A negative permittivity metamaterial composed of planar resonators with randomly detuned resonant frequencies and randomly distributed in space

2018 ◽  
Vol 10 (9) ◽  
pp. 1028-1034
Author(s):  
Jan Machac
Keyword(s):  
Periodic Structure ◽  
Random Distribution ◽  
Effective Permittivity ◽  
Three Dimensional ◽  
Negative Real Part ◽  
Fabrication Process ◽  
Negative Permittivity ◽  
Resonant Frequencies ◽  
Electric Polarizability

AbstractThis paper investigates metamaterials composed of resonant particles with negative electric polarizability located in a three-dimensional net. The main problem in fabricating these materials is the spread of the resonant frequencies of particular planar resonators. This spread is caused by the tolerances of the fabrication process for planar resonators. The simulation shows that there is a limit to the dispersion of resonant frequencies that allow the metamaterial to behave as a metamaterial with negative effective permittivity. Two metamaterials with a negative real part of the effective permittivity were designed on the basis of simulations. The first metamaterial has a regular periodic structure. The second is a metamaterial in which the resonant particles are randomly distributed both in space and in orientation, and it offers an isotropic response. This metamaterial was fabricated by inserting planar resonators into plastic shells that can be poured into any volume and ensure a random distribution of the resonant particles in space. The results of the simulations have been verified by measurements.

scholarly journals Enhancement of inductance along metallic mesh wires in three-dimensional quasi-isotropic metamaterials using high-ε dielectric particles for impedance-matching with free space

2019 ◽  
Vol 6 ◽  
pp. 21
Author(s):  
Takuya Yamaguchi ◽  
Takumi Ishiyama ◽  
Tetsuya Ueda ◽  
Tatsuo Itoh
Keyword(s):  
Free Space ◽  
Composite Structures ◽  
Impedance Matching ◽  
Effective Permittivity ◽  
Three Dimensional ◽  
Wave Impedance ◽  
Negative Permittivity ◽  
Patterned Structures ◽  
Unit Cells ◽  
Metallic Mesh

In this paper, we consider cube-shaped unit cells including high-ε dielectric cubes under magnetic dipole-like resonance placed at the center and metallic mesh wires for negative permittivity to construct three-dimensional quasi-isotropic metamaterials in the microwave region. Basically, such structures suffer from their low wave impedance due to inclusion of high-ε materials. To reduce effective permittivity of the composite structures, we propose to insert additional inductance into the metallic mesh. For the insertion of lumped inductors along the wires, dispersion diagram and the Bloch-impedance are numerically estimated, and converted to effective permittivity and permeability. The numerical simulation results clearly show almost 3-D isotropic propagation characteristics in a specific frequency region and enhancement of the Bloch-impedance close to free space in the left-handed region. The lumped inductors are replaced by meander-line strip patterns for practical configurations. The metallic patterned structures also achieve the enhanced Bloch impedance that is well-matched to free space.

scholarly journals Parallel LC shaped metamaterial resonator for C and X band satellite applications with wider bandwidth

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Rashed Iqbal Faruque ◽  
Air Mohammad Siddiky ◽  
Eistiak Ahamed ◽  
Mohammad Tariqul Islam ◽  
Sabirin Abdullah
Keyword(s):  
Refractive Index ◽  
Negative Refractive Index ◽  
Coupling Effect ◽  
Research Work ◽  
Negative Permittivity ◽  
Electromagnetic Properties ◽  
Conducting Layer ◽  
Resonant Frequencies ◽  
New Era ◽  
Satellite Applications

AbstractThe electromagnetic properties of the metal based dielectric in the field of millimeter and sub-millimeter technology attracts a new era for innovation. In this research work, we have introduced a parallel LC shaped metamaterial resonator with wider bandwidth. The negative refractive index for two resonant frequencies is located from the negative permittivity from 5.1 to 6.3, 10.4 to 12.9 GHz, where the negative refractive index is located from 5.4 to 6.3 and 10.5 to 13.5 GHz. The electromagnetic wave polarizing in the proposed structure with parallel LC shaped metallic structure shows a fascinating response of wider bandwidth for the external electric and magnetic field. This paper focuses on the design of conducting layer for the suggested design with the parallel metallic arm for analysing the mutual coupling effect of the scattering response where the sub-branch in metallic design is shown more resonant frequencies with the enhancement of the compactness. This proposed structure is analysed with different metallic arrangements and array structures for different boundary conditions.

scholarly journals Stable, high-order computation of impedance–impedance operators for three-dimensional layered medium simulations

2018 ◽  
Vol 474 (2212) ◽  
pp. 20170704 ◽  
Author(s):  
David P. Nicholls
Keyword(s):  
Applied Sciences ◽  
Numerical Simulations ◽  
Periodic Structure ◽  
Layered Medium ◽  
Three Dimensional ◽  
High Order ◽  
Surface Integral ◽  
Dirichlet Eigenvalues ◽  
Linear Waves ◽  
Spectral Algorithm

The faithful modelling of the propagation of linear waves in a layered, periodic structure is of paramount importance in many branches of the applied sciences. In this paper, we present a novel numerical algorithm for the simulation of such problems which is free of the artificial singularities present in related approaches. We advocate for a surface integral formulation which is phrased in terms of impedance–impedance operators that are immune to the Dirichlet eigenvalues which plague the Dirichlet–Neumann operators that appear in classical formulations. We demonstrate a high-order spectral algorithm to simulate these latter operators based upon a high-order perturbation of surfaces methodology which is rapid, robust and highly accurate. We demonstrate the validity and utility of our approach with a sequence of numerical simulations.

Design Considerations Pertaining to the Application of Complementary Split Ring Resonators in Microstrip Antennas

2019 ◽  
pp. 25-56
Author(s):  
Sivaranjan Goswami ◽  
Kumaresh Sarmah ◽  
Angana Sarma ◽  
Kandarpa Kumar Sarma ◽  
Sunandan Baruah
Keyword(s):  
Effective Permittivity ◽  
Microstrip Antennas ◽  
Negative Permittivity ◽  
Ring Resonators ◽  
Dual Band ◽  
Split Ring ◽  
Complementary Split Ring Resonator ◽  
Dual Band Antennas ◽  
Notch Filtering ◽  
Filtering Element

Metamaterial-based design of microstrip antennas and other microwave structures have gained enormous popularity worldwide among researchers. The complementary split ring resonator (CSRR) is one of the most commonly used metamaterial structures in this direction. The CSRR structure yields a negative value of its effective permittivity at a narrow band near its resonant frequency. CSRR structure was initially proposed as a notch filtering element in microstrip transmission lines because of the negative permittivity. Later, the CSRR structure found its use in antennas and other microwave applications. The CSRR structure is reported to enhance the performance of a microstrip antenna in terms of its gain and bandwidth. In addition, CSRR structure is also used in the design of dual band antennas and antennas with integrated filters. This chapter deals with the practical design aspects relative to these applications of CSRR structures.

A Novel Scheme for Wide Bandwidth Chip-to-Chip Communications

2007 ◽  
Vol 4 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Qing Liu ◽  
Patrick Fay ◽  
Gary H. Bernstein
Keyword(s):  
Integrated Circuits ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Three Dimensional ◽  
Fabrication Process ◽  
Silicon Substrates ◽  
Electromagnetic Simulations ◽  
Communication Paradigm ◽  
On Chip ◽  
Test Chips

Quilt Packaging (QP), a novel chip-to-chip communication paradigm for system-in-package integration, is presented. By forming protruding metal nodules along the edges of the chips and interconnecting integrated circuits (ICs) through them, QP offers an approach to ameliorate the I/O speed bottleneck. A fabrication process that includes deep reactive ion etching, electroplating, and chemical-mechanical polishing is demonstrated. As a low-temperature process, it can be easily integrated into a standard IC fabrication process. Three-dimensional electromagnetic simulations of coplanar waveguide QP structures have been performed, and geometries intended to improve impedance matching at the interface between the on-chip interconnects and the chip-to-chip nodule structures were evaluated. Test chips with 100 μm wide nodules were fabricated on silicon substrates, and s-parameters of chip-to-chip interconnects were measured. The insertion loss of the chip-to-chip interconnects was as low as 0.2 dB at 40 GHz. Simulations of 20 μm wide QP structures suggest that the bandwidth of the inter-chip nodules is expected to be above 200 GHz.

Multi-interfaced graphene aerogel/polydimethylsiloxane metacomposites with tunable electrical conductivity for enhanced electromagnetic interference shielding

2020 ◽  
Vol 8 (34) ◽  
pp. 11748-11759 ◽  
Author(s):  
Jingnan Ni ◽  
Ruoyu Zhan ◽  
Jun Qiu ◽  
Jincheng Fan ◽  
Binbin Dong ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Three Dimensional ◽  
Interface Structure ◽  
Negative Permittivity ◽  
Electromagnetic Interference Shielding ◽  
Graphene Aerogel

Three-dimensional graphene aerogel/polydimethylsiloxane metacomposites with an integral multi-interface structure possess adjustable negative permittivity, excellent microwave absorption and electromagnetic interference shielding.

scholarly journals Study of Abnormal Group Velocities in Flexural Metamaterials

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hong Woo Park ◽  
Joo Hwan Oh
Keyword(s):  
Group Velocity ◽  
Periodic Structure ◽  
Three Dimensional ◽  
Wave Dispersion ◽  
Abnormal Behavior ◽  
Flexural Wave ◽  
Negative Group ◽  
One Dimensional ◽  
Optical Branch ◽  
Negative Group Velocity

Abstract Generally, it has been known that the optical branch of a simple one-dimensional periodic structure has a negative group velocity at the first Brillouin zone due to the band-folding effect. However, the optical branch of the flexural wave in one-dimensional periodic structure doesn’t always have negative group velocity. The problem is that the condition whether the group velocity of the flexural optical branch is negative, positive or positive-negative has not been studied yet. In consequence, who try to achieve negative group velocity has suffered from trial-error process without an analytic guideline. In this paper, the analytic investigation for this abnormal behavior is carried out. In particular, we discovered that the group velocity of the optical branch in flexural metamaterials is determined by a simple condition expressed in terms of a stiffness ratio and inertia ratio of the metamaterial. To derive the analytic condition, an extended mass-spring system is used to calculate the wave dispersion relationship in flexural metamaterials. For the validation, various numerical simulations are carried out, including a dispersion curve calculation and three-dimensional wave simulation. The results studied in this paper are expected to provide new guidelines in designing flexural metamaterials to have desired wave dispersion curves.

scholarly journals Challenges in a Hybrid Fabrication Process to Generate Metallic Polarization Elements with Sub-Wavelength Dimensions

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5279
Author(s):  
Stefan Belle ◽  
Babette Goetzendorfer ◽  
Ralf Hellmann
Keyword(s):  
Final Height ◽  
Three Dimensional ◽  
Fabrication Process ◽  
Degree Of Polarization ◽  
Direct Laser Writing ◽  
Free Standing ◽  
Laser Writing ◽  
Additive Fabrication ◽  
Direct Laser ◽  
Sub Wavelength

We report on the challenges in a hybrid sub-micrometer fabrication process while using three dimensional femtosecond direct laser writing and electroplating. With this hybrid subtractive and additive fabrication process, it is possible to generate metallic polarization elements with sub-wavelength dimensions of less than 400 nm in the cladding area. We show approaches for improving the adhesion of freestanding photoresist pillars as well as of the metallic cladding area, and we also demonstrate the avoidance of an inhibition layer and sticking of the freestanding pillars. Three-dimensional direct laser writing in a positive tone photoresist is used as a subtractive process to fabricate free-standing non-metallic photoresist pillars with an area of about 850 nm × 1400 nm, a height of 3000 nm, and a distance between the pillars of less than 400 nm. In a subsequent additive fabrication process, these channels are filled with gold by electrochemical deposition up to a final height of 2200 nm. Finally, the polarization elements are characterized by measuring the degree of polarization in order to show their behavior as quarter- and half-wave plates.

Three-dimensional honeycomb-like porous carbon derived from tamarisk roots via a green fabrication process for high-performance supercapacitors

Ionics ◽  
2019 ◽  
Vol 25 (9) ◽  
pp. 4315-4323 ◽  
Author(s):  
Yingjie Wang ◽  
Lianchun Zhao ◽  
Hui Peng ◽  
Xiuwen Dai ◽  
Xueni Liu ◽  
...  
Keyword(s):  
Porous Carbon ◽  
High Performance ◽  
Three Dimensional ◽  
Fabrication Process
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