Controlling Radiated EMI Through PCB Stack Controlling Radiated EMI Through PCB Stack-up (09/08/00, 12:33 p.m. ET) By Rick Hartley, L-3 Communications, Avionic Systems There's more than one way to skin a cat and even more ways to battle EMI, beginning at one of the most basic levels of PCB design. Clearly there are a number of circuit and PCB design techniques that designers and engineers need to master in order to control high-frequency, radiated EMI. It's fairly well understood that circuit board stack-up can play a major role in the effort to control EMI. A good stack-up helps to contain electric and magnetic fields and is a very strong aid in the effort to bypass/decouple the power bus. This article will examine these issues and detail several board stack-ups designed to accomplish these goals. The power bus When an IC ……