Absorption Frequency Band Research Articles

A Semi-Empirical Model for Sound Absorption by Perforated Plate Covered Open Cell Foam and Improvements from Optimising the Perforated Plate Parameters

Composite structures can be designed with specific parameters for efficient sound absorption in specific frequency bands; however, determining the optimal parameters and topology to maximize sound absorption is a computationally challenging task. In this work, a semi-empirical model is constructed to predict the sound absorption performance of composite structures consisting of open-cell foam and perforated plates. The calculated results of the semi-empirical model are in good agreement with the experimental results carried out in the B and K tube impedance measurement system. The parameters such as perforation ratio, plate thickness, air gap, etc., of the composite structure within limited thickness were optimized by using a genetic algorithm (GA) to improve the sound absorption coefficient at a lower frequency band. The calculation and experimental results show that when the thickness is fixed, the peak sound absorption frequency can be reduced by 400 Hz; on the contrary, with the goal of broadening the sound absorption frequency band, the optimized composite structure can widen the sound absorption frequency band by 55.38%. The results of this work have potential engineering applications for the calculation of the sound absorption of porous materials and perforated plate composite structures and their optimal design, particularly when the total volume or total weight of the sound-absorbing material is strictly limited.

Interfacial electronic heterostructure engineering of cobalt boride nanosheets toward broadband efficient electromagnetic absorption

Vigorous reflection loss (RL), wide bandwidth together with suitable absorption frequency band are key application indicators for cutting-edge electromagnetic (EM) absorbers to avoid EM pollution in the aerospace. However, the rational design of EM absorbers, especially for the integration of multiple properties, remains highly challenging. Here, we report a novel two-dimensional (2D) nanosheets-like heterostructure constructed by a molten salt-assisted dissolution-growth strategy and linked via strong interfacial electronic interactions, namely, cobalt boride (CoB) with boron, nitrogen co-doped carbon (CoB/BNC). Density functional theory (DFT) calculations demonstrate that stable heterointerfaces formed by strong interfacial electronic interactions are beneficial for enriching polarization effects, while contributing sufficient dielectric loss to boost the EM absorption (EMA) performance. Accordingly, the minimum RL (RLmin) of −70.76 dB and effective absorption bandwidth (EAB) of 4.72 GHz are simultaneously accomplished for CoB/BNC at the thickness of 3.48 mm. Moreover, radar cross section (RCS) simulation results confirmed that the as-prepared absorber coating could perfectly suppress the metal scattering sources in different directions. Generally, this work offers an ingenious engineering strategy for the precise synthesis of functional heterostructures, which holds great promise for developing innovative EMA materials in the aerospace.

A practical procedure for vehicle sound package design using statistical energy analysis

Vehicle sound package has a substantial role in attenuation of vehicle noise for the purpose of improving interior comfort and reducing environmental noise pollution. In this paper, two approaches of absorptive design and multi-layer design are investigated to improve the performance of a sound package in automotive applications. For this purpose, the sound package of the engine compartment including hoodliner and dash insulator is studied. Furthermore, this paper proposes an experimentally validated prediction model through Statistical Energy Analysis (SEA) to evaluate the sound insulation of a vehicle body sound package. For this purpose, the research includes characterization techniques of sound package materials to determine intrinsic parameters of different layers required to develop a reliable SEA model. The inverse method and time-temperature superposition principle (TTSP) are utilized to characterize porous materials and heavy layer properties, respectively. The comparison of results that are experimentally obtained by acoustic cabin shows a fairly well agreement with the proposed SEA modeling procedure for the desired frequency range. By observing the results of the simulation for the hoodliner and dash insulator, it was revealed that the absorptive design combines the benefits of high sound absorption capability, wide absorption frequency band, and lightweight. Indeed, with an appropriate combination of layers, the multi-layer design can simultaneously provide a mixture of absorptive design attributes and sound insulation capabilities. The transmission loss obtained from the proposed design of the dash insulator revealed an increase by 42% without any reduction in the amount of sound absorption. Also, the sound absorption of the proposed hoodliner is enhanced more than twice in reference to the base design.

Real-Time Prediction of Characteristic Parameters of Inductively Coupled Plasma Based on Artificial Neural Network

Artificial neural networks (ANNs) were implemented to predict the plasma parameter distribution to actively control the plasma absorption frequency band. Taking the inductively coupled plasma (ICP) fluid dynamics simulation results as the initial data, the general regression neural network (GRNN) is introduced to predict the plasma characteristic parameters under any external conditions. The electron density and electron temperature are measured by the Langmuir probe and compared with the fluid simulation results and model prediction results. It is found that the fluid simulation result of the electron density is higher than the experimental diagnosis result but slightly lower than the model prediction result. The fluid simulation result of electron temperature is lower than the experimental diagnosis result, but it is basically consistent with the model prediction result. Comparing the fluid simulation results, model prediction results, and experimental diagnosis results of the plasma characteristic parameters, grasp the distribution law of the characteristic parameters of the ICP. A prediction model for real-time prediction of plasma characteristic parameters is obtained. The rapid and active adjustment of the plasma characteristic parameter distribution is realized, and then, the active adjustment of the plasma absorption frequency band can be quickly realized.

Research on Dynamic Characteristics of Joint of RC Frame Structure with NES

The NES (nonlinear energy sink) is a new type of nonlinear tuned mass damper that is connected to the shock-absorbing main structure through strong nonlinear stiffness and viscous damping. The vibrational energy in the main structure is transferred to the NES oscillator by means of target energy transfer. A shaking table test of a 1:4 scaled RC (Reinforced Concrete) frame structure model with a new type of NES shock absorber was conducted to study the damping effect of the NES shock absorber, especially for the influence of joint strength and deformation. The NES used in this experiment has a relatively large nonlinear stiffness and a wide vibration absorption frequency band. The variation of reinforcement strains, node failure mode, and structural natural frequency of 1 story and two-layer joints of the model frame structure with NES were studied. The test results showed that NES could effectively reduce the strains of longitudinal reinforcement and stirrup in beams and columns and delay the plastic hinge development at the bottom and the top of the column. The frame model with NES installed has failures at the beam ends and shear failures at the nodes, realizing the seismic mechanism of solid columns and weak beams. Compared with ordinary seismic structures, the NES can effectively reduce the shear stress of concrete at the joints and alleviate the shear failure of joints. The final failure of the NES shock absorbing structure was the yielding of the steel bars at the bottom of the column and the crushing of the concrete at the foot of the column, and the connection between the column foot and the backplane became loose simultaneously. The decreasing rate of the vibration frequency declined due to the NES with varied broadband absorbing capability. It can be seen that the NES shock absorber not only has a good effect on reducing the seismic response of the structure, but more importantly, the damage of the structural nodes is greatly reduced, and therefore, the seismic capacity of the structure improved.

Influential trivalent ion (Cr3+) substitution in mixed Ni–Zn nanoferrites: Cation distribution, magnetic, Mossbauer, electric, and dielectric studies

Herein, we report the influence of trivalent chromium (Cr3+) ion substitution on the electric, dielectric, and hyperfine interaction properties of a mixed Ni–Zn nanoferrite system synthesized by an auto combustion solution-gelation route. The XRD analysis verified the monophase nanocrystalline formation of prepared ferrites belonging to the spinel group with a cubic structure. TEM images displayed the sphere-like morphologies of the typical nanoferrite sample. FT-IR spectra uncover the occurrence of two absorption frequency bands in the desired region belonging to spinel ferrite. The magnetic parameters decreased significantly with increasing Cr3+ concentration. Mossbauer parameters, such as the hyperfine field, line-width, isomer shift and quadrupole splitting, were deduced for all the samples. DCR studies confirmed the semiconducting behavior of all the samples with an increasing resistivity trend after Cr3+ substitution. The dielectric study showed a decreasing trend with an increase in Cr3+ concentration. All the results display the influential substitution of Cr3+ ions in the Ni–Zn ferrite system, which shows the usability of the prepared samples in higher frequency ranging systems.

Strain-responsive 3D hierarchical composites for smart microwave absorption modulation within broad C-Ku band

The achievement of superior microwave absorption performance and the intelligent regulation of electromagnetic properties has become a key point in the field of developing advanced high-performance microwave absorbers. Especially for fabricated absorbers, effectively tuning their electromagnetic microwave absorption (EMA) properties within a broad frequency range has been a largely under-explored domain. In this study, hierarchical polyaniline annular flocculation@carbon foam (PACF) composite has been constructed to achieve excellent wave absorption properties as well as unique strain-responsive EMA performance. The synergistic effect of multiple attenuation mechanism and special morphology endows PACF composite with superior EMA properties, where the optimal microwave absorption strength is up to −59.19 dB and the corresponding effective absorption bandwidth (EAB) reaches 7.40 GHz. Additionally, the porous 3D microstructure is conducive to realizing ultralight characteristic and its density is only around 0.0422 g/cm3. Most importantly, the absorbing frequency band of PACF composite can be significantly controlled by adjusting strain. The frequency corresponding to the optimal absorption intensity and EAB can successively be adjusted in broad C-X-Ku bands when the strain of PACF composite varies from 0% to 40%. This work proposes a strain-responsive EMA composite for multi-frequency absorbing modulation, providing an innovative direction for developing intelligent-controlled absorbers.

Investigation into wideband electromagnetic stealth device based on plasma array and radar-absorbing materials

Manipulation of electromagnetic waves is essential to various microwave applications, and absorbing devices composed of low-pressure gas discharge tubes and radar-absorbing materials (RAM) can bring new solutions to broadband electromagnetic stealth. The microwave transmission method is used to measure the physical parameters of the plasma unit. The designed structure exhibits superior absorption performance and radar cross-section (RCS) reduction capability in the 2–18 GHz band, with unique absorption advantage in the S and C frequency bands. It is found that the combination of the plasma and the RAM can significantly broaden the absorption frequency band and improve the absorption performance with excellent synergistic stealth capability. Experimental and simulation results present that broadband, wide-angle, tunable electromagnetic wave absorption and RCS reduction can be achieved by adjusting the spatial layout of the combined plasma layer and the type of RAMs, which creates opportunities for microwave transmission and selective stealth of equipment. Therefore, the wave manipulation by combined plasma array and RAM provides a valuable reference for developing numerous applications, including radar antenna stealth, spatial filter, and high power microwave shielding.

A Novel Method to Synthesize Co/Fe3O4 Nanocomposites with Optimal Magnetic and Microwave Performance.

The magnetic interactions between neighboring magnetic nanoparticles make the synthesis of nanocomposites made of two kinds of magnetic nanoparticles extremely difficult. In this paper, to achieve an effective nanocomposite of Co and Fe3O4 nanoparticles, a special urchin-like Co nanomatrix was used to prepare the Co/Fe3O4 nanocomposites. The Fe3O4 nanoparticles are evenly embedded into the branches of the CO clusters, bringing the two types of particles into close contact and ensuring the optimal magnetic and microwave properties. The electromagnetic (EM) parameters at 1–18 GHz and the magnetic loss tangents can be effectively modulated, and the absorption frequency bands of the EM waves are shifted to the X-Ku bands (8–18 GHz) from the S-C bands (2–8 GHz) after the Fe3O4 nanoparticles are compounded.

Synergistic enhancement of thermal conduction and microwave absorption of silica films based on graphene/chiral PPy/Al2O3 ternary aerogels

Severe problems of heat dissipation and electromagnetic (EM) interference are quite detrimental to modern electronics, prompting researchers to develop advanced integrated materials of thermal conduction, microwave absorption, and electrical insulation. However, their simultaneous improvement is restricted by some inevitable contradictions among them. Herein, we pioneered graphene (GN)/PPy/Al2O3 ternary aerogels as an advanced membrane filler for a synergistic enhancement of thermal conduction, EM wave absorption, and electrical insulation. GN/PPy/Al2O3 ternary aerogels are produced via a simple solution blending and vacuum freeze-drying process, and then filled into silica oils to form silica gel films via a hot-pressing process. A few thermal conduction-electric conductivity-type graphene and PPy (3–5 wt%) were uniformly dispersed in thermal conduction-electrical insulation-type Al2O3 nanoparticles, forming multiple polarizations and constructing an effective heat-conducting but electrical-insulating pathway for phonon transmission. In this case, GN/PPy/Al2O3 ternary aerogels (1:1:15, 50% loading) possessed a wide absorption frequency band (6.48 GHz, 2.0 mm thickness), high thermal conduction (4.649 W/(m·K)), and excellent electrical insulation (σ = 0.0282 S/m). Notably, their thermal conduction and microwave absorption abilities significantly outperform most reported fillers. This paper provides a simple and effective method for designing advanced thermal conduction-microwave absorption-electrical insulation integrated materials with great potential in modern electronics.

Novel fractal acoustic metamaterials (FAMs) for multiple narrow-band near-perfect absorption

In this work, we introduce fractal acoustic metamaterials (FAMs), in thicknesses ranging from 5 (λ/69) to 25 mm (λ/18), which are observed to provide multiple narrow-band low-frequency absorptions of acoustic signals. The fractal structures used in this work are carefully designed and fabricated using a side branch Helmholtz resonator design, making these structures easily tunable to multiple frequencies. Using different sizes of the side branches distributed in a fractally oriented configuration onto a plane rigid baseplate, the propagation velocity of acoustic waves is slowed down considerably. There is also a shifting resonating response of the structures toward lower frequencies (<1600 Hz). These FAM structures exhibit no dependence on the acoustic traverse length, as is otherwise commonly seen in coiled meta-structures and others. In order to achieve a near-perfect sound absorption behavior, the geometry of the structure is theoretically ascertained and validated numerically and experimentally. Significant emphasis has been placed on the associated physical mechanism modulating the loss of intensity of the incident acoustic signals. Moreover, with regression analysis performed on a response surface-based optimization scheme (using Design Expert 11 software), the geometric parameters are determined in a way that the absorption demonstrates a narrow-band characteristic at a frequency of 1 K Hz. We have shown in this work the tunability aspect of the various absorption frequency bands through appropriate designs of the FAM. It opens up wide application possibilities of multiple frequency sound absorptions (acoustic cloaking).

Broadband Electromagnetic Absorption Effect of Topological Structure Using Carbon Nanotube Based Hybrid Material.

The development of microwave absorbing technology raises the demands for all-band absorption. The topological structures expand the frequency range of electromagnetic wave absorption and eliminate the differences caused by scattering in different incident directions. The multi-wall carbon nanotube and carbonyl iron particles were mixed with polylactic polymer to fabricate filaments for fused deposition. The distribution characteristics of the structures using carbonyl iron/carbon nanotube hybrid material for the key absorption frequency band are obtained. The reflectivity of the honeycomb structure in X and Ku bands is verified experimentally through the preparation method of fused deposition modeling 3D printing. With the decrease of the fractal dimension number, the electromagnetic loss performance basically increases. Preliminary research results showed that the topological structure could significantly expand the absorbing frequency range, and the effective frequency band less than −10 dB is 2–40 GHz, which has a clear application potential for radar absorption.

Recent Research Progress of Ferrite Multielement Microwave Absorbing Composites

With the extensive application of electrical and wireless equipment, several electromagnetic pollution‐related issues have emerged. Therefore, the manufacturing of absorbing materials has become important to electromagnetic pollution. Ferrite is a common absorbing material; its single absorbing mechanism and narrow absorbing frequency band resist the wider usage as an ideal absorbing material. Adding different materials to ferrite has become a popular way to enhance its microwave absorption properties. Herein, the recent research on ferrite multicomponent microwave absorbing composites is summarized. For ferrite binary composite absorbing materials, the research progress of ferrite and graphene, carbon nanotubes, carbon fiber and other carbon materials, ferrite and polypyrrole, polyaniline and other polymer materials, and ferrite and MXene composites is introduced. In addition, the advancement of ferrite ternary absorbent materials research is also discussed. The growing development trend of ferrite composite absorbing materials is finally summed up, and the prospects of fabricating the “thin, light, wide, and strong” ferrite absorbing materials are put forward.

Microwave absorption properties of Ni0.6Zn0.4Fe2O4 composites with nonmagnetic nanoferrite percentages

Microwave absorption materials need to be thin and lightweight and possess strong wave absorption ability and a wide absorption frequency band. To satisfy these conditions, we changed the microstructure of the composite by mixing ferrite material with different particle sizes. Specifically, we mixed nanosized nonmagnetic ZnFe2O4 powder into Ni0.6Zn0.4Fe2O4 powder, investigated the microwave absorption properties depending on the packing fraction. The crystal structure of the synthesized ferrite powders was analyzed through XRD, and the particle size was analyzed using a PSA and SEM. The density of the powders, which is required to measure the packing fraction, was determined via the gas disposition method, and the magnetic properties of the composites were analyzed using a VSM. The reflection loss represents the electromagnetic wave absorption characteristics, and it was calculated by substituting the measured permittivity and permeability values, into the equation based on the transmission line theory. The Ni0.6Zn0.4Fe2O4/ZnFe2O4 composite showed 99.9% absorption with a high packing fraction, and the absorption peak shifted to high frequencies. These characteristics suggest that the absorption ability and frequency range of the electromagnetic-wave-shielding composite can be easily controlled. Because of the high-absorption characteristic, absorption frequency control, and cost effectiveness, this composite can be applied to products such as thin electromagnetic-wave-shielding sheets.

Tailoring Self‐Polarization of Bimetallic Organic Frameworks with Multiple Polar Units Toward High‐Performance Consecutive Multi‐Band Electromagnetic Wave Absorption at Gigahertz

AbstractMultiple relaxation behaviors are promising for broad frequency band and strong electromagnetic wave (EMW) absorption based on polarization‐controlled electromagnetic (EM) attenuation. However, rational selection of materials and structure manipulation through tunable substitution or phase control are challenging toward optimization of EMW absorption. Herein, bi‐metallic organic frameworks (B‐MOFs) with various morphologies are employed as EMW absorbers. Remarkably, the polar units can be enhanced by introducing Ni‐metal nodes into the Cu‐coordinated MOFs, rendering the B‐MOFs with self‐polarized properties and consecutive multifrequency EMW absorption behaviors. The maximum reflection loss of acetylene black (ACET) filled NiCu‐MOFs can reach –40.54 dB together with a wide bandwidth (<‐10 dB) of 5.87 GHz at a thickness of 2.5 mm. As a counterpart of the Ni/Cu/C derivatives, significantly increased broad band absorption (6.93 GHz) and multifrequency absorbing and polarization characteristics are also maintained in bimetal coexisting carbonized architectures as prepared by calcination of CuNi‐MOFs. This work demonstrates that the performance of effective absorbing frequency band can be enhanced in multi‐metallic organic frameworks‐based architectures, and paves a novel avenue for developing broadband and strong EMW absorbers.

Eigenvalue analysis of wideband acoustic immittance in secretory otitis media in children of different ages

Objective:The characteristic values of broadband acoustic immittance of children of different ages during secretory otitis media were collected resonance frequency and absorption rate of middle ear in children of different ages were compared. Methods:Eighty-two children with secretory otitis media were selected for the broadband acoustic immittance test, including 62 cases （83 ears） in the young effusion group（[3.5±0.7]months）, and 20 cases （40 ears） in the older effusion group（[4.0±0.6]years old）. 82 normal children were selected for broadband acoustic immittance test in the same environment, including 62 cases （124 ears） in the younger normal group and 20 cases （40 ears） in the older normal group. The resonance frequency and absorptivity of different age groups under broadband peak pressure were compared, and the frequency absorptivity curve was drawn for analysis. Results:The resonance frequencies of older normal group and younger normal group, older effusion group and older normal group, younger effusion group and younger normal group, older effusion group and younger effusion group were statistically significant（P<0.001）. Analysis of sound energy absorption rate at different ages. There was significant difference in sound energy absorption rate between older normal group and younger normal group at 226-1155 / 4757-8000 Hz（P<0.001）. The difference of full frequency sound energy absorption rate between the older effusion group and the older normal group was statistically significant（P<0.001）, among which the difference of 866-1542 / 2520-4362 Hz absorption rate was the largest. The difference of full frequency sound energy absorption rate between young effusion group and young normal group was statistically significant（P<0.001）, and the difference of 1091-2245 / 3776-5494 Hz absorption rate was the largest. Conclusion:Middle ear effusion in children of different ages has different performance under broadband acoustic immittance peak pressure, and has its own characteristic acoustic energy absorption frequency band. This study provides a reference basis for the analysis of the characteristics of middle ear sound transmission in children with secretory otitis media in the future.

Structure design and experimental analysis of a perforated dielectric elastomer sound absorber

A large part of research on membrane mufflers focuses on the sound insulation performance of the membrane, and there is less research on the sound absorption performance of the membrane. In most cases, membrane mufflers only have some narrow absorption peaks in the low frequency band. In this paper, a micro-perforated dielectric elastomer membrane sound absorber is introduced to broaden the sound absorption frequency band of the membrane in the low frequency band. Different initial thickness, perforation aperture, and perforation spacing of the dielectric elastomer membranes were designed and fabricated, and the effect of the variation of the parameters was investigated by testing the sound absorption performance of the structural specimens. It was found that increasing the initial thickness of the membrane, appropriately decreasing the perforation aperture, and appropriately controlling the perforation spacing could improve the sound absorption performance of the structure. And based on the perforated membrane, a ring electrode structure was further designed to realize the electrically adjustable sound absorption frequency of the membrane. After the membrane with the ring electrode structure was perforated in the central region, the sound absorption band of the membrane was broadened significantly, and the applied voltage could realize the electrically adjustable sound absorption performance of the structure in the low frequency band.

Effect of cooling medium on the preparation and microwave absorption properties in low frequency for LiZn ferrites hollow microspheres

The lack of research on low-frequency absorbing materials working at frequencies lower than 8 GHz makes it difficult to meet the military needs of the large wavelength electromagnetic shielding. In this study, crystalline and amorphous lithium zinc ferrites hollow microspheres (LiZn FHMs) were prepared by self-reactive quenching technology, based on Fe+Zn+Fe2O3 +O2 +Li2CO3 reactive system, using distilled water and 15 wt% NaCl solution as cooling medium, respectively. Effect of cooling medium on the formation mechanism and microwave absorption properties in low frequency range for two kinds of LiZn FHMs was studied. The results show that LiZn FHMs surface with distilled water as cooling medium has polygonal crystal structure. While the surface of LiZn FHMs is smooth by using 15 wt% NaCl solution, and XRD patterns prove that LiZn FHMs are of amorphous structures. When the cooling medium is changed from distilled water to NaCl solution, the magnetic loss of amorphous LiZn FHMs changes from double loss mechanism (natural resonance and eddy current loss) to a single loss mechanism (natural resonance). Compared with crystalline materials, the emergence of "rheology unit" and the change of magnetic loss mechanism are the main reasons for the improvement of microwave absorption properties in low frequencies. When the thickness of the amorphous sample is equal to 2 mm, the minimum reflectivity is −29.8 dB, and the corresponding frequency is 7.1 GHz. The absorption frequency band below −10 dB is 5.3–10.3 GHz, and its bandwidth is 5 GHz. This effectively meets the low frequency new absorbent "thin, light, wide and strong" demand, and it could be promising in the application of invisible coatings on the weapon equipments. The survival performances of weapon equipments in the complex electromagnetic field are expected to be improved.

Metasurface-based electromagnetic structure for electromagnetic absorption and radiation application

AbstractIn this paper, a metasurface (MS)-based multi-functional electromagnetic (EM) structure is proposed to realize its two different applications, namely absorption and radiation. The proposed structure is based on periodic arrays of disk-shaped metallic patches and split rings with four embedded lumped resistors. The metallic vias are inserted from top to bottom to connect the disk-shaped patches with a feeding network designed on the bottom layer where two p-i-n switches are embedded in the feeding network to alter the different functions of the proposed structure. For free space incident plan wave, the designed structure works as an absorber when the p-i-n switches are switched OFF. The absorber operates over a frequency band from 6.2 GHz to 8.2 GHz and unchanged over an incident angle from 0° to 30° for both TE and TM polarized incident waves. The same structure also works as a low scattering and high gain radiator when the p-i-n switches are turned ON and radiate within absorbing frequency band, i.e. from 7.5 to 8.0 GHz. The designed structure is fabricated and experimentally verified for EM absorption and radiation applications.

Tunable Perfect Absorber of Graphene Metamaterial in the Terahertz Band and Its Sensing Properties

Herein, a dual‐band tunable ideal absorber based on graphene array, and the dynamic tuning performance of the perfect absorber in the terahertz band and its sensing properties based on graphene metamaterials are studied. The absorber shows two perfect absorption peaks at 1.01 and 1.86 THz, with an absorbance of 99.5% and 99.9%, respectively. With an elevation angle in the range of 0°–30° and a frequency in the range of 0.971–1.100 THz or 1.794–1.897 THz, the absorber designed herein can achieve an absorbance greater than 90%. Owing to the superior properties of graphene, dynamic tuning of the absorption frequency band, absorption bandwidth, and relative bandwidth of the absorber can be achieved by adjusting the Fermi level of graphene. In addition, adjusting the relaxation time realizes dynamic tuning of the absorption bandwidth and the absorbance with constant resonant frequency and fixed geometric parameters. Moreover, the sensitivity of the absorber reaches 492.5 GHz/RIU, which can achieve the sensing resolution required for the resonance frequency. This research provides a new concept for the development of high‐performance terahertz devices.