Characteristic Mode Formulations for Penetrable Objects Based on Separation of Dissipation Power and Use of Single Surface Integral Equation

Novel characteristic mode (CM) formulations for penetrable objects based on explicit separation of dissipation power from the total active power and use of single surface integral equation (SSIE) are proposed. Due to the separation of the dissipation power, the right-hand side of the generalized eigenvalue equation can be set to be exclusively related to the radiated power, which permits the far-field pattern by different CMs to be orthogonal whether the material is lossless or not. The use of SSIE allows both the equivalent electric and magnetic currents to be expressed by a single effective electric or magnetic current, so that the conventional inverse to express the equivalent electric current by the equivalent magnetic current or vice versa is avoided, which is favorable for frequency sweeping simulations. Numerical examples for verifications are provided by comparing with acknowledged results or measured data.