Block EMI/RFI with: Shields and Filters

摘要

Noise can start from inside or outside an RF/microwave circuit or system, but it's controllable when adding filters and shields that target electromagnetic interference (EMI) and radio-frequency interference (RFI). Both types of components provide reasonable noise suppression and, with proper planning, add little to the size and cost to a design. But why use one noise-suppressing component rather than another—what's the difference? Some suppliers offer EMI/RFI filters as well as shielding materials and may even recommend using both at the same time. So, when does one noise blocker make more sense than the other?