5 results about "Absorption frequency" patented technology

This invention discloses a porous Helmholtz resonator with adaptively adjustable sound absorption frequency band, belonging to the fields of noise control and virtual reality technology. It comprises a sound-absorbing structure consisting of a rotating perforated panel, a fixed perforated panel, and a perforated porous material plate arranged sequentially from top to bottom, as well as an adaptive adjustment system composed of a sound pressure sensor, a controller, and a motor. The motor drives the rotating perforated panel to rotate via gear transmission, changing the perforation overlap area; the perforated porous material plate compensates for acoustic impedance, maintaining sound absorption performance. The controller pre-stores spectral data at different rotation angles and selects the optimal rotation angle by comparing the real-time noise spectrum with the pre-stored data. This invention achieves adaptive adjustment of the sound absorption frequency band, maintains a high sound absorption peak value over a wide parameter range, is suitable for large-area deployment, has a compact structure, and low cost, and can be used for noise control and auditory virtual scenes.

This invention discloses a reconfigurable absorbing metasurface based on heterogeneous absorbing units using a tenon-and-mortise interlocking structure, and its configuration method, belonging to the field of electromagnetic wave absorption and metasurface structure technology. The metasurface is formed by assembling multiple lightweight absorbing units through a tenon-and-mortise interlocking structure. The absorbing units use melamine foam, PMI foam, polyurethane foam, or aerogel porous framework materials as the matrix, and are loaded with absorbing components such as graphene, carbon nanotubes, MXene, ferrite particles, carbonyl iron particles, or conductive polymers. The tenon-and-mortise connection structure has multiple levels of insertion positions and limiting structures, allowing adjacent units to form different insertion states, thereby adjusting the unit spacing, air layer thickness, array period, and equivalent electromagnetic parameters, achieving reconfigurable control of the absorption frequency band and response characteristics. Furthermore, heterogeneous absorbing units with different geometries and absorption parameters can be optimized through parametric design and electromagnetic simulation to form planar or curved broadband absorbing structures. This invention combines the advantages of lightweight, modularity, detachability, surface adaptability, and wideband absorption, and can be applied to fields such as electromagnetic stealth, radar absorption, electromagnetic protection, and complex curved electronic equipment.

This invention relates to the field of noise control and acoustic metamaterials technology, and discloses a device and method for synergistically regulating the sound absorption frequency by adjusting the neck length and cavity volume. The sound-absorbing device includes a Helmholtz main structure and an adjustable neck assembly. The main structure includes a perforated top plate, hexagonal honeycomb sidewalls, rubber lining, and a central base plate, which is connected to a drive device via a push rod. The adjustable neck assembly employs a three-layer nested sleeve design, utilizing a spring return mechanism and a sliding hook slot mechanism to achieve graded adjustment of the neck length. The drive device drives the push rod to raise and lower the central base plate, providing thrust to the adjustable neck assembly and simultaneously changing the cavity volume. This metastructure overcomes the limitations of traditional underwater Helmholtz sound-absorbing structures, which suffer from fixed frequency bands and poor adaptability. By synergistically regulating the sound absorption frequency band with dual parameters, it dynamically responds to changes in the complex underwater acoustic environment, significantly reducing the acoustic target intensity of underwater equipment and providing an efficient solution for acoustic stealth in deep-sea equipment.

The application relates to the technical field of wave-absorbing materials, in particular to a wide-band calcium ferrite wave-absorbing material and a preparation method and application thereof. 1.8 La 0.2‑x Ce x Fe2O5, wherein 0<=x<0.14. The application solves the problems of narrow absorption frequency band and low efficiency of the oxide wave-absorbing material by adjusting the composition and dielectric properties of the material through La and Ce double-element co-doping, and the prepared material has the advantages of wide absorption frequency band and high absorption intensity.

This application relates to the field of electromagnetic functional structure design technology, and particularly to a design method, system, and device for a broadband absorbing helical superstructure. The design method for the broadband absorbing helical superstructure includes: designing a structural unit with a square base shape, whose surface is simultaneously scaled down and rotated counterclockwise in the Z direction; establishing the influence of the helical rotation angle and the scaled-down ratio of the wedge on the absorption performance through parameter scanning in simulation software; applying this influence law, optimizing the structure based on its actual absorption performance surface and the target absorption frequency band, adjusting the structure's absorption performance to approach application standards. This application can significantly reduce the intensity of incident electromagnetic waves, thereby achieving a wide and effective absorption function across an extremely wide frequency band, effectively improving the absorption performance of the absorbing supermaterial.