EXPERIMENTAL DEMONSTRATION OF THE DEPENDENCY OF THE NEGATIVE OPTICAL INDEX OF A LEFT-HANDED MATERIAL VERSUS THE INCIDENCE ANGLE

In this study, we present the results of the characterisation of a left-handed material performed in free space between 7 and 16 GHz with an increasing incidence angle. We demonstrate that this material has a negative optical index depending on the incidence. The value of this index is comprised between −0.1 and −0.5 for an incidence angle between 5 and 25°. The bidimensional structure of the material is the origin of this dependency.