Multilayer Resonator Research Articles

HYBRID BROADBAND 60-GHZ DOUBLE NEGATIVE METAMATERIAL HIGH GAIN ANTENNA

This paper proposes a double negative metamaterial surface as a superstrate for a multilayer cylindrical dielectric resonator antenna (MCDRA). The aim is to achieve a broadband and high gain Electromagnetic Band Gap (EBG) antenna that can be used in harsh propagation areas to satisfy all the requirements for the 60GHz wireless communications offering a bandwidth of 7GHz in the unlicensed ISM band (57–65 GHz), permitting to reach data rates of 10Gbit/s and more. To meet these objectives various techniques are combined. Numerical and experimental results showed satisfactory performances with achievable impedance bandwidth of more than 10.5% (from 58.1 to 64.2GHz) and a 18 dBi gain, an enhancement of 13 dBi compared to a homogenous DRA without metamaterial superstrate. The proposed antenna exhibits directive and stable radiation pattern in the entire operating band.

Selective normal mode excitation in multilayer thin film bulk acoustic wave resonators

A method for selective normal mode excitation in thin film bulk acoustic wave resonators, based on multilayer structures with any number of ferroelectric films in the paraelectric phase, is presented. The possibility to control the excitation of thin film bulk acoustic resonators' normal modes by simultaneous manipulating both the polarities and the magnitudes of the dc bias voltages applied to the ferroelectric layers is demonstrated. The proposed method was verified using the Lakin's model, modified to describe the electro-mechanical behavior of a structure with four active ferroelectric layers.

Optomechanical coupling between a multilayer graphene mechanical resonator and a superconducting microwave cavity.

The combination of low mass density, high frequency and high quality factor, Q, of mechanical resonators made of two-dimensional crystals such as graphene make them attractive for applications in force/mass sensing and exploring the quantum regime of mechanical motion. Microwave optomechanics with superconducting cavities offers exquisite position sensitivity and enables the preparation and detection of mechanical systems in the quantum ground state. Here, we demonstrate coupling between a multilayer graphene resonator with quality factors up to 220,000 and a high-Q superconducting cavity. Using thermomechanical noise as calibration, we achieve a displacement sensitivity of 17 fm Hz(-1/2). Optomechanical coupling is demonstrated by optomechanically induced reflection and absorption of microwave photons. We observe 17 dB of mechanical microwave amplification and signatures of strong optomechanical backaction. We quantitatively extract the cooperativity C, a characterization of coupling strength, from the measurement with no free parameters and find C = 8, which is promising for the quantum regime of graphene motion.

Optical limiting properties of a nonlinear multilayer Fabry-Perot resonator containing niobium pentoxide as nonlinear medium.

The optical limiting effect was numerically simulated and experimentally observed for a 25-layer thin-film Fabry-Perot microresonator by 7 ns laser pulses at 532 nm. The sample, made by vacuum evaporation and consisting of alternating Nb2O5 and SiO2 layers, has an ultranarrow line of transparency at near 532 nm within a wide spectral band of reflection. By adjusting simulated results in accordance with experimental dependencies of transmittance, reflectance, and absorbance on incident light intensity, the coefficient of optical nonlinearity of Nb2O5 was estimated at (6+1i)·10(-12) cm2/W.

Numerical investigation of a grating and graphene-based multilayer surface plasmon resonance biosensor

A multilayer surface plasmon resonance biosensor (SPRB) incorporating a grating-graphene configuration is investigated for enhanced sensitivity. The numerical analysis of the impact of integrating a periodic array of subwavelength grating on top of a layer of graphene sheet for improving sensitivity is presented. The result of monitoring the biomolecular interactions of DNA hybridization is compared against the outcome of the conventional SPRB, a graphene-based multilayer SPRB, and a multilayer layer grating SPRB, and is mathematically validated. It is demonstrated that the inclusion of a grating and graphene layer on top of the gold thin film is an excellent candidate for a highly sensitive SPRB. To achieve further enhancement of sensitivity, the subwavelength grating is numerically optimized against its geometry including grating configurations (rectangular, sinusoidal, and triangular), grating depth, volume factor, and grating period.

DESIGN OF MINIATURIZED BANDPASS FILTERS USING QUASI-LUMPED MULTILAYER RESONATORS

A novel design procedure for a compact multilayer bandpass filter is proposed and examined. The filter is realized using quasi-lumped multilayer resonators. Based on the orientation of these coupled-resonator pairs, a second-order bandpass filter is realized with transmission zeros. In order to achieve a low external quality factor, i.e., a wider filter bandwidth, different types of feeder realization are considered. The design methodology with all relevant steps is presented and the equivalent-circuit of the resonator is also derived and verified. The filter design is simulated using a 3D electromagnetic model and validated by measurements on the fabricated filter. The simulation and experimental results are in good agreement.

Investigation of the Q-Factor of Optical Resonators in Photonic Crystals and Principles of Designing Highly Selective Filters on Their Basis

Designs of optical resonators comprising a half-wavelength dielectric layer bounded from both ends by quarter-wavelength layers with permittivity higher or lower than that of the half-wavelength layer are investigated. Electrodynamic analysis demonstrates a significant increase in the Q-factor of the multilayered resonator in comparison with the conventional single-layer half-wavelength resonator. Principles of designing highly selective passband filters based on photonic crystal structures are considered.

Sensitivity analysis of multi-layered C-axis inclined zigzag zinc oxide thin-film resonators as viscosity sensors

This paper presents a theoretical analysis of a new zigzag C-axis inclined multi-layer ZnO thin-film bulk acoustic wave resonator (FBAR) as a viscosity sensor to monitor the lubrication performance of engine oil and other liquids. Free vibration and forced vibration for the FBAR loaded with liquids are analyzed. Equations necessary to calculate the sensitivity are derived. The numerical analysis shows that as the number of layers increases, the absolute sensitivity increases as well. The influences on the sensitivity of C-axis inclined angle, Q-factor, and thickness are also investigated. The results provide a foundation for further design of multi-layer FBAR viscosity sensors.

Multilayer Interdigital Structures for Compact Bandpass Filters Providing High Selectivity and Wideband Rejections

Two compact microwave filters designed using multilayer inter-digital resonators are introduced. The first structure combines vertically and horizontally coupled interdigital resonators for optimizing the surface occupation while realizing high-order filters. A 12-pole filter centered at 18 GHz, with a 2.4 GHz passband, is designed and characterized. The second structure is composed of stepped-impedance interdigital resonators for widening the upper stopband. The filter is centered at 3 GHz with a 0.9 GHz passband, and both simulated and experimental results show an extended stopband up to 21 GHz.

A thin-reflector microfluidic resonator for continuous-flow concentration of microorganisms: a new approach to water quality analysis using acoustofluidics.

An acoustofluidic device has been developed for concentrating vegetative bacteria in a continuous-flow format. We show that it is possible to overcome the disruptive effects of acoustic streaming which typically dominate for small target particles, and demonstrate flow rates compatible with the testing of drinking water. The device consists of a thin-reflector multi-layered resonator, in which bacteria in suspension are levitated towards a glass surface under the action of acoustic radiation forces. In order to achieve robust device performance over long-term operation, functional tests have been carried out to (i) maintain device integrity over time and stabilise its resonance frequency, (ii) optimise the operational acoustic parameters, and (iii) minimise bacterial adhesion on the inner surfaces. Using the developed device, a significant increase in bacterial concentration has been achieved, up to a maximum of ~60-fold. The concentration performance of thin-reflector resonators was found to be superior to comparable half-wave resonators.

Multistability and Torus Reconstruction in a DC–DC Converter With Multilevel Control

By virtue of their limited size and relatively low costs, multilevel dc-dc converters have come to play an important role in modern industrial power supply systems. When operating in a regime of high corrector gain, such converters can display a variety of new dynamic phenomena associated with the appearance of additional oscillatory modes. Starting in a state where four pairs of stable and unstable period-6 cycles coexist with the basic period-1 cycle, the paper describes a sequence of smooth and nonsmooth bifurcations through which the cycles and their basins of attraction transform as the output voltage is increased. The paper also describes the birth of a multilayered resonance torus through a transverse pitchfork bifurcation of the saddle cycle on an ordinary resonance torus.

Compact Low-Loss Wideband Differential Bandpass Filter With High Common-Mode Suppression

Compact low-loss wideband differential bandpass filters are presented in this letter. The proposed filters are constructed by a pair of multilayer differential microstrip-slotline transitions (MDMSTs) and microstrip line resonators. Wideband common-mode suppression and low insertion loss can be easily achieved by employing the MDMSTs. Wideband differential-mode passband and sharp notched band can be obtained by combining the microstrip resonators at the middle and the two sides with the pair of MDMSTs, respectively. The demonstrated filters with a compact size of 24 mm × 12 mm (0.56λg × 0.28 λg) exhibits a fractional bandwidth of 115% centered at 4.25 GHz (f0) with minimum insertion loss of 0.43 and 20 dB common-mode suppression from 1 to 10 GHz (2.35 f0).

Theory of aperture-coupled hemispherical dielectric resonator antennas with radiating elements

A new approach based on hybrid volume-surface integral equation (VSIE) formulation in combination with spherical dyadic Green's function (DGF) is presented in this paper to analyze aperture-coupled multilayer hemispherical dielectric resonator antennas (DRA) with conformal conducting patches. Hybrid VSIE is used for the planar part of the structure and is solved with the aid of spatial-domain method of moments (MoM) in order to compute magnetic surface current in a slot cut in a finite planar perfect electric conductor (PEC) sheet. Multilayer spherical electromagnetic DGFs are used to compute loading effects of hemispherical dielectric resonators and conformal patches on antenna characteristics. The effects of variation in some parameters of the structure on the return loss of the antenna are studied. Accuracy of the presented method is validated by comparing the results obtained from the proposed method with those of CAD simulations.

Simulation and Analysis of a Sub-Wavelength Grating Based Multilayer Surface Plasmon Resonance Biosensor

This paper presents a subwavelength grating based multilayer surface plasmon resonance biosensor (SPRB) which includes a periodic array of subwavelength grating on top of a layer of graphene sheet in the biosensor. The proposed biosensor is named grating-graphene SPRB (GG-SPRB). The aim of the proposed multilayer structure is to improve the sensitivity of the SPRB through monitoring of the biomolecular interactions of DNA hybridization. Significant sensitivity improvement is obtained for the GG-SPRB compared with the conventional SPRB. The result of the numerical investigation of the GG-SPRB is presented and compared with a theoretically developed multilayer matrix formalism, and a good agreement has been observed. In addition, an optimization of the grating dimensions including volume factor, grating depth, grating angle, grating period, and grating geometry (e.g., rectangular, sinusoidal and triangular) is presented. The outcome of the investigation presented in this paper identifies desired functioning conditions corresponding to the best design parameters for the GG-SPRB.

Varying the agglomeration position of particles in a micro-channel using Acoustic Radiation Force beyond the resonance condition

It is well-known that particles can be focused at mid-height of a micro-channel using Acoustic Radiation Force (ARF) tuned at the resonance frequency (h=λ/2). The resonance condition is a strong limitation to the use of acoustophoresis (particles manipulation using acoustic force) in many applications. In this study we show that it is possible to focus the particles anywhere along the height of a micro-channel just by varying the acoustic frequency, in contradiction with the resonance condition. This result has been thoroughly checked experimentally. The different physical properties as well as wall materials have been changed. The wall materials is finally the only critical parameters. One of the specificity of the micro-channel is the thickness of the carrier and reflector layer. A preliminary analysis of the experimental results suggests that the acoustic focusing beyond the classic resonance condition can be explained in the framework of the multilayered resonator proposed by Hill [1]. Nevertheless, further numerical studies are needed in order to confirm and fully understand how the acoustic pressure node can be moved over the entire height of the micro channel by varying the acoustic frequency. Despite some uncertainties about the origin of the phenomenon, it is robust and can be used for improved acoustic sorting or manipulation of particles or biological cells in confined set-ups.

Novel Compact Interdigital Bandpass Filters with Multilayer Stepped Impedance Resonators/Folded Quarter–Wavelength Resonators

Novel compact interdigital bandpass filters (BPFs) which used multilayer stepped impedance resonators (SIRs)/folded quarter–wavelength resonators were presented. Two measures were taken to reduce the sizes of the proposed filters. Firstly, two resonators (SIRs and folded quarter–wavelength resonators) with novel structures were designed. Secondly, all the designed resonators were located on different dielectric layers. The proposed interdigital BPFs, which were simulated with the high frequency structure simulator (HFSS), show excellent performance and could realize the miniaturization purpose. Furthermore, it is found that the proposed filter with folded quarter–wavelength resonators is more excellent in realizing miniaturization and improving performance than that with SIRs.

Metamaterial absorber and extending absorbance bandwidth based on multi-cross resonators

In this paper, we report the design, simulation, and measurements of a broadband metamaterial absorber (MA) based on a periodic array of multi-layer cross-structure resonators. A perfect narrowband MA consists of cross-structure resonator, dielectric substrate, and continuous metal films, and the absorption frequency can be tunable by changing the geometrical parameters based on L-C resonance circuit theory. Furthermore, the absorption band of our design is effectively extended by simply stacking several such structural layers with different geometrical dimensions. Finally, the 4-layer cross-structure MA is only 2 mm, which can achieve a full width at half maximum (FWHM) bandwidth of 2 GHz by numerical simulations, and 90 % bandwidth of 1.9 GHz by experiments.

Approach for plasmonic based DNA sensing: amplification of the wavelength shift and simultaneous detection of the plasmon modes of gold nanostructures.

In this article, the detection of DNA hybridization taking advantage of the plasmonic properties of gold nanostructures is described. The approach is based on the amplification of the wavelength shift of a multilayered localized surface plasmon resonance (LSPR) sensor interface upon hybridization with gold nanorods and nanostars-labeled DNA. The amplification results in a significant decrease of the limit of detection from ≈40 nM as observed for unlabeled DNA to 0.2 nM for labeled DNA molecules. Furthermore, the plasmonic band, characteristic of the labeled DNA, is different from that of the LSPR interface. Indeed, next to the plasmon band at around 550 nm, being in resonance with the plasmon band of the LSPR interface, additional plasmonic peaks at 439 nm for gold nanostar-labeled DNA and 797 nm for gold nanorod-labeled DNA are observed, which were used as plasmonic signatures for successful hybridization.

Broadband four-element multi-layer multi-permittivity cylindrical dielectric resonator antenna

In this article, a four-element multi-layer multi-permittivity (MLMP) cylindrical dielectric resonator antenna (CDRA) for broadband application is proposed. The proposed antenna provides the measured input impedance bandwidth of 58.1% (at resonance frequency 4.03 GHz) from 3.48 GHz to 5.82 GHz for input reflection coefficient (S11) less than −10 dB. The measured average gain is 4.82 dB in the frequency range of 3.48 to 5.82 GHz. The design provides consistent omnidirectional characteristics and low cross polarization within the operating band. Design details of the proposed antenna and the results of both simulation and experiment are presented and discussed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:932–937, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27452

Compact LTCC balanced bandpass filter using distributed‐element resonator

Presented is a vertically and horizontally folded half-wavelength resonator in a three-dimension (3D) environment and its application to a balanced bandpass filter (BPF). Benefiting from the multilayered resonator based on the transmission line theory and low temperature co-fired ceramic (LTCC) technology, the proposed balanced BPF can obtain compact size and good performance. For demonstration, a LTCC balanced BPF centred at 2.45GHz has been designed using the proposed resonator, and the size of the circuit is 6.0 × 5.0 × 1.6 mm3.