Composite-Shaped External Cloaks With Homogeneous Material Properties

Abstract

Two composite shaped external cloaks are proposed based on the concept of linear transformation method and complementary media. Each composite shaped cloak is sub-divided into regions of rectangular and triangular shapes. The advantage of the proposed cloak designs is that the material properties are finite, homogeneous and non-singular within all sub-regions of the cloaks which is good for practical realization. The cloak size of each of the proposed designs is smaller compared to the conventional external cloaks. Moreover the cloaking area of proposed cloaks can be increased in the vertical direction without any change in material parameters of core and complementary regions which is an additional benefit for hiding long objects. Full-wave simulations reveal that the proposed cloaks have good performance even for hiding multiple objects of different shapes and sizes inside it for all angles of incidence of electromagnetic wave.

Three-Dimensional Reciprocal Invisibility Cloak with Multilayered Structure

“…proposed [18]- [21]. However, all of the above-mentioned cases describe two-dimensional (2D) cloaks, which are easy to implement and simulate but inconvenient in practical applications, as the incident waves have unforeseeable angles.…”

Ultra-Thin Wideband Polarization-Insensitive Metasurface Absorber for Aviation Technology

“…6,7 The state-of-the-art technology of metamaterials has revealed numerous applications in the domain of radio-frequency (RF) and microwave engineering like antennas, cloaks, sensors, and absorbers. [8][9][10][11][12][13][14][15][16] Electromagnetic absorbers are one of the most widely used applications in modern technology to mitigate electromagnetic interference by a radome and to minimize the radar cross-section. [17][18][19][20] During World War II, Salisbury (single layer) and Jaumann (multilayer) absorbers were introduced for radar camouflage.…”

Parabolic transformation function‐based external cloak with finite and realisable material parameters

“…The non-linear transformation function based cloak in [25] provides spatially invariant axial material parameter in the core region in contrast to [23,24]. External cloaks designed by using linear transformation function [25][26][27] provides homogeneous material properties, but looses smooth transition and finite scale of cylindrical shape as reported in [21,[23][24][25]. A complementary cloak composed of circular sector and two triangular sectors has been proposed in [28] which yields a small size invisibility cloak compared to [21].…”