TWI255585B - Light and super broadband microwave absorbent material - Google Patents

Abstract

Disclosed is a light and super broadband microwave absorbent material, which comprises the homogeneous electric material and the metal material with two different ratios of resistivity, or the electromagnetic wave high reflection material. The resistivity of the electric homogeneous consuming material of the first layer is 1500 to 3000 Omega/□ and the thickness ranges from 2.5 to 3.5 mm, while the resistivity of the electric homogeneous consuming material of the second layer is 100 to 400 Omega/□ and the thickness is 3.5 to 4.5 mm. The third layer is made of metal material or electromagnetic wave high reflection material. The three kinds of materials are in turn jointed tightly with one anther. The light and super broadband microwave absorbent material features with the vertical reflectance less than -10 dB of the broadband over 5.2 to 18 GHz and the total thickness within 7 mm while the weight of every square meter less than 1.5 kilograms.

Description

1255585 V. INSTRUCTIONS (1) [Technical field to which the invention belongs] The wireless communication industry in the world is in the vicinity of several satellite relay stations and the residents or satellite relay stations near the Tailin station of the Big Brother station are exposed to electromagnetic radiation. Radiation microwave absorbers at large stations or satellite relay stations to reduce microwave radiation are all agreed by everyone. Information and communication technologies are changing with each passing day. • The development of functionalization, the weight of such products, the application of light, thin and high absorption benefits. The generation of electronic products, information, communication and other electrical products (EMC) problems are extremely urgent. Years have flourished, radar stations, staff living in radar stations, large rooms, because; = station connection affects health; rabbit II J radiation threat, should be in place $ = protection of residents and staff personal = Related products are mostly toward miniaturization and multi-electromagnetic interference (EMI) problems. The electromagnetic wave absorbers are used to solve the electromagnetic interference and electromagnetic compatibility of the new product. Whether it is a radar station, a satellite relay station or a large station Or solve the electronic, information, communication and other power crying ', Koda E:! EMC problems can use electromagnetic wave absorbing materials to minimize the threat ^iHdi^DeteCtiQn And (10) heart, Jane DAR) means = line electric measurement and ranging; since the invention of the 194s = alternative visual tools; The advantage is that the wave is too far away from the visible light, near-infrared light and infrared light. The modern science and technology can effectively improve the radar emission and the detection sensitivity. Raising the radar can detect the distance; therefore

Page 5 1255585 V. Description of the invention (2) In military applications, the former military's heaviest weapon carrier, the RCS), indicates that the radar interception of the military vehicle is weak, and because of its knowledge, it is easy to approach and can fully play its role. The combat performance of a new type of weapon. Reducing the radar wave of the weapon Vehicle The radar wave reflection point of the weapon carrier The amount of the radar wave detection method is one of the equipments that have been widely used as a radar. , the cross-sectional area (Radar Cross Sectl〇n, abbreviated as the echo intensity of the scattering after the radar is irradiated by the radar, the smaller the area, the reflected echo signal strength of the radar wave is weaker, the vehicle must be closer The radar can be detected by the party, T is discovered, so the low radar cross-sectional area vehicle has the effect of the beginning and the surprise attack. Nowadays, all the advanced weapons research institutes in the world are required to reduce the radar cross-sectional area to enhance the weapon low RCS will be nowadays. And the important means of future weapon design, the method of radar cross-sectional area divided by the modeling method will scatter the radiation to a direction different from the incident, so that the radar can not receive the echo signal to reduce the RCS of the vehicle, and the lightning part of the vehicle Applying a radar wave absorbing material to absorb the intensity of the incident radar wave energy to reduce the RCS value of the vehicle is another feasible method. [Prior Art] 'Electromagnetic wave absorbing material, according to the material characteristics of the material It is divided into electric absorbing materials, magnetic absorbing materials and integrated kneading machines ^ ^ ^ mouth i 芩頬, generally with the electric conductivity (permittivity, ε = 〇ι, · 〇 · factory strong, ^ ^ ε1 + ], /-1) Describe the electric absorption material shell 4 inch ' £ 1 for the lure you say each u · electric coefficient only part, £ 2 is the imaginary part of the electric induction coefficient. With magnetic permeability (permeabi 1 i tv, " ,,. y ^ = // 1 +j // 2) Description Magnetic Absorber Material Page 6255585

The electric radiation ' V 1 is the real part of the magnetic permeability or the magnetic part of the magnetic permeability is called the electric energy or magnetic energy of the electromagnetic wave. "2 is the loss term of the imaginary part of the magnetic permeability coefficient. The absorption energy of the absorbing material into the electromagnetic wave absorbing material can be distinguished according to the size of the absorption frequency range. The narrow frequency absorbing material has a narrower frequency domain than the fixed wave. See: electromagnetic energy absorption:; fixed transmission frequency radar station, satellite to m: large station to use it as electromagnetic radiation protection, "radar day elimination, etc.. Broadband absorbers can absorb electromagnetic waves. The valve can be applied as a weapon carrier radar wave echo reduction material and electromagnetic wave =, from the dark room absorbing material, etc.. ..., echoes the Republic of China patent No. 42 1 9 88, Inoue Masahiro and other inventors, The pyramidal shape formed by the former electric material uses the shape of the pyramid to control the reflection of the incident wave to achieve the absorbing effect. The patent of the Republic of China Patent No. 42880 No. 1 is a pyramidal suction formed by the non-combustible and flexible conductive materials. Wave material, US 2 patent US #5381 1 49, the inventor Th〇mas κ. et al. adopts 5 layers of progressive type: electricity to form absorbing materials, all of the above patents use electrical materials to ^ ^ absorbing materials Electrical absorbing materials are usually made of toner or other gold. The powder is suitably mixed with a filler or a binder to form a block or a piece of a certain density and thickness. The absorbing property of the electric absorbing material is different from the material of the raw material (/, _ its magnetic permeability// = 1) The relevant external and material thickness are also closely related, except for special plasticization: if the pyramidal absorption material is used, the effect of wide-band absorption by thin sheet material must be verified by material detection, absorbing material design, fabrication and absorbing properties. Such technology is very difficult to develop.

V. INSTRUCTIONS (4) Zn-Zn in the United States Mn-Zn is usually used to join the powder. The thickness of the material is also poor. The absorption of the absorbing material is less than that of the absorbing material. In the layer of the present invention, the electromagnetic wave penetrates the first layer, and the inventor of the US #323160 Kyung Y, which uses the absorbing wave > electromagnetic wave mass transfer material, uses a special Ferrer to make a magnetic absorbing material. The magnetic absorbing material is made of a metal micropowder such as iron or cobalt or a ferrite micro-filler or a binder to form a block or a sheet of a certain thickness, and the absorbing property is different from the raw material used (//). Related, and closely related. In the prior art, it is desired to produce a wide frequency band in such a manner, and the magnetic wave absorbing material has a small high frequency magnetic permeability coefficient value, a small difference in weight per unit volume, and is used as an outdoor aging resistance meter. The main drawback. As a name suggests, broadband microwave absorbing materials can absorb absorption of certain incident electromagnetic waves. The invention patent is achieved by matching the appropriate thickness with appropriate impedance. The layer of the absorbing material that is firstly irradiated by the electromagnetic wave is called the layer in which the first incident wave penetrates the first incident layer, and the layer that the electromagnetic two incident layer hits is called the third layer. The three layers are materials that reflect high conductivity and the like. The surface where the material first contacts the incident wave is called the incident surface, and the incident surface f produces an impedance called the input impedance (7/). In general, the input impedance can be defined as:

V ( βτ / ε r ) t an h ( - i k 0 d • · · · · · · (1) ^55585

i relative conductor material relative dielectric constant, π is homogeneous material field wave wave vector = 2 absorbing material is pure dielectric material, ... 1), k 〇 is electricity, d is homogeneous absorption material 2 / λ 〇, λ 0 The electromagnetic wave is in the free space sPaCe). The electromagnetic wave is in free space (the impedance of the free space is 4 i is 20, Ζ〇 = 377 Ω / □. For convenience, the freedom is shown as follows: Knowing the difference (Ζ0 = 1), the reflection of the material on the incident wave

r"〇- V)/(U

V (2) The reflectance R is defined as follows: R = rr * = [(1 - α) / (1 + the reflectivity in decibels dB is R (dB) = 20 · iog ( | r丨).. (3) (4) According to the above theoretical analysis, the absorption efficiency of the absorbing material is directly affected by the input impedance of the material, and the relationship between the input impedance of the dielectric absorbing material and the material ε r of the material can be 1) It is concluded that the material of the dielectric absorbing material has a certain relationship with the resistivity (P) of the material, and the surface resistance value (R □, Ω / □) of the material

1255585

• (5) V. Description of invention (6) Electricity and the relationship between rates is as follows

R p L/A In formula (5), (L) is the length of the dielectric absorber, and (A) is the electromagnetic wave between the two interfaces of the material (wave in, match ing is good, reflectivity is better) 22) The in-line impedance into the inner layer of the material is absorbed by the absorbing material, and the absorption characteristics of the absorbing material are better, and the absorbing material of the absorbing material in the inner layer of the inner layer is just injected against the material interface. The position is reflected by the anti-I, so that the electromagnetic is absorbed by the material, so the high efficiency of the absorbing material library; ^ ^ into the inner layer of the material is well matched. +Page should pay attention to the input impedance. The invention uses three materials of different material properties (= and material characteristics) to design and manufacture the absorbing material. The second eight-eighth reflectance (R) is less than -l〇dB. 5 2GHzi18gHz with ^, -l〇dB absorption bandwidth is greater than 12GHz, as shown in Figure 2, ::: broadband absorbing material is only 4GHz bandwidth. This suction = two at 7mm, per square meter The total weight is less than i 5 kg light weight, and suitable for long-term use, household, internal and external, weather resistance, sufficient to reach the thickness (thickness), width (absorption bandwidth), large (absorption rate) special # (重里) the way】

PU Two kinds of materials with different uniform resistivity, such as HABS, rubber, etc.:: Square smelting can be used in ΡΕ, uniform immersion

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Page 11 1255585 Brief description of the diagram [Simple description of the diagram] Figure 1 shows the structure of the lightweight ultra-wideband microwave absorber. Fig. 2 is a graph showing the relationship between the absorption rate and the frequency of the lightweight ultra-wideband microwave absorbing material (the horizontal axis is the frequency (G Η z ), and the vertical axis is the absorption rate (d B )). [Description of main component symbols] 1 : Schematic diagram of the structure of the lightweight ultra-wideband microwave absorber 2: Incident electromagnetic wave 丨 § 3: The first layer of electrically homogeneous depletion material 4: The second layer of electrically homogeneous depletion material 5: Metal (or electromagnetic wave) High reflection

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Claims (1)

1255585 VI. Scope of Application Patent 1. A lightweight ultra-wideband microwave absorbing material consisting of two layers of electrically uniform and lossy materials with different resistivity and metal or electromagnetic wave high-reflection materials; the first layer of electrically homogeneous wear and loss materials The resistivity is 1 0 0 0~3 Ο Ο Ω Ω / □, the thickness is 2. 5~3. 5 mm, the resistivity of the second layer of electrically homogeneous consumables is 100~400Ω/Ε], and the thickness is 3.5. ~4.5 mm, the third layer is made of metal or electromagnetic wave high-reflection material, which are composed of two materials in close contact with each other. 2. The microwave absorbing material according to claim 1, wherein the first layer is the layer to which the incident microwave is firstly incident, and the second layer is the incident micro 丨 波 wave penetrates the first layer and is irradiated The layer, the third layer is the layer that the incident microwave penetrates after the second layer is penetrated. 3. For the first layer and the second layer of electrically homogeneous consumables as described in item 1 of the patent application, the method of making the same may be to uniformly knead or evenly use a substrate such as PE, PU, PS, PP, ABS or rubber. The conductive material is immersed to form a uniform conductive sheet of a specific resistivity. Page 13