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2. PHD Thesis / Tesis PHD
3. Institute of Climate Change / Institut Perubahan Iklim

Title:	Coding based metamaterial for C- and Ku-Band applications
Authors:	Tayaallen Ramachandran (P94128)
Supervisor:	Mohammad Rashed Iqbal Faruque, Assoc. Prof. Dr.
Keywords:	Metamaterial Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	12-Mar-2022
Description:	Metamaterial research works have become popular due to their unique electromagnetic properties and the evolution of this type of material over the past few decades are changes the characteristics and as well found new behaviours for many application fields. This work aims to develop a coding metamaterial with a compact cuboid metamaterial for C- and Ku-bands applications. Meanwhile, the novel conventional metamaterial structure designs for desired resonance bands were also developed in this research. A high-frequency electromagnetic simulator which is based on the Finite Integration Technique was utilised throughout the simulation process. The 1-bit and 2-bit coding sequences were adopted throughout this research. The 1-bit coding metamaterial possesses '0'and '1' metamaterial particle elements with a 0 phase response and π phase response. On the other hand, the 2-bit coding metamaterial has four types of unit cells to mimic elements such as '00', '01', '10', and '11'. The proposed coding metamaterial design was gradually changed by adding more layers and finally, a cuboid structure was constructed. In addition, three types of substrate materials were analysed for coding metamaterial elements such as FR-4, Rogers RT6002 and Rogers RO3006. As a result, promising outcomes were obtained from this research study. Firstly, a few novel metamaterial structures were successfully designed and developed for the C- and Ku-bands applications. For instance, a circular split-ring resonator based left-handed metamaterial for C- and Ku-bands were investigated. Meanwhile, a square-shaped passive metamaterial design manifested quintuple resonance frequencies for satellite applications. Secondly, several 1-bit and 2-bit coding metamaterial designs for the single-layered and multi-layered structures manifest promising outcomes which almost reach 0 dBm2 RCS reduction values. Meanwhile, the coding metamaterial designs with larger lattices exhibit optimised results and can be utilised for larger-scale devices or applications. Therefore, these larger coding metamaterials draw a significant setback for the development of miniaturisation devices. Hence, the cuboid coding metamaterial was proposed with 4, 6, 8, and 12 lattices which exhibit unique outcomes by satisfying miniaturisation constraints. The results indicate that the 2-bit has greater freedom than the 1-bit coding metamaterials, for instance, the 4 lattices coding design in 2-bit manifests a bistatic RCS reduction value (at 4 GHz) of -25.10 dBm2, while 1-bit manifest -27.80 dBm2, respectively. Finally, the conventional metamaterial was validated by fabricating and measuring the proposed design by utilising Vector Network Analyser. Meanwhile, the coding metamaterial was validated by performing several frameworks and optimal characteristics analysis in C- and Ku-bands applications. Due to the ability of coding metamaterial to manipulate electromagnetic waves to obtain different functionalities, it has a high potential to be applied in a wide range of applications. Overall, the very interesting coding metamaterial with many different sizes and shapes helps to achieve unique RCS reduction performances.,Ph.D
Pages:	177
Publisher:	UKM, Bangi
Appears in Collections:	Institute of Climate Change / Institut Perubahan Iklim

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