Distributed Circuit Component
The circuit component editor includes a distributed option that increases accuracy when a component is attached to a transmission line. When selected, the excitation is spread across the width of the transmission line connected to the component.
XF assumes an analytic field distribution under the transmission line where the voltage and current density are evenly distributed across the component's width. XF accounts for components that are placed across inhomogeneous materials.
Surface Current Sensor
The surface current sensor computes the electrical current on a metal surface, and is primarily used for building antennas that perform well at multiple frequencies. Users can view the surface current on only the antenna rather than the entire complex circuit in order to more easily identify issues and make the appropriate changes.
The sensor can collect data on any part that is a good electrical conductor, and it supports both XACT and staircased parts.
XFdtd Release 7.8.0 includes an array analysis macro that optimizes input phases for either arrays or subarrays in order to obtain the maximum possible realized gain in all directions. It then plots the cumulative distribution function of EIRP for the array configurations.
Apply Matching Circuit Script
As of XF 7.10, this script is no longer available. It has been replaced with the schematic editor.
The apply matching circuit macro used to insert a matching circuit into an unmatched feed as a post-processing step and update the results to reflect a matched antenna.
Users designing an antenna's matching circuit can pass S-parameters and efficiency results to a circuit solver, such as Optenni Lab or ADS, where a matching circuit is synthesized. After the matching circuit is exported to an *.s2p file and then imported into XF, this script places the matching circuit between the voltage source and antenna and recomputes results.
Standalone Radiation Efficiency
XF's system sensor reports the standalone radiation efficiency in cases where there are inactive waveguides or circuit components. This is similar to radiation efficiency, but it does not include the losses from inactive components or waveguides. This is primarily used to directly feed the system's antenna ports and export the efficiencies and S-parameters to an external tool, making it particularly useful to ADS users who export XF's S-parameter matrix.
Cloud Computing with Rescale
This release introduces the rescaleqs.py multithreaded daemon script, which configures and submits XF simulations for remote execution via the Rescale high performance cloud computing platform. It also downloads simulation results and places them back in the appropriate location on the local filesystem upon completion, allowing XF users to submit simulations to Rescale and view the results without manually setting up both the jobs and compute clusters, or monitoring simulations for completion and then retrieving their output.
XF's slice modeling operation cuts one part into two parts. It is similar to a boolean chop, except that it utilizes a single cutting plane. This operation can be used to separate an undesired portion of a part for deletion, such as the feeding structure of an antenna needing to be redesigned.
Users can also slice multiple parts simultaneously.
Photoconductive Semiconductor Switch
The photoconductive semiconductor switch (PCSS) circuit component definition simulates a semiconductor device that conducts electricity when illuminated. PCSS components should be used when only time-domain results are of interest.
Users can password protect both material and circuit component definitions in order to secure an object's associated information. The encrypted information can be viewed and edited by reentering the password.
This protective measure ensures that the intellectual property associated with the object is accessible only to authorized users, while still allowing the object to be shared in projects and included in simulations.
The surface roughness of a copper trace affects its conductivity by creating resistance and causing power loss as the current moves along the trace toward the antenna. Higher frequencies increase the current's deviation from an ideal, perfectly smooth surface and result in decreased efficiency.
Users can control this deviation by adjusting the surface roughness in the material editor, allowing them to assess the conductivity loss captured in the output and its effect on efficiency.
Optenni Lab Integration
Support for Optenni Lab 4.2 has been added, so users can export to Optenni Lab through the right-click menu of XF's results browser when a 3-D far zone radiation pattern is selected. Based on the far zone selection, XF determines the full S-parameter matrix, efficiencies, available powers, and other data to send to Optenni Lab.
This release includes three main updates to XF's graphing capabilities:
- Users can copy a plot and paste it into a different graph.
- The create region highlight tool allows users to shade both vertical and horizontal sections, as well as regions bound in both directions.
- Users can select a plot, giving it a bold appearance both in the graph and the legend.
There are over 40 usability, performance, scripting, and other updates in this version.
Here is a select list of modifications:
- Added the complex correlation and envelope correlation result types, which are computed on S-parameter simulations when a far zone sensor covering the full sphere is present.
- Tx and Rx goals can be defined separately in the circuit element optimizer (CEO), even if the response matrix was generated with Tx and Rx defined as one band.
- Changed the default time unit from millisecond to nanosecond.
- Imported tissue data for a tissue voxel mesh has been updated to IT'IS database version 3.1, which supports higher frequencies. The original database can be downloaded from from IT'IS.
- The NVIDIA GV100 graphics processing unit (GPU) is supported.
- Full control over frequency range and sampling density is available when exporting S-parameters to Touchstone format.
- An Ubuntu 18-specific build is included in the Linux installer.
- The Open MPI distributions included with RHEL6/CentOS6, RHEL7/CentOS7 and Ubuntu 18 are supported. To use the system Open MPI on CentOS6, issue the command module load openmpi-x86 64 before running XFsolver. On CentOS7, issue the command module load mpi, then use the -openmpi command line flag to XFsolver.
- External Queue Integration (EQI) is automatically enabled for all users. EQI supports multiple queue selections, such as a local cluster and a remote cluster, by having different daemons watch the eqi-control folder and its subfolders. EQI allows users to submit to one of several queues when creating a simulation by using the same workflow as with local queuing.
- The create line graph menu is accessible when either multiple solid sensor or far zone sensor results are selected, provided that all result dimensions match for the selected results.
- Improved the appearance of the geometry view's bounding boxes.
- Added the xfsolver command line option --xstream-disable-peer-memory-access. This command line option is for cases involving multi-GPU simulations that are slower than be expected, and should only be retained if tests show that its presence improves performance.
- Added the ability to remove unused parameters and definitions. This replaces the remove unused materials capability of previous versions.
- [Scripting API] Added App.showGraph()
- Resolved an issue causing the solver to not support two different user-defined waveforms in the same simulation.
- Resolved an issue causing some required files for computing SAR not to be written during simulation creation.
- Resolved an issue causing the slow application of faceting options while the mesh was being viewed.
- Resolved an issue causing a Part to be meshed incorrectly when applying a high level of custom faceting.
- Improved nodal waveguide mode selection for coplanar waveguides.
- Corrected a units typo from kilwatt hours to kilowatt hours.
- Resolved an issue causing the application to quit unexpectedly when editing a parameter while performing a translation operation.
- Resolved an issue causing external excitations not to grey out in the project tree when set to invisible.
- Resolved an issue causing netlist component names that contained slashes to not be handled properly.
- Resolved an issue causing auto-repeat sequence not to repeat.
- Fixed an issue causing the application to quit unexpectedly when rapidly changing a mesh slice while viewing the mesh.
- Resolved multiple issues causing the application to quit unexpectedly when performing a wrap operation.