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Title:	Development of miniaturized metamaterials and metamaterial-based absorbers for microwave and visible regime
Authors:	Mohammad Jakir Hossain (P83346)
Supervisor:	Mohammad Rashed Iqbal Faruque, Assoc. Prof. Dr.
Keywords:	Metamaterials Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	19-Mar-2019
Description:	Due to the attractive electromagnetic properties of artificial material, researchers have attracted with the incredible interest in this area. The conventional materials cannot work with electromagnetic waves suitably, and their characteristics do not comply. The existing absorber is a low rate, large sizes, multiple layers with different elements which makes the size of the absorber bulky. This thesis focuses on the design, characterization, development, and prototyping of metamaterial-based absorber for C- and X-band in microwave spectra and numerical analyses in the visible regime. Moreover, very few absorbers are invented operating in C- and X- band in the microwave frequency band. Hence, designing a metamaterial based miniaturized sized, single layer, perfect absorber in a microwave and visible frequency band has become a new task for the scientific community. In this research, the design process of four metamaterials and metamaterial-based absorbers were developed and investigated their performances. Finite Integration Technique (FIT) based electromagnetic simulator was adopted to design and analyses of the proposed metamaterials and metamaterial-based absorbers. The designed metamaterial and metamaterial absorbers are characterized by Nicolson-Ross-Weir method and Fresnel method using permittivity, permeability, and refractive index of scattering parameters. Four designs worked based on metamaterial properties. The first design considered compact single layer metamaterial-based absorber. The designed metamaterial contains a double C-shaped metamaterial and exhibits μ negative property in the X-band. It shows the maximum absorption of 96.13% and full width half maximum (FWHM) of 280 MHz. The second design includes a triple ring octagonal shaped, planar, single metamaterial-based absorber. It shows the double negative property at C-band and negative refractive index property at X-band. The absorber achieves a maximum absorption rate of 97.11% with 270 MHz FWHM at C-band and 97.11% with 250 MHz FWHM at X-band, respectively. The third one includes hexagonal shaped with meander line to achieve better performance compared with first and second design structure. It also exhibits μ negative property at X-band. It attains an absorption peak of 98.64% with 190 MHz FWHM at C-band and 96.77% with 150 FWHM at X-band, respectively. The fourth design structure considered multi-circular miniaturized planar metamaterial-based absorber. It also displays zero refractive index property at C-and X- band. The design structure attains the highest absorption rate of 99.77% with 220 MHz FWHM at C-band and 99.01% with 300 MHz FWHM at X-band. Finally, rescale the all design structures to nanoscale to absorb solar energy in a visible frequency band. The maximum absorption peaks and FWHMs are 99.80% and 70.04 THz for double C-shape; 99.91% and 37.06 THz for octagonal shape; 99.66% and 56.10 THz for hexagonal shape; 99.67% and 61.88 THz for circular shape structure, respectively. The circular-shaped proposed structure is the best for absorbing electromagnetic radiation in microwave spectra and solar energy in the visible regime.,Ph.D.
Pages:	214
Call Number:	TK7871.15.M48H637 2019 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Institute of Climate Change / Institut Perubahan Iklim

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