I have designed a few PCBs for one of my projects. The PCB is picking up FM radio signals. I can see this as spikes in the spectrum where each radio station is broadcasting.
I tried covering the PCB with a grounded aluminum foil (many layers) to act as a Faraday cage. Although it reduced the signal's amplitude a little, the suppression is minimal.
The PCBs have highly sensitive sections where this amount of noise cannot be tolerated. The PCB has its ground connected to the copper pour.
Can anyone suggest ideas on how to get rid of this noise?
I am attaching an image of the noise spectrum.
A schematic of the PCB is attached below.
We are seeing RF interference on every conductive material, not necessarily on the PCB. Hence, any general techniques typically used in such situations would be useful. I have included a ruler to enable scale measurements.