Transmission Properties of Dual-period Arrays of Cylinders

D. SKIGIN; M. LESTER

Simposio; The 29th PIERS 2011 in Marrakesh, Morocco; 2011

THE ELECTROMAGNETICS ACADEMY

Abstract— We investigate the potential of dual-period structures to control and manipulate thetransmitted intensity. We consider supergratings (periodic arrays with a compound unit cell) inwhich each period comprises several cylinders. We show that this kind of structures permits one tocontrol the diffracted response, regardless of the cylinder material and the incident polarization.A given diffraction order can be either enhanced or suppressed by appropriately choosing thegeometrical parameters of the structure, and this property is basically a geometric effect. Forsubwavelength cylinders, if their axes are aligned in a plane tilted with respect to the periodicitydirection, the structure behaves like a blazed grating in the sense of its capability to enhancethe intensity in a pre-designed direction. This blazed-like behaviour is found for both incidentpolarization modes and for dielectric as well as for metallic cylinders. If the array is illuminatedby an evanescent wave, the system exhibits resonances and the inhomogeneous wave is convertedinto propagating waves that radiate to the far field. This effect can be controlled by varyingthe geometrical parameters of the structure, such as the period and the inclination angle, whatmakes these structures good potential candidates for many applications.