JPS62234399A - Wave absorber in wave dark room - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a radio wave absorber used in an anechoic chamber, and more specifically, the present invention relates to a radio wave absorber used in an anechoic chamber, and more specifically, the base material is foamed polyurethane or foamed polystyrene, and carbon black or the like is used as a dielectric loss material. This invention relates to a radio wave absorber for use in an anechoic chamber, which reinforces a wave-shaped radio wave absorber containing.

[Prior art]

In recent years, computers, world processors, etc.
With the development of A-type equipment (office automation equipment) and other electrical products that use IC circuits (integrated circuits), electromagnetic interference oscillated by these products has become a problem.

In other words, OA equipment and electrical products that use IC circuits oscillate electromagnetic waves at a certain frequency, and this electromagnetic wave can cause errors when OA equipment and electrical products are used in close proximity to each other. The current situation is that when a device is activated, or if you watch a TV or listen to a radio in the vicinity, it has a great effect on radio waves such as TV images and radio sounds.

Therefore, in recent years, in order to reduce electromagnetic interference, OA
We inspect whether the frequency of electromagnetic waves oscillated by equipment and electrical products using IC circuits falls within certain standards, and only products that fall within certain standards are allowed to enter the market. I try to give it a ride.

By the way, in the past, in order to measure the amount of radio waves oscillated by OA equipment and electrical products that use RC circuits, an anechoic chamber in which a material that absorbs radio waves in the low frequency band is placed indoors has been used. There is. In this anechoic chamber, it is necessary to use radio wave absorbing materials with as good radio wave absorption performance as possible so that the room becomes a large free space. Radio wave absorbers are used that absorb magnetic lossy materials.

Examples of conventional radio wave absorbing materials 1a and lb include those having square pyramid-shaped protrusions 2 on the surface, as shown in FIG.
As shown in FIG. 5, a device having wavy projections 3 on its surface is known.

The constituent materials of these radio wave absorbers 1a and lb include foamed polyurethane or foamed polystyrene as a base material,
It contains carbon black or the like as a dielectric loss material, and is used by attaching the back surfaces of the radio wave absorbing materials 1a and 1b to the inner wall surface of the radio anechoic chamber via an adhesive or the like. However, when such conventional radio wave absorbing materials 1a, lb are used on the wall surface of an anechoic chamber for a long period of time, the protrusions 2 may form due to the properties of the constituent materials of the radio wave absorbing materials 1a, lb.
．． 3 tilts downward, a so-called "sagging phenomenon" occurs. When this sagging phenomenon occurs, the electromagnetic wave absorption performance deteriorates, and there is a problem in that it is impossible to accurately measure the amount of electromagnetic waves generated.

[Purpose of the invention]

This invention was devised by focusing on such conventional problems, and its purpose is that even if the radio wave absorbing material is used for a long period of time on the side walls of an anechoic chamber, the tip of the radio wave absorbing material To provide a radio wave absorber in an anechoic chamber, which effectively prevents downward tilting and can always measure the amount of electromagnetic waves generated in the anechoic chamber with high precision.

[Structure of the invention]

In order to achieve the above object, the present invention provides a radio wave absorber to be installed on the inner wall of an anechoic chamber, in which the radio wave absorber is placed between an uneven radio wave absorber containing a dielectric loss material and a concave portion of the radio wave absorber. It is said that it is composed of a plurality of radio wave transparent materials that are fitted at predetermined intervals, and that the tip of the radio wave absorbing material is tilted downward by fitting the radio wave transparent material into the recess of the radio wave absorbing material. The main point is that this was effectively prevented.

[Embodiments of the invention]

The present invention will be described in detail below based on the accompanying drawings.

FIG. 1 shows a perspective view of a radio wave absorbing material 12 and a plurality of radio wave transparent materials 13 constituting a radio wave absorber 11 according to the present invention. The base material is foamed polyurethane or foamed polystyrene containing a dielectric loss material, and carbon black or the like is contained as the dielectric loss material.

Further, as shown in FIG. 2, the plurality of radio-transparent materials 13 are made of a material radio-equivalent to air, such as foamed polyurethane or foamed polystyrene, and are arranged between the protrusions 12a of the wave-shaped radio wave absorbing material 12. It is formed into a curved shape that fits into the recess 12b (trough) of the groove.

When such a plurality of radio-transparent materials 13 are fitted into the recesses 12b (troughs) between the protrusions 12a of the wave-shaped radio-wave absorbing material 12 at predetermined intervals, a structure shown in FIG. 3 is formed. The radio wave absorber 11 has a shape having an inverted pyramid-shaped concave portion 14 on the surface as shown in FIG. This is possible.

〔Effect of the invention〕

The present invention provides a radio wave absorber to be installed on the inner wall of an anechoic chamber as described above, in which the radio wave absorber is formed of an uneven radio wave absorber containing a dielectric loss material and a predetermined concave portion of the radio wave absorber. Because it is composed of multiple radio-transparent materials that fit together at intervals, it is possible to construct a strong radio-wave absorber without changing the radio-wave absorption performance compared to conventional methods.As a result, it always has high precision in an anechoic chamber This has the effect of being able to measure the amount of electromagnetic waves generated.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of a radio wave absorber and a radio transparent material embodying the present invention, FIG. 2 is a perspective view of the radio transparent material, and FIG.
The figure is an overall perspective view of a radio wave absorbing material body constructed by fitting a radio wave absorbing material and a radio transparent material, and FIGS. 4 and 5 are perspective views of conventional radio wave absorbing materials. 11... Radio wave absorber, 12... Radio wave absorber, 12a
...Concave portion, 13...Radio wave transparent material.

Claims (1)

[Claims] A radio wave absorber installed on the inner wall of an anechoic chamber includes a plurality of radio wave absorbers fitted at predetermined intervals into recessed portions of the radio wave absorber and an uneven radio wave absorber containing a dielectric loss material. A radio wave absorber for use in a radio anechoic chamber, characterized in that it is constructed of a radio wave transparent material.