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Combined wave-absorbing pyramid and preparation method thereof

A technology of pyramids and absorbing materials, applied in the field of combined absorbing pyramids and its preparation, can solve the problems of increasing the weight of absorbing pyramids and being unable to test antenna PIM

Inactive Publication Date: 2019-12-27
AEROSPACE INST OF ADVANCED MATERIALS & PROCESSING TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But in this way, on the one hand, the weight of the absorbing pyramid is greatly increased. At the same time, since the ferrite material is a magnetic material, it is an important source of passive intermodulation (PIM) interference, and cannot be used in an anechoic chamber for testing the PIM performance of the antenna.

Method used

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  • Combined wave-absorbing pyramid and preparation method thereof
  • Combined wave-absorbing pyramid and preparation method thereof
  • Combined wave-absorbing pyramid and preparation method thereof

Examples

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Embodiment 1

[0031] In the combined absorbing pyramid provided by this embodiment, the dimensions of each part are as follows image 3 As shown, the height (thickness) of the absorbing pyramid is 335mm, the side length of the large end of the single cone is 125mm, and the side length of the small end is 10mm. Both the large end and the small end are square. The mass ratio of carbon black in the absorbing pyramid is 15%; the thickness of the flexible absorbing material is 15mm, which is obtained by alternate lamination of hot-melt adhesive film and hybrid fiber mat. The main component of the hot-melt adhesive film is ethylene-vinyl acetate copolymer, with a single layer thickness of 0.2mm, a total of 50 layers ; The mass percentage of chopped carbon fiber in the hybrid fiber mat is 0.5%, the thickness of a single layer is 0.1mm, and there are 50 layers in total.

[0032] The preparation method of the combined absorbing pyramid of the present embodiment comprises the following steps:

[003...

Embodiment 2

[0040] In the combined wave-absorbing pyramid provided by the present embodiment, the height (thickness) of the wave-absorbing pyramid is 200mm, the side length of the large end of the single cone is 125mm, and the length of the small end side is 10mm. The mass of carbon black in the wave-absorbing pyramid is The ratio is 5%; the thickness of the flexible absorbing material is 10mm, which is obtained by alternate lamination of hot-melt adhesive film and hybrid fiber mat. The main component of the hot-melt adhesive film is ethylene-vinyl acetate copolymer, and the thickness of a single layer is 0.1mm. Layer: The mass percentage of chopped carbon fiber in the hybrid fiber mat is 0.1%, the thickness of a single layer is 0.1 mm, and there are 50 layers in total.

[0041] The preparation method of the combined absorbing pyramid of the present embodiment comprises the following steps:

[0042] Step 1: Cut the polyurethane sponge into the required size, dip the sponge into the slurry...

Embodiment 3

[0048]In the combined wave-absorbing pyramid provided by the present embodiment, the height (thickness) of the wave-absorbing pyramid is 500mm, the side length of the large end of the single cone is 125mm, and the length of the small end side is 10mm. The mass of carbon black in the wave-absorbing pyramid is The ratio is 30%; the thickness of the flexible absorbing material is 30mm, which is obtained by alternate lamination of hot-melt adhesive film and hybrid fiber mat. The main component of the hot-melt adhesive film is ethylene-vinyl acetate copolymer, and the thickness of a single layer is 0.2mm. layer; the mass percentage of chopped carbon fiber in the hybrid fiber mat is 0.2%, the thickness of a single layer is 0.1 mm, and there are 100 layers in total.

[0049] The preparation method of the combined absorbing pyramid of the present embodiment comprises the following steps:

[0050] Step 1: Cut the polyurethane sponge into the required size, dip the sponge into the slurr...

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Abstract

The invention relates to a combined wave-absorbing pyramid and a preparation method thereof, and belongs to the technical field of functional materials. The combined wave-absorbing pyramid sequentially comprises a wave-absorbing pyramid body and a flexible wave-absorbing material in the electromagnetic wave propagation direction. The wave-absorbing pyramid body is composed of polyurethane sponge and carbon black, and the carbon black is uniformly dispersed in pores of the polyurethane sponge; the flexible wave-absorbing material is formed by alternately laminating a hot melt adhesive film andhybrid fiber felt, the hot melt adhesive film is a thermoplastic bonding material and needs to have a good interface bonding characteristic with polyethylene; and the hybrid fiber felt is composed ofchopped polyethylene fibers and chopped carbon fibers uniformly dispersed in the chopped polyethylene fibers. The flexible wave-absorbing material has high electromagnetic parameters at low frequencyafter being doped with the carbon fiber absorbent, the difficulty that an existing wave-absorbing pyramid is poor in low-frequency wave-absorbing performance when the thickness is small is overcome through the matching design of the flexible wave-absorbing material and the wave-absorbing pyramid, and the low-frequency wave-absorbing performance of the combined wave-absorbing pyramid is improved.

Description

technical field [0001] The invention relates to a combined wave-absorbing pyramid and a preparation method thereof, belonging to the technical field of functional materials. Background technique [0002] With the development of technology, the antenna test chamber tends to be miniaturized and portable, which requires reducing the thickness of the absorbing material installed on the wall of the chamber. Most of the absorbing materials used in anechoic chambers are absorbing pyramid materials. The effective wavelength of absorbing pyramids is generally proportional to the thickness of the pyramids. Reducing the thickness of the absorbing pyramids will affect its low-frequency absorbing performance. Generally, in order to reduce the thickness of the absorbing pyramid while still maintaining a certain low-frequency absorbing performance, a layer of ferrite material is often used to match the bottom surface of the absorbing pyramid. But in this way, on the one hand, the weight o...

Claims

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Application Information

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IPC IPC(8): B32B27/12B32B27/40B32B9/00B32B9/04B32B7/12B32B27/20B32B27/02B32B27/32B32B33/00H01Q17/00B29C70/44
CPCB29C70/44B32B5/02B32B5/18B32B7/12B32B9/046B32B27/12B32B27/20B32B2262/0253B32B2262/106B32B2266/0278B32B2307/20H01Q17/008
Inventor 邢孟达宫元勋赵宏杰马向雨张天翔
Owner AEROSPACE INST OF ADVANCED MATERIALS & PROCESSING TECH