10 Commandments of Electromagnetic Compatibility
- Create control plan and tabulate all known frequencies and wave shapes to predict EMI profile.
- Filter Power Lines at immediate entry point.
- Filter all I/O lines and signal lines with selected tailored pass band response filters.
- Design all modules to have an aluminum stiffener backplane under P.C board that bonds to printed circuit commons.
- Use multilayer boards with a ground layer wherever possible to contain fast rise time energy.
- Monitor Surface resistively of plating on all metal finishes to maintain less than 3 milliohms per square centimeter R.
- Install ferrite cores / beads over input power lines and signal lines, coax lines etc. to minimize common mode emissions.
- Twist all pairs of wires at 18 turns per foot to minimize magnetic pickup.
- Shield and wiper ground / bond all backplanes and interfaces to modules.
- Close or inter-bond all apertures and gaps longer greater than Lambda (wavelength) / 20.