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Metamaterials show properties different from the properties present in the natural occurring materials. In ordinary way, materials are constructed at the chemical level but metamaterials are constructed at the macroscopic level and derive their properties from geometry. Metamaterials simultaneously exhibit negative permittivity and permeability resulting in negative refractive index. It is because of these unusual properties that metamaterials change the electric and magnetic property of electromagnetic waves. The reflection pattern as displayed by metamaterials has been a field of research worldwide with various theories and models being suggested. However, development of the desired commercially viable metamaterials is directly dependent on advancement in the field of nano-technology as even the best conventional photolithography techniques are not able to fabricate the element at the molecular levels. Metamaterial are expected to impact most of the technological fields where electromagnetic radiation are used. They provide a fast emerging flexible platform for technological advancement. Metamaterials have a prominent role in Aerospace and Defence which enable its application in enhanced communication, radar improvement, drones, light aircrafts, next generation composites and invisibility cloaks. Research undertaken for design of low density but high strength radar absorbing materials has been limited due to key factors such as mechanical strength, environmental resistance, thickness, absorptivity and weight. Research efforts have now shifted towards radar absorbing structures, a field which enables multiple military application, wherein metamaterial offer one such lucrative option. COMSOL Multiphysics Electro Magnetics RF Module software has been used in order to simulate various metamaterial designs. The aim of the paper is to study various designs of metamaterials and its applications as Electromagnetic wave absorbers. |
