is successfully finished and 0 if it failed.

Detailed Solver Control Options (SBR Solver)

Please note that these settings will only take effect if the AccuracyLevel is set to Custom. Otherwise these settings will be overridden by the values given by the predefined accuracy levels.

SetMeshCurved ( bool flag )

This setting specifies whether the mesh triangles will be curved for a better representation of non-planar geometries. If this option is set to false, the mesh will be created such that it consists of planar triangles only. Using curved triangles will usually improve accuracy, at the expense of a little bit higher memory consumption and longer simulation times. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetMeshNormalTolerance ( double value )

This parameter specifies the maximum allowable tolerance of the (planar) triangle normals as compared to the true normals of the structure's geometry. Lower settings will lead to a more accurate geometrical representation at the expense of generating more triangles. If this parameter is set to zero, no constraint concerning the normal tolerance will be applied during the mesh generation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetMeshSurfaceTolerance ( double value )

This parameter specifies the maximum allowable deviation of the (planar) triangle from the actual geometry in model dimensions. Lower settings will lead to a more accurate geometrical representation at the expense of generating more triangles. If this parameter is set to zero, no constraint concerning the surface tolerance will be applied during the mesh generation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetMeshMaxEdgeLengthPerLambda ( double value )

This setting specifies the maximum allowable length of the triangle edges as compared to the wave length of the upper frequency limit as it is specified globally. This parameter has a strong influence on the number of triangles generated for a particular mesh. The solver run time will suffer from drastically varying triangle sizes, so extreme settings should be avoided. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetMeshMaxEdgeLengthPerDiagonal ( double value )

This setting specifies the maximum allowable length of the triangle edges as compared to the size of the structure (bounding box diagonal). This parameter has a strong influence on the number of triangles generated for a particular mesh. The solver run time will suffer from drastically varying triangle sizes, so extreme settings should be avoided. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverRayDensityPerLambda ( double value )

This parameter specifies the number of rays which are launched per wavelength of the actual simulation frequency. For electrically smaller structures, this parameter may need to be increased in order to achieve a better accuracy. Typical values are in between 10 for electrically very large structures and 40 or more for electrically not very large structures. This parameter is the main parameter to vary for controlling solver accuracy and performance. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverMaxAreaOfRayTube ( double value )

This parameter controls the maximum ray tube cross section for consideration of a particular beam for the scattered field computation. The scattering results become inaccurate for beams with very large cross sections, therefore it makes sense not to consider these beams since their contribution will be very small anyway. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverMinimumNumberOfRays ( int value )

For electrically smaller structures, there may be too few rays launched due to the Ray density / wavelength setting. In order to ensure that a reasonable number of rays are launched to properly illuminate all regions of the structure, this parameter defines a lower bound for the number of rays. For more accurate simulations of electrically not very large structures you may need to increase this parameter. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverExitBlockageCheck ( bool flag )

This option specifies whether the visibility of a reflection point for a particular ray from the current observation point will be checked or not. For better accuracy it is recommended to turn this option on. In some cases it may be useful to turn this option off in order to quickly obtain potentially less accurate results. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverIncludeMetallicEdgeDiffraction ( bool flag )

This option specifies whether diffraction at edges should be included in the simulation which will improve the accuracy at the expense of longer simulation times. It is generally recommended to turn this option on for more accurate results. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverAllowStorageOfIncidentRays ( bool flag )

This option controls whether the incident rays will be stored if the corresponding rays option is set for the excitation. If this option is turned off, ray storage will be suppressed for all incident rays. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverAllowStorageOfInitialHits ( bool flag )

This option controls whether the points where the incident rays hit the structure will be stored if the corresponding rays option is set for the excitation. If this option is turned off, the initial hit point storage will be suppressed for all incident rays. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverAllowStorageOfObservedRays ( bool flag )

This option controls whether the scattered rays will be stored if the corresponding rays option is set for the excitation as well as the observation direction. If this option is turned off, scattered ray storage will be suppressed. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverMaximumNumberOfIncidentRaysOutput ( int value )

This option allows you to set an upper limit for the number of incident rays being stored per direction and per reflection level. This option is important in order to avoid storing huge files which may slow down the computation tremendously. Please note that this limit is set for each reflection level independently. Therefore, a limit of e.g. 1000 means that up to 1000 rays will be stored which do not intersect with the structure, another up to 1000 rays will be stored which are reflected once and so on. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverMaximumNumberOfInitialHitsOutput ( int value )

This option allows you to set an upper limit for the number of points where the incident rays hit the structure being stored per excitation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverMaximumNumberOfObservedRaysOutput ( int value )

This option allows you to set an upper limit for the number of scattered rays being stored per incident direction and per reflection level. This option is important in order to avoid storing huge files which may slow down the computation tremendously. Please note that this limit is set for each incident direction and reflection level independently. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

SetSolverObservedRaysAngleTolerance ( double value )

This option allows you to set an angular tolerance for the scattered rays which will be used for assigning these rays to a particular observation angle. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR solver.

Detailed Solver Control Options (SBR_RAYTUBES Solver)

Please note that these settings will only take effect if the AccuracyLevel is set to Custom. Otherwise these settings will be overridden by the values given by the predefined accuracy levels.

SetMeshNormalToleranceRT ( double value )

This parameter specifies the maximum allowable tolerance of the (planar) triangle normals as compared to the true normals of the structure's geometry. Lower settings will lead to a more accurate geometrical representation at the expense of generating more triangles. If this parameter is set to zero, no constraint concerning the normal tolerance will be applied during the mesh generation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetMeshSurfaceToleranceRT ( double value )

This parameter specifies the maximum allowable deviation of the (planar) triangle from the actual geometry in model dimensions. Lower settings will lead to a more accurate geometrical representation at the expense of generating more triangles. If this parameter is set to zero, no constraint concerning the surface tolerance will be applied during the mesh generation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetMeshMaxEdgeLengthPerLambdaRT ( double value )

This setting specifies the maximum allowable length of the triangle edges as compared to the wave length of the upper frequency limit as it is specified globally. This parameter has a strong influence on the number of triangles generated for a particular mesh. The solver run time will suffer from drastically varying triangle sizes, so extreme settings should be avoided. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetMeshMaxEdgeLengthPerDiagonalRT ( double value )

This setting specifies the maximum allowable length of the triangle edges as compared to the size of the structure (bounding box diagonal). This parameter has a strong influence on the number of triangles generated for a particular mesh. The solver run time will suffer from drastically varying triangle sizes, so extreme settings should be avoided. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverRaySpacingRT ( double value )

This parameter specifies the distance in between the rays launched in wavelengths. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverAdaptiveRaySubdivisionRT ( bool flag )

This option specifies whether the ray tubes shall be automatically refined when needed. The actual refinement is controlled by the two parameters SetSolverMaximumRayDistanceRT and SetSolverMinimumRayDistanceRT. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMaximumRayDistanceRT ( double value )

This parameter controls the maximum edge length of a ray tube before it gets automatically refined. This setting will only be considered when the AccuracyLevel is set to Custom and the SetSolverAdaptiveRaySubdivisionRT option is active. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMinimumRayDistanceRT ( double value )

This parameter controls the minimum edge length of a ray tube which can be further refined automatically. This setting is needed in order to avoid excessive refinement of ray tubes at discontinuities. This setting will only be considered when the AccuracyLevel is set to Custom and the SetSolverAdaptiveRaySubdivisionRT option is active. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMinimumNumberOfRaysRT ( int value )

For electrically smaller structures, there may be too few rays launched due to the Ray density / wavelength setting. In order to ensure that a reasonable number of rays are launched to properly illuminate all regions of the structure, this parameter defines a lower bound for the number of rays. For more accurate simulations of electrically not very large structures you may need to increase this parameter. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverExitBlockageCheckRT ( bool flag )

This option specifies whether the visibility of a reflection point for a particular ray from the current observation point will be checked or not. For better accuracy it is recommended to turn this option on. In some cases it may be useful to turn this option off in order to quickly obtain potentially less accurate results. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverIncludeMetallicEdgeDiffractionRT ( bool flag )

This option specifies whether diffraction at edges should be included in the simulation which will improve the accuracy at the expense of longer simulation times. It is generally recommended to turn this option on for more accurate results. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverAllowStorageOfIncidentRaysRT ( bool flag )

This option controls whether the incident rays will be stored if the corresponding rays option is set for the excitation. If this option is turned off, ray storage will be suppressed for all incident rays. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverAllowStorageOfInitialHitsRT ( bool flag )

This option controls whether the points where the incident rays hit the structure will be stored if the corresponding rays option is set for the excitation. If this option is turned off, the initial hit point storage will be suppressed for all incident rays. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverAllowStorageOfObservedRaysRT ( bool flag )

This option controls whether the scattered rays will be stored if the corresponding rays option is set for the excitation as well as the observation direction. If this option is turned off, scattered ray storage will be suppressed. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMaximumNumberOfIncidentRaysOutputRT ( int value )

This option allows you to set an upper limit for the number of incident rays being stored per direction and per reflection level. This option is important in order to avoid storing huge files which may slow down the computation tremendously. Please note that this limit is set for each reflection level independently. Therefore, a limit of e.g. 1000 means that up to 1000 rays will be stored which do not intersect with the structure, another up to 1000 rays will be stored which are reflected once and so on. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMaximumNumberOfInitialHitsOutputRT ( int value )

This option allows you to set an upper limit for the number of points where the incident rays hit the structure being stored per excitation. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverMaximumNumberOfObservedRaysOutputRT ( int value )

This option allows you to set an upper limit for the number of scattered rays being stored per incident direction and per reflection level. This option is important in order to avoid storing huge files which may slow down the computation tremendously. Please note that this limit is set for each incident direction and reflection level independently. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.

SetSolverObservedRaysAngleToleranceRT ( double value )

This option allows you to set an angular tolerance for the scattered rays which will be used for assigning these rays to a particular observation angle. This setting will only be considered when the AccuracyLevel is set to Custom. Please note that this setting is only valid for the SBR_RAYTUBES solver.