Coupling of Characteristic Modes on PEC and Lossy Dielectric Structures

The surface integral equation-based theory of characteristic modes (TCM) is presented for structures including perfect electric conductors (PECs) and lossy dielectric bodies. The formulation is a combination of the classical TCM formulation for PEC structures and a recently developed one for penetrable bodies. The potential of the methodology for practical antenna design problems is demonstrated by studying the coupling of the modes on a PEC plate (antenna ground plane) and an adjacent highly lossy dielectric block (user's hand). This analysis reveals the existence of different types of modes having weak or strong interactions between PEC and dielectric parts.