Designers of microcontrollers are caught between the conflicting goals of making microcontrollers that are very fast and making microcontrollers that do not have the problem of radiated emissions. They can be filtered, enclosed, shielded, converted to something else – the bottom line is simply this: even modified signals can still, and probably will, cause some type of problem. In other words, the only good radiated emissions are the ones that never get generated in the first place.