Controlling Radiated EMI Throu...

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