Microwave darkroom

Abstract

The invention provides a microwave anechoic chamber, and relates to the technical field of communication equipment testing, and the microwave anechoic chamber comprises an electromagnetic shielding chamber, a wave absorbing material, a non-metal sealing cover and a measuring antenna; wherein the wave-absorbing material is laid on the inner wall of the electromagnetic shielding chamber; the non-metal sealing cover is of a hollow and symmetrical structure and is installed on the ground of the electromagnetic shielding chamber. A measuring antenna and a to-be-tested equipment turntable are arranged in the electromagnetic shielding chamber, and to-be-tested equipment is arranged on the to-be-tested equipment turntable; the surface, facing the measuring antenna and the equipment to be measured, of the non-metal sealing cover is a spherical surface, and the center of the spherical surface is the phase center of the measuring antenna and the center of a rotary table of the equipment to be measured. The non-metal sealing cover is filled with absorptive liquid; when the anechoic chamber is filled with the absorptive liquid, a free space non-reflection test environment is simulated, and the anechoic chamber is equivalent to a full anechoic chamber; when no filling exists, the anechoic chamber is equivalent to a semi-anechoic chamber.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication equipment testing, and in particular to a microwave anechoic chamber. BACKGROUND

[0002] This section is intended to provide background or context to the embodiments of the application. The description herein does not constitute admission that the information provided herein is prior art.

[0003] A microwave anechoic chamber is a special device that effectively absorbs electromagnetic waves by laying absorbing materials on the inner walls (including side walls, floor and top) of an electromagnetic shield chamber. Referring to Figure 3 , it is a schematic diagram of the structure of a microwave anechoic chamber of the prior art. In Figure 3 , the inner walls of the electromagnetic shield chamber 301 are lined with absorbing materials 302, and the measurement antenna 303 and the device under test turntable 304 are set in the electromagnetic shield chamber 301 according to requirements.

[0004] This design can effectively reduce or eliminate the reflection and scattering of electromagnetic waves, thereby simulating a free-space test environment and providing an ideal environment for antenna measurement and other related tests. Microwave anechoic chambers are widely used in the fields of antenna parameter measurement, electromagnetic wave diffraction, scattering and radiation characteristic testing, and their core function is to provide a stable and controllable electromagnetic signal environment to meet measurement requirements.

[0005] According to the different installation methods of absorbing materials, microwave anechoic chambers can be divided into full-wave anechoic chambers and half-wave anechoic chambers. The inner surface of a full-wave anechoic chamber is completely covered with absorbing materials, which can effectively reduce the influence of reflected signals on test results and simulate a free-space electromagnetic wave propagation environment without reflection, so it plays an important role in the parameter measurement of microwave antenna systems. For example, a full-wave anechoic chamber can be used to measure the gain, pattern, polarization characteristics and other parameters of an antenna, ensuring the accuracy and consistency of test results.

[0006] In contrast, a half-wave anechoic chamber only covers the side walls and top with absorbing materials, and the ground uses a metal conductive floor as a reflecting surface. This design simulates an open field test environment, where the signal received by the receiving antenna is the sum of the direct and reflected path signals. Half-wave anechoic chambers are mainly used for electromagnetic compatibility (EMC) testing, such as radiation disturbance and sensitivity measurement. Due to its lower cost, simple structure and lower space requirements, it is often used for conducted and radiated noise testing of wireless communication equipment and automotive electronic products.

[0007] The design and construction of the existing darkroom generally considers less compatibility of full-wave darkroom and half-wave darkroom scheme. The darkroom user generally selects to build a full-wave darkroom or a half-wave darkroom according to the technical needs. In addition, considering that the main difference between the full-wave darkroom and the half-wave darkroom lies in the coverage of the wave-absorbing material: the wave-absorbing material of the full-wave darkroom covers the six inner walls to simulate a free-space non-reflection test environment; and the half-wave darkroom only covers five surfaces, and the ground is used as a reflection surface to simulate an open field. Therefore, when needed, the test environment without ground reflection can be simulated by manually laying wave-absorbing material on the ground of the half-wave darkroom, thereby constructing a similar full-wave darkroom effect. By manually laying or removing the ground wave-absorbing material, the switching and compatibility between the full-wave darkroom and the half-wave darkroom can be realized.

[0008] The main disadvantage of the prior art is that the construction of the full-wave darkroom and the half-wave darkroom is separately constructed without considering the compatibility between the darkroom schemes, which greatly increases the cost of system construction and use and maintenance; manually laying or removing the ground wave-absorbing material not only takes time and effort, but also has a complex and cumbersome operation process; the process of repeatedly moving the wave-absorbing material can also cause wear of the wave-absorbing material itself, thereby reducing its wave-absorbing performance and affecting the efficiency of constructing the full-wave darkroom; in addition, the wave-absorbing material needs to be replaced regularly, which greatly increases the use and maintenance cost of the system.

[0009] In summary, there is an urgent need for a technical scheme that can overcome the above-mentioned defects, can be compatible with multiple darkroom schemes, and can reduce the construction cost. SUMMARY

[0010] To solve the problems existing in the prior art, the present application provides a microwave darkroom, which comprises: an electromagnetic shielding room, a wave-absorbing material, a non-metallic closed cover and a measurement antenna; wherein,

[0011] The wave-absorbing material is laid on the inner wall of the electromagnetic shielding room;

[0012] The non-metallic closed cover is a hollow and symmetrical structure, and is installed on the ground of the electromagnetic shielding room;

[0013] A measurement antenna and a device under test turntable are arranged in the electromagnetic shielding room, and a device under test is arranged on the device under test turntable;

[0014] The surface of the non-metallic closed cover facing the measurement antenna and the device under test is a spherical surface, and the center of the spherical surface is the phase center of the measurement antenna and the center position of the device under test turntable, respectively; the inside of the non-metallic closed cover is filled with an absorbent liquid; when the absorbent liquid is filled, a free-space non-reflection test environment is simulated, and the microwave darkroom is equivalent to a full-wave darkroom; when there is no filling, the microwave darkroom is equivalent to a half-wave darkroom.

[0015] In an embodiment of the present application, the wave-absorbing material is laid on the inner wall side wall and upper surface of the electromagnetic shielding chamber to eliminate reflection and refraction of wireless signals.

[0016] In an embodiment of the present application, for the non-metallic enclosure, the opening angle of the spherical surface facing the measurement antenna or the device to be measured relative to the elevation direction of the corresponding spherical center is not less than 90°.

[0017] In an embodiment of the present application, for the non-metallic enclosure, the opening angle of the spherical surface facing the measurement antenna or the device to be measured relative to the azimuth direction of the corresponding spherical center is not less than 120°.

[0018] In an embodiment of the present application, for the non-metallic enclosure, the absorption angle of the non-metallic enclosure in the elevation direction after filling is adjusted by adjusting the filling height of the absorbing liquid.

[0019] The maximum absorption angle of the non-metallic enclosure in the elevation direction satisfies the following condition:

[0020]

[0021] wherein, represents the maximum absorption angle of the non-metallic enclosure in the elevation direction; , are the half-power beam widths of the measurement antenna and the device to be measured antenna, respectively;

[0022] The distance between the filling height of the absorbing liquid and the height of the measurement antenna axis satisfies the following relationship:

[0023]

[0024] wherein, represents the distance between the filling height of the absorbing liquid and the height of the measurement antenna axis; is the working wavelength; D is the test distance; and k is the height adjustment factor.

[0025] In an embodiment of the present application, the height adjustment factor k is in the range of 0.8 to 1.2.

[0026] In an embodiment of the present application, the material of the non-metallic enclosure is glass or resin, and the thickness is not less than 8 cm.

[0027] In an embodiment of the present application, the absorbing liquid is a mixture of water, heavy oil and salt water.

[0028] In an embodiment of the present application, the absorbing liquid is a mixture of water, heavy oil, salt water and carbon powder.

[0029] In one embodiment of the present invention, a propeller agitator is provided inside the non-metallic enclosure.

[0030] The propeller agitator is used to agitate the absorbent liquid.

[0031] The microwave anechoic chamber proposed in this invention can achieve the conversion between a fully anechoic chamber and a semi-anechoic chamber by changing the filling material and filling state of the non-metallic enclosure without changing the anechoic chamber structure. While meeting various testing requirements, it expands the flexibility of the anechoic chamber and reduces testing and maintenance costs. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a microwave anechoic chamber architecture according to an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram of a microwave anechoic chamber architecture according to another embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the existing microwave anechoic chamber architecture. Detailed Implementation

[0036] The principles and spirit of the invention will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are given merely to enable those skilled in the art to better understand and implement the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided to make this disclosure more thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0037] According to an embodiment of the present invention, a microwave anechoic chamber is proposed, relating to the field of communication equipment testing technology.

[0038] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0039] Figure 1 This is a schematic diagram of a microwave anechoic chamber architecture according to an embodiment of the present invention. Figure 1 As shown, the microwave anechoic chamber includes: an electromagnetic shielding chamber 101, a microwave absorbing material 102, a non-metallic enclosure 103, and a measuring antenna 104; wherein,

[0040] The absorbing material 102 is laid on the inner wall of the electromagnetic shielding room 101;

[0041] The non-metallic enclosure 103 is a hollow, symmetrical structure and is installed on the ground of the electromagnetic shielding room 101;

[0042] A measuring antenna 104 and a turntable 105 for the device under test are provided in the electromagnetic shielding chamber 101, and the device under test is mounted on the turntable 105.

[0043] The surfaces of the non-metallic enclosure 103 facing the measuring antenna 104 and the device under test are both spherical, and the centers of the spheres are the phase center of the measuring antenna 104 and the center of the turntable 105 of the device under test, respectively; the interior of the non-metallic enclosure 103 is filled with an absorbent liquid.

[0044] When filled with absorbent liquid, simulating a free-space, non-reflective testing environment, this microwave anechoic chamber is equivalent to a fully anechoic chamber.

[0045] When unfilled, this microwave anechoic chamber is equivalent to a semi-anechoic chamber.

[0046] In one embodiment, the absorbing material 102 is laid on the inner wall, sidewall, and upper surface of the electromagnetic shielding room 101 to eliminate the reflection and refraction of wireless signals.

[0047] For the non-metallic enclosure 103, the spherical surface facing the measuring antenna 104 or the device under test has an elevation angle of not less than 90° relative to the corresponding center of the sphere.

[0048] The spherical surface facing the measuring antenna 104 or the device under test shall have an angle of not less than 120° relative to the azimuth direction of the corresponding center of the sphere.

[0049] By adjusting the filling height of the absorbent liquid, the absorption angle of the non-metallic enclosure 103 in the pitch direction after filling can be adjusted.

[0050] The maximum absorption angle of the non-metallic enclosure 103 in the pitch direction satisfies the following condition:

[0051]

[0052] in, This indicates the maximum absorption angle of the non-metallic enclosure 103 in the pitch direction; , These are the half-power beamwidths of the measuring antenna and the antenna of the device under test, respectively.

[0053] The distance between the filling height of the absorbent liquid and the height of the measuring antenna axis satisfies the following relationship:

[0054]

[0055] in, This indicates the distance between the filling height of the absorbent liquid and the height of the measuring antenna axis; λ is the operating wavelength; D is the test distance; k is the height adjustment factor.

[0056] Specifically, the height adjustment factor ranges from 0.8 to 1.2.

[0057] In one embodiment, the non-metallic enclosure 103 is made of glass or resin and has a thickness of not less than 8 cm. In practical applications, the specific thickness can be adjusted according to actual needs.

[0058] In one embodiment, the absorbent liquid can be a mixture of water, heavy oil, and brine, or a mixture of water, heavy oil, brine, and toner. In practical applications, other mixtures can also be used as the absorbent liquid. The purpose is to ensure that when the non-metallic enclosure 103 is filled with the absorbent liquid, the absorbent liquid can strongly absorb the incident electromagnetic waves, thereby simulating a free-space, non-reflective testing environment, equivalent to a completely anechoic chamber.

[0059] refer to Figure 2 As shown, for absorbent liquids containing carbon powder, a propeller agitator 201 is provided inside the non-metallic enclosure 103; the propeller agitator 201 is used to agitate the absorbent liquid to keep the mixture uniform.

[0060] The microwave anechoic chamber proposed in this invention can achieve the conversion between a fully anechoic chamber and a semi-anechoic chamber by changing the filling material and filling state of the non-metallic enclosure without changing the anechoic chamber structure. While meeting various testing requirements, it expands the flexibility of the anechoic chamber and reduces testing and maintenance costs.

[0061] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A microwave anechoic chamber, characterized in that, The microwave anechoic chamber includes: an electromagnetic shielding chamber, absorbing materials, a non-metallic enclosure, and a measuring antenna; among which... The absorbing material is laid on the inner wall of the electromagnetic shielding room; The non-metallic enclosure is a hollow, symmetrical structure and is installed on the floor of the electromagnetic shielding room; A measuring antenna and a turntable for the device under test are provided in the electromagnetic shielding room, and the device under test is placed on the turntable. The surfaces of the non-metallic enclosure facing the measuring antenna and the device under test are both spherical, and the centers of the spheres are the phase center of the measuring antenna and the center of the turntable of the device under test, respectively. The interior of the non-metallic enclosure is filled with an absorbent liquid. When filled with absorbent liquid, it simulates a free space non-reflection test environment, and the microwave anechoic chamber is equivalent to a fully anechoic chamber. When there is no filling, the microwave anechoic chamber is equivalent to a semi-anechoic chamber.

2. The microwave anechoic chamber according to claim 1, characterized in that, The absorbing material is laid on the inner wall, side wall and upper surface of the electromagnetic shielding room to eliminate the reflection and refraction of wireless signals.

3. The microwave anechoic chamber according to claim 1, characterized in that, For the non-metallic enclosure, the angle of elevation of the spherical surface facing the measuring antenna or the device under test relative to the center of the sphere is not less than 90°.

4. The microwave anechoic chamber according to claim 1, characterized in that, For the non-metallic enclosure, the angular angle of the spherical surface facing the measuring antenna or the device under test relative to the azimuth direction of the corresponding sphere center is not less than 120°.

5. The microwave anechoic chamber according to claim 1, characterized in that, For the non-metallic enclosure, the absorption angle of the non-metallic enclosure in the pitch direction after filling is adjusted by adjusting the filling height of the absorbent liquid; The maximum absorption angle of the non-metallic enclosure in the pitch direction satisfies the following condition: in, This indicates the maximum absorption angle of the non-metallic enclosure in the pitch direction; , These are the half-power beamwidths of the measuring antenna and the antenna of the device under test, respectively. The distance between the filling height of the absorbent liquid and the height of the measuring antenna axis satisfies the following relationship: in, This indicates the distance between the filling height of the absorbent liquid and the height of the measuring antenna axis; λ is the operating wavelength; D is the test distance; k is the height adjustment factor.

6. The microwave anechoic chamber according to claim 5, characterized in that, The height adjustment factor ranges from 0.8 to 1.

2.

7. The microwave anechoic chamber according to claim 1, characterized in that, The non-metallic enclosure is made of glass or resin and has a thickness of not less than 8 cm.

8. The microwave anechoic chamber according to claim 1, characterized in that, The absorbent liquid is a mixture of water, heavy oil, and brine.

9. The microwave anechoic chamber according to claim 1, characterized in that, The absorbent liquid is a mixture of water, heavy oil, brine, and carbon powder.

10. The microwave anechoic chamber according to claim 9, characterized in that, A propeller agitator is installed inside the non-metallic enclosed casing; The propeller agitator is used to agitate the absorbent liquid.

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