JPH0322718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of an anechoic chamber for measuring electromagnetic waves.

[Conventional technology]

Generally, weak electromagnetic waves are measured in an anechoic chamber that eliminates the effects of interfering radio waves or harmful reflected waves. Conventionally, as a structure of this type of anechoic chamber, an anechoic chamber structure A shown in FIG. 3 is known. To explain the anechoic chamber structure A, reference numeral 1 in the figure is an anechoic chamber provided within a concrete building 1a. The anechoic chamber 1 is composed of a top panel 2 made of a thin iron plate, a floor section 3, and side walls 6a and 6b having an air supply port 4 and an exhaust port 5, and a measurement chamber 7 is formed therein. It is something that Inside the top plate portion 2 and side wall portions 6a and 6b,
An electromagnetic wave absorbing material 8 is stretched. Further, an air supply fan 9 and a wire mesh 10 are attached to the air supply port 4,
An exhaust fan 11 and a wire mesh 12 are attached to the exhaust port 5. On the other hand, a cable pit 13a is provided below the bottom 3 of the measurement chamber 1.
The top panel 2 is equipped with a lighting device 13b. The anechoic chamber structure A blocks electromagnetic waves from the outside by the iron plates and wire meshes 10 and 12 that constitute the anechoic chamber 1, absorbs electromagnetic waves generated inside by the electromagnetic wave absorbing material 8, and The interior is ventilated by an air supply fan 9 provided at the exhaust port 5 and an exhaust fan 11 provided at the exhaust port 5.

[Problem that the invention seeks to solve]

By the way, in the above anechoic chamber structure A,
Because the electromagnetic waves from the outside world that entered from the air supply port 4 and the exhaust port 5 were blocked by the wire meshes 10 and 12,
There was a problem in that electromagnetic waves penetrated through the meshes of the wire meshes 10 and 12, and the shielding performance of the air supply port 4 and exhaust port 5 portions deteriorated. In addition, in the above-mentioned anechoic chamber structure A, since the electromagnetic wave absorbing material 8 is not stretched over the air supply port 4 and the exhaust port 5, the electromagnetic waves generated inside are reflected at the air supply port 4 and the exhaust port 5. This caused a problem in that it interfered with electromagnetic wave measurements performed in the measurement room. Furthermore, there is a problem in terms of cost in applying electromagnetic wave absorption and electromagnetic wave shielding treatments to the air supply port 4 and the exhaust port 5. This invention was made in view of the above circumstances, and the problem is how to realize an anechoic chamber structure that can eliminate the above drawbacks.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 are diagrams showing an anechoic chamber structure B, and in these figures, reference numeral 14 is an anechoic chamber provided within a concrete building 14a. The anechoic chamber 14 has side walls 15a, 15b, 15c, and 15c made of thin iron plates (electromagnetic shielding bodies).
15d, a top plate part 16, and a floor part 17, and a measurement chamber 18 is formed inside thereof. Said side wall portions 15a, 15b, 15c, 15d
And inside the top plate part 16, an electromagnetic wave absorbing material 19 is provided.
is installed.

Further, the floor portion 17 of the anechoic chamber 14 is located at the ground m.
A parallel floor surface 20a and a floor surface 20
b, and these floor surfaces 20
A space 23 is formed between a and the floor surface 20b. An air supply port 24 and an exhaust port 25 are formed in the floor surface 20a, and iron plates 27 and 28 having air circulation holes 26, 26, . . . are respectively attached to these air supply ports 24 and exhaust port 25. ing.

In the space 23 below the air supply port 24 and the exhaust port 25, an air supply pit 31 and an exhaust pit 32 are provided.
are provided for each. The air supply pit 31 and the exhaust pit 32 are connected to an air supply pipe 33 and an exhaust pipe 34, respectively. In this case, both the air supply pipe 33 and the exhaust pipe 34 are arranged further below the lower floor surface 20b, that is, in the ground. Inside the air supply pit 31 and the exhaust pit 32, an air supply fan and an exhaust fan (not shown) for supplying and exhausting the inside of the measurement chamber 18 are provided, respectively. Further, the floor portion 1
A cable pit 35 is provided in the space 23 of 7. On the other hand, on the floor surface 20a of the floor section 17, stand-type lighting devices 36, 36 for illuminating the inside of the measuring section 18 are mounted from the floor.

In the above-mentioned anechoic chamber structure A, the iron plate constituting the measurement chamber 18 blocks electromagnetic waves from the outside, the electromagnetic wave absorbing material 19 absorbs the electromagnetic waves generated inside, and the The interior is ventilated by an air fan and an exhaust fan provided in the exhaust pit 32.

When using the anechoic chamber structure B having the above configuration, the interior is first illuminated by lighting devices 36, 36 as required, and then the air supply fan and exhaust fan are operated. Through the operation of these air supply fans and exhaust fans, external air is taken into the measurement chamber 18 through the air supply pipe 33 and the air supply port 24, while air inside the measurement chamber 18 is taken into the measurement chamber 18 through the air supply pipe 33 and the air supply port 24.
It is released to the outside through 4.

Through the above operations, ventilation is performed and a state is reached in which electromagnetic waves can be measured. On the other hand, in the anechoic chamber structure B having the above configuration, the iron plate blocks electromagnetic waves from outside, and the electromagnetic wave absorbing material 19 absorbs electromagnetic waves within the measurement chamber 18 generated by electromagnetic wave measurement or the like.

In the above anechoic chamber structure B, an air supply port 24 and an exhaust port 25 are provided like the conventional anechoic chamber structure A, but unlike the conventional anechoic chamber structure B, these air supply ports 24 and exhaust port 25 is provided on the floor 17 near the ground m, the ground m blocks electromagnetic waves from the outside world, and can prevent electromagnetic waves from entering from the air supply port 24 and the exhaust port 25. In addition, in the above-mentioned anechoic chamber structure B, unlike the conventional anechoic chamber structure A, there is no need to provide an air supply port and an exhaust port on the side wall, so it is susceptible to the influence of electromagnetic waves from the outside world and is susceptible to electromagnetic waves generated inside. There are no defects in the side walls 15a to 15d and the top plate 16, where electromagnetic waves are likely to be reflected.Therefore, all of the side walls 15a to 15d and the top plate 16 are made of iron plates and electromagnetic wave absorbing material. 19. Therefore, in the above-mentioned anechoic chamber structure B, the shielding performance is improved compared to the conventional anechoic chamber structure A, and the measurement chamber 18
The absorption performance of electromagnetic waves generated within the chamber is improved, and as a result, weak electromagnetic waves can be measured within the anechoic chamber structure B without any hindrance. Further, the floor portion 17 is connected to a floor surface 20 made of an iron plate through the space portion 23.
Since it has a double structure with a and 20b, leakage electromagnetic waves from the floor 17 can be reliably shielded even though openings such as the air supply port 24 and the exhaust port 25 are formed in the floor 17. be able to. This is because the openings such as the air supply port 24 and the exhaust port 25 are formed on the upper floor surface 20a (that is, on the inside of the measurement chamber), and there is a further floor surface 2 below the floor surface 20a.
0b is arranged at the boundary with the ground m, so that electromagnetic waves from the ground m side are substantially blocked by the lower floor surface 20b. Furthermore, in that case, as mentioned above, the air supply pit 31, exhaust pit 32, cable pit 35, etc.
Since it is arranged in the space 23 between the holes 20a and 20b, the formation of a defective portion on the lower floor surface 20b is prevented as much as possible, and a more perfect shielding effect can be obtained. Furthermore, in the above-mentioned anechoic chamber structure B, since the air supply port 24 and the exhaust port 25 are provided in the floor portion 17, construction and management costs can be kept low.

〔Effect of the invention〕

According to the anechoic chamber of the present invention, the floor portion is formed in double form with an electromagnetic wave shielding member through the space portion, and openings such as an air supply port and an exhaust port are formed in the upper floor surface, and Since the air supply pit and the exhaust pit for the air supply port and the exhaust port are configured inside the space, it is possible to almost completely prevent electromagnetic waves from entering from the air supply port and the exhaust port, and There is no damage to the side walls and top panel, which are easily affected by external electromagnetic waves and where internally generated electromagnetic waves are likely to be reflected. It can be shielded with electromagnetic wave absorbing material, and therefore, when compared to a conventional anechoic chamber with air supply and exhaust ports on the side wall, both shielding performance and electromagnetic wave absorption performance are improved, and as a result, the internal It has the advantage that weak electromagnetic waves can be measured without any problems. Furthermore, since the air supply and exhaust ports are provided on the floor, there is an advantage that construction and management costs are low.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a radio anechoic chamber structure shown as an embodiment of the present invention, FIG. 2 is a plan view taken along line a-a, and FIG. 3 is a longitudinal sectional front view showing a conventional radio anechoic chamber structure. B...Anechoic chamber structure, 17...Floor, 20a...
...Floor surface, 20b...Floor surface, 23...Space part, 24
...Air supply port, 25 ...Exhaust port, air supply pit...3
1. Exhaust pit...32, 36...Lighting equipment.

Claims (1)

[Scope of Claims] 1. A structure of an anechoic chamber surrounded by an electromagnetic wave shielding body, in which the floor portion is formed double with the electromagnetic wave shielding body through a space, and an air supply port and an exhaust port are formed. 1. A structure of an anechoic chamber, characterized in that an opening such as a mouth is formed in an upper floor surface, and an air supply pit and an exhaust pit for the air supply port and the exhaust port are formed inside the space. 2. The structure of the anechoic chamber according to claim 1, characterized in that the lighting equipment is installed on the floor.