I'm making a metal container for to enclose all my components including raspberry pi 3 -B, motor controllers and batteries. I wanted to know if on board wifi module requires clearance or distance from metals in order to avoid shielding. I have mounted my raspberry pi on a acrylic sheet using brass screw pillars. One of these pillars is very close to the wifi antenna. Does it have any effect on wifi signal strength?
The wavelength is ~125mm so anything within this distance will affect the radiation pattern, but if you are going to put the whole thing in a Faraday cage this is irrelevant, as you will prevent all radiation (depending on the quality of the shielding).