scholarly journals Metamaterial Cell-Based Superstrate towards Bandwidth and Gain Enhancement of Quad-Band CPW-Fed Antenna for Wireless Applications

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 457 ◽  
Author(s):  
Samir Salem Al-Bawri ◽  
Md Shabiul Islam ◽  
Hin Yong Wong ◽  
Mohd Faizal Jamlos ◽  
Adam Narbudowicz ◽  
...  
Keyword(s):  
Refractive Index ◽  
Wave Propagation ◽  
Negative Refractive Index ◽  
Coplanar Waveguide ◽  
Ring Resonators ◽  
Wireless Applications ◽  
Gain Enhancement ◽  
Wide Range ◽  
Measurement Results ◽  
High Bandwidth

A multiband coplanar waveguide (CPW)-fed antenna loaded with metamaterial unit cell for GSM900, WLAN, LTE-A, and 5G Wi-Fi applications is presented in this paper. The proposed metamaterial structure is a combination of various symmetric split-ring resonators (SSRR) and its characteristics were investigated for two major axes directions at (x and y-axis) wave propagation through the material. For x-axis wave propagation, it indicates a wide range of negative refractive index in the frequency span of 2–8.5 GHz. For y-axis wave propagation, it shows more than 2 GHz bandwidth of near-zero refractive index (NZRI) property. Two categories of the proposed metamaterial plane were applied to enhance the bandwidth and gain. The measured reflection coefficient (S11) demonstrated significant bandwidths increase at the upper bands by 4.92–6.49 GHz and 3.251–4.324 GHz, considered as a rise of 71.4% and 168%, respectively, against the proposed antenna without using metamaterial. Besides being high bandwidth achieving, the proposed antenna radiates bi-directionally with 95% as the maximum radiation efficiency. Moreover, the maximum measured gain reaches 6.74 dBi by a 92.57% improvement compared with the antenna without using metamaterial. The simulation and measurement results of the proposed antenna show good agreement.

Compact ring resonators using negative-refractive-index microstrip line

2005 ◽  
Vol 45 (4) ◽  
pp. 294-295 ◽  
Author(s):  
Aaron D. Scher ◽  
Christopher T. Rodenbeck ◽  
Kai Chang
Keyword(s):  
Refractive Index ◽  
Microstrip Line ◽  
Negative Refractive Index ◽  
Ring Resonators ◽  
Compact Ring

Negative Refractive Index of Meta-materials at Optical Frequencies

2006 ◽  
Vol 964 ◽  
Author(s):  
S. Anantha Ramakrishna ◽  
Sangeeta Chakrabarti
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Magnetic Activity ◽  
Ring Resonators ◽  
Split Ring ◽  
Complex Behaviour ◽  
High Frequencies ◽  
Displacement Currents ◽  
Very High Frequencies ◽  
Very High

ABSTRACTScaling the performance of metamaterials to obtain negative refractive index at optical frequencies has been of great interest. One of the great barriers to the scaling is that real currents cannot be driven at very high frequencies and one is more dependent on displacement currents to generate negative magnetic permeability. Moreover to keep the dimensions of the metamaterials physically accessible, the structural lengthscales of the metamaterials begin approach the wavelength of the radiation in free space and homogenisation is often questionable. Here we will show that metamaterials such as Split ring resonators in these high frequency limits exhibit complex behaviour. Magnetic activity and Negative refractive index behaviour can, indeed, be obtained at optical frequencies but will need to be interpreted very carefully. The plasmonic nature of the metallic system and excitation needs to be considered in detail.

scholarly journals Chiral metamaterials with negative refractive index based on four “U” split ring resonators

2010 ◽  
Vol 97 (8) ◽  
pp. 081901 ◽  
Author(s):  
Zhaofeng Li ◽  
Rongkuo Zhao ◽  
Thomas Koschny ◽  
Maria Kafesaki ◽  
Kamil Boratay Alici ◽  
...  
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Chiral Metamaterials

scholarly journals Nanofabrication of planar split ring resonators for negative refractive index metamaterials in the infrared range

2006 ◽  
Vol 71 (6) ◽  
pp. 695-703 ◽  
Author(s):  
Zoran Jaksic ◽  
Dana Vasiljevic-Radovic ◽  
Milan Maksimovic ◽  
Milija Sarajlic ◽  
Zoran Djuric
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Building Blocks ◽  
Ring Resonators ◽  
Infrared Range ◽  
Process Conditions ◽  
Split Ring ◽  
Crystal Silicon ◽  
Split Ring Resonators ◽  
Positive Photoresist

Experimental nanofabrication of planar structures for one-dimensional metamaterials designed to achieve a negative effective refractive index in the mid-infrared range (5-10 micrometers) was performed. Double split ring and complementary double split ring resonators (SRR and CSRR) with square and circular geometries, were chosen to be fabricated since these are the basic building blocks to achieve a negative effective dielectric permittivity and magnetic permeability. Scanning probe nanolithography with z-scanner movement was used to fabricate straight-line and curvilinear segments with a line width of 80-120 nm. The geometries were delineated in 20 nm thin silver layers sputter-deposited on a positive photoresist substrate spin-coated on polished single crystal silicon wafers, as well as on polycarbonate slabs. The morphology of the structures was characterized by atomic force microscopy. The feature repeatibility was 60-150 nm, depending on the process conditions and the feature complexity. The nanolithographic groove depth in different samples ranged from 4 nm to 80 nm.

scholarly journals A new double ш-shaped compact negative refractive index metamaterial for wideband applications

2020 ◽  
Vol 20 (2) ◽  
pp. 863
Author(s):  
Pujan Chandra Paul ◽  
Mohammad Jakir Hossain ◽  
Ashish Kumar Karmaker ◽  
Md. Jakirul Islam
Keyword(s):  
Refractive Index ◽  
Wave Propagation ◽  
Material Properties ◽  
Negative Refractive Index ◽  
Simulation Software ◽  
Unit Cell ◽  
Electromagnetic Simulation ◽  
Vertical Array ◽  
Array Structure ◽  
Compact Design

<p>This paper analyzed the new compact design and negative refractive index (NRI) metamaterial for wideband applications. The proposed metamaterial exhibits NRI and wideband characteristics of the x-axis wave propagation. It displayed the NRI property at the frequency of 1.54 GHz and wideband from 1.26 GHz to 7.08 GHz frequency (L, S, and C band). Moreover, the response of the 1×2 horizontal and 2×1 vertical array structure showed the wideband frequency in the 7.17 GHz to 13.62 GHz and 1.46 GHz to 9.53 GHz, respectively. Electromagnetic simulation software called CST has been used to design the metamaterial unit cell. The metamaterial has been displayed the multi-band characteristics such as L, S, C, X and K<sub>u</sub> bands with negative index material properties.</p>

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