Study on the relationships between eigenmodes, natural modes, and characteristic modes of perfectly electric conducting bodies

Abstract

We specify the corresponding relationships between eigenmodes, natural modes, and characteristic modes of perfectly electric conducting (PEC) bodies. The internal resonant frequencies, external resonant frequencies, current distributions, and radiation patterns of the three kinds of modes are compared to identify the relationships. Firstly, we review the definitions of the three kinds of modes and discuss their characteristics of the electromagnetic power. After that, we illustrate the relationships between these modes with three typical structures, that is, the infinite circular cylinder, sphere, and rectangular plate.