Preamble: . As for any organized EMI control, ESD protection consist in anticipating or correcting the unwanted effects of an hostile electromagnetic ambient. Like many EMI threats, ESD manifests through conducted and radiated phenomena, with the latest being often the dominant mode. But there is a unique aspect to ESD, not found in common radiated EMI episodes where the victim box and cables are illuminated by a uniform field. Instead, ESD generates locally a strong field pulse, typically > 1kV/m near the discharge point, dropping quickly as one move away. Therefore, although ESD hardening should be part of a general EMI control, not handled as a separate constraint, some classical EMC solutions may not be sufficient and should be complemented by additional protections.
Electrostatic Discharge (ESD) . is a very common, yet often overlooked problem that can plague electronic equipments in a mysterious way. ESD is like an invisible, mischievous gremlin that come and go un-noticed, until the related failures or malfunctions become apparent. Yet, ESD by its elusive but superfast characteristics and very high frequency spectrum definitely belong to the EMI family. Once understood, the solutions to it are not very different than those for the more classical interference problems, bearing in mind that we will be dealing with a frequency domain up to the GHz, where some EMI solutions are simply not appropriate.
Background . PIM is an acronym for Passive InterModulation, an interference problem in wireless systems. The problem is not new, but has been known since long time back by designers of, for instance cell phone systems, space probes, connectors, coaxial cables, antennas and filters. The problem most frequently occurs, when dealing with high RF-currents in confined spaces. In this text, the basic theories behind PIM will be briefly discussed.