Constant Permeability Design of Cylindrical Invisibility Cloaks with Hyperbolic Coordinate Transformation Based on Transformation Electromagnetics

We propose a novel hyperbolic coordinate transformation for cylindrical invisibility cloaks based on the transformation electromagnetics. It is mathematically shown that the cloak with the proposed transformation can be implemented by a medium with a position independent permeability, which potentially leads to wideband and low loss operations with easy implementations at microwave or higher frequency regions. A transmission-type cloak is designed and the required permittivity and permeability are calculated. We demonstrate the operation of the cylindrical cloak based on the circuit theory and the validity of the proposed concept is shown by comparing the radar cross section of the cloak with that of a conventional one.