A Minimized Invisibility Complementary Cloak With a Composite Shape

Composite-Shaped External Cloaks With Homogeneous Material Properties

“…So, by increasing 'd', the size of the cloaked region can be increased in Ydirection without any change in the material properties which is an advantage for hiding long objects compared to previously reported external cloaks [11,12]. Also, the advantage in asymmetrical design is that the material parameters in entire complementary region and rectangular core region are just diagonally homogeneous whereas only triangular core regions have anisotropic tensor properties.…”

“…In 2009, Lai et al proposed the concept of 'cloaking at a distance' [6] called external cloaking, where an object is hidden exterior to the cloak and is not blinded in contrast to internal cloaking. The idea of external cloaking is based on the concept of complementary medium and transformation optics [6][7][8][9][10][11][12][13]. A diamond shaped external cloak with homogeneous material parameters has been proposed in [11].…”

“…Recently, a new minimized invisibility cloak with reduced size [12] has been proposed. The disadvantage of [11] is its bigger size and that of [12] is its radially varying material parameters inside the central complementary region.…”

“…All the material parameters inside each sub-region are homogeneous. The central (rectangular) regions (1q and 2q) in both the cloaks have homogeneous diagonal material properties which is an advantage over radially varying material properties in central (annular) regions of [12]. The triangular core regions (1p and 1r) in both the cloaks have homogeneous anisotropic tensor properties.…”

“…So, the proposed cloak designs remove the disadvantages of large cloak size in [11] and inhomogeneity of material parameters in [12] while keeping the advantages of both [11] and [12]. The finite and homogeneous material parameters simplifies the practical realization of cloak.…”