JPS5857800A - Radio wave absorbing wall - 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] This invention relates to a radio wave absorbing wall.

Radio interference caused by reflections from high-rise buildings has become a problem in recent years, but no effective countermeasures have been taken so far. Until now, attempts have been made to make the walls of high-rise buildings have special structures that scatter incoming radio waves, or to converge and annihilate them at close range, and to attach radio wave absorbing plates such as ferrite tiles to the walls. I came.

However, it is difficult to completely eliminate radio wave interference due to the shape of the walls, and the floor plan inside the building is also subject to significant restrictions.

In addition, ferrite tiles had problems in structure, size, weight, weather resistance, and economy, and were not suitable as wall materials for high-rise buildings. In particular, in the case of television VHF waves, since the wavelength is relatively long, even a thickness of λ/4 is quite large, making it difficult to obtain a small and lightweight radio wave absorption wall.

SUMMARY OF THE INVENTION In consideration of these points, an object of the present invention is to provide a radio wave absorption wall that is relatively thin relative to the wavelength, has a simple structure, is highly economical, and has a heat insulating effect.

According to the present invention, a dielectric outer wall plate with a resistive film formed on the indoor side and a dielectric inner wall plate are arranged on the indoor side, and an air layer and a radio wave absorbing material are provided between the outer wall plate and the inner wall plate. are arranged to form a heat insulating layer, and the radio wave absorbing material has a special shape to enhance the radio wave absorption effect.

Embodiments of the radio wave absorbing wall of the present invention shown in the drawings will be explained below.

An exterior wall board 3 is formed by arranging a resistive film 2 on the indoor side of a dielectric concrete board 1. The resistive film 2 is formed by mixing approximately 10% by weight of carbon fibers into pulp. An inner wall plate 4 made of a concrete plate is provided on the indoor side at a predetermined distance from the outer wall plate 3.

A heat insulating layer 5 is formed between the outer wall board 3 and the inner wall board 4. This heat insulating layer 5 has an air layer 6 provided on the side of the outer wall board 3.
and a radio wave absorbing material 7 arranged on the inner wall board-4 side. The radio wave absorbing material 7 is a heat insulating material mixed with a predetermined amount of carbon, and is formed to have a sawtooth cross section toward the outdoor side, that is, a wavy draft shape or a pyramid shape when viewed from the front.

In the radio wave absorbing wall having this structure, the entire wall is made of a dielectric material, a standing wave is generated in the wall, and the radio wave is absorbed by the resistive film 2 and the radio wave absorbing material 7. In this way, it is possible to increase the transmission loss by combining materials with different dielectric constants, and at the same time, to obtain desired characteristics by adjusting the thickness of other layers in accordance with the thickness of the concrete part.

In model experiments according to this example, the overall wall thickness was 15 cm.
rn, but the TV VI (Low channel A/(1ch to 3ch) in the F wave band) was 2.5' db.
degree, 1 on High channel (4Ch to 12Ch)
Absorption amount of about 0db and 1 piece.

In this way, the concrete plate 1, the resistive film 2, and the specially shaped radio wave absorbing material 7 effectively absorb incoming radio waves with a wall thickness thinner than λ/4.

The radio wave absorbing wall according to the present invention has the following effects as described above.

It has a simple structure, has a relatively thin wall thickness relative to the wavelength, has a high radio wave absorption effect, is lightweight, economical, and highly practical.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the radio wave absorbing wall according to the present invention, Fig. 2 is a perspective view of the radio wave absorbing material, and Figs. 6 and 4 each show the shape of the radio wave absorbing material of other embodiments. FIG. 1...Concrete board, 2...Resistive film, Ro...Outer wall board, 4...Inner wall board, 5...
...Insulation layer, 6...Air layer, 7...
...Radio wave absorbing material, 8...Rebar net. Patent applicant Figure 1 Figure 7 Figure 3 Figure 4

Claims (1)

[Claims] an outer wall plate with a resistive film formed on the dielectric indoor side, an inner wall plate made of a dielectric, and an air layer formed between the outer wall plate and the inner wall plate, and provided on the outer wall plate side air space and the inner wall plate side, 1. A radio wave absorbing wall comprising: a heat insulating layer having a radio wave absorbing material having a substantially serrated cross section and protruding toward the outside of the room;