ENHANCEMENT OF ELECTROMAGNETIC FIELDS CAUSED BY INTERACTING SUBWAVELENGTH CAVITIES

摘要

This article is devoted to the asymptotic analysis of the electromagnetic fields scattered by a perfectly conducting plane containing two subwavelength rectangular cavities. The problem is formulated through an integral equation, and a spectral analysis of the integral operator is performed. Using the generalized Rouche theorem on operator valued functions, it is possible to localize two types of resonances, symmetric and antisymmetric, in a neighborhood of each zero of some explicit function, associated to the limiting geometry. For the symmetric modes, the fields in the cavities interact in phase, and the system of two cavities essentially acts as a dipole. In the antisymmetric case, the fields oscillate in antiphase, and the system behaves like a quadripole. Asymptotic expansions of the resonances, the far-field, and the near-field are given.