Full Equiphase Characteristic Mode Solution to Lossless Composite Metallic-Dielectric Problems

We present a new surface integral equation-based formulation for the characteristic modes of lossless composite metallic–dielectric objects. Compared with the existing formulations, the proposed formulation has a more compact form and is easier to be implemented for complex structures, especially for multilayer structures. The full modal electric and magnetic currents are obtained simultaneously, and both modal electric and magnetic currents are equiphase. It should be mentioned that the derivation of the proposed formulation completely avoids the commonly used process of current elimination to obtain most of the existing formulations. Numerical results validate that the proposed formulation can provide accurate modal solutions to lossless composite metallic–dielectric problems.