I designed microstrip array antenna at 110GHz at CST MWS with taylor amplitude distribution and I get the wanted taylor amplidute coefficients with help of Matlab software to SLL=-30 dB.
With these coefficients I get at my antenna that the SLL is (-12.5)dB
I want with help of the optimizer function at CST to reduce the SLL to (-17)dB at least.
How to define at CST optimizer Side Lobe Level (SLL) goal?
To minimize the overall S11 min value, you'll need to add a User Defined Goal... In online help you can find this example:
Global minimum:
Code:
Option Explicit Function GoalFunction() As Double Dim s11 As Object Set s11 = Result1D("d1(1)1(1)") 'Minimize S11 GoalFunction = s11.GetY(s11.GetGlobalMinimum()) End Function
which takes the Global Minimum value of S11 and assigns this value to the goalfunction (to be minimized).
The achieved SLL is (-12.5 dB) which a bit higher than that for the uniform array. The Taylor tapering seems as if it is not working. The reason can be you have not considered the mutual coupling effect between the elements. This effect is more pronounced when the element separation is less half a wave wavelength. Elements of larger size lead to stronger effect. Using the optimizer can give you the desired SLL. In such case you may start with uniform distribution.
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