SISL Antennas Based on Characteristic Mode Analysis

The characteristic mode analysis (CMA), since its evolution in the early 1960s, has vigorously gained momentum recently in the antenna community. The characteristic modes (CMs) pioneered by Garbacz made the following observations: (1) The CMs share the orthogonality properties of spherical wave functions. The only difference is the CMs apply to the solution of scattering or radiation from any arbitrary objects, while spherical wave functions relate to the solution of scattering or radiation from a spherically symmetric object. (2) For any perfectly conducting object, the CMs possess a particular set of surface currents and corresponding radiated fields which are characteristic of the object shape but independent of any excitation. The theory of CMs formulations by Garbacz applied in solving scattering problems.