The 2D microwave cloaking structure (background image) with a plot of the material parameters that are implemented. μ′_r (red line) is multiplied by a factor of 10 for clarity. μ′_θ (green line) has the constant value 1. ε′_z (blue line) has the constant value 3.423. The SRRs of cylinder 1 (inner) and cylinder 10 (outer) are shown in expanded schematic form (transparent square insets). From reference [48]. Reprinted with permission from AAAS.