Resonant Behavior Research Articles

Direction of Arrival Algorithm for Acoustic Sensors Operating Near Resonance

Recently, it has been possible to detect sound direction using phase-sensitive sensors placed much closer to each other than the sound wavelength. A typical setup combines two phase-sensitive sensors placed perpendicular to each other with a third omnidirectional sensor, the latter to determine the bearing quadrant. So far, algorithms that extract the sound direction from the sensor voltages have only been applicable to sensors with identical frequency responses. However, we have developed microelectromechanical systems (MEMS) sensors with simple harmonic oscillator-like resonance behavior for which these algorithms no longer apply. The operation near resonance greatly increases their performance, but the frequency dependencies of any two sensors are different from each other and from the omnidirectional sensor. In this letter, we show how to accommodate these differences, first, by forcing the two sensor peaks to conform to each other in both magnitude and phase, and second, by adjusting the phase of the omnidirectional sensor to approximately match the phases of the resonant sensors near their resonant frequencies. We then present two algorithms to extract the sound direction. We lay out the theoretical basis for our algorithms and present measurements of acoustic noise to show the algorithms’ effectiveness.

Nonlinear primary resonance behavior of graphene platelet-reinforced metal foams conical shells under axial motion

Nonlinear primary resonance behavior of graphene platelet-reinforced metal foams conical shells under axial motion

Nonlinear energy localisation in a model of plane metamaterial

Applying the concepts of nonlinear normal modes and limiting phase trajectories introduced by Manevitch in Manevitch (Arch Appl Mech 77:301–312, 2007) to a two-dimensional mass–spring system, the authors propose a generalised method to tune a plane metamaterial and get the desirable resonant behaviour at short wavelengths. Indeed, the account of nonlinear coupling between the oscillators enables the localisation of energy leading the origin of a bandgap at short wavelengths regardless the existence of external disturbances. Moreover, further restrictions on the modes amplitude allow the observation of Fermi–Pasta–Ulam–Tsingou recurrence and super-recurrence in the two-dimensional metamaterial. These findings can open the way to further research in order to improve efficiency and performance of resonant metamaterials.

Optimized absorption performance of a terahertz single mode metamaterial for gas and liquid detection

Metamaterial absorbers are widely used in the sensing field based on their rich resonance behaviors. So far, the applications of metamaterial absorbers in gas sensing have not been paid much attention by researchers. A single-mode narrow bandwidth THz metamaterial absorber is suggested and validated. An absorption peak is excited based on local surface polarization mode resonance and dielectric loss in the 2 to 36 THz band. In experiments, the hole array diameter R is increased, the absorption peak is increased from 0.51 to 0.66, and resonance position is moved to the high-frequency region. When the dielectric layer thickness h2 is increased, the absorption peak is increased from 0.51 to 0.57, and resonance position is moved to the low-frequency region. Similarly, when the dielectric layer thickness h3 is increased, the absorption peak is increased from 0.51 to 0.53, and resonance position is also moved to the low-frequency region. This metamaterial absorber exhibits the feasible for gas and liquid sensing.

Resonant scattering between dark matter and baryons: Revised direct detection and CMB limits

Traditional dark matter models, e.g., weakly interacting massive particles (WIMPs), assume dark matter (DM) is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by the Born approximation; most direct detection experiments are analyzed according to that assumption. We show that when the fundamental DM-baryon interaction is attractive, dark matter-nucleus scattering is nonperturbative in much of the relevant parameter range. The cross section exhibits rich resonant behavior with a highly nontrivial dependence on atomic mass; furthermore, the extended rather than pointlike nature of nuclei significantly impacts the cross sections and must therefore be properly taken into account. The repulsive case also shows significant departures from perturbative predictions and also requires full numerical calculation. These nonperturbative effects change the boundaries of exclusion regions from existing direct detection, astrophysical and CMB constraints. Near a resonance value of the parameters the typical velocity-independent Yukawa behavior, $\ensuremath{\sigma}\ensuremath{\sim}{v}^{0}$, does not apply. We take the nontrivial velocity dependence into account in our analysis, however it turns out that this more accurate treatment has little impact on limits given current constraints. Correctly treating the extended size of the nucleus and doing an exact integration of the Schr\"odinger equation does have a major impact relative to past analyses based on the Born approximation and naive form factors, so those improvements are essential for interpreting observational constraints. We report the corrected exclusion regions superseding previous limits from XQC, CRESST Surface Run, CMB power spectrum and extensions with Lyman-$\ensuremath{\alpha}$ and Milky Way satellites, and Milky Way gas clouds. Some limits become weaker, by an order of magnitude or more, than previous bounds in the literature which were based on perturbation theory and pointlike sources, while others become stronger. Gaps which open by correct treatment of some particular constraint can sometimes be closed using a different constraint. We also discuss the dependence on mediator mass and give approximate expressions for the velocity dependence near a resonance. Sexaquark ($uuddss$) DM with mass around 2 GeV, which exchanges QCD mesons with baryons, remains unconstrained for most of the parameter space of interest. A statement in the literature that a DM-nucleus cross section larger than ${10}^{\ensuremath{-}25}\text{ }\text{ }{\mathrm{cm}}^{2}$ implies dark matter is composite, is corrected.

Abundant Resonant Behaviors of Soliton Solutions to the (3+1)-dimensional BKP-Boussinesq Equation

Resonant phenomena have been observed and investigated in various situations, such as plasma experiments, the maritime security and the microtubule in cell physiology. In this paper, abundant resonant behaviors are studied for the (3+1)-dimensional BKP-Boussinesq equation. We mainly discuss the resonant two- and three-soliton solutions in the (x, y)-plane and (x, z)-plane. The characteristics are given for the kink soliton waves, including expressions, maximums, minimums and velocities. The kink soliton waves in the (x, y)-plane are parallel, and the fusion or fission may occur. The kink soliton waves in the (x, z)-plane are not parallel and the resonant phenomena among them are more complicated.

Modal model prediction of surface waves and resonant characteristics of rectangular grooved gratings.

A modal model formulation explains many aspects of sound propagation over complex grooved surfaces. Insights that such a formulation offers about the intrinsic resonant properties of rectangular grooved surfaces shall be explored and applied to predict phenomenon such as surface waves and non-specular energy redistribution (blazing). Furthermore, the effects of filling the grooves with a porous material are investigated. A brief summary is made of the modal method and the mechanisms involved with sound propagation over rough surfaces to provide the context before exploring, in detail, how the modal method may be applied to predict various resonant behaviours of rectangularly grooved gratings. As well as their general predictive capabilities, the modal methods also provide significant insight into the wave modes diffracted by grooved surfaces under incident excitation at a low computational cost.

Tunable resonant absorption emanating from in-plane hyperbolic phonon polaritons

Resonances play a key role in the practical application of polaritons because they can be easily detected from the far field and integrated with various devices. Although the mechanism and implementation of polariton resonances have been studied extensively, the resonant behaviors of in-plane anisotropic polaritons and their tuning strategies remain largely unexplored so far. Here, using in-plane hyperbolic phonon polaritons in α-MoO3 as an example, we analyze their resonant absorption upon multiple conditions theoretically. We unveil the collective resonant mode originating from synergistic Fabry−Pérot cavity resonances and Bragg resonances. Beyond controlling polarizations and geometries, active tuning of resonant absorption is further achieved by rotating resonators or changing polariton topologies. Our results bridge the gap between polariton dispersions and resonant absorption, and provide a bottom-up strategy for the design of polariton-based resonators, photonic crystals, and metasurfaces. The resonant structures proposed here could serve as versatile building blocks for infrared absorbers, polarization detectors, sensors, modulators, and other photonic devices.

Tailoring of the nonlinear optical rectification in vertically and laterally coupled InxGa1-xAs/GaAs quantum dots for Tera-hertz applications: Under In/Ga inter-diffusion, indium segregation, and strains effects

We numerically investigate the Nonlinear Optical Rectification (NOR) of two laterally coupled lens-shaped InxGa1-xAs/GaAs quantum dots and two layers of InxGa1-xAs/GaAs coupled QDs along the growth axis. In addition, we have examined the impact of applying an external electric field, hydrostatic pressure, and temperature on the NOR under indium segregation inside the wetting layer (WL) and In/Ga inter-diffusion in the QD region. The three-dimensional Schrödinger equation (3D) is solved numerically using the finite difference method (FDM) within the framework of the effective mass. We have used the compact density matrix formalism to compute the NOR coefficient. Our findings reveal that the indium segregation and inter-diffusion phenomena significantly affect the NOR coefficient and should be considered appropriately. It is also found that the lateral and vertical coupling thicknesses significantly impact the NOR coefficient, and the structure under investigation has a resonant behavior in the terahertz domain (0.1–10 THz). Moreover, obtained results reveal that the applied electric field orientation and intensity significantly affect the NOR magnitude. Therefore, the NOR intensity reaches the maximum value, χ(0)(2)=50.10-7m/V, for a negative applied electric field, F = −10 kV/cm. Additionally, it was shown that the increase in the hydrostatic pressure shifts the NOR spectrum to higher energies (blue-shift), whereas increasing temperature has the contrary effect. It is worth noting that the NOR magnitude and its attributed resonance energy can be adjusted for THz devices with a good choice of the external factors mentioned above.

Verification of the Effect of Local Electric Field Resonance Behaviors on the Transmission Properties of the Dual-Band Terahertz Metasurface

Verification of the Effect of Local Electric Field Resonance Behaviors on the Transmission Properties of the Dual-Band Terahertz Metasurface

Broadside‐Coupled Split Ring Resonators as a Model Construct for Passive Wireless Sensing

AbstractPassive and wireless Radio‐Frequency (RF) sensors are a unique, enabling modality for emerging applications in environmental sensing. These sensors exhibit several key features that may unlock new functionalities in complex environments: sensors are composed of zero electronic components, are wirelessly interrogated even in opaque media, and structures are often inherently biocompatible. Such capabilities make it unique in the realm of sensing architectures. Here, the broadside‐coupled, split‐ring resonator is studied as a compact and versatile model structure for RF sensing (of potentially mechanical and biochemical environments). A new analytical model is derived to assess resonator behavior—these yield a rapid, first‐order approximation of the resonator resonant frequency or sensitivity. Finally, experimental investigations into how sensors may be optimally designed, sized, and interrogated to enhance sensitivity or spectral intensity are performed. These studies encompass a wide variety of potential dimensional and dielectric modifications that may be relevant to emerging sensors. Last, hydrogel polymeric sensors are synthesized and studied to assess how practical sensors may deviate in response from expectations. Such investigations lay the groundwork for how such sensing architectures may be adapted to fit application needs.

Pentaband Dual-Polarized Antenna for Multiservice Wireless Applications

This paper presents a novel design for and an experimental study of a dual-polarized quad-port MIMO antenna. The design achieves resonance at five distinct frequency bands with reduced mutual coupling. The design includes a single annular ring slot, four truncated rectangular corners, and a truncated aperture to improve resonance behavior. The design is then extended to a four-port MIMO antenna by including a ground-plane slit to enhance isolation between antenna elements at the center resonance band. The antenna achieves resonances at 5 distinct bands, ranging from 1.5 to 8.4 GHz, with significant mutual coupling reductions. The resonances of the quad-port pentaband MIMO antenna are achieved at 1.55 GHz (1.5–1.65 GHz), 2.5 GHz (2.4–2.7 GHz), 5.2 GHz (5–5.85), 7.3 GHz (7.1–7.4), and 8.15 GHz (7.9–8.4), with respective mutual coupling reductions of 27 dB, 37 dB, 21 dB, 29 dB, and 21 dB. Additionally, the 3 dB axial ratio bandwidth (ARBW) is observed at 6.5% (1.5–1.6 GHz) and 15% (2.4–2.7 GHz) in 2 distinct bands, and the envelope correlation coefficient and diversity gain are calculated within the specified band range. Experimental measurements of the prototype for the quad-port antenna are conducted, with excellent agreement found between the results and the simulations.

Modelling and nonlinear analysis of the wave-induced vibrations of a single hybrid riser conveying two-phase flow

This paper analyses the nonlinear dynamic response of a single hybrid riser pipe to wave excitations. Detailed nonlinear equations of motion are derived for the riser pipe as it conveys two-phase flow. Hence its dynamics are described by two coupled nonlinear equations, relating to both longitudinal and transverse displacements. Wave excitations forcing the system are imposed as oscillating inline flow. In addition, considering that the riser is a structure that is vibrating in a moving fluid, the inline force is modelled with the extended Morison equation. These equations are solved by the method of multiple scale perturbation. Theoretical results show that longitudinal and transverse responses are coupled at some specified natural frequencies. Similarly, the riser pipe is also prone to primary and super-harmonic resonance excitations at some wave frequencies. This presents a complex nonlinear multi-frequency excitation problem identical to the numerical studies conducted on a typical single hybrid riser pipe based on the frequency response curves. The uncoupled primary resonance behaviour of the transverse displacements for all the void fractions studied exhibited a hardening nonlinear behaviour of non-unique responses and jump phenomenon. However, a distinctive feature of the harmonics was observed where the curves separate into two to form an isolated branch of periodic solutions. These are known as Isola. Also, the presence of internal resonance results in the transfer of energy between the planar axis resulting in undesirable axial resonance peaks which are destabilized by the presence of the nonlinear anti-resonance effect.

All-dielectric metasurface-based color filter in CMOS image sensor

The development of all-dielectric metasurfaces vigorously prompts the applications of optical metasurfaces for a CMOS (Complementary Metal-oxide-semiconductor) image sensor. Dielectric nanostructures, due to their resonant behavior and its tunability, offer the possibility to be assembled into flexible and miniature spectral filters, which could potentially replace conventional pigmented and dye-based color filters. In this paper, a transmission filter based on a GMR (Guided Mode Resonance) mode of all-dielectric metasurface is adopted as an example to study the effect of application scenario of integrated CMOS image sensor chip and manufacturing mistakes, such as the small size of pixel, special dielectric environment around, surface roughness and structural defects. Numerical calculations based on the FDTD (finite difference time domain) method are used to study the relationship between the robustness of the metasurfaces and the optical resonant modes. More important, a method simplifying different manufacturing mistakes as basic geometry structure during the FDTD simulation is also proposed and demonstrated. This work deepens our understanding of the working mechanism of all-dielectric metasurfaces and paves the way for their use in CMOS image sensor.

Compact magnetoelectric power splitter with high isolation using ferrite/piezoelectric transformer composite

A compact, passive magnetoelectric (ME) power splitter, with a ferrite/piezoelectric transformer bilayer composite with a coil wound around it, as well as a structure-constructing strategy, was presented and developed in this research. The impedance differences in a Rosen-type PT induced by integrated transverse/longitudinal polarizations facilitated the device realization with higher isolation rather than elementary LCR lumped elements. Furthermore, the measurements of the material properties and electrical resonance behaviors for the presented ME splitter were implemented, and the power-dividing capabilities were verified by measuring the output and corresponding power for each port of the device. The experimental results demonstrated that the power for Port I in the ME power splitter reached its maximum values of 154.26 nW at R = 6 kΩ and 475.95 nW at R = 5.5 kΩ. Correspondingly, the power for Port II reached its maximum values of 12.73 nW at R = 30 kΩ and 27.85 nW at R = 12 kΩ. Consequently, a power division ratio of 3:1 was obtained under optimum load resistance and EMR conditions with constant input power. These results provided an innovative approach to constructing novel functional power electronics with solid-state materials while suggesting the promising applications for some special scenarios such as powering and controlling multi-channel LCD strings.

Nonlinear Finite Element Calculations of Layered SAW Resonators.

In this work the nonlinear behavior of layered SAW resonators is studied with the help of Finite Element (FE) computations. The full calculations depend strongly on the availability of accurate tensor data. While there are accurate material data for linear computations, the complete sets of higher-order material constants, needed for nonlinear simulations, are still not available for relevant materials. To overcome this problem, scaling factors were used for each available nonlinear tensor. The approach here considers piezoelectricity, dielectricity, eletrostriction and elasticity constants up to fourth order. These factors act as a phenomenological estimate for incomplete tensor data. Since no set of fourth order material constants for LiTaO3 is available, an isotropic approximation for the fourth order elastic constants was applied. As a result, it was found that the fourth order elastic tensor is dominated by one fourth order Lamé constant. With the help of the FE model, derived in two different, but equivalent ways, we investigate the nonlinear behavior of a SAW resonator with a layered material stack. The focus was set to third order nonlinearity. Accordingly, the modeling approach is validated using measurements of third order effects in test resonators. In addition, the acoustic field distribution is analyzed.

Generalized stochastic resonance in a time-delay fractional oscillator with damping fluctuation and signal-modulated noise

In this study, we propose a time-delayed fractional oscillator (FO) subjected to damping fluctuation and signal-modulated noise, and investigate the generalized stochastic resonance (GSR) behaviors. By using (fractional) Shapiro–Loginov formula and Laplace transform, we obtain the first-order moment of system stationary state response, and the output amplitude gain (OAG). Based on the analytical results, it is observed that the GSR behaviors widely exist in the system, and they can be effectively controlled by the system parameters, including driving frequency, noise parameters, fractional order and time delay. It is also demonstrated that fractional order and time delay are two effective dimensions to regulate the GSR intensity under different parameter conditions, and the diversity of GSR behaviors mainly depends on the fractional order.

Design of Uncoupled and Cascaded Array of Resonant Microwave Sensors for Dielectric Characterization of Liquids

In this article, we introduce an array of uncoupled and cascaded microwave sensors with a novel structure for the dielectric characterization of liquid samples for biomedical applications. The developed array consists of four cascaded resonators and can measure the complex permittivity of multiple samples simultaneously and independently, contributing to microwell plate measurements. The fabricated sensors consist of couplers and defected grounded interdigitated capacitors (IDCs), yielding a high sensitivity. Each sensor in the array acts as a resonator, with the resonance frequency and quality factor changing according to the material under test (MUT). We have used water/ethanol mixtures in different concentrations to calibrate the sensor and later relate the changes in resonance behavior to the one in dielectric permittivity. The corresponding fitting functions based on IDC’s model have a high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$r$ </tex-math></inline-formula> -squared value and result in a high precision permittivity extraction of the liquids with the volume of 20 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{L}$ </tex-math></inline-formula> in the frequency range of 3.87 GHz (for the sample with the highest permittivity) to 8 GHz.

Electrostatic Induction Nanogenerator Boosted by One‐Dimensional Metastructure: Application to Energy and Information Transmitting Smart Tag System (Adv. Sci. 11/2023)

Energy and Information-Transmitting Smart Tag System An energy and information-transmitting smart tag system is designed and demonstrated based on the electrostatic induction nanogenerator. The acoustic one-dimensional metastructure showing resonant behavior boosts the performance of nanogenerators, which is enough to transfer the electrical energy and signal simultaneously in free space. More details can be found in article number 2205141 by Geon-Ju Choi, Sang-Hyun Sohn, and Il-Kyu Park.

Nonlinear Resonance Characteristics Analysis of DBD Load Based on State Plane Trajectory

Dielectric barrier discharge (DBD) loads and driving converters are widely utilized in low-temperature plasma generation, but their resonant tanks have typical nonlinear characteristics with control issues. The state plane trajectory analysis is used in this article to investigate the resonant behavior of a DBD load. The converter's working principle and state plane modeling are first discussed. The impact of a high-ratio step-up transformer with parasitic capacitance is then explored, and the updated trajectory model is examined. The DBD platform is created to verify the suggested model, and the associated experimental data are provided. The results of the experiment demonstrate that the discharge trajectory is a zone with distinct borders. The trajectory equations can be utilized to calculate the load equivalent capacitance, and the difference in the boundary equivalent capacitance represents the discharge intensity. The pattern of resonant frequency variation with discharge power is given. The impact mechanism of discharge phenomena and resonance characteristics is discussed.