Design method for three-dimensional external electromagnetic cloaks

In this article, design method of 3-dimensional external cloak based on the coordinate transformation theory has been studied. The relative constitutive parameters of the complementary media and the core material of the external cloak are derived. In the proposed external cloak, the cloaked object is not blinded within the cloaking shell because it's located outside of the cloak and can communicate with the outer region while the object is hides from electromagnetic waves incident from different angles. Full-wave simulations in three dimension domain with both plane and spherical wave irradiations for cloaking homogeneous and inhomogeneous objects have been carried out to verify the efficiency of the proposed 3-D external cloak.