CST2013: Field Source

Simulation: Sources and Loads Field Source

This dialog offers the possibility to define near field sources.

Available import formats are:

CST MICROWAVE STUDIO field source monitor data (FSM files)

CST CABLE STUDIO or CST PCB STUDIO radiation data (RSD files)

Sigrity? radiation data (NFD files)

Either electric current information (for RSD files) or complex electric and magnetic fields on a bounding box (for FSM and NFD files) are imported and used as  excitations in CST MICROWAVE STUDIO. More details can be found in the nearfield source overview.

The defined source is listed in the navigation tree. Furthermore, it appears in the solver excitation list, where it can be selected for excitation, either as a single simulation or as a simultaneous excitation together with other field sources or other source types.

Moreover, it is possible to down-sample the input data frequency points for the transient solver. As the simulation time depends on the frequency sampling rate, this may provide a significant speed up for the computation.

Note: The imported file contains field values at a specific spatial discretization. Since this discretization does not match to the one used in the simulation, the field values are interpolated between the original and the simulation grid. Due to this, a sufficiently fine simulation grid in the imprint region is required for accurate simulations. For FSM and NFD sources, local mesh properties can be set.

CST MICROSTRIPES compact source data (ESF files).

The compact source is used to excite previously calculated emissions on a region. These emissions, stored in a ESF file, are typically calculated using a fine model of a device, and are then used to represent emissions from the device in a larger system. The equivalent surface over which the emissions were calculated must be the same size as the compact source excitation region. The frequency samples in the ESF file must be uniformly spaced. The emissions in the ESF file can be rotated to fit onto the compact source excitation region if they are of a different orientation. Moreover, this is only supported by the TLM solver.

Name

Define a name for the imported field source.

Import file (".fsm", ".rsd", ".nfd" or ".esf")

Browse here for a CST MICROWAVE STUDIO FSM file (*.fsm), CST CABLE STUDIO / CST PCB STUDIO RSD file (*.rsd), Sigrity? NFD file (*.nfd) or. CST MICROSTRIPES ESF file (*.esf).

The data is read from this file every time the model is rebuilt.

Use relative path

Use this checkbox to toggle between relative and absolute path names for the import file.

Use local copy only

Enabling this checkbox will cause the field source to only use the local copy of the import file. This local copy is created when hitting the OK button.

Data reduction frame

This frame offers the possibility to down-sample the frequency data for the transient solver selecting start and end point of the frequency range. Based on the following parameters, the frequency samples considered for the transient solver will be highlighted in the List of frequencies. Please see the note on the requirement for equidistant - zero frequency base sampling.

Downsampling ratio

The spin box (directly connected to a slider) allows to select the down sampling ratio. A minimum vale of "1" corresponds to no down-sampling at all (dense sampling).

Freq min

The spin box allows to select the first desired frequency sample to be considered for the simulation. Click on the spin control to select one of the frequency samples in the import file as minimum frequency.

Freq max

The spin box allows to select the last desired frequency sample to be considered for the simulation. Click on the spin control to select one of the frequency samples in the import file as maximum frequency.

List of frequencies

After selecting a specific file with the browse facility, all correspondent frequencies available in the file are presented in this list. The frequency points considered for the transient solver, possibly down-sampled, are highlighted. Moreover, an automatic tool tip displays the position of each sample in the sequence. During the transient simulation, the applied field data is interpolated from the values in the simulation frequency range.

OK

Accepts the current settings and closes the dialog box.

Cancel

Closes this dialog box without performing any further action.

Help

Shows this help text.