Antennas and DRC issues

Some time ago I had a question about antenna footprints, where 2 alternatives were given on how to use the antenna footprint. @maui was kind enought to provide with a variant where instead of using a polygon copper pour, a custom pad shape was used instead.

I recently ported my design to Kicad 6 and I don’t know how to handle the DRC errors.
If I use the footprint from the builtin libraries: RF_Antenna:Texas_SWRA117D_2.4GHz_Right
The errors shown are:

However If I used the generated by @maui the DRC complains about this:

One might think, go with the later, less errors. It also makes the antenna “naked” which with ENIG finishing looks sick :open_mouth: However I want to make sure that I handle it correctly and I don’t whitelist a violation that can bite me in the ass somewhere else.

For both cases unless I set the routing options to “Allow DRC violations” I can’t route the AE2-Pad1 net as both pads are “shorted”. And eventually from session to session the NET would change to GND or show an “unconnected” error or whatnot.

How can I handle this ?

You are shorting two nets together without using a Net-Tie, KiCAD is letting you know that you have an error.

I understand the error, I am asking whats the way of solving the particular case where in a antenna footpring both pads are meant to be shorted. So, how can I make the net-tie to avoid the error?

There is an open issue about this in gitlab.

…and if you create a footprint with this shape? I don’t think it throws this error, you can also customize it as you want

Net ties are part of the standard library in KiCad (as a schematic symbol and a footprint), they are KiCad’s hackish way of joining two nets together. If the ones from the library do not suit your needs, you can of course create a net-tie that fits as it should.


as described in Need a way to avoid DRC violations for footprints with copper polygons (#6860) · Issues · KiCad / KiCad Source Code / kicad · GitLab
adding the keywords “net tie” in the antenna footprint fixed the issue. Thanks for your help !

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I was looking for a FAQ about net ties, unfortunately I could not find one, so the information is a bit dispersed in the forum.

The net-ties from the library are two pads connected using a graphic line drawn in the copper layer, what makes them special is the use of the word “net tie” in the keywords (therefore I refer to them as ‘hackish’), this renders them ‘invisible’ to the DRC. net ties as “first class” components are planned for v7.

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