Near-field and Far-field

Near-field and far-field refer to different zones around a source of waves, like an antenna or speaker. The near-field is the area close to the source, where the wave patterns are complex and can vary significantly; energy tends to stay localized, and field strength decreases rapidly with distance. Beyond this zone is the far-field, where waves spread out more evenly and behave predictably, following simple inverse-square law rules. The transition point between these zones depends on the source’s size. Understanding these zones is essential for optimizing wireless communication, imaging, and radar systems.