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Avoid piecewise linear gaps after polygon pour

ilia.vitsnudel
Contributor

Avoid piecewise linear gaps after polygon pour

ilia.vitsnudel
Contributor
Contributor

Hello,

 

I am routing smooth curved traces that automatically generates gaps in the polygon poured ground. The problem is that the gaps looks like piecewise linear approximations on the gap borders instead of rounded outlines that will follow pads and traces. Please see in the attached image. I need rounded outlines because my design involves 6Ghz RF Grounded Coplanar Waveguides which calls for an accurate layout. What would be the solution to this behivor?

 

@jorge_garcia 

Jorge please also look at the 

https://forums.autodesk.com/t5/fusion-electronics/closing-small-gaps-in-poured-ground-layer/m-p/1324...

"Closing small gaps in poured ground layer" which might also help to resolve this issue.

 

Thank you,

Ilia Vitsnudel

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jorge_garcia
Autodesk
Autodesk

Hello @ilia.vitsnudel,

 

I hope you're doing well. This is an outstanding issue, there's no way to avoid the piecewise linear approximation. I have made an open ticket for this. In the manufacturing process, these approximations often get smoothed out but the only way to know if it would work for your application is to make a test board. 

 

I'll add your comments to the ticket.

 

Let me know if there's anything else I can do for you.

 

Best Regards,



Jorge Garcia
​Product Support Specialist for Fusion 360 and EAGLE

Kudos are much appreciated if the information I have shared is helpful to you and/or others.

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ilia.vitsnudel
Contributor
Contributor

I see, as I mentioned in the other post the working frequency is 6Ghz and it is important to have a controllable gaps for the Grounded Coplanar Waveguide. My simulations show that I have about -8dB degradation only because of the polygonal approximation around through hole pads that serve as feed point to patch antennas.

Can you think of any trick to resolve this issue? I have hoped using small polygon pours would solve it, but they just do not work as I experienced it.

 

I love the integrated environment of Fusion and being able to make an incorporated electronic design, but it seems very challenging to get around the issues in the current version of the software. Iam trying my best to work with Fusion electronics, but I am really very close to give up.

 

Thank you,

Ilia

 

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jorge_garcia
Autodesk
Autodesk

Hello @ilia.vitsnudel,

 

8dB of loss is definitely not acceptable, thank you for sharing that result with me. It gives me more info to take to the developers and product managers.

The best you could do is draw ground traces side by side to the main signal trace that have the correct curve, when the polygon fills it will consume those extra ground traces and the curve will be smooth. See the images

jorge_garcia_0-1736453733888.png

jorge_garcia_1-1736453758769.png

 

This might be enough to get your design completed.

 

Let me know if you continue to run into problems.

 

Best Regards,



Jorge Garcia
​Product Support Specialist for Fusion 360 and EAGLE

Kudos are much appreciated if the information I have shared is helpful to you and/or others.

Did this resolve your issue? Please accept it "As a Solution" so others may benefit from it.
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ilia.vitsnudel
Contributor
Contributor

Thank you, Jorge.

It might help. So, I will need first to finish all the traces together with accompanying ground traces and only then pour the ground polygon. How do I keep the accompanying ground trace at precise distance from the main trace?

And do we have an option to place a trace as a spline curve through the knots? I think this option would greatly help to have smooth and very well defined traces.

 

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jorge_garcia
Autodesk
Autodesk

Hello @ilia.vitsnudel,

 

I hope this message finds you well. You would have to calculate the vertices of the various curves. The last bend style of the line command gives you a spline, I find these tricky to freehand but you can feel free to try it out.

 

Let me know if there's anything else I can do for you.

 

Best Regards,



Jorge Garcia
​Product Support Specialist for Fusion 360 and EAGLE

Kudos are much appreciated if the information I have shared is helpful to you and/or others.

Did this resolve your issue? Please accept it "As a Solution" so others may benefit from it.
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