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Torben Voigt

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Posts posted by Torben Voigt


  1. Hi @lostarmour,

     

    You should make all regions PEC and then use "Simplify". This deletes 24 (small) redundant faces:

    image.thumb.png.24f1e2de68d80b4ae68fdfa60e8b45b2.pngimg_057.png.2def504f26ca9a92784beec7d487a190.png

     

     

     

     

     

     

     

     

     

    Then I found out that these areas are the tricky parts:


    img_060.png.2131db4714bb816544205faf955b2df6.png        img_061.png.8565b0dd9cefc5940aedc83714896ef8.pngimg_059.png.43d6aa2e41dc730f008af4811ae9881b.png

    I closed these two and now it works 9,072 triangles (compared to 51,554 in the original model): 08262019_Feko_two_blades_alt.cfx

     

    It solves in a couple of minutes. Please make sure to refine the mesh slightly and compare the results. This is just an example.


  2. Hi @Marcus Chang,

     

    20 lambda is just a rough estimation for RL-GO, it always depends on the model.

    Your model seems ideal for PO or LE-PO (only one interaction on the reflector). The solution should be quite accurate. RL-GO would work but it will require much more time because the near field source will be transformed into a spherical modes source first (and same for the Rx antenna). 

    Just apply PO (full ray tracing) to the reflector face and you should be good. Also compare with LE-PO (full ray tracing).


  3. Hi @Haj Hassan,

     

    interpreting the far field in a lossy halfspace unfortnately isn't easy. When using the Reflection Coefficient Approximation for example, FEKO deactivates the computation of far fields below z=0 completely. In principle the far field in FEKO is computed in an infinite distance by neglecting the term exp(-j*beta*r)/r. bet however is different for the two media..

     

    I would suggest to rather calculate near field values in a certain distance if you're really interested in the field below ground.


  4. Hi @Kuzi,

     

    this doesn't seem to be the correct model. In your pics I see an antenna structure and also a polar plot of far field results. In the attached model only a plane wave excitation is present and the far field request is set to "Calculate fields in plane wave incident direction". Could you please check?


  5. Hi @Lydia He, these are just comments (not warnings). They say that you can increase the speed of your simulations by activating parallel computation and also that the former *.str file has been re-written. FEKO stores the currents in *.str files so that they can be re-used in later simulations of the same model, if e.g. different requests are made.

    image.png.c24502627dbf028f2eb3ef25c07179b6.png


  6. Hi @Marcus Chang,

     

    the code temp.lua seems to work. It successfully adds 3 NearFieldData in CADFEKO:

    image.thumb.png.cf66ed0fb86a48afa0ac85c9ad8b63d7.png

    What's still missing is the "Start reading from line" which is 1 in all cases. You should change line 15

     

       properties.ReadFromLine = "1"    to    properties.ReadFromLine = "1+(20*20)*"..(i-1)

     

    20 is the number of field points in x and y, so this will ensure that the starting number will be like 1, 401, 801.

     

    Hope this helps!

     


  7. Hi @Marcus Chang,

     

    It's not necessary to use EDITFEKO for this anymore. In principle you need one configuration per frequency. Also you need one Field data per configuration. Please have a look at the attached CADFEKO script.

    • It imports field data and makes sure that the "start reading from line" is correct
    • It creates near field sources
    • it sets the right frequency
    • ...

    It was all created using Macro recording and a little editing. You can use it and fit it to your model.

     

    Open base_model.cfx and run the script from there, it should give you some insight in the process.

     

     

    base_model.cfx MacroRecording_1.lua antenna_only_nf_export.efe antenna_only_nf_export.hfe

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