Export antenna design to a CAD file

Hi,

I am trying to design an antenna using Antenna Designer app and would like to export the antenna I have designed in a format which can be imported into other software such as CST, sim4life etc?

Conversion to stil file does not seem to be very optimum. Is there a way to export it as a CAD model?

Thanks

Answer 1

[Harsh]

Hi Vignesh,

I understand that you are looking for a method to export the antenna design as a CAD model.

You can use stlwrite function to write the antenna design as an STL file. Please feel free to refer to the link below, as it also presents an example for the same.

https://in.mathworks.com/help/antenna/ref/stlwrite.html

Currently, MATLAB does not support exporting the design as any other CAD model.

[Vignesh Radhakrishnan]

Hello Harsh,

Thanks for the reply. I did try stlwrite but was not able to add a substrate to the generated file even using a different software.

For example, when converting a vivaldiAntipodal antenna to stl, there does not seem to be a distrinction between the top part and bottom part of the antenna and I was not able to project it onto a substrate.

Any suggestions on how to proceed with this?

[Harsh]

Hi Vignesh,

Can you share code, such that I can reproduce this vivaldiAntipodal antenna issue at my end?

[Vignesh Radhakrishnan]

Hi Harsh,

PFA the code. I have not included stlwrite command.

Thanks,

Vignesh

[Harsh]

Thanks Vignesh for sharing the code. The following are the two snapshots of the generated output, showing different z-axis location. The result looks good to me because we can see here that two arms are not at the same Z level. One is at z = 0 and other one is higher. Thus, top and bottom part are distinct. Please let me know if there is discrepancy in my understanding of the issue.

[Vignesh Radhakrishnan]

Hello Harsh,

Sorry. The stl file also had distinct arms. I think the software I imported in was not able to project is onto any substrate since it would need to fit it between the two arms.

Just to check, is there a way to separate the arms and write them onto two stl files?

[Harsh]

Hi Vighnesh,

I was working to resolve your query about separating the arms of antenna. I have been able to get the following workaround to resolve the antenna arms separately. Kindly include the following code at the bottom of your code ("m"-file).

pcb = pcbStack(antennaObject);
figure,show(pcb.Layers{1})
figure,show(pcb.Layers{3})

It uses the "Layers" property to separate out the top and bottom layer. Further, the separated layers can be written in two different STL files.

[Vignesh Radhakrishnan]

Hi Harsh,

Thanks. That works but unfortunately I get an error stating that a triangulation object is needed for stlwrite when I use the pcbstack layers.

Thanks

[Harsh]

Hi Vighnesh,

I understand the triangulation object error you were facing. I have been able to get the following workaround to resolve the antenna arms separately, such that they can also be written as STL file. Please try the following code.

% Create a vivaldiAntipodal antenna
% Generated by MATLAB(R) 9.13 and Antenna Toolbox 5.3.
% Generated on: 22-Dec-2022 19:28:27

%% Antenna Properties 

antennaObject = design(vivaldiAntipodal, 1500*1e6);
antennaObject.BoardLength = 0.145;
antennaObject.BoardWidth = 0.05;
antennaObject.Height = 0.00158;
antennaObject.StripLineWidth = 0.00025;
antennaObject.OuterTaperLength = 0.135; 
antennaObject.InnerTaperLength = 0.139;
antennaObject.ApertureWidth = 0.015;
antennaObject.GroundPlaneWidth = 0.049;
antennaObject.Substrate.Name = 'Taconic RF-35';
antennaObject.Substrate.EpsilonR = 10;
antennaObject.Substrate.LossTangent = 0.0035;
antennaObject.Substrate.Thickness = 0.00158;

pcb = pcbStack(antennaObject);
top = pcb.Layers{1};
bottom = pcb.Layers{3};

figure,mesh(top,'MaxEdgeLength',2e-3)
[p,t] = exportMesh(top);
tr = triangulation(t(:,1:3),p);
figure,triplot(tr)
stlwrite(tr,'top.stl');

figure,mesh(bottom,'MaxEdgeLength',2e-3)
[p,t] = exportMesh(bottom);
tr = triangulation(t(:,1:3),p);
figure,triplot(tr)
stlwrite(tr,'bottom.stl');