Extraordinary electromagnetic transmission through a circular aperture surrounded by surface corrugations

The authors investigate extraordinary electromagnetic transmission through a circular aperture surrounded by surface corrugations. An electromagnetic boundary-value problem of a circular aperture surrounded by surface corrugations in a conducting plane is solved based on the mode matching method. The eigenfunction expansion and Hankel transform are used to represent the scattered fields in terms of the discrete and continuous modes, respectively. The boundary conditions are enforced to obtain a set of simultaneous equations. The transmission coefficient and the radiated fields are represented in a fast-convergent series. Computation is performed to illustrate the behaviours of transmission and radiation against the corrugation geometries. The effects of the corrugation geometries on the extraordinary electromagnetic transmission are discussed.