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Torben Voigt

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Everything posted by Torben Voigt

  1. Hi tejaswi, Do you have different versions of FEKO installed? If yes, could it be that you tried to run the Parameter Sweep: Combine Phase in an older version? What happens if you open the attached dipole.cfx and execute the parameter sweep like this? Can you see the results in POSTFEKO?
  2. Hi sem, Primitive objects can be moved/copied like any other geometry part. What happens if you try to copy & translate it?
  3. Hi tejasw, Could you please check if you can open it by double-clicking. When double-clicking a *.fek or a *.bof file POSTFEKO should open. I assume that the simulation of at least this model failed. You would also see error messgages in the related out file in that case. The Parameter Sweep: Combine Phase tool can only work with models that succesfully finished.
  4. Hi tejaswi, The 'parameter sweep:combine phase' script tries to load models (*.bof and *.fek files) into the session, which are specified in the *.xml file. The error message says that coupling_lua_new_freq_01.bof' can't be opened. Could you please check if this file exists and if you can open it by double-clicking. By default the parameter script stores the models and additional files in a subfolder called parameter_sweep. Look there first.
  5. Hi Husam, The description pretty much says it all. More illustrative may be this video: move_articulated_human_SEP.mp4
  6. Hi sem, I would just add circular ellipses to the patches (!!! use snapping with ctrl + shift !!!) and then change face properties. The attached video shows how to do: rounding_patches.mp4
  7. Hi sem, I'm not sure why you expect the ff_VN far field to be symmetric? The model is not symmetric to the VN plane, and as Johan Huysman already mentioned, the (strong) currents in the feed lines contribute to the far field radiation: You may specify which faces contribute to a far field by using Scope in the far field diaogue. Here, only the patches are taken into acount: Now the patterns are almost symmetric. Of course still the position of the feedlines disturbs.
  8. Hi sem, A symmtry plane has already been applied in the attached model. In your model these two faces were not symmetric: "Simplify" deleted the edges and symmetry could be applied.
  9. Hi sem, For 100% symmetric results, the mesh needs to be symmetric. Keep in mind that not the geometry but the mesh is solved (currents on edges between adjacent triangles). Plus, when applying symmetry planes in CADFEKO you will drastically decrease runtime/memory. In your model a magnetic symmetry plane can be applied (after simplifying), see 4.3 GHz Dual Patch Antenna_sym.cfx.
  10. Hi tejaswi, The pics/graphs in your pdf do all come from a StandardConfiguration. Figure 1: 3D view - FarField - Gain [dB] Figure 2: VoltageSource - Reflection- dB Figure 3: VoltageSource - VSWR - dB If I understand correctly you want Reflection coeficient and VSWR for both antennas while one is active and one is passive. For this you would create two StandardConfigurations. One with port 1 excited and port 2 loaded and one vice versa.
  11. Hi tejaswi, Could you attach an example model, please?
  12. Hi tejaswi, Maybe a SParameterConfiguration in CADFEKO is what you're looking for? It'll take care of exciting ports while terminating others. Multiple different configurations can be set in one model, e.g. SParameterConfiguration for S11 ... S22 and a StandardConfiguration for the radiated far field of two active antennas. Note, you can set Frequency, sources, loads and power to be per configuration instead of global. This allows you to e.g. calculate the s-parameters for a wide frequency range while calculating the far field only for single frequencies. UserExample B.1 Antenna Coupling on an Electrically Large Object may get you going.
  13. Hi FieldForcer, There are only two faulty faces in your model. I copied them and deleted them from the original part. After unioning the faces and the origibnal part again the part is fault-free. The model can be downloaded here: https://securefiletransfer.altair.de/link/ZHfgEDvz7uVl9n1IK83Fm8 PS: In the file you uploaded a 3.2 GByte (!) out file was included, which obviously does not belong to the model.
  14. Hi FieldForcer, The file size of 650 MB indicates a very complex structure. I will have a look and see if I can recommend something. In general, for extremely complex structures an external mesher may be better than the internal FEKO mesher. External meshing tools like HyperMesh offer a lot of powerful tolls for simplifying/de-featuring geometry.
  15. Hi pmcardle, What does the warning/error say?
  16. Hi FieldForcer, Why not reduce the signal duration itself? One could just use miltiples of 2*Pi for the duration:
  17. Hello Professor Hussain Al-Rizzo, I was only concentrating on the creation of the infinite structure like shown in Hi_imp_sievenpiper.pdf Regarding the option of dispersion diagrams of infinite (Periodic Boundary Condition) structures in FEKO, there is a feature request under discussion. This feature request was originally started from an email from you to FEKO Support in November 2012 I will in any case keep you updated if there are good news for you.
  18. Hi FieldForcer, The direction of the currents in 3D views can be visualized by activating currents. A magnitude as such is always positive.
  19. Hi FieldForcer, WARNING 594: Due to rounding errors the solution may be totally invalid typically indicates that the model is small compared to the wavelength at the lower end of the frequency range. Using double precision may help.
  20. Attached an example Sievenpiper.cfx, based on the paper. I did not take into account the dimensions/distances in the paper, but you can can change these easily by changing variables ra, h (distance to ground) and distance (spacing between the hexagons). Sievenpiper.cfx
  21. Hi Professor Hussain Al-Rizzo, I will try to set up a FEKO model for you.
  22. Hi FieldForcer, Looks like the radiating element's gain is oriented in the -y direction. From the picture it's hard to figure out. Could you attach the model?
  23. Hi bouvy, I thhink that the Directivity in that case should not be available in POSTFEKO at all, but on the other hand WARNING 3976: Directivity cannot be computed for far field calculations involving real ground with losses, gain will be computed instead makes it quite clear.
  24. Hi bouvy, Coming back to your original assumption that the Directivity should be ~3 dB larger than for an isotropic radiator. Could you please clarify why you expect this? And please remember: Directivity will not be calculated when using infinite dielectric ground. Only Gain will be calculated. Apart from the results, FEKO 7 is quite outdated. If possible you should install the current version of FEKO (2018.1).
  25. Hi bouvy, Sorry, it seems I forgot to attach the models. It's a reduced test model, antenna only. I asume the more faces break the > lambda/10 rule for the RCA ground, the less acurate the results get. Comparing to Sommerfeld ground, the test model is quite close. Model is attached. test_model_reduced_BO.cfx
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