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mel

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Everything posted by mel

  1. For the AR card you should use the Position and Rotation boxes. But it would be easier with CADFEKO. Use Field data and the Workplane tab to orient/position the antenna.
  2. Any chance you can send the model? Or maybe just even a section of the model that still generates the error should do. If you can't upload here, contact your local support - see "Technical support" in the Feko User Manual.
  3. mel

    GPU & RL-GO

    It will depend on what angular increment or ray front spacing you specify. You should do a run with GPU on and with GPU off.
  4. I would have to check with the developers on this specific error message, limitations, etc. This will probably only be in the 2nd week of January.
  5. This happens when the waveguide is over-moded. For example if a horn antenna is designed for 3 GHz and you solve it for 10 GHz there will be many propagating modes, where, usually, you would want only 1 mode to propagate.
  6. Just plot the loads/networks results on a new Cartesian graph in POSTFEKO. The image below for a monopole with a load on the wire port and a plane wave over 3 frequencies solved.
  7. Two waveguide ports cannot touch. Maybe offset the center one as seen in the attached file. A very small offset in terms of wavelength would likely not change the results much. triaxialcable_Alt2.cfx
  8. mel

    GPU & RL-GO

    Limited scope for GPU support for RL-GO is currently (Feko 2019) as follows: Only for flat PEC and dielectric triangles but also including isotropic and anisotropic thin dielectric sheets, coated PEC, lossy metallics, surface impedance and characterised surfaces. Note also it is only when manual ray launching settings have been set. If the graphics card is a CUDA card there should be no need to install additional drivers, but always ensure you have the latest drivers installed.
  9. The scope tab only operates on surface currents. So you should specify the Faces not the Regions to include in the near field calculation.
  10. You can add the inductance to a port on the wire that connects to the ground. For a port on the cylinder, you can use the edge port. See e.g here below an edge port for a cylinder dipole. (Or you can make a small gap and use a short wire with a wire port.)
  11. >> However, how can we mesh the cylinder into triangles with the edge lengths the same as the spacing between the inner and outer conductor Just apply a local mesh size on the inner cylinder face. >> what about the outer conductor connection to the ground? should i use wire approximation or cylindrical? You can use either. You will be adding stray inductance to ground with either of them. But at low frequencies this inductance will be very small.
  12. Feko uses the thin wire approximation. You will not necessarily get accurate results by just specifying the wire radius. It only modifies the self impedance of the wires and will not necessarily accurately model the coupling to the shield, which is critically based on the physical spacing between the inner and outer conductors. It would be better, although computationally more expensive, to model the center conductor as a cylinder meshed into triangles. You must ensure that the meshed triangle edge lengths are roughly the same as the spacing between the inner and outer conductor. Secondly the radiation from the terminations can become significant if the the electrical length of the termination segments become large (so at high frequencies). This electrical length is not modeled in the MTL terminations. At higher frequencies you can compensate for the inductive effect by adding an equivalent capacitance.
  13. That problem was fixed in a later version of Feko. Please download and install version 2019.
  14. Hi Lostarmour. Could you please attach the .out file as well. Thanks.
  15. Feko does not support anisotropic Green's functions.
  16. If the imaginary part of the impedance is positive then you will get the inductance. E.g. Impedance in Ohm 1.4910E+03 9.1526E+02 1.7495E+03 31.54 Inductance in H 3.1862E-06
  17. This problem was fixed in Feko 2019.2. Please update. Else disable the MLFMM to use FEM/MoM instead of FEM/MLFMM.
  18. You can plot the 1000 discrete samples that were calculated already. They will be correct. In POSTFEKO you can set the graph to plot as follows (Trace, Sampling Settings): The interpolated data could be inaccurate but only in some areas of the frequency range where there may be e.g. some numerical noise - the interpolation could have tried to interpolate that unsuccessfully. If the temporary files of a continuous run have been kept a continuous run can be resumed by setting the start frequency to the last incomplete frequency. Also see the User Manual - search for ADAPTFEKO.
  19. The error is referring to the fact that the MLFMM is only for ELECTRICALLY large models, so models with at least 5 or more wavelengths in a direction. For the model you attached just switch off MLFMM. This will then be a standard MoM solution. P.S. You could do with finer meshing - maybe set a local mesh size on the metallic faces of the patches since they are the critical radiators.
  20. The Planar Multilayer Green's function is used to model your substrates and MLFMM is not supported together with the Green's Function. If you want to use MLFMM, you would have to use a finite substrate instead of infinite.
  21. If you add any voltage or current source the results will be available in POSTFEKO under Source data. It will also be in the OUT file. If not, please provide an example of where this data is not given?
  22. Inserting a capacitor onto a wire loop is very simple. Add a wire port and then add a load. You may need to split the loop and then Union the two parts again (or create multiple sections of loop which are Unioned together) to ensure you a vertex at the exact position where you want to place the port (load).
  23. The Output tab has more information: It seems your cir file does not meet the requirements. Have you worked through the ExampleGuide example "E.3.1 Dipole Matching Using a SPICE Network?"
  24. Yes, see "Automatic Meshing for Regions" in the Altair_Feko_User_Guide.pdf
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