电磁干扰和无线电干扰PCB设计EMI/RFI Board Design EMI/RFI Board Design National Semiconductor Application Note 643 Joe Cocovich April 2001 INTRODUCTION The control and minimization of Electro-Magnetic Interference (EMI) is a technology that is, out of necessity, growing rapidly. EMI will be defined shortly but, for now, you might be more familiar with the terms Radio Noise, Electrical Noise, or Radio Frequency Interference (RFI). The technology’s explorations include a wide frequency spectrum, from dc to 40 GHz. It also deals with susceptibility to EMI as well as the emissions of EMI by equipment or components. Emission corresponds to that potential EMI which comes out of a piece of equipment or component. Susceptibility, on the other hand, is that which couples from the outside to the inside. In HPC designs to dat……