Miniaturizing Electromagnetic Invisibility Cloaks Using Double Near Zero Slabs

A novel method to miniaturize electromagnetic invisibility cloaks is introduced using Double Near Zero (DNZ) slabs, in which both the permittivity and permeability are close to zero. Based on the proposed technique, the phase pattern tailoring property of DNZ materials is utilized to miniaturize electromagnetic devices. The concept is applied to both types of internal and external cloaks, where their sizes are reduced by 50% by changing their structure from a cylindrical shape to a half cylinder shell. The half-sized internal and half-sized external cloaks can still conceal any object with any shape and material, inside and outside the cloaks, respectively. To illustrate that, the results show that an arbitrary shape of dielectric with arbitrary high value of relative permittivity of 20 is concealed by the half-sized internal cloak. For the half-sized external cloak, the presented results show that it can conceal an external half ring dielectric with high relative permittivity of 20 using anti-object in the structure of the cloak. For the analysis, the transverse electric (TE) Z-polarization is used. For the transverse magnetic (TM) Z-polarization, the duality principal can be applied.