Figure 1
From: Highly-efficient three-dimensional waveguide couplers using impedance-tunable transformation optics
Schematics of the coaxial waveguide coupler using impedance-tunable transformation optics. (a) Structure, where the outer and inner radius of WG1 and WG2 are (a–d) respectively. The length of the coupler is l. It is embedded within a transformation medium. (b) Illustration of the coordinate transformation.
