Interpretation of Antenna Scattering Phenomena with the Aid of Characteristic Mode Theory

摘要

This article is a study of electromagnetic (EM) antenna scattering phenomena from the Characteristic Mode (CM) standpoint and aims to shed some light on scattering from antennas. Using CM theory, the modes can be classified to yield two different sets of modes. One set is orthogonal with the localized antenna's source field in the vicinity of the feed point and this set of modes are referred to as the short circuit “Scattered Modes”. The other set includes the modes that can be excited by the antenna's source at the feed point and this set forms the so-called re-radiated fields or “Antenna Modes”. These modes are studied to determine the effect of each set on the overall scattering by an antenna within these scattering/re-radiation environments. This analysis provides additional physical insight as well as a new and different approach that can be used in various antenna applications.