Reflection/transmission not defined due to possible grating lobes

jinye tong
jinye tong Altair Community Member
edited May 2022 in Community Q&A

"Reflection/transmission not defined due to possible grating lobes "

Above is the warning of the simulation. I want to simulate a frequency selective surface (FSS) made of metal, here I use the PEC, and I search for the reason, I find the setting of nearfield may help a little, but I don't know the exact size of the nearfield settings. Maybe the one forth of the lambda at fmin is the right answer? I am not sure.

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Answers

  • Mel
    Mel Altair Community Member
    edited May 2022

    The warning is due to the unit cell electrical size at the frequency being simulated. 

    The unit cell should be smaller or equal to 1 lambda. Else, grating lobes will occur (spatial aliasing effect). 

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