1217 results about "Metamaterial" patented technology

The invention relates to the technical field of fault diagnosis of power electronic equipment, and particularly discloses a fault analysis and diagnosis method and system for a mining high-voltage frequency converter, and the method comprises the steps: collecting the skin effect depth and parasitic parameter drift distance in real time under a high-frequency working condition through a multi-physics field sensor array; constructing three-dimensional current density distribution of the conductor based on a non-Euclidean space mesh generation technology, and dynamically correcting the equivalent resistivity of the conductor in combination with a metamaterial database to calculate a dynamic eddy current loss characteristic value; optimizing and solving the parasitic parameter time-varying evolution equation by using a quantum annealing algorithm to obtain a voltage peak sensitivity characteristic value; inputting the characteristic value into a pre-trained deep residual shrinkage network diagnosis model for multi-modal fusion analysis, and outputting a fault risk assessment result; according to the method, the problem of parasitic parameter time-varying characteristic modeling in the vibration environment is innovatively solved, and early warning of hidden faults is achieved.

The invention belongs to the technical field of all-dielectric metamaterial optical devices and machine learning, and discloses an all-dielectric metasurface target spectral response reverse design method based on deep learning. And realizing efficient prediction of the transmission spectrum by using a convolutional neural network-recurrent neural network-residual network architecture. A fitness function is designed, and a machinable structure is generated by aiming at single-peak and multi-peak target wavelength optimization and combining a linear and shape optimization strategy. The method breaks through the limitation of spectrum dependence and fixed structure type of the traditional reverse design, realizes on-demand design, and remarkably improves the design efficiency and processing compatibility of the integrated photonic device.

The technology described herein is directed towards one or more modular metasurfaces arranged with unit cells for sound absorption, in which the unit cells are based on Helmholtz resonators that are deployed proximate to a server, without substantially obstructing airflow from the server fan(s). Each sound absorbing unit-cells is designed and constructed based on a specific resonance frequency, and includes a neck portion and air chamber dimensioned to resonate at the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. The metasurfaces can be arranged in a modular frame structure of surrounding unit cells, positioned behind the server's fan(s), with an opening in the frame structure to facilitate airflow therethrough, without obstructing or substantially obstructing the airflow to the surrounding environment.

A lightweight absorption-transmission integrated metamaterial to electromagnetic waves with polarization stability and wide-incident-angle stability, which has a symmetric structure including at least one square frequency-selective structure-unit arranged periodically. The square frequency-selective structure-unit includes a first dielectric substrate, a metal array structure layer, a second dielectric substrate, a first carbon-based conductive film array structure layer, a third dielectric substrate, and a second carbon-based conductive film array structure layer, which are laminated in sequence with the first dielectric substrate as the bottom. A method for preparing such lightweight absorption-transmission metamaterial to electromagnetic waves is also provided.

The invention discloses an intelligent optimization driving electromagnetic information metasurface multi-dimensional dynamic regulation and control system, solves the problem that the function solidification of an existing metasurface is difficult to dynamically adjust, and belongs to the crossing field of electromagnetic metamaterials and intelligent control technologies. The method comprises the steps that a sensor network collects environment multi-dimensional information of a programmable metasurface unit in real time; the controller processes the environment multi-dimensional information to obtain a multi-dimensional sensing result; the multi-dimensional interaction layer inputs design parameters, the intelligent decision-making layer combines the design parameters and a multi-dimensional perception result to construct a target joint optimization model, reverse design is carried out on the super-surface array coding sequence, and a display array coding pattern and a three-dimensional radiation pattern / two-dimensional radiation pattern are obtained according to the designed super-surface array coding sequence; displaying on the multi-dimensional interaction layer; and the controller performs real-time electromagnetic response reconstruction and 1-bit or 2-bit phase modulation on the programmable metasurface unit through the field programmable gate array according to the designed metasurface array coding sequence.

The invention discloses a dual-frequency / broadband switchable dynamic tuning metamaterial terahertz absorber which comprises M * N terahertz absorption units of a multi-layer structure, the M * N terahertz absorption units of the multi-layer structure are distributed in an M * N two-dimensional mode, and M and N are positive integers. Each terahertz absorption unit with the multi-layer structure comprises a metal substrate, a dielectric layer and a resonance layer which are sequentially arranged from bottom to top; the dielectric layer and the metal substrate are square and have the same side length; the resonance layer comprises a single-layer graphene layer with a hollow cross, and a solid cross-shaped vanadium dioxide layer is embedded in the hollow part of the single-layer graphene layer with the hollow cross; and the appearance of the single-layer graphene layer with the hollow cross is cross-shaped. The absorber can be dynamically tuned, has the characteristic of polarization insensitivity, and can keep stable absorption in an incidence angle range of 0-60 degrees. The invention further discloses a preparation method of the dual-frequency / broadband switchable dynamic tuning metamaterial terahertz absorber.

The invention relates to a radial frequency-doubled sound filtering metamaterial and a topological optimization design method thereof.The radial frequency-doubled sound filtering metamaterial comprises scatterers which are arranged on a base body and distributed in a concentric circle mode, and the topological optimization design method comprises the following steps that a two-dimensional axial symmetry model is established, the two-dimensional axisymmetric model corresponds to the cross section of the radial frequency-doubled sound filtering metamaterial in the radius direction and comprises periodically arranged unit structures, and each unit structure comprises a main board and a square design domain; a Floquet periodic boundary condition is applied to parallel boundaries of a unit structure in the radius direction, other boundaries are set as free boundaries, a genetic algorithm is adopted to carry out iterative optimization on the material distribution topology of a square design domain, the optimal material distribution topology of the square design domain is obtained, and then the final optimized shape of the radial double-frequency sound filtering metamaterial is obtained. Compared with the prior art, the invention has the advantages of capability of realizing omni-directional sound wave frequency doubling filtering, high design reliability and the like.

The invention belongs to the technical field of radar wave-absorbing materials, and discloses a double-sided wave-absorbing broadband stealth composite material and a preparation method thereof. The broadband stealth composite material with the double-sided wave absorbing function comprises a non-metal-based composite material body and at least five metamaterial layers arranged in the thickness direction of the non-metal-based composite material body at intervals. The number of the metamaterial layers is an odd number, a middle metamaterial layer is arranged in the middle of the metamaterial layers in the thickness direction, and the rest metamaterial layers are symmetrically distributed on the two sides of the middle metamaterial layer; the metamaterial layer comprises conductive pattern units which are periodically arranged; the relative dielectric constant of the nonmetal-based composite material body is not greater than 10; the double-sided wave-absorbing broadband stealth composite material does not contain a metal reflecting layer. When electromagnetic waves with the frequency of 1-18 GHz vertically enter the material, the transmissivity of the material is small (smaller than-13 dB, namely smaller than 5%), and meanwhile the material has low reflectivity in a broadband. And the preparation method is simple to operate and easy to realize large-scale production.

The invention discloses a multi-structure novel auxetic metamaterial replaceable energy dissipation metal damper, and relates to the technical field of anti-seismic equipment, the multi-structure novel auxetic metamaterial replaceable energy dissipation metal damper comprises a fixing seat, through the fixing seat, plate-shaped auxetic supporting and columnar double-deformation mechanism novel auxetic metamaterial double structures are used for energy dissipation at the same time, so that the anti-seismic function is achieved; the building can be dynamically protected under the earthquake vibration impact effect; the modular replaceable energy consumption core body design is adopted, and quick disassembly and replacement of damaged components are achieved through the assembly type design; meanwhile, a self-adaptive displacement compensation structure is combined, and the stability of the main body structure is maintained in the continuous energy consumption process; according to the device, the anti-seismic reliability of a building structure in the whole life cycle is remarkably improved, the later operation cost is reduced through the maintenance-friendly design, and all-around performance optimization from earthquake protection to daily maintenance is achieved.

The technology described herein is directed towards a metasurface arranged with unit cells for broadband and / or multiband sound absorption, in which the unit cells are based on the principles of Helmholtz resonators. Deeply subwavelength sound absorbing unit cells are designed and constructed based on desired resonance frequencies. Each unit cell includes a neck portion and air chamber dimensioned to resonate at a desired resonance frequency and thereby inverse phase cancel corresponding frequencies of incoming sound waves. Differently designed and arranged subgroups of unit cells are part of the metasurface, which can be positioned proximate to a noise source. As practical examples, the metasurface or multiple metasurfaces can be placed near or wrapped around a computer server or rack of servers to absorb fan noise. The metasurface components (including the unit cells) can be printed by a 3D printer to result in a thin, light-weight, and cost effective noise absorbing metasurface.

The invention belongs to the technical field of terahertz detection, and discloses a terahertz metamaterial enhanced spectrum detection system. Comprising the following steps: constructing a metamaterial enhancement factor tensor matrix according to the interaction between terahertz waves and a metamaterial; performing local field enhancement and surface plasma resonance optimization on the target sample based on the metamaterial enhancement factor tensor matrix to obtain a feature enhancement spectroscopy mapping function; constructing a multi-dimensional detection feature space based on a feature enhancement spectroscopy mapping function; a spectral signal enhancement topology network is formed based on the multi-dimensional detection feature space; enhancing the topological network based on the spectral signal, and generating an enhanced spectral feature discrimination function; obtaining a high-precision terahertz spectrum detection result based on the enhanced spectrum characteristic discrimination function; according to the invention, internal correlation between spectral characteristics can be mined, and comprehensive description of sample information is enhanced, so that high-precision terahertz spectrum detection is realized.

The invention discloses an ultra-large octave wave absorber based on a photoconductive material, and belongs to the field of electromagnetic metasurfaces and metamaterials. Comprising a light response wave-absorbing metasurface and a light driving module capable of projecting different patterns on the surface of the light response wave-absorbing metasurface, array wave-absorbing units of different sizes are obtained on the light response wave-absorbing metasurface by switching the projected patterns, and impedance of a target frequency band is matched by changing equivalent capacitance / inductance of a wave-absorbing unit structure; the light driving module can project a preset light pattern on the light response wave-absorbing metasurface, so that the equivalent impedance distribution of the light response wave-absorbing metasurface is changed; according to the light response wave-absorbing metasurface, the conductivity distribution of the metasurface units is changed through light control, and the wave-absorbing frequency band is adjusted in real time, that is, dynamic adjustment of the wave-absorbing performance is achieved through non-contact light control. According to the invention, the limitation of narrow bandwidth and passive fixation of a traditional wave absorber is broken through, and electromagnetic wave control with ultra-large octave, high absorptivity and real-time reconfigurability is realized.

Devices configured to emit colored light when illuminated with ultraviolet light and color-shifting displays containing the same are disclosed.

The invention belongs to the technical field of electromagnetic wave absorption, and particularly discloses a three-dimensional structure wave-absorbing metamaterial which comprises a first three-dimensional structure layer, a second three-dimensional structure layer and a metal backboard which are sequentially arranged from top to bottom, the first three-dimensional structure layer comprises a first top layer and a first three-dimensional absorption enhancing framework arranged on the lower surface of the first top layer, and the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancing framework arranged on the lower surface of the second top layer. A first high-impedance metasurface and a second high-impedance metasurface are loaded on the lower surface of the first three-dimensional absorption enhancement skeleton at intervals; the second three-dimensional structure layer comprises a second top layer and a second three-dimensional absorption enhancement skeleton arranged on the lower surface of the second top layer, and a third high-impedance metasurface is loaded on the top surface of the second top layer. By adopting the three-dimensional structure wave-absorbing metamaterial, ultra-wideband absorption and large-angle stability can be achieved under the condition that the thickness is small, light and thin wideband application of a wave-absorbing body is facilitated, and the three-dimensional structure wave-absorbing metamaterial has great practical value in the field of electromagnetic compatibility.

The invention provides a multifunctional passive cooling optical metamaterial fiber, yarn and fabric and a preparation method thereof. The passive cooling optical metamaterial fiber is composed of high-refractive-index inorganic micro-nano particles and / or a micro-nano functional material and a polymer substrate material. Wherein wavelength / sub-wavelength scale micro-nano particles are uniformly distributed in a substrate material as a random scattering medium to form a random optical metamaterial system, and reflection enhancement of the optical metamaterial fabric in a solar spectrum band is realized by utilizing a multiple Mie resonance collective effect. According to the passive cooling optical metamaterial fiber, a circular structure, a skin-core structure and the like are prepared through melt spinning, high-refractive-index inorganic micro-nano particles are added into a skin layer and used for sunlight band wide spectrum regulation and control, and a micro-nano functional material is added into a core layer, so that multiple functions are effectively achieved.

The invention belongs to the technical field of metamaterials, and particularly relates to a diamond substrate lattice metamaterial and an additive manufacturing method thereof. The structure is designed based on the geometric configuration of a diamond lattice, and has excellent high specific absorption mechanical properties. The design process comprises the following steps: firstly, carrying out spatial registration positioning on the basis of a unit cell structure with a preset wall thickness t and a unit cell width a; then, through a multi-unit-cell splicing design, the unit cells are spliced repeatedly for 12 times to form three-dimensional periodic stacking; then, the stacked structure is cut along the six datum planes; then cross plates are inserted into the six cutting faces respectively to enhance the integrity and strength of the structure; and finally, a complete DM plate lattice metamaterial structure is formed. The structure is provided with a plate-plate cross supporting framework, a complex three-dimensional inner cavity and highly symmetrical space distribution, the energy absorption capacity under unit mass is greatly improved, the mechanical properties are basically consistent in multiple directions, and the structure is suitable for the engineering fields of impact protection, energy absorption buffering and the like.

The invention discloses an all-dielectric structure type broadband wave-absorbing metamaterial and a design method thereof. The all-dielectric structure type broadband wave-absorbing metamaterial comprises a substrate and a plurality of resonators, the plurality of resonators are periodically and uniformly arrayed on the surface of the substrate, the adjacent resonators are connected with each other, each resonator comprises a pyramid structure unit and a grid structure unit, the pyramid structure units are nested in the grid structure units to form a pyramid-grid composite resonator, and the substrate and the resonators are both made of a high dielectric loss composite material. Based on the brand new design angle of wave absorbing performance complementation, the limitation of the wave absorbing performance of a single structure is broken through, the wave absorbing performance is improved from the microstructure level, meanwhile, efficient electromagnetic wave energy absorption is achieved in a wider frequency range, multi-stage dissipation and broadband impedance matching of incident electromagnetic waves are achieved, and the wave absorbing performance is improved. And the technical limitation of thickness constraint and narrow-band response of the traditional wave-absorbing material is broken through.

The invention discloses a digital coding metamaterial forward-looking video imaging method and system based on sparse low-rank decomposition, and mainly solves the problems of motion blur and poor imaging stability in a non-sparse observation scene of a moving target in the prior art. According to the implementation scheme, echo data of N frames of observation scenes are collected; decomposing a scattering coefficient vector of an observation scene corresponding to each frame of echo into a low-rank vector of a background area corresponding to the observation scene and a sparse vector of a dynamic change area, and expressing a separation problem of the two change areas as a joint low-rank and sparse optimization problem; performing convex relaxation processing on the optimization problem, and converting the optimization problem subjected to the convex relaxation processing into an optimization problem in an unconstrained form to obtain a sparse low-rank decomposition-based metamaterial forward-looking video imaging model; and solving the constructed imaging model, and realizing multi-frame image reconstruction and video synthesis based on a solving result. According to the method, the imaging resolution and reconstruction stability of the non-sparse scene containing the moving target are improved, and the method can be used for intelligent security check and medical detection.

The invention provides an optical transparent flexible electromagnetic wave-absorbing metamaterial, and relates to the technical field of wave-absorbing materials, the electromagnetic wave-absorbing metamaterial comprises a plurality of wave-absorbing units arranged periodically, and the wave-absorbing units are made of optical transparent materials; each wave absorbing unit comprises a dielectric compensation layer, a first resonance layer, a first dielectric layer, a second resonance layer, a second dielectric layer and a reflecting layer which are sequentially arranged from top to bottom; the dielectric compensation layer is used for expanding an absorption frequency band and improving the stability of an incident angle; the first resonance layer is used for adjusting a first resonance frequency point of a reflectivity curve; the second resonance layer is used for adjusting a second resonance frequency point of the reflectivity curve; the first dielectric layer and the second dielectric layer are used for consuming electromagnetic energy; and the reflecting layer is used for reflecting redundant electromagnetic energy back to the electromagnetic wave-absorbing metamaterial for loss again. The light-transparent flexible electromagnetic wave-absorbing metamaterial provided by the invention has the advantages of flexibility, high light transmittance, good broadband wave-absorbing performance and oblique incidence angle stability.

The invention discloses a quasi-zero stiffness vibration double-control device based on metamaterials, and relates to the technical field of vibration isolation and vibration reduction control. The device comprises a vertical vibration isolation structure, a horizontal vibration isolation layer, a middle plate, an upper connecting plate and a lower connecting plate, the vertical vibration isolation structure is connected to the top face of the horizontal vibration isolation layer, and the device is characterized in that the vertical vibration isolation layer is composed of a plurality of quasi-zero-stiffness metamaterial cell elements which are horizontally and evenly distributed, and each quasi-zero-stiffness metamaterial cell element comprises a buckle mechanism and a wave-shaped beam mechanism; the negative stiffness generated in the movement process of the buckle mechanism and the positive stiffness generated in the loading process of the wave-shaped beam mechanism counteract each other, and a quasi-zero stiffness mechanism is formed. According to the quasi-zero-stiffness metamaterial cell element, the initial stiffness of the quasi-zero-stiffness metamaterial cell element can be changed by adjusting the pre-tightening force of the bolts, so that the vertical bearing capacity is changed, different engineering requirements are met, the problem that low-frequency vibration isolation of a traditional vibration isolation device fails is solved, and the quasi-zero-stiffness metamaterial cell element is particularly suitable for meeting the earthquake and vibration dual-protection requirements of rail transit upper cover buildings.

The invention discloses a bifunctional chiral metamaterial surface capable of switching polarization conversion and wave absorption, and belongs to the technical field of electromagnetic metamaterials. The method is used for solving the problem that most existing chiral super-structure surfaces cannot realize dynamic adjustability and quantitative controllability and cannot have dual functions of polarization conversion and wave absorption at the same time. The super-structure surface unit structure is composed of a graphene film layer, a gold-vanadium dioxide resonance layer, a silicon dielectric layer and a bottom-layer continuous gold film. Switching of two functions of polarization conversion and wave absorption is realized by changing the conductivity of vanadium dioxide; polarization conversion and dynamic regulation and control of the wave absorbing efficiency are realized by changing the Fermi level of the graphene; quantitative controllability of polarization conversion and a wave absorbing function is realized by controlling a function weighting function. Besides, the chiral super-structure surface also has the advantages of incident angle robustness, small thickness and small size, has double functions of broadband, and has potential application value in the fields of optical devices, communication equipment, biomedical sensors and the like.

The invention discloses a broadband wave-absorbing metamaterial of a cone-cap-like structure and application of the broadband wave-absorbing metamaterial, and belongs to the technical field of electromagnetic metamaterials. The broadband wave-absorbing metamaterial with the cone-cap-like structure comprises a rectangular shell, a hollow cylindrical table and a cone, an open groove is formed in one surface of the rectangular shell; the hollow cylindrical table is arranged in the open groove, and the outer side wall of the hollow cylindrical table is externally tangent to the inner side wall of the rectangular shell; the cone is arranged in the hollow cylindrical table, and the bottom face of the cone is connected with the bottom face of the hollow cylindrical table. The broadband wave-absorbing metamaterial structure adopting the cone-cap-like design shows excellent broadband wave-absorbing capacity in a microwave frequency band, wave-absorbing characteristics can be accurately controlled by adjusting key parameters, different application requirements are met, the broadband wave-absorbing metamaterial has excellent anti-polarization interference capacity and stability of wave-absorbing performance, and the broadband wave-absorbing metamaterial is suitable for being used in the microwave field. The method has the production advantages of rapidness, low cost and high efficiency.

The invention discloses a preparation method of a large-area and distance-adjustable gold nanoparticle single-layer superlattice film and a product and application thereof, and belongs to the technical field of nanomaterials, the method comprises the following steps: modifying the surfaces of gold nanoparticles by using sulfydryl polystyrene and 1, 8-octyldithiol to obtain double-ligand co-modified gold nanoparticles; an interface assembly strategy is adopted to enable the double-ligand co-modified gold nanoparticles to form a film at the interface of toluene and diethylene glycol, and after toluene volatilizes, the large-area gold nano single-layer superlattice film with the adjustable distance is obtained. According to the method disclosed by the invention, by accurately regulating and controlling double-ligand modification on the surfaces of the gold nanoparticles and optimizing interaction among the particles in the assembly process, accurate regulation and control of the particle spacing of the gold nanoparticle single-layer superlattice film from 1nm to 8nm are realized. The electromagnetic field intensity can be obviously enhanced by accurately regulating and controlling the particle gaps to the sub-nanometer scale, so that the material becomes an ideal SERS substrate, and possibility is provided for developing a metamaterial with a high optical index.

The invention discloses a high-elastic graphene-based metamaterial and a preparation method thereof.The preparation method comprises the steps that a graphene oxide solution is processed through a wet method and extruded through a large-size flow channel, blocky graphene oxide hydrogel is obtained, a fluid subdivision device is additionally arranged in front of a solution spraying opening, graphene oxide sheets generate a velocity gradient difference when subjected to subdivision multi-flow-field shearing, and the high-elastic graphene-based metamaterial is obtained; graphene oxide hydrogel with C-shaped superstructure arrangement is obtained by rearranging a graphene oxide lamellar texture, and the high-elasticity graphene-based metamaterial is obtained after freeze drying and reduction treatment.

The invention provides an aero-engine blade damage assessment method based on an elastic metamaterial structure, and belongs to the technical field of nondestructive testing, and the method comprises the steps: S1, determining the size of a detection region according to an actual detection demand; s2, determining the size of the metamaterial array; s3, determining the structure of the metamaterial unit; s4, calculating a meta-material unit energy band diagram through a finite element method, and determining an excitation signal frequency; s5, arranging a metamaterial array and a sensor array; and S6, calculating pixel values of all the detection areas by adopting a DAS algorithm, carrying out positioning evaluation on the damage according to the pixel value distribution condition of the detection areas, and generating an image. According to the method, the wave field of the Lamb wave in the variable-thickness blade is controlled by using the elastic metamaterial structure with a special size, so that efficient and accurate positioning and damage identification of various types of damages are realized.

The invention belongs to the technical field of metamaterial sensors, and particularly relates to a metamaterial multi-parameter sensor for a complex environment, which comprises a dielectric substrate, a temperature sensor, a pressure sensor and a strain sensor, and is characterized in that the dielectric substrate is made of high-temperature co-fired alumina ceramic; the temperature sensor is arranged at the left end of the dielectric substrate; the pressure sensor is arranged in the middle of the medium substrate; and the strain sensor is arranged at the right end of the dielectric substrate and comprises a metal sheet structure capable of generating relative displacement. According to the invention, long-distance signal monitoring is realized by adopting a microwave scattering technology, and the problem that a traditional wired sensing transmission line is damaged at a high temperature is solved; the high-temperature-resistant aluminum oxide HTCC ceramic is used as the dielectric substrate, temperature measurement within the range of 25 DEG C to 1200 DEG C, pressure within the range of 0 kPa to 700 kPa and strain measurement within the range of-400 mu epsilon to + 400 mu epsilon are achieved, the sensor is smaller in size and higher in sensitivity, and application of a traditional sensor in the multi-metal environment is expanded.

The invention discloses a carbon-based metamaterial electromagnetic wave absorber and a preparation method and application thereof. The wave absorbing body adopts a three-layer composite structure, wherein the bottom layer is a copper plate reflecting layer; the lower layer is of a honeycomb-like structure and is formed by periodically arranging regular octagons and square hollow quadrangular prisms externally connected with the regular octagons, and the adjustable wave absorbing frequency band is achieved by adjusting and controlling the width and height of the hollow cores; the upper layer is of a pointed cone structure, and the impedance matching characteristic is enhanced by optimizing the vertex angle of the regular rectangular pyramid. The wave absorber is made of photosensitive resin, based on the photocuring 3D printing technology, honeycomb-like and pointed cone structures are printed step by step and bonded and combined, and high-precision forming is achieved in combination with parameterized regulation and control. The wave absorber has the advantages of light weight, broadband absorption and adjustable mechanical performance, can be applied to the fields of EMI shielding of electronic equipment, military radar stealth, high-frequency communication protection, electromagnetic environment protection and the like, and remarkably improves the electromagnetic wave absorption and shielding effectiveness through the metamaterial structure design and a multi-component cooperative loss mechanism.

The invention provides a robust optimization method and device for a low-frequency sound absorption metamaterial, and relates to the technical field of punching, and the method comprises the steps: obtaining a response function of a target metamaterial through employing a linear one-dimensional rheological model; determining a target coupling region by using an imaginary part of a transfer function zero point corresponding to the response function or a size relationship between inherent loss and radiation loss as a coupling criterion, and determining a closed coupling region where a preset parameter point is located as an initial robust region; the target coupling region comprises a closed coupling region; the preset parameter point meets the one-dimensional frequency domain response of the target metamaterial; and determining the size of the initial robust region by using the Lexberg measure of the Euclidean space, and optimizing the robust region by maximizing the Lexberg measure of the initial robust region in the Euclidean space to obtain a target robust region. According to the method, the maximum robust region in the parameter space is found through maximum measurement, so that the response characteristics of the viscoelastic damping material under the actual working condition can be accurately described.

A carbon-based conductive film-based ultralight wide-angle absorbing metamaterial with full-frequency absorption within 2-18 GHz, including a first dielectric substrate, a first carbon-based conductive film array structure layer, a second dielectric substrate, a second carbon-based conductive film array structure layer, a third dielectric substrate, and a third carbon-based conductive film array structure layer, which are laminated in sequence with the first dielectric substrate as a bottom. The first, second, and third carbon-based conductive film array structure layers are each composed of discrete carbon-base conductive film patches arranged in a periodic array. A method for preparing such absorbing metamaterial is also provided.

A system for millimeter RADAR object recognition and classification using sub-band frequency interference and resonance effects from primary targets signals and reflected signals from secondary target preferably in the form of Wideband Chaos Generating Material (WCGM) objects, preferably detecting frequency dependent absorbing material, frequency dependent resonance effects from the second and primary target objects, frequency signal resonance effects caused by water molecule dipole effects in different sugar solutions, impedance of material, shape of metamaterial, and interference effects due to combination of signal sources resulting in a wider range of transmitter and scanning frequency band for RADAR based interrogation of target objects. The RADAR system makes opportunistic use of traditionally seen problematic interference signals, as extra signal sources providing extended range and frequency bandwidth for frequency-based interrogation of target object signatures in a frequency-intensity plane, a frequency-polarization plane, and a frequency-phase shift plane for doppler effects.