CST 2012: Spiral antenna design

[vladouch]

Hello all,
I have one problem with designing log-spriral antenna. I used CST MWS 2012. I created analytical curve with these parameter:

' body

Sub Main ()

'@ define curve analytical: curve1:rameno

With AnalyticalCurve
     .Reset 
     .Name "rameno" 
     .Curve "curve1" 
     .LawX "0.5*diameter_inner*Exp(Ln(diameter_outer/diameter_inner)*t/(2*pi*num_turns))*Cos(t)" 
     .LawY "0.5*diameter_inner*Exp(Ln(diameter_outer/diameter_inner)*t/(2*pi*num_turns))*Sin(t)" 
     .LawZ "0" 
     .ParameterRange "0", "2*pi*num_turns" 
     .Create
End With

End Sub

But I have problem with number of points (we can see in the apendix). I need to increase the number of points the analytical curve and create a smoother curve. Of course, I wrote a matlab coda for sprial antenna generating, but I would use the analytical curve in CST.

Do you have some idea? How to increase the number of points?

Thank you for answer
Vladouch

 

[juicedry]

When I did my Terahertz spiral antenna design in ADS, I created all the points in a Excel spreadsheet, then I imported those points as the X-Y coordinates to draw a custom line. I am sure you can do the same in CST.

I did a logarithmic Spiral using this equation

See attached Excel spreadsheet.



It was about 10 years ago.