I’m designing a circular light with a Particle Photon in the middle. I need to make sure it will fall in within the EMC regulations.
I read already interesting about EMC and Ground loops in this forum which already contain good tips from @hfiennes and others:
From this topics I understand that ground loops are a problem, and that you have to keep the Photon free at one side. However I see several board designs (like BrewPi) that have the Photon in the middle.
The problem is that have a giant ground plane all around the Photon (the design is 40cm/16inch in diameter) with one small keep out area in the middle.
- Does this count as a ground loop or is this only the case with small traces?
- Is the keep out area (a small square field in the middle) good enough to receive WiFi, or is it better to work with an external antenna?
- If I use an external antenna do I need to respect the keep auto area? Or is it only important for the onboard SMD antenna?
- Should I play more with the keep out size. In this topic they needed to make it 2mm wider, however they also seemed to have removed a ground loop.
I need the best design for EMC approval, so if that means that it’s better to use an wire antenna on the uFL connector I prefer that.
I hope you have some tips.