Side Lobe Level (SLL) goal

Haj Hassan
Haj Hassan Altair Community Member
edited October 2020 in Community Q&A

Hello,

How to define in FEKO  the Side Lobe Level (SLL) goal?

Thanks in Advance.

 

Best Regards

Haj Hassan

 

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Answers

  • Johan_Huysamen
    Johan_Huysamen
    Altair Employee
    edited June 2020

    Dear @Haj Hassan

     

    I don't think it is currently possible to define SLL directly as an optimization goal in Feko, but it should be possible to define an indirect goal to achieve this.

     

    <?xml version="1.0" encoding="UTF-8"?>Dipole_array_gain.png

    If you consider the gain of a 5-dipole linear array as in the graph above, you will see that the side lobe is defined as the maximum gain value outside the main beam. If we then minimize this value, we should reduce the SLL.

    We can achieve this by requesting a far field cut outside the main beam. In the example above this would be for Theta from 25 to 90 degrees. Let us call this far field request 'Sidelobes':

     

    Sidelobes_farFieldRequest.png

     

    We can then define a goal as follows:

     

    Goal1.png


    This goal would then aim to reduce the highest peak outside the main lobe - which would reduce the SLL.

     

    It is important to note that the above goal does not consider the main beam gain value. If your optimization parameters might also affect your main beam gain, you would have to also include a goal to maximize your main beam gain or to optimize it to be equal to a required value. You might also have to play around with the 'Weight' values of these two goals to achieve the best results.
     

  • Haj Hassan
    Haj Hassan Altair Community Member
    edited June 2020

    Thank you very much.

    This is very helpful.

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