Highly Directional Small-Size Antenna Designed with Homogeneous Transformation Optics
Figure 1
(a) The schematic of the square antenna system. A big square region (ABCD) with radius has been compressed to a small one (A′B′C′D′) with radius . Green region represents the antenna device compressed from a large size one described by dashed lines. (b) The square in the virtual coordinate space filled with isotropic material is divided into several triangle segments grouped by Segment I and Segment II. (c) The square metamaterial shell in the physical coordinate space is constructed by the transformed segments with homogeneous constitutive tensors.