TW201323889A - Anechoic chamber - Google Patents

Abstract

An anechoic chamber includes a wall and a floor, there are absorbing material building on the surface of the wall, the surface of the absorbing material form serial awl parts. The wall includes the connecting first wall and second wall, the first wall is semi-column shape, the serial awl parts of the surface of the first wall point at the central axis of the first wall on the radius direction. The second wall is semi-ball shape, the serial awl parts of the surface of the second wall point at the globe center of the first wall on the radius direction.

Description

Radio darkroom

The present invention relates to the field of electromagnetic compatibility, and more particularly to an anechoic chamber.

General Electromagnetic Compatibility (EMC) testing requires the use of an anechoic chamber as a test site. Generally, the anechoic chamber is divided into a full anechoic chamber and a semi-anechoic chamber. The inner surface of the full anechoic chamber is completely covered with absorbing material, and the semi-anechoic chamber has a part of the inner surface covered with absorbing material. A typical anechoic chamber is a rectangular body structure. The absorbing material is generally a ferrite and polyurethane foam having a plurality of tapered protrusions on its surface. An electromagnetic radiation source that requires EMC testing, such as an electronic device such as a computer, can be placed in the anechoic chamber. When the pointed conical protrusion on the surface of the absorbing material is perpendicular to the electromagnetic radiation source to be measured, the absorbing material has the largest absorption rate for the electromagnetic wave generated by the object to be tested. However, due to the shape limitation of the conventional anechoic chamber, it is difficult to make all or most of the pointed pyramidal protrusions formed on the surface of the absorbing material laid on the inner surface thereof at the same time perpendicular to the electromagnetic radiation source to be measured, which is difficult to obtain sufficiently large. Electromagnetic wave absorption rate.

In view of this, it is necessary to provide an anechoic chamber having a high absorbing rate.

An anechoic chamber comprising a peripheral wall and a bottom surface, the inner surface of the peripheral wall is provided with an absorbing material, and the surface of the absorbing material forms a closely arranged tapered portion. The peripheral wall includes a first peripheral wall and a second peripheral wall that are joined together, the first peripheral wall is in the shape of a semi-cylindrical shell, and the top end of the tapered portion formed on the surface of the absorbing material laid on the inner surface of the first peripheral wall It extends in the radial direction of the first peripheral wall and points to the central axis of the first peripheral wall. The second peripheral wall has a semi-spherical shell shape, and a tip end of the tapered portion formed on the surface of the absorbing material laid on the inner surface of the second peripheral wall extends perpendicularly in the radial direction of the second peripheral wall to point toward the center of the second peripheral wall. The anechoic chamber is placed with an electronic device to be tested and an antenna for performing EMC testing.

The anechoic chamber is designed to have a semi-cylindrical shell shape and a hemispherical shell shape by the first peripheral wall and the second peripheral wall, so that the top end of most of the tapered portions formed on the surface of the absorbing material laid on the surface of the peripheral wall can be vertical The electronic device and antenna are being measured. In this way, when the electronic device to be tested and the antenna generate unnecessary electromagnetic radiation to the peripheral wall, the absorbing material can absorb the electromagnetic waves to the greatest extent, reduce the unnecessary reflectance of the electromagnetic wave, and ensure the accuracy of the test result, thereby improving the anechoic chamber. As the precision of the laboratory.

Referring to FIG. 1, an anechoic chamber 100 in accordance with a preferred embodiment of the present invention is a semi-anechoic chamber including a peripheral wall 10, a bottom surface 20, a rotating stage 30, and an antenna 40. The peripheral wall 10 of the anechoic chamber 100 is disposed on the bottom surface 20 and surrounds the bottom surface 20 to form a closed accommodating space 110. The rotating table 30 and the antenna 40 are both located on the bottom surface 20 and are accommodated inside the accommodating space 110. The rotating table 30 and the antenna 40 are placed at a certain distance. The anechoic chamber 100 can be used to test the EMC quality of electromagnetic radiation sources such as computers, televisions or refrigerators. In this embodiment, the EMC quality of the computer 50 to be tested is tested as an example. The peripheral wall 10 includes a first peripheral wall 12, a second peripheral wall 14, and a third peripheral wall (not shown) that are sequentially joined together. The first peripheral wall 12 has a substantially semi-cylindrical shape, and the second peripheral wall 14 has a substantially semi-spherical shape. The third peripheral wall may have a flat shape, and the first peripheral wall 12 and the third peripheral wall are respectively connected to the first Both ends of the wall 14 of the second week. The inner surface of the peripheral wall 10 is covered with an absorbing material 16, and the surface of the absorbing material 16 forms a closely-arranged tapered portion 162 for absorbing electromagnetic waves. The tip end of the tapered portion 162 formed on the surface of the absorbing material 16 on the inner surface of the first peripheral wall 12 extends in the radial direction of the first peripheral wall 12 so as to be directed to the central axis of the first peripheral wall 12. The tip end of the tapered portion 162 formed on the surface of the absorbing material 16 on the inner surface of the second peripheral wall 14 extends in the radial direction of the second peripheral wall 14 so as to both point toward the center of the second peripheral wall. The tip end of the tapered portion 162 formed on the surface of the absorbing material 16 on the inner surface of the third peripheral wall is directed to the accommodating space 110. In this way, the top end of most of the tapered portion 162 can be directed to the central position of the accommodating space 110 along the radial direction of the semi-cylindrical surface or the hemispherical surface.

Preferably, the rotary table 30 is located at a central position below the second peripheral wall 14 of the anechoic chamber 100 of the present embodiment. A test table 32 is carried on the rotary table 30. The computer to be tested 50 is placed on the test table 32. The antenna 40 is placed at a central position below the first peripheral wall 12 and aligned with the computer 50 to be tested. The receiving portion of the antenna 40 has a certain height so as to be placed at the center of the semi-cylindrical structure of the first peripheral wall 12. Thus, the tips of most of the tapered portions 162 formed on the surface of the absorbing material 16 laid on the inner surface of the first peripheral wall 12 are also perpendicular to the receiving portion of the antenna 40.

Referring to FIG. 2, the test table 32 has a height such that the computer 50 to be tested placed on the test table 32 is substantially at the center of the hemispherical structure of the second peripheral wall 14. Thus, the top ends of most of the tapered portions 162 formed on the surface of the absorbing material 16 laid on the inner surface of the second peripheral wall 14 can be vertically aligned with the computer 50 to be tested.

When the EMC test is performed in the anechoic chamber 100, when the computer 50 to be tested is turned on to operate, the antenna 40 receives the work signal generated by the computer 50 to be tested and converts it into an electrical signal for reading by the receiver (not shown). The value is used to detect the intensity of the working signal radiated by the computer 50 to be tested. When the noise generated by the computer 50 to be tested and other electromagnetic waves not required for the test are radiated to the peripheral wall 10, it can be absorbed by the absorbing material 16 to avoid being reflected to the antenna 40 and causing interference to the test. The top end of most of the tapered portion 162 of the inner peripheral wave absorbing material 16 of the second peripheral wall 14 in this embodiment is perpendicular to the computer 50 to be tested. When electromagnetic waves are radiated to the peripheral wall 10, the absorbing materials 16 can be maximized. Absorbing these electromagnetic waves to reduce the unnecessary reflection rate of electromagnetic waves and improving the accuracy of the test results can reduce the normalized Site Attenuation (NSA) deviation in the electromagnetic interference test. In addition, the top end of most of the tapered portion 162 of the inner surface absorbing material 16 of the first peripheral wall 12 is perpendicular to the receiving portion of the antenna 40, and the unnecessary electromagnetic waves generated by the antenna 40 can be absorbed as much as possible, for example, due to resonance. The electromagnetic radiation generated thereby further improves the accuracy of the test results.

The anechoic chamber 100 is formed into a semi-cylindrical shell shape and a hemispherical shell shape by the first peripheral wall 12 and the second peripheral wall 14, so that most of the tips formed on the surface of the absorbing material 16 on the inner surface of the peripheral wall 10 are formed. The top end of the tapered portion 162 can be perpendicular to the computer 50 and the antenna 40 to be tested. Thus, when the computer 50 and the antenna 40 to be tested generate unnecessary electromagnetic radiation to the peripheral wall 10, the absorbing material 16 can absorb the electromagnetic waves to the greatest extent, reduce the unnecessary reflectance of the electromagnetic wave, and ensure the accuracy of the test result, thereby improving the accuracy. The anechoic chamber 100 serves as a laboratory precision.

It is to be understood that those skilled in the art can make various other changes and modifications in accordance with the technical concept of the present invention, and all such changes and modifications are intended to fall within the scope of the appended claims.

100. . . Radio darkroom

110. . . Housing space

10. . . Zhou wall

12. . . First week wall

14. . . Second week wall

16. . . Absorbing material

162. . . Tip cone

20. . . Bottom

30. . . Rotary table

32. . . Test table

40. . . antenna

50. . . Computer to be tested

1 is a schematic view of an anechoic chamber in accordance with a preferred embodiment of the present invention.

Figure 2 is a partial cross-sectional view of the anechoic chamber of Figure 1.

100. . . Radio darkroom

110. . . Housing space

10. . . Zhou wall

12. . . First week wall

14. . . Second week wall

16. . . Absorbing material

162. . . Tip cone

20. . . Bottom

30. . . Rotary table

32. . . Test table

40. . . antenna

50. . . Computer to be tested

Claims (8)

An anechoic chamber comprising a peripheral wall and a bottom surface, wherein the inner surface of the peripheral wall is coated with an absorbing material, and the surface of the absorbing material forms a closely arranged tapered portion, the improvement being that the peripheral wall comprises a first peripheral wall and a second joint a peripheral wall having a semi-cylindrical shell shape, and a tip end of the tapered portion formed on the surface of the absorbing material laid on the inner surface of the first peripheral wall extends in a radial direction of the first peripheral wall to be directed to the first peripheral wall a central axis; the second peripheral wall is in the shape of a hemispherical shell, and the tip end of the tapered portion formed on the surface of the absorbing material laid on the inner surface of the second peripheral wall vertically extends along the radial direction of the second peripheral wall and points to the ball of the second peripheral wall heart. The anechoic chamber of claim 1, wherein the peripheral wall further comprises a third peripheral wall, the first peripheral wall and the third peripheral wall being respectively connected to both ends of the second peripheral wall. The anechoic chamber according to the second aspect of the invention, wherein the first peripheral wall, the second peripheral wall, the third peripheral wall and the bottom surface are surrounded to form a sealed accommodating space. The anechoic chamber according to claim 3, wherein the tapered portion formed on the surface of the absorbing material laid on the inner surface of the peripheral wall is directed to the accommodating space. The anechoic chamber according to claim 3, wherein the accommodating space is provided with a rotating table, a test table, a test object and an antenna, the rotating table is placed on the bottom surface, and the test table is placed on the rotating table and used Place the electronic device to be tested. The anechoic chamber according to claim 5, wherein the rotating table is spaced apart from the antenna by a predetermined distance, and the antenna is aligned with the object to be tested. The anechoic chamber of claim 5, wherein the antenna is located at a central position of the semi-cylindrical structure of the first peripheral wall. The anechoic chamber of claim 5, wherein the rotating table is located at a central position of the hemispherical structure of the second peripheral wall.