Composite Right/left-handed Metamaterials Research Articles

A Review on the History and Current Literature of Metamaterials and Its Applications to Antennas & Radio Frequency Identification (RFID) Devices

Metamaterials are artificially engineered novel substances (or matter) that exhibit properties not found in nature. One of the earliest examples of a metamaterial structure is the split-ring resonator. This article is a current review of metamaterials, what it is, its classification, and its applications towards the field of antennas and radio frequency identification (RFID) devices. There are two major types of metamaterial antennas: leaky-wave antennas, and resonant antennas. Antennas can be made from composite right-left handed metamaterials, or antennas can be loaded with a metamaterial screen such as a shelled electrically small antenna (ESA) fed by coax. Metamaterial resonators can aid in reducing the antenna size, help improve the gain, improve the directivity, improve the return loss, and control the radiation pattern (by loading the antenna with a tunable unit). Recent advances in printing and fabricating technologies have allowed for use of metamaterial antennas in wearable gadgets and textiles; and can be used in conjunction with RFID devices and tags to advance and aid (emergency) equipment used by first responders.

Compact Co-design of Conformal 4G LTE and mmWave 5G Antennas for Mobile Terminals

An integrated design of conformal 4G and 5G Multiple-Input Multiple-Output (MIMO) antenna system is proposed. The 4G MIMO antenna system consists of electrically small two-element Composite Right/Left Handed (CRLH)-based Coplanar waveguide (CPW)-fed monopole antennas, which cater to the class 7 4G Long-Term evolution (LTE) band. For mmWave 5G MIMO antenna system, two-element high gain microstrip patch antennas are proposed. The conformal CPW-fed CRLH Metamaterial (MTM)-based 4G LTE antenna is electrically small with dimensions 20 × 20 × 0.254 mm3. The proposed antenna system has a forward gain of 2.15 dBi. Also, a conformal microstrip-fed patch antenna with an orthogonal pattern diversity at 28 GHz with a forward gain of 9 dBi is presented. Both the proposed antennas are integrated electrically close by 0.004 λ for minimal physical footprint post-integration in a typical smartphone case. The isolation is less than 35 dB. Real-world deployment studies have been presented.

A compact dual-band bandpass SIW filter using uniplanar combination of the CRLH and resonant type metamaterials

ABSTRACTA new manner of obtaining dual bandpass behaviour in substrate-integrated waveguide (SIW) using a uniplanar combination of composite right/left-handed (CRLH) transmission line and complimentary double split single ring resonator (CDSSRR) is presented and analysed in this paper. The proposed dual band structure has the advantage of miniaturisation due to the presence of both the passbands below the characteristic cutoff frequency of the SIW.A high passband transmission zero overcomes the poor frequency selectivity, and the two resonant frequencies are independently controllable. There are very low insertion losses in both passbands as compared to DGS structures and fabrication simplicity is ensured due to an intact ground. The potential for application of the proposed structure to the design of completely planar miniaturised dual band bandpass metamaterial filters has been verified by fabricating a two-stage filter based on the proposed combination. The measured results are in good agreement with the simulation results.

Extended Aperture Miniature Antenna Based on CRLH Metamaterials for Wireless Communication Systems Operating Over UHF to C‐Band

AbstractThis paper presents a simple technique to extend the aperture of planar composite right/left‐handed (CRLH) metamaterial antennas with minimal impact on the antenna's dimensions. Unlike most CRLH antenna structures the proposed antenna is via‐free. The proposed antenna is shown to operate over a wideband from UHF to C‐band with good radiation characteristics. The antenna configuration consists of a vertically stacked CRLH unit cells comprising a patch and meandered lines, where the patch is engraved with an S‐shaped slot. The design uses minimal ground plane area. The meander line inductance is grounded using coplanar waveguide (CPW) ground which eliminates conventional CRLH transmission line metallic via into ground plane. The antenna is feed through a coplanar waveguide (CPW) match stub that is electromagnetically coupled to the unit cells. Antenna dimensions are 17.5 × 32.15 × 1.6 mm3, which corresponds to 0.204 λ0 × 0.375 λ0 × 0.018 λ0 where free‐space wavelength (λ0) is 3.5 GHz. Parametric study enabled the optimization of the antenna performance in terms of impedance bandwidth, radiation gain, and radiation efficiency. Measured results confirm that the antenna can operate from 850 MHz to 7.90 GHz, which is equivalent to a fractional bandwidth of 161.14%. The antenna has a maximum gain and radiation efficiency of 5.12 dBi and ~80%, respectively, at 3.5 GHz.

CRLH Transmission Lines for Telecommunications: Fast and Effective Modeling

A different parameter extraction approach based on zero immittances for composite right/left-handed (CRLH) structure is presented. For lossless unit cell equivalent circuit model, LC parameters of series and parallel branches are extracted according to series resonance frequency and parallel resonance frequency, respectively. This approach can be applied to symmetric and unbalanced CRLH structures. The parameter extraction procedure is provided and validated by T-type unit cell model. The responses of distributed prototype and extracted equivalent LC circuit model are in good agreement. The equivalent circuit modeling can improve the degree of freedom in the CRLH TLs design. This parameter extraction method provides an effective and straightforward way in CRLH metamaterials design and applications in telecommunication systems.

Compact low noise amplifier with high stable gain using distributed CRLH metamaterial

In this letter, a compact low noise amplifier (LNA) with high stable gain using distributed elements with composite right/left-handed (CRLH) metamaterial is presented. In the proposed LNA, the CRLH is composed of distributed elements with a compact meander-line structure. The transistor (TR) in the proposed LNA is selected as a HEMT device due to its low noise and high stable gain performances. In this structure, the CRLH is adopted as the input and output matching networks in the LNA. The operating frequency of the proposed LNA is 2.0 GHz, the minimum noise figure is 0.71 dB, and the maximum stable gain is 10.4 dB. Also, the total size of the proposed LNA is 10.8 × 13.6 mm2. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1715–1720, 2016

Miniaturized band‐pass filter based on composite right‐/left‐handed transmission‐line unit cell

ABSTRACTThis article presents the design and implementation of a band‐pass filter using a novel composite right‐/left‐handed (CRLH) structure. To minimize the overall size of filter, the concept of CRLH metamaterial is used. Only one unit cell of CRLH is used in this filter to reduce size. The proposed CRLH structure for this filter shows smaller size than the filters designed using traditional methods. The designed filter is simulated and, thereafter, validated by physical realization and its testing. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1713–1717, 2015

Multilayered CRLH Metamaterials Using Magnetic Dipole-Like Resonant Dielectric Particles and Cut-Off TE Modes in Metallic Structures

Composite right/left handed (CRLH) metamaterial structures designed based on one-dielectric-resonator (DR) scheme in an epsilon-negative host medium are discussed. The scheme is a combination of dielectric and metals, but can avoid several problems often met in the other schemes composed of all dielectric metamaterials. The structure under consideration is composed of stacked layers including TE-cut-off metallic mesh plates with holes and dielectric layers with 2-D array of DRs. A volumetric multilayered 2-D CRLH structure that is impedance-matched to free space can be designed by optimally adjusting electromagnetic couplings between neighboring dielectric layers through metallic mesh holes. In addition, the multilayered structure is promising for easy fabrication of the 3-D isotropic CRLH metamaterials, compared to the other structures reported previously. It can support balanced CRLH propagation not only in the in-plane direction, but also in the direction normal to the layers. The structure has strong uniaxial anisotropy and polarization dependence, but the dispersion diagram can have almost isotropic characteristics in a specific frequency region by appropriately designing the configuration parameters.

A Dual-Band Narrow Band-Pass Filter with Half-Wavelength Open Stubs Using the CRLH Metamaterial

A narrow-bandwidth dual-band (DB) band-pass filter (BPF) with λg/2 open stubs constructed using composite right/left-handed (CRLH) metamaterial transmission lines (TLs) is presented. A conventional narrow BPF with λg/2 open stubs is first designed using series λg/2 open stubs and λg/4 TLs. Then, a DB filter can then be easily implemented by replacing the microstrip lines with the CRLH-TL unit cells. The DB BPF using the CRLH-TL unit cell is experimentally demonstrated at dual-operating frequencies of 5.8 and 10.02 GHz. The experimental results are in good agreement with the simulation results. The DB BPF shows 11 and 13% pass bandwidth at the center frequencies of 5.8 and 10.02 GHz, respectively. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1887–1890, 2013

Design of small planar antennas based on double-layered CRLH metamaterials

This letter presents the design of a new efficient double negative metamaterial antennas. The design of the unit cell of these antennas is based on the composite right/left-handed (CRLH) transmission line model. The zeroth-order resonance of this kind of antennas depends mainly on the equivalent circuit of the unit cell and provides the opportunity to design the antenna with very small electrical size. The previous published results show that the conventional CRLH mushroom radiator suffers from narrow bandwidth and low gain. In this letter, we introduce a new method of design of CRLH metamaterial antennas to tackle the above problem using two layers of CRLH mushroom structure. The upper layer of the CRLH is used to reduce the reactance of the small antenna and to improve the matching between the antenna and the feeding line. The results at the zeroth-order resonance show improvements in the antenna gain and bandwidth by introducing the upper layer. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2224–2229, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27078

Metamaterial Dispersion Engineering Concepts and Applications

Metamaterial dispersion engineering is presented as a general concept for engineering the phase versus frequency response of microwave materials and devices. Two categories of metamaterials are considered, composite right/left-handed (CRLH) transmission line and multiscale ferromagnetic nanowire (FMNW) metamaterials. The dispersive Drude properties of CRLH metamaterials are derived and corresponding application examples are described in terms of CRLH dominant Taylor dispersive parameters: a tight broadband coupled-line coupler (phase velocity parameter), an ultra-wideband pulse position modulator transmitter (group velocity parameter), and a leaky-wave antenna based real-time spectrum analyzer (group velocity dispersion parameter). FMNW metamaterials are discussed as a double-Lorentz example of a multiscale metamaterial with unique properties, and their applications are illustrated with the example of a dual-band edge-mode isolator based on the recently discovered double ferromagnetic resonance.

Composite right/left‐handed extended equivalent circuit (CRLH‐EEC) FDTD: stability and dispersion analysis with examples

AbstractA composite right/left‐handed (CRLH) extended equivalent circuit (EEC) FDTD method with a stability criterion based on a Liapunov discrete energy function is presented and applied to investigate several transient and refractive phenomena occurring at the interface between a CRLH metamaterial (MTM) and a purely right‐handed (PRH) structure. This formulation consists in an extension of the equivalent circuit (EC) Yee scheme including a left‐handed (LH) series capacitance and shunt inductance in addition to the canonical right‐handed (RH) series inductance and shunt capacitance, so as to model general CRLH transmission line (TL) MTMs. This CRLH‐EEC FDTD scheme is shown to represent a convenient numerical scheme, with remarkable formulation compactness and high computational efficiency, for the analysis of any type of MTM structure. Moreover, this scheme, coupled with a Y‐matrix representation of the EEC Yee cell, is shown to rigorously restore the dispersion/attenuation relation of CRLH MTMs. Transient solutions for the propagation of a modulated Gaussian pulse through a PRH–CRLH interface highlights interesting effects such as space‐domain compression, infinite phase velocity modulation and the well‐known backward wave effect. Frequency‐domain analysis of the fields radiated by dipoles through the Veselago–Pendry lens shows how focusing is affected both qualitatively and quantitatively by the orientation of the dipoles. Copyright © 2006 John Wiley & Sons, Ltd.

The challenge of homogenization in metamaterials

The problem of homogenization, i.e. substantial reduction of the electrical size of the average lattice constant, of electromagnetic left-handed (LH), or more generally composite right/left-handed (CRLH) metamaterials (MTMs), is presented. The undesirable effects of an electrical very large structural unit cell are explained and illustrated by full-wave simulations and experiments with CRLH mushroom structures. These effects are limited bandwidth, anisotropy, poor refraction due to coupling of the fundamental wave with space harmonics and diffraction at interfaces with other media. Transmission line method (TLM) simulations demonstrate that homogenization may mitigate or suppress these parasitic effects. In addition, the challenging necessity of drastically increasing inductances and capacitances in the homogenization process is demonstrated for CRLH MTMs.