Ferrite type radio wave absorber
Japan Shield Enclosure Co., Ltd.
About This Product
■Summary
A radio wave absorber is a material that absorbs radio wave energy by converting it into heat. There are two main types of radio wave absorbers: dielectric loss type and magnetic loss type. The dielectric loss type is a type of radio wave absorber that has existed for a long time, and is made of a foamed resin such as expanded polystyrene impregnated with a conductive material such as carbon.
Dielectric loss types can be roughly divided into radio wave absorbers with pyramid- or wedge-shaped three-dimensional shapes that have good radio wave absorption characteristics over a wide range and are used in anechoic chambers, etc., and radio wave absorbers that have a three-dimensional shape such as pyramid or wedge shapes, and those used in wireless LAN, ETC, RFID, etc. There are sheet-type radio wave absorbers that support specific frequencies or relatively narrow bands.
Pyramid-shaped (wedge-shaped) radio wave absorbers also have various peak heights. Generally, the thickness (height of the peak) is determined by magnetic permeability, permittivity, and the lowest frequency (wavelength) of the radio waves you want to absorb.
When electromagnetic waves propagating through free space enter a radio wave absorber, unless the impedance of the absorber's surface is close to the characteristic impedance of free space (377Ω), reflection will occur on the surface and the radio wave will not be absorbed much. . This surface impedance is a function of magnetic permeability, permittivity and material thickness, and frequency.
In the case of dielectric materials, the magnetic permeability (complex relative magnetic permeability) is 1, so it can be omitted. Calculating this surface impedance shows that the lower the frequency (the longer the wavelength), the more thickness is required (the height of the pyramid becomes higher).
■Applicable frequency/radio wave absorption characteristics
・It has high absorption performance mainly in the low frequency region below 1GHz and is thin. (Thickness approx. 6-19mm)
・Depending on the target frequency, there are two types: broadband grit ferrite type radio wave absorber (20dB/~approx. 800MHz) and thin (6.2mm) flat ferrite tile type radio wave absorber (20dB/~approx. 450MHz).
・The product comes in two shapes: a 10cm square unit (piece) and a 30cm square panel made up of 9 pieces, which can be selected depending on the area and shape of the installation location. .
・It can be attached to the base by adhesion (for a single unit) or screws (for a panel).
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Product
Ferrite type radio wave absorber
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Handling Company
Japan Shield Enclosure Co., Ltd.
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Categories
2 Models of Ferrite type radio wave absorber
Items marked with have different values depending on the model number.
Click on the part number for more information about each product
| Product Image | Part Number | Price (excluding tax) | Standard dimension panel | Standard dimensions Single unit (1 piece) | Standard dimensions panel plywood | Standard weight panel | Standard weight panel plywood | Standard weight single unit (1 piece) |
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Flat tile type ferrite radio wave absorber |
Available upon quote | - | 100x100x6.2mm | Glue 9 pieces to 300x300x18.2mm (12mm thick) to form a unit. | - | Glue 9 pieces to 3.7kg (12mm thick) to form a unit. | 0.3kg |
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Grid ferrite type radio wave absorber |
Available upon quote | 300x300x20mm | 100x100x19mm | - | 5.4kg | - | 0.51kg |
Click on the part number for more information about each product
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