Reciprocity of Electromagnetic Waves Scattered by Anisotropic Composite Obstacles

It is shown that reciprocity holds for electromagnetic waves scattered by various anisotropic composite obstacles, including obstacles touched together, isolated obstacles, obstacles composed of stratified layers, and combinations of them. The individual obstacles can be of different media, provided that the medium of each obstacle is either anisotropic with tensor permeability and tensor permittivity which are continuous functions of position or perfectly conducting. The incident waves are considered uniform plane waves.