Development of Optimization Techniques for Multilayered Metamaterial Structures

Abstract

This thesis work aims to design and develop Optimisation Techniques for the development of Multilayered Metamaterial Structures. In the recent times, there have been a rise in the need of development of structures and materials which are able to provide Electromagnetic Shielding as these Electromagnetic devices not only interfere with communication devices, but have detrimental effects on the performance of many devices. Especially coming to the area of Stealth Technology, and improvement in the performance of various surveillance and communication devices, the Multilayered Metamaterial Structures are used and required not only to reduce interference between radar signals and surrounding structures like radar masts, but also to help reduce detection by hostile radars. A number of approaches have been used for this traditionally such as Salisbury Screen, Jaumann Screen, Embedded single layer composite structures, however there is always an issue of trade-off between the reduced thickness of the absorber substance and the maximum absorption of incident EM wave. So mutilayering of the composite substances in order to develop MMMS is one such effective technique which has recently been studied upon. Optimisation Techniques are must for multilayering as number of parameters need to be optimally selected and modified for the development of a multilayered substance. These parameters include selection of materials from the database, their sequence on the conductive substance and the thickness of the layers. This research aims to design such structures with the help of Genetic Algorithm and Particle Swarm Optimisation, which are thin enough to be practically implemented on the radars as well as should satisfy the requirement of high EM absorption in a wide range of frequencies, thus the design of a thin, cost-effective, broadband Multilayered Metamaterial Structure.