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mel

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  1. The following two videos about meshing and mesh fixing in CADFEKO would also help, here and here.
  2. The *.out file will show something as follows: Intersection found between Triangle 316 and Triangle 442562 Triangle x y z 316 1.4928E-03 3.2447E+00 -1.2687E-01 1.3875E-03 3.2445E+00 -1.2686E-01 2.5084E-04 3.2444E+00 -1.2685E-01 442562 5.8163E-04 3.2436E+00 -1.2686E-01 2.5084E-04 3.2444E+00 -1.2685E-01 3.2470E-03 3.2449E+00 -1.2687E-01 Intersecting elements found. Review the mesh connectivity in CADFEKO and correct the CAD model or merge coincident vertices for mesh models. Incorrectly detected intersections might also be caused by model extents that are set too large or by the maximum identical distance that is set incorrectly for the mesh. ERROR 40619: Intersecting elements found In POSTFEKO view the elements as follows:
  3. This usually happens if there are more than 1 part in the model and you did not Union all the parts that have ohmic connections. Or it could happen when you import a mesh and the mesh connectivity is poor. Open the OUT file in POSTFEKO. It will show the element numbers causing the error. On the Mesh tab you can find the elements in the 3D view. Then you will have to fix the mesh in those areas in CADFEKO, or in the external application if you imported the mesh from elsewhere.
  4. You need to add a near field request in CADFEKO and solve the model again. It should be fast since by default Feko stores the solution (.str file). Then in POSTFEKO add e.g an empty Cartesian graph and add the near field from the Time Analysis tab to the graph. Of course the above assumes that you have set in CADFEKO sufficient bandwidth and frequency samples to be able to represent your input signal in the time domain.
  5. The coating is what you are looking for. (Cable modeling is not suitable for antenna modeling as a return path for the current is required)
  6. The pdfs are in help\feko\pdf in your Feko installation folder. See "Command Line Arguments for Launching CADFEKO" and similarly "... POSTFEKO" in the Altair_Feko_User_Guide.pdf. The --run-script option is probably what you are looking for. You could write a simple .bat script for the Feko terminal where you first launch your CADFEKO script and when that is finished the POSTFEKO script. And that can easily be placed in a loop.
  7. mel

    Limits of FEKO SE

    This is not relevant to the original post/topic. Kindly post a new thread.
  8. As you are using two different formulations, SEP vs FEM, these would require different sizes for their meshing. Mesh convergence checks are recommended. As the manual states, you should re-run the model with 50% more mesh elements and see if there are significant changes in the results. Nevertheless, it is not uncommon to have a small difference remain in results between solvers.
  9. The port construction is correct. I would make the air box height slightly thicker and set the mesh growth factor one blip to the right (advanced tab of mesh). You want to have a pretty much uniform mesh on the air boundary for saving of resources. You could set on those outer surfaces a local mesh size of lam0/10 (where lam0 is for the highest frequency). Attached my modifications. I did not get a RUNFEKO error. If it happens again, save the standard screen output and last two out files generated and attach here. Array_FEM_v2_alt.cfx
  10. Create a cuboid of size slightly larger than the substrate cuboid in your model. The degree of extra size required is explained in the video. Create a dielectric with default parameters and label it "air" Set the region of the new cuboid to this "air" dielectric and the solution method of the region to FEM. Set the solution method on the region of the Antenna array part also to FEM. Remove the wire ports and their voltage sources. Create FEM line ports on the wire feeds of the 4 patches. Add current sources to the line ports. Union the air cuboid with the Antenna Array. Try the above steps and if there is still a problem, upload the modified model you have tried. Note:When using continuous frequency sampling, it is recommended to interpolate as little output requests data as possible. Quite likely the 3D Far field interpolation is causing several extra frequency samples. You could add a second StandardConfiguration in CADFEKO where you only calculate the 3D far fields at a few discrete frequencies. With a uniform excitation, if you position the array in the center of the origin on the X-axis, then with magnetic symmetry you will save substantial runtime and memory.
  11. You could try script recording. Record the setup of a few spherical mode sources. Modify the script, e.g. put in a FOR loop, maybe read the phases from file, or use an equation for the phases. Then playback the script. It may be that 10000 spherical mode sources could slow down CADFEKO. The alternative is to create just one spherical mode source in CADFEKO and then modify the .pre file in EDITFEKO where you use a FOR loop around the AS card (line of ASCII text starting with AS).
  12. There are no correction terms used. Fields are calculated exactly from the Green Function. You could see the following paper:
  13. There is no quick way I'm afraid in Feko. You would have to implement the equations for mean, standard deviation, and process the data in a Lua automation script. Else, you could export the data and do the statistical analysis and graph generation with Altair Hypergraph. If you mean you don't have access to Matlab anymore, you could try Altair Compose, which functions on a very similar level as Matlab. https://www.altair.com/mbd2019/compose/
  14. You can use script recording and playback to record the setup of a basic model in CADFEKO. Then modify the script to use a random function e.g. print(math.random()) in positioning and size of the objects. The choice of object can also be made with the random function and using an IF statement for example, provided you have written a separate script that you can call to create each pre-decided object with the random numbers. In POSTFEKO you can write an automation script to export the data. Look in the help folder of Feko for Altair_Feko_Scripting_API_Reference_Guide.pdf and there search for "DatasSet" and "ExportDataSet". Also see the Example Guide I.1 "Introduction to Application Automation".
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