Resonant reradiation of electromagnetic waves by thin conductors with transverse gaps

Abstract

Transverse gaps are introduced in thin-wire conductors to extend the region of phase variations of currents that are induced on them by an incident electromagnetic wave. Periodically placed gaps lead to qualitative changes in the properties of reradiated waves, such as the appearance of resonances corresponding to total reflection and total transmission of the incident wave. It is shown that total reflection occurs in a narrow band and depends very weakly on the incident angle of the illuminating radiation. This idea leads to novel filters and switches, whose operation is practically independent of the structure of the incident wave. Total resonant reflection can occur for conductors with high optical transparency, a property that is useful for various microwave diagnostic devices. Because of the increased radiation resistance of such structures, the resonant effects under consideration depend weakly on conductivity. For gratings made using these conductors with gaps stacked above a metal ground plane, it is possible to controllably collimate the rays. Expansion of the scattered fields in terms of Rayleigh's series, together with Poisson's summation formula, are used for numerical simulations of such structures.