Frequency selective characteristics of gratings with arbitrary profiles composed of left-handed materials

The frequency selective surface (FSS) of gratings with arbitrary profiles composed of left-handed materials is systematically analysed by a method that combines the staircase approximation and the multimode network theory with the rigorous mode matching procedure. The effects of different periodic groove profiles, such as rectangle, ellipse and trapezoid on the reflection characteristics of the FSS are carefully studied and compared with each other. The variations of the frequency selective characteristics with dielectric loss and the comparisons between left-handed and right-handed gratings are also presented with the physical explanations of the related phenomena.