Theory of Characteristic Mode and its Application in Antenna Design

Over the past decade, characteristic mode (CM) research has grown from a niche topic to a mainstream topic. CMs provide a versatile tool to analyze the inherent resonant properties of an arbitrarily shaped radiating structure, without considering the excitation source. In this talk, we start with a simple description of characteristic modes, where basic properties are discussed. We also talk about the applications of classical CMs and N-port CMs in various kinds of radiation and scattering problems. CM-based methods are illustrated, for achieving the targets of multi-band antennas, MIMO antennas, circular polarization, pattern synthesis, filter antennas and etc. Lossy scenarios are also taken into consideration during antenna design, to increase the radiation efficiencies of the antennas. In the end, we examine the trends in this field, followed by providing possible contributions to be made, such as CMs on periodic structures, large structures and etc.