Sikder Sunbeam Islam

A New Compact Double-Negative Miniaturized Metamaterial for Wideband Operation

The aim of this paper is to introduce a compact double-negative (DNG) metamaterial that exhibits a negative refractive index (NRI) bandwidth of more than 3.6 GHz considering the frequency from 2 to 14 GHz. In this framework, two arms of the designed unit cell are split in a way that forms a Modified-Z-shape structure of the FR-4 substrate material. The finite integration technique (FIT)-based Computer Simulation Technology (CST) Microwave Studio is applied for computation, and the experimental setup for measuring the performance is performed inside two waveguide ports. Therefore, the measured data complies well with the simulated data of the unit cell at 0-degree and 90-degree rotation angles. The designed unit cell shows a negative refractive index from 3.482 to 7.096 GHz (bandwidth of 3.61 GHz), 7.876 to 10.047 GHz (bandwidth of 2.171 GHz), and 11.594 to 14 GHz (bandwidth of 2.406 GHz) in the microwave spectra. The design also exhibits almost the same wide negative refractive index bandwidth in the major region of the C-band and X-band if it is rotated 90 degrees. However, the novelty of the proposed structure lies in its effective medium ratio of more than 4, wide bandwidth, and compact size.

The Design and Analysis of a Novel Split-H-Shaped Metamaterial for Multi-Band Microwave Applications

This paper presents the design and analysis of a novel split-H-shaped metamaterial unit cell structure that is applicable in a multi-band frequency range and that exhibits negative permeability and permittivity in those frequency bands. In the basic design, the separate split-square resonators are joined by a metal link to form an H-shaped unit structure. Moreover, an analysis and a comparison of the 1 × 1 array and 2 × 2 array structures and the 1 × 1 and 2 × 2 unit cell configurations were performed. All of these configurations demonstrate multi-band operating frequencies (S-band, C-band, X-band and Ku-band) with double-negative characteristics. The equivalent circuit model and measured result for each unit cell are presented to validate the resonant behavior. The commercially available finite-difference time-domain (FDTD)-based simulation software, Computer Simulation Technology (CST) Microwave Studio, was used to obtain the reflection and transmission parameters of each unit cell. This is a novel and promising design in the electromagnetic paradigm for its simplicity, scalability, double-negative characteristics and multi-band operation.

A Near Zero Refractive Index Metamaterial for Electromagnetic Invisibility Cloaking Operation

The paper reveals the design of a unit cell of a metamaterial that shows more than 2 GHz wideband near zero refractive index (NZRI) property in the C-band region of microwave spectra. The two arms of the unit cell were splitted in such a way that forms a near-pi-shape structure on epoxy resin fiber (FR-4) substrate material. The reflection and transmission characteristics of the unit cell were achieved by utilizing finite integration technique based simulation software. Measured results were presented, which complied well with simulated results. The unit cell was then applied to build a single layer rectangular-shaped cloak that operates in the C-band region where a metal cylinder was perfectly hidden electromagnetically by reducing the scattering width below zero. Moreover, the unit cell shows NZRI property there. The experimental result for the cloak operation was presented in terms of S-parameters as well. In addition, the same metamaterial shell was also adopted for designing an eye-shaped and triangular-shaped cloak structure to cloak the same object, and cloaking operation is achieved in the C-band, as well with slightly better cloaking performance. The novel design, NZRI property, and single layer C-band cloaking operation has made the design a promising one in the electromagnetic paradigm.

An Object-Independent ENZ Metamaterial-Based Wideband Electromagnetic Cloak

A new, metamaterial-based electromagnetic cloaking operation is proposed in this study. The metamaterial exhibits a sharp transmittance in the C-band of the microwave spectrum with negative effective property of permittivity at that frequency. Two metal arms were placed on an FR-4 substrate to construct a double-split-square shape structure. The size of the resonator was maintained to achieve the effective medium property of the metamaterial. Full wave numerical simulation was performed to extract the reflection and transmission coefficients for the unit cell. Later on, a single layer square-shaped cloak was designed using the proposed metamaterial unit cell. The cloak hides a metal cylinder electromagnetically, where the material exhibits epsilon-near-zero (ENZ) property. Cloaking operation was demonstrated adopting the scattering-reduction technique. The measured result was provided to validate the characteristics of the metamaterial and the cloak. Some object size- and shape-based analyses were performed with the cloak, and a common cloaking region was revealed over more than 900 MHz in the C-band for the different objects.

A two-component NZRI metamaterial based rectangular cloak

A new two-component, near zero refractive index (NZRI) metamaterial is presented for electromagnetic rectangular cloaking operation in the microwave range. In the basic design a pi-shaped, metamaterial was developed and its characteristics were investigated for the two major axes (x and z-axis) wave propagation through the material. For the z-axis wave propagation, it shows more than 2 GHz bandwidth and for the x-axis wave propagation; it exhibits more than 1 GHz bandwidth of NZRI property. The metamaterial was then utilized in designing a rectangular cloak where a metal cylinder was cloaked perfectly in the C-band area of microwave regime. The experimental result was provided for the metamaterial and the cloak and these results were compared with the simulated results. This is a novel and promising design for its two-component NZRI characteristics and rectangular cloaking operation in the electromagnetic paradigm.

Design and absorption analysis of a new multiband split-S-shaped metamaterial

Abstract The design and absorption analysis of a unit cell of a new multiband split-S-shaped metamaterial is presented in this paper. The computer simulation technology (CST) software based on finite-difference time-domain method was used for the design of the unit cell and its S-parameter calculations. The proposed design shows the resonance frequency within the S-band, X-band, and Ku-band of the microwave spectra. In addition, the proposed material can be used in ε-negative, μ-negative, near-zero refractive index, and double-negative applications as well. The measured result is presented, which shows good conformity with the simulated result. The material shows nearly the same characteristics with bit shifted transmittance at the higher frequency side after reducing the coupling capacitance in the y- or z-axis of the proposed metamaterial. Moreover, it is evident from the investigation that, for shifting the lower ring in the z-axis, 15% more absorption can be achieved for the proposed metamaterial. The simple design, multipurpose applications, and compact size have made the design novel in the electromagnetic paradigm.

A novel biaxial double-negative metamaterial for electromagnetic rectangular cloaking operation

Abstract This paper presents the design and analysis of a novel biaxial double-negative (DNG) metamaterial for electromagnetic cloaking operation in the microwave range. The proposed metamaterial exhibits DNG characteristics for the three axes (x, y, and z axes) wave propagation through the material. For the z-axis wave propagation, it shows resonance in the X-band and shows DNG characteristics there. Similarly, for the x-axis wave propagation, the material displays resonances in the multi-band (S-, C-, and X-bands) microwave frequency ranges with DNG characteristics at the S-, C-, and X-bands. The material exhibits DNG properties at the S- and C-bands for y-axis wave propagation as well. In the basic design, a new metamaterial structure was developed that was split into two arms. The commercially available finite-difference time-domain (FDTD)-based computer simulation technology (CST) Microwave Studio software was adopted to obtain the reflection and transmission parameters of the unit cell. The metamaterial was then used in designing a rectangular electromagnetic cloaking device where a metal cylinder was perfectly cloaked in the C-band region of the microwave spectra. The metamaterial shows near-zero refractive-index property as well in the cloaked zone. This is a novel and promising design in the electromagnetic paradigm for its biaxial DNG characteristics and rectangular cloaking operation.

Design and analysis of a complementary split ring resonator (CSRR) metamaterial based antenna for wideband application

Abstract In this article, a compact complementary split ring resonator (CSRR) based double-negative (DNG) metamaterial antenna is presented for wideband (4.49 GHz–21.85 GHz) wireless application. The antenna is incorporated with a DNG metamaterial patch: 50Ω microstrip feed line and partial ground plane. The antenna shows measured fractional bandwidth of 131.81% with a compact size of 0.37λ×0.37λ×0.01λ. The commercially available finite integration technique (FIT)-based simulation software, computer simulation technology (CST) microwave studio was adopted to investigate the performance of the proposed antenna. Several parametric studies were performed to investigate the effect of key structural parameters on antenna performances. The double-negative characteristics of the metamaterial were investigated as well.

A new NZRI metamaterial for electromagnetic cloaking operation

The paper reveals a near zero refractive index (NZRI) property based metamaterial unit cell for electromagnetic cloaking operation. The metamaterial unit cell displays resonance in the frequency of 8.29 GHz and exhibits near zero refractive index property there. The metamaterial was then utilized in designing a single layer rectangular cloaking device. The rectangular cloaking device hides a cylindrical metal object in the C-band region where almost zero scattering cross section is achieved for the object. The metamaterial also exhibits NZRI property there. The commercially available CST Microwave Studio simulation software, was utilized to obtain all the reflection and transmission parameters of the unit cell and the cloak. The experimental results were presented as well for both of the metamaterial and the cloak. It was also revealed that the cloak was object size independent in the certain region of C-band. This is a promising design in the electromagnetic paradigm for the rectangular and C-band cloaking operation.

A new SNG metamaterial for S-band microwave applications

The paper proposes a new metamaterial unit cell structure that shows resonance in the microwave S-Band frequency range. It also shows negative permittivity and positive permeability at that frequency, which has characterized the material as single negative material. In this design two separate split ring resonator have been used. Commercially available CST Microwave Studio simulation software has been used to get the reflection and transmission parameters for this unit cell.