42results about How to "Broaden the absorbing bandwidth" patented technology

The invention discloses a broadband wave-absorbing material based on sub-wavelength metal structures, and belongs to the field of microwave absorbing materials. The broadband wave-absorbing material is divided into three layers from top to bottom, namely a first dielectric substrate, a traditional wave-absorbing material substrate and a second dielectric substrate, wherein the first dielectric substrate is covered with rectangular metal structures which are periodically arrayed; the second dielectric substrate is covered with periodically-arrayed metal structures shaped like a Chinese character 'Hui'. On the basis of a traditional wave-absorbing material, the periodic sub-wavelength metal structures are introduced; the electromagnetic wave loss effect of the traditional wave-absorbing material is improved according to the local electromagnetic wave control characteristics of the metal structures; broad bands can be strongly absorbed by virtue of double-layer metal structures. The broadband wave-absorbing material can be used for radar stealth, electromagnetic compatibility, electromagnetic shielding and the like.

The present invention discloses an electromagnetic-wave absorption-material having a periodic structure. The material comprises magnetic-wave absorption-blocks and a dielectric material grid, wherein meshes on the dielectric material grid are through holes, and the magnetic-wave absorption-blocks are embedded in the through holes of the dielectric material grid according to a certain periodicity. The preparation method for the electromagnetic-wave absorption-material comprises the following steps: selecting a magnetic-wave absorption-raw material, and cutting the magnetic-wave absorption-raw material into a desired shape and a desired size to prepare into magnetic-wave absorption-blocks; selecting a dielectric material with a dielectric constant in a preset requirement range, arranging insert holes on the dielectric material in a periodic arrangement manner to obtain a dielectric material grid; and individually embedding the magnetic-wave absorption-blocks into the insert holes arranged on the dielectric material grid, and adopting an adhesive to connect the magnetic-wave absorption-blocks and the dielectric material grid into the integration to obtain the electromagnetic-wave absorption-material having the periodic structure. According to the present invention, the work bandwidth of the wave absorption material can be effectively expanded without increase of the thickness, and the volume density of the magnetic-wave absorption-material can be substantially reduced.

The invention relates to the field of high-temperature-resistant wave-absorbing materials, and specifically discloses a silicon carbide fiber-reinforced ceramic-based ultra-broadband wave-absorbing composite material with an electric gradient distribution. Starting from the incident direction of electromagnetic waves, the first high-resistance silicon carbide fiber-reinforced ceramic-based composite material is sequentially included. Material layer, the first lossy silicon carbide fiber array reinforced ceramic matrix composite material layer, the second high resistance silicon carbide fiber reinforced ceramic matrix composite material layer, the second lossy silicon carbide fiber array reinforced ceramic matrix composite material layer, the third high The resistance silicon carbide fiber reinforced ceramic matrix composite material layer, the third lossy silicon carbide fiber array reinforced ceramic matrix composite material layer, the fourth high resistance silicon carbide fiber reinforced ceramic matrix composite material layer; the lossy silicon carbide fiber array is periodic Composed of two-dimensional fiber cloth patch units arranged in an array, the size of the periodic unit is the same, the size of the patch increases sequentially, and the square resistance decreases sequentially. The wave-absorbing composite material of the present invention has significantly improved wave-absorbing bandwidth, can cover the 3-40 GHz band, and has excellent wave-absorbing performance.

The invention discloses a broadband wave-absorbing material based on sub-wavelength metal structures, and belongs to the field of microwave absorbing materials. The broadband wave-absorbing material is divided into three layers from top to bottom, namely a first dielectric substrate, a traditional wave-absorbing material substrate and a second dielectric substrate, wherein the first dielectric substrate is covered with rectangular metal structures which are periodically arrayed; the second dielectric substrate is covered with periodically-arrayed metal structures shaped like a Chinese character 'Hui'. On the basis of a traditional wave-absorbing material, the periodic sub-wavelength metal structures are introduced; the electromagnetic wave loss effect of the traditional wave-absorbing material is improved according to the local electromagnetic wave control characteristics of the metal structures; broad bands can be strongly absorbed by virtue of double-layer metal structures. The broadband wave-absorbing material can be used for radar stealth, electromagnetic compatibility, electromagnetic shielding and the like.

The invention provides a preparation method and application of the microwave absorbing composite material used as coating or a packing layer and relates to a preparation method and application of a microwave absorbing composite material. The preparation method is used for solving the problem that a microwave absorbing composite material prepared by adopting the prior art is single in microwave absorbing frequency, narrow in microwave absorbing bandwidth and low in microwave absorbing decibel. The preparation method of the microwave absorbing composite material comprises the following steps: firstly, preparing a polyethylene glycol 600 / dispersing solvent mixed liquor; secondly, preparing a mixed liquor A; thirdly, carrying out ball milling; fourthly, carrying out ultrasonic treatment; fifthly, preparing a mixture B; sixthly, carrying out ultrasonic treatment; seventhly, solidifying and curing. The microwave absorbing composite material used as the coating or packing layer can be taken as a coating coated on the surface of a composite material or a packing layer packed into an interlayer of a composite material structure. The prepared microwave absorbing composite material used as the coating or packing layer has obvious microwave absorbing property and can be applied to the fields of aviation, communication and military. By adopting the preparation method provided by the invention, the microwave absorbing composite material used as the coating or packing layer can be obtained.

The invention discloses a light transmitting structured broadband wave absorbing material with water acting as the loss medium, and belongs to the technical field of the wave absorbing material. The structured broadband wave absorbing material comprises a loss medium loading device and a bottom backboard. The loss medium loading device and the bottom backboard form an enclosed structure. The lossmedium loading device is filled with the loss medium. The loss medium loading device is made of transparent material. The loss medium is the deionized water. The bottom backboard is the ITO conductivefilm backboard. The bottom part of the loss medium loading device is also provided with two through holes used for injecting and draining the deionized water. The deionized water is used as the lossmedium so that the wave absorbing bandwidth can be obviously extended without increasing thickness. The selected component material has the characteristic of high light transmittance in the visible light band so that the formed wave absorbing material is enabled to have the characteristic of high light transmittance.

The invention discloses a water-solution-based broadband wave-absorbing metamaterial and relates to the technical field of electromagnetic functional materials. The water-solution-based broadband wave-absorbing metamaterial comprises an electrically-conductive reflecting layer, a dielectric matrix layer and a periodic array layer which are laminated sequentially from bottom to top, the dielectric matrix layer is composed of a composite frame and deionized water injected into the composite frame, the thickness of the composite frame is 0.8-3.5 mm, injection depth of the deionized water is 0.5-1.5 mm, the deionized water contacts with the upper surface of the electrically-conductive reflecting layer, and the periodic array layer is arranged on the top surface of the composite frame and is formed through arrayed arrangement of metal patches. The water-solution-based broadband wave-absorbing metamaterial has the advantages that with the aid of frequency dispersion characteristics of a water solution in a microwave frequency band, the metamaterial is capable of remarkably widening a wave-absorbing bandwidth without being thickened, and is simpler in structure, mature in preparation technology, easily available to raw materials, low in cost and easy for large-scale production and application.

The invention discloses a preparation method of a honeycomb sandwich composite material, which belongs to the technical field of aerospace material preparation, and is characterized in that it comprises the following steps: a. preparing an impregnating solution; b. placing a rectangular cross-section honeycomb core in an impregnating tank c. Prepare impregnating solution 2; d. Put trapezoidal cross-section honeycomb core 2 in the dipping tank and fully impregnate; e. Use adhesive film to bond rectangular cross-section honeycomb core 1 and trapezoidal cross-section honeycomb core 2 together to obtain Composite honeycomb core; f, bonding the upper panel on the upper surface of the composite honeycomb core, bonding the lower panel on the lower surface of the composite honeycomb core, and finally solidifying and cooling to room temperature to obtain a honeycomb sandwich composite material. The invention obtains two types of honeycomb cores containing different absorber coatings by wet impregnation, and obtains a composite honeycomb sandwich structure through reasonable design, and then glues and solidifies it with the panel, which can effectively improve the wave absorption of the entire honeycomb sandwich composite material Bandwidth, enhance the absorption effect of electromagnetic waves.