CN113271757A - Radio wave shielding room and radio wave test method - Google Patents

Abstract

The invention provides a radio wave shielding room and a radio wave testing method. The radio wave shielding room is provided with: a chamber; a first partition wall which divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space and through which radio waves can pass; a temperature adjusting unit for adjusting the temperature of the inner space; and a dehumidifying part for dehumidifying the outer space. This can suppress the diffuse reflection of radio waves due to dew condensation in the chamber.

Description

Radio wave shielding room and radio wave test method

Technical Field

The present invention relates to a radio wave shielding room and a radio wave testing method.

Background

Conventionally, as described in japanese patent No. 4440002 (patent document 1), a radio wave shielding room used for performance evaluation tests of communication equipment is known. The radio wave shielding chamber is designed such that radio waves do not enter the chamber from the outside and such that radio waves do not leak from the chamber to the outside, and particularly a chamber in which a radio wave absorber is disposed on the inner surface of the chamber is called a radio wave anechoic box (anechoic chamber).

In the anechoic chamber described in patent document 1, an electromagnetic wave absorber is disposed on an inner surface of an electromagnetic shielding chamber, and a cover surrounding an electronic device as a test object is disposed in the electromagnetic shielding chamber, and the temperature of a space in the cover can be adjusted by an air conditioner disposed outside the electromagnetic shielding chamber. Accordingly, the performance evaluation test was performed while the ambient temperature of the electronic device was kept constant.

In the anechoic chamber described in patent document 1, when a test is performed in a state where the temperature of the space in the cover is adjusted to a low temperature, the following problems may occur. That is, if low-temperature air is supplied from the air conditioner to the space inside the cover via the duct, the cover is also cooled by the low-temperature air, and the outer surface temperature of the cover may decrease to the dew point temperature of the outside space (the space between the outer surface of the cover and the radio wave absorber) or lower. In this case, dew condensation occurs on the outer surface of the cover, and radio waves are diffusely reflected by the dew condensation in the chamber.

Disclosure of Invention

The invention aims to provide a radio wave shielding room and a radio wave testing method which can inhibit the diffuse reflection of radio waves caused by dew condensation water in a cavity.

A radio wave shielding room according to an aspect of the present invention includes: a chamber; a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate; a temperature adjusting unit for adjusting the temperature of the inner space; and a dehumidification section that dehumidifies the outer space.

Another radio wave shielding room according to another aspect of the present invention includes: a chamber; a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate; a temperature adjusting unit for adjusting the temperature of the inner space; and a heating unit that heats the first partition wall.

An electric wave test method according to an aspect of the present invention includes the steps of: a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and evaluating a transmission/reception state of the radio wave between the test object and the antenna while adjusting the temperature of the inner space and dehumidifying the outer space.

A radio wave test method according to another aspect of the present invention includes the steps of: a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and evaluating a transmission/reception state of radio waves between the test object and the antenna while adjusting the temperature of the inner space and heating the first partition wall.

According to the present invention, it is possible to provide a radio wave shielding room and a radio wave testing method capable of suppressing diffuse reflection of radio waves due to dew condensation water in a chamber.

Drawings

Fig. 1 is a diagram schematically showing the structure of a radio wave shielding room according to embodiment 1 of the present invention.

Fig. 2 is a flowchart for explaining the radio wave test method according to embodiment 1 of the present invention.

Fig. 3 is a flowchart for explaining operation control of the dry air unit in the modification of embodiment 1 of the present invention.

Fig. 4 is a flowchart for explaining operation control of the dry air unit in embodiment 2 of the present invention.

Fig. 5 is a diagram schematically showing the structure of a radio wave shielding room according to embodiment 3 of the present invention.

Fig. 6 is a diagram schematically showing the structure of a radio wave shielding room according to embodiment 4 of the present invention.

Fig. 7 is a diagram schematically showing the structure of the radio wave shielding room according to embodiment 5 of the present invention.

Fig. 8 is a flowchart for explaining the radio wave test method according to embodiment 5 of the present invention.

Fig. 9 is a flowchart for explaining control of the dry air unit and the heating unit in embodiment 6 of the present invention.

Fig. 10 is a flowchart for explaining control of the dry air unit and the heating unit in the modification of embodiment 6 of the present invention.

Fig. 11 is a diagram schematically showing the structure of a radio wave shielding room according to embodiment 8 of the present invention.

Fig. 12 is a diagram schematically showing the structure of a radio wave shielding room according to embodiment 9 of the present invention.

Detailed Description

Hereinafter, a radio wave shielding room and a radio wave testing method according to an embodiment of the present invention will be described in detail with reference to the drawings.

(embodiment mode 1)

First, the structure of a radio wave shielding room 1 according to embodiment 1 of the present invention will be described with reference to fig. 1. The radio wave shielding chamber 1 is used for performance evaluation of, for example, communication equipment and in-vehicle modules using high-frequency radio waves. As shown in fig. 1, the radio wave shielding room 1 mainly includes a chamber 10, a first partition wall 30, a radio wave absorber 40, a temperature control unit 50, a dehumidifying unit 60, a shielding member 80, and a control unit 70. These components are described below.

The chamber 10 is a box body having a space 20 formed therein, and is configured to suppress radio waves from entering the space 20 from outside the chamber and to suppress radio waves from leaking out of the chamber from the space 20. The chamber 10 includes an outer box 11 and an inner box 12 disposed inside the outer box 11 with an air layer 10A interposed therebetween, the outer box 11. The outer casing 11 and the inner casing 12 are formed of a conductive material such as a stainless steel plate, and are grounded. Further, a heat insulator 13 made of foamed urethane or the like is provided on an outer surface (a surface facing the opposite side of the air layer 10A) of the outer box 11.

The first partition wall 30 is used to divide the space 20 in the chamber 10 into an inner space 21 and an outer space 22 surrounding the inner space 21. Specifically, the first partition wall 30 is formed of a box body smaller than the inner box 12, and the test object S1 such as a communication device and an in-vehicle module is disposed in the inner space 21. The first partition wall 30 is permeable to the radio wave transmitted and received by the test object S1, and for example, a foam material such as a foam plastic or a resin material such as FRP (Fiber Reinforced Plastics) is used, but the present invention is not limited thereto. Further, an inner temperature sensor 23 and an inner humidity sensor 24 are disposed in the inner space 21, and an outer temperature sensor 25 and an outer humidity sensor 26 are disposed in the outer space 22.

The radio wave absorber 40 is formed by mixing carbon powder with, for example, foamed polyurethane or the like, and absorbs radio waves by dielectric loss (dielectric radio wave absorber). The radio wave absorber 40 is disposed in the outer space 22, specifically, on the inner surface (the surface facing the outer space 22 side) of the inner box 12 (fig. 1). The radio wave absorber 40 is not limited to the dielectric radio wave absorber, and may be, for example, a conductive radio wave absorber formed of a conductive fiber and absorbing radio waves by resistance inside the material, or a magnetic radio wave absorber absorbing radio waves by magnetic loss such as a ferrite core.

The temperature control unit 50 is for controlling the temperature of the inner space 21, and includes a temperature control unit 51, an air supply pipe 52, and an air discharge pipe 53. The temperature adjusting unit 51 includes an unillustrated device such as a heater, a refrigerator, a humidifier, and a fan, and generates air-conditioned air whose temperature and humidity are adjusted.

One end of the air supply pipe 52 is connected to the air outlet of the temperature control unit 51, and extends to the inner space 21 through the heat insulator 13, the outer box 11, the inner box 12, and the first partition wall 30. An air supply port 52A that opens into the inner space 21 is formed in the other end portion (end portion on the opposite side from the one end portion connected to the temperature adjusting portion 51) of the air supply pipe 52. The conditioned air whose temperature and humidity have been adjusted by the temperature adjusting unit 51 flows through the air supply duct 52 and is supplied to the inner space 21 from the air supply port 52A.

One end of the air outlet pipe 53 is connected to the air inlet of the temperature control unit 51, and extends to the inner space 21 through the heat insulator 13, the outer box 11, the inner box 12, and the first partition 30, as in the air supply pipe 52. An air outlet 53A that opens into the inner space 21 is formed in the other end portion (end portion on the opposite side to the one end portion connected to the temperature adjusting portion 51) of the air outlet pipe 53.

The air in the inside space 21 is discharged from the air outlet 53A into the air outlet duct 53, and is returned to the air inlet of the temperature adjusting portion 51 through the air outlet duct 53. Thus, the conditioned air whose temperature and humidity have been adjusted circulates between the temperature adjustment unit 51 and the inner space 21 through the air supply duct 52 and the air discharge duct 53.

The dehumidification section 60 is used to dehumidify the outer space 22. The dehumidification section 60 in the present embodiment includes: a dry gas generating unit 61 disposed outside the chamber 10; a dry gas supply path 62 for supplying the dry gas generated in the dry gas generation unit 61 to the outer space 22; and a dry gas discharge passage 63 for discharging the dry gas from the outer space 22 to the outside of the chamber 10.

The dry gas generating unit 61 is formed of, for example, a dry air unit, and generates dry air by removing moisture from compressed air by a moisture absorbent such as silica gel. The dry gas generator 61 may be a cooler to remove moisture, or may be a dry dehumidifier. One end of the dry gas supply path 62 is connected to the outlet of the dry gas generator 61, and extends to the outer space 22 through the heat insulator 13, the outer box 11, and the inner box 12. The other end portion (the end portion opposite to the one end portion connected to the dry gas generating part 61) of the dry gas supply passage 62 is formed to be opened to the outer space 22 and to be positioned in the dry gas generating part 6₁The generated dry gas (dry air) is supplied to the dry gas supply port 62A of the outer space 22. The dry gas supply path 62 is formed of, for example, a pipe.

The dry gas discharge passage 63 is formed with a dry gas discharge port 63A opening to the outer space 22 and a dry gas discharge port 63B opening to the space (in the atmosphere) outside the chamber 10. The dry air supplied into the outside space 22 is discharged to the outside of the chamber 10 through the dry gas discharge passage 63, and thereafter discharged to the atmosphere from the dry gas discharge port 63B.

As shown in fig. 1, the dry gas discharge port 63A is located on the opposite side of the dry gas supply port 62A with respect to the space 20 of the chamber 10. Specifically, the dry gas discharge passage 63 penetrates a wall 15 opposed to the wall 14 through which the dry gas supply passage 62 penetrates among the plurality of walls constituting the chamber 10. The dry gas supply port 62A and the dry gas discharge port 63A are disposed with the inner space 21 therebetween. The dry gas supply port 62A and the dry gas discharge port 63A may or may not face each other.

The shield member 80 is a member that allows air to pass therethrough but reflects radio waves, and is attached to the air supply port 52A, the air discharge port 53A, the dry gas supply port 62A, and the dry gas discharge port 63A, respectively, as shown in fig. 1. Accordingly, air conditioning air can be circulated through the air supply port 52A and the air discharge port 53A, and dry air can be circulated through the dry gas supply port 62A and the dry gas discharge port 63A, and leakage of radio waves from these 4 opening portions is suppressed. The shield member 80 is not an essential component of the radio wave shielding chamber of the present invention, and measures for preventing radio waves from leaking from the opening by other methods generally used may be taken.

The control unit 70 is a controller that controls various operations in the radio wave shielded room, and includes a reception unit 71, a storage unit 72, a determination unit 73, a temperature control unit 75, and a dry gas control unit 76. The reception Unit 71, the determination Unit 73, the temperature control Unit 75, and the dry gas control Unit 76 are functions executed by a Central Processing Unit (CPU) of the controller. The storage unit 72 is constituted by a storage device such as a memory.

The reception unit 71 receives signals of measurement data from each of the inside temperature sensor 23, the inside humidity sensor 24, the outside temperature sensor 25, and the outside humidity sensor 26. The storage unit 72 stores data of the set temperature and the set humidity of the inner space 21. The storage unit 72 also stores reference data (for example, a dry gas supply reference temperature) for determining whether or not to supply the dry gas to the outer space 22.

The determination unit 73 compares the data of the set temperature and humidity of the inner space 21 acquired from the storage unit 72 with the data of the measured temperature and humidity of the inner space 21 acquired from the reception unit 71, and determines the magnitude relationship therebetween. The determination unit 73 compares the data of the set temperature of the inner space 21 acquired from the storage unit 72 with the data of the drying gas supply reference temperature, and determines the magnitude relationship thereof.

The temperature control unit 75 controls the operation of the temperature control unit 51 based on the determination result of the determination unit 73 (the comparison determination result of the set temperature and humidity of the inner space 21 and the measured temperature and humidity of the inner space 21). Specifically, the temperature control unit 75 controls (feedback controls) the outputs of the heater, the refrigerator, and the humidifier based on the determination result so that the actual temperature and humidity of the inner space 21 approach the set temperature and humidity.

The dry gas control unit 76 in the present embodiment controls the dry gas generating unit 61 (dry air unit) based on the set temperature of the inner space 21. Specifically, the dry gas control unit 76 operates the dry air unit based on the determination result of the determination unit 73 (the comparison determination result of the set temperature of the inner space 21 and the dry gas supply reference temperature).

Next, the radio wave test method according to the present embodiment will be described with reference to the flowchart of fig. 2. In the radio wave test method, as described below, the transmission/reception state of the radio wave between the test object S1 and the antenna S2 is evaluated while the temperature of the inner space 21 in the chamber 10 is adjusted and the outer space 22 is dehumidified.

First, the test object S1 (for example, a communication device such as a smartphone, an in-vehicle module, or the like) is set in the inside space 21, and the antenna S2 is set in the outside space 22 (step S10). The antenna S2 is used to transmit and receive radio waves between the test subjects S1.

Next, the temperature (test temperature) of the inner space 21 in the chamber 10 is set (step S20). In the present embodiment, the set temperature of the inner space 21 is set to, for example, minus 40 ℃.

Then, the temperature control unit 50 is operated (step S30). In step S30, the temperature control unit 75 controls the operation of the temperature control unit 51 so that the conditioned air circulates between the temperature control unit 51 and the inner space 21 and the temperature of the inner space 21 approaches the set temperature. Specifically, the temperature of the inner space 21 is measured by the inner temperature sensor 23, and when the measured temperature is higher than the set temperature, the temperature control unit 75 decreases the output of the heater or increases the output of the refrigerator. On the other hand, when the measured temperature of the inner space 21 is lower than the set temperature, the temperature adjustment control portion 75 increases the output of the heater or decreases the output of the refrigerator.

On the other hand, after the temperature of the inner space 21 is set in step S20, the determination unit 73 determines whether or not the set temperature of the inner space 21 is equal to or lower than the reference temperature for supplying the dry gas (step S40). In the present embodiment, the reference temperature for supplying the dry gas is set to, for example, 10 ℃. Therefore, the determination unit 73 determines that the set temperature (minus 40 ℃) of the inner space 21 is equal to or lower than the dry gas supply reference temperature (10 ℃) (yes in step S40).

Based on the determination result, the dry gas control unit 76 operates the dry air unit (step S50). Accordingly, the dry air is supplied to the outer space 22, and the outer space 22 is dehumidified. As a result, the dew point temperature of the outer space 22 decreases.

As described above, the transmission/reception state of the radio wave between the test object S1 and the antenna S2 was evaluated when the temperature control of the inner space 21 and the dehumidification of the outer space 22 were performed in parallel. Specifically, the antenna S2 receives the radio wave emitted from the test specimen S1, and evaluates whether or not an appropriate radio wave is emitted from the test specimen S1. Then, whether or not the test object S1 receives the radio wave emitted from the antenna S2 is evaluated. If the test termination condition is satisfied (yes at step S60), the operation of the temperature control unit 50 and the dry air unit is stopped, and the radio wave test method is terminated.

On the other hand, when the test end condition is not satisfied (no at step S60), the process returns to the judgment at step S40. Then, the set temperature of the inner space 21 is changed during the test, and when the changed set temperature is higher than the dry gas supply reference temperature (no at step S40), the dry gas control unit 76 stops the operation of the dry air unit (step S70). Thereafter, the set temperature of the inner space 21 is changed again until the test end condition is satisfied, and when the changed set temperature is equal to or lower than the dry gas supply reference temperature (yes at step S40), the dry gas control unit 76 resumes the operation of the dry air unit (step S50).

As described above, according to the radio wave shielding chamber 1 of the present embodiment, the dehumidification section 60 can reduce the humidity of the outer space 22 in the chamber 10. Therefore, even if the temperature of the outer surface of the first partition wall 30 decreases by adjusting the temperature of the inner space 21 in the chamber 10 to a low temperature (for example, minus 40 ℃), the outer surface temperature can be suppressed from becoming equal to or lower than the dew point temperature of the outer space 22. That is, the outer space 22 can be dehumidified so that the dew point temperature of the outer space 22 is reduced to the temperature of the outer surface of the first partition wall 30 or lower. This can suppress the occurrence of dew condensation water on the outer surface of the first partition wall 30, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber 10. Further, deterioration of the performance of the radio wave absorber 40 due to dew condensation water can be suppressed.

In addition, if the first partition wall 30 is formed thick to improve the heat insulating performance in order to suppress a decrease in the temperature of the outer surface of the first partition wall 30, the radio wave transmission performance of the first partition wall 30 is reduced. In contrast, in the present embodiment, since the dry air is supplied to the outer space 22, it is not necessary to form the first partition wall 30 thick. Therefore, the occurrence of dew condensation water on the outer surface of the first partition wall 30 can be suppressed while suppressing the decrease in the radio wave transmission performance of the first partition wall 30.

Here, a modification of the present embodiment will be described.

< modification 1>

In the present embodiment, the case where the dry air unit is controlled based on the set temperature of the inner space 21 has been described, but the dry gas control unit 76 may control the dry air unit based on the measured temperature of the inner space 21 (the measured value of the inner temperature sensor 23). Specifically, the control shown in the flowchart of fig. 3 may be executed.

Steps S11 to S31 in fig. 3 are the same as steps S10 to S30 in fig. 2. In the present modification, after the operation of the temperature control unit 50 is started in step S31, the temperature of the inner space 21 is measured by the inner temperature sensor 23 at all times or at predetermined time intervals, and the determination unit 73 determines whether or not the measured temperature is equal to or lower than the reference temperature for supplying the dry gas (e.g., 10 ℃) (step S41).

For example, when the set temperature is low, and the temperature of the inner space 21 does not sufficiently decrease immediately after the operation of the temperature control unit 50 is started, it is determined that the measured temperature of the inner space 21 is higher than the dry gas supply reference temperature (no in step S41). At this time, the dry air unit maintains the stopped state (step S71), and if it is determined as no at step S61, returns to step S41.

Then, if a predetermined time has elapsed since the start of the operation of the temperature control unit 50, the measured temperature in the inner space 21 decreases, and it is determined that the measured temperature is equal to or lower than the reference dry gas supply temperature (yes at step S41). At this time, the dry gas control unit 76 starts the operation of the dry air unit (step S51).

While the determination of step S41 is repeated until the test end condition is satisfied, the operation of the dry air unit is continued as long as the measured temperature of the inner space 21 is kept equal to or lower than the dry gas supply reference temperature. According to the present modification, the dry air unit is maintained in the stopped state while the temperature of the inner space 21 is decreased to the dry gas supply reference temperature or less, and therefore, power saving can be achieved compared to the case where the dry air unit is operated together with the start of temperature adjustment of the inner space 21.

< modification 2>

In step S40 in fig. 2, it may be determined whether or not the set temperature of the inner space 21 is equal to or lower than the measured temperature of the outer space 22. Then, when the set temperature of the inner space 21 is equal to or lower than the measured temperature of the outer space 22, the operation of the dry air unit is started (or continued), and when the set temperature of the inner space 21 is higher than the measured temperature of the outer space 22, the operation of the dry air unit is stopped (or continued).

< modification 3>

In step S41 in fig. 3, it may be determined whether or not the measured temperature of the inner space 21 is equal to or lower than the measured temperature of the outer space 22. Then, when the measured temperature of the inner space 21 is equal to or lower than the measured temperature of the outer space 22, the operation of the dry air unit is started (or continued), and when the measured temperature of the inner space 21 is higher than the measured temperature of the outer space 22, the operation of the dry air unit is stopped (or continued).

(embodiment mode 2)

Next, a radio wave shielding room and a radio wave testing method according to embodiment 2 of the present invention will be described. The radio wave shielding room and the radio wave testing method according to embodiment 2 are basically the same as those of embodiment 1, but differ in that the dry gas control unit 76 controls the dry air unit so as to supply the dry air to the outer space 22 when the set temperature of the inner space 21 is equal to or lower than the dew point temperature of the outer space 22. Only the differences from embodiment 1 will be described below.

In embodiment 2, the control unit 70 includes a calculation unit (not shown) in addition to the configuration described in embodiment 1. The calculation unit calculates dew point temperatures of the inner space 21 and the outer space 22 based on the temperature and humidity data of the inner space 21 and the outer space 22.

Fig. 4 shows a radio wave test method (a control flow of the dry air unit by the control unit 70) in embodiment 2. Steps S12 to S32 in fig. 4 are the same as steps S10 to S30 in fig. 2.

In the present embodiment, after step S22, the temperature and humidity of the outer space 22 are measured by the outer temperature sensor 25 and the outer humidity sensor 26 at all times or at predetermined time intervals, and the calculation unit calculates the actual dew point temperature of the outer space 22 based on the measurement results. Then, in step S42, the determination unit 73 determines whether or not the set temperature of the inner space 21 is equal to or lower than the dew point temperature of the outer space 22.

When the set temperature (e.g., minus 40 ℃) of the inner space 21 is equal to or lower than the dew point temperature of the outer space 22 (yes in step S42), the dry gas control unit 76 starts the operation of the dry air unit (step S52). Accordingly, the dry air is supplied to the outer space 22, the humidity of the outer space 22 decreases, and the dew point of the outer space 22 decreases.

Until the test end condition is satisfied, the determination of step S42 is repeated. Then, if the dew point temperature of the outer space 22 is decreased by the supply of the dry air, and it is determined that the set temperature of the inner space 21 is higher than the dew point temperature of the outer space 22 (no at step S42), the dry gas control unit 76 stops the operation of the dry air unit (step S72). On the other hand, when the set temperature of the inner space 21 is not higher than the dew point temperature of the outer space 22 (yes in step S42), the dry gas control unit 76 continues the operation of the dry air unit (step S52).

As described above, in the present embodiment, the timing of supplying the dry air to the outer space 22 is adjusted in consideration of the dew-point temperature of the outer space 22. Therefore, it is possible to supply dry air to the outside space 22 at an appropriate timing after more accurately determining whether dehumidification is necessary in the outside space 22.

As a modification of the present embodiment, the supply/stop of the dry air to the outer space 22 may be controlled based on the result of comparison between the measured temperature of the inner space 21 (the measured temperature of the inner temperature sensor 23) and the dew point temperature of the outer space 22. That is, the temperature of the inner space 21 may be measured at all times or at predetermined time intervals after step S22 in fig. 4, and the determination unit 73 may determine whether or not the measured temperature of the inner space 21 is equal to or lower than the dew point temperature of the outer space 22 in step S42. The dry gas control unit 76 starts (or continues) the operation of the dry air unit when the measured temperature of the inner space 21 is equal to or lower than the dew point temperature of the outer space 22, and the dry gas control unit 76 stops (or continues to stop) the operation of the dry air unit when the measured temperature of the inner space 21 is higher than the dew point temperature of the outer space 22.

(embodiment mode 3)

Next, the structure of the radio wave shielding room 3 according to embodiment 3 of the present invention will be described with reference to fig. 5. The radio wave shielding chamber 3 according to embodiment 3 has basically the same structure and provides the same effects as the radio wave shielding chambers 1 according to embodiments 1 and 2 described above, but differs in the point of circulating the dry air. Only the differences from embodiment 1 will be described below.

The dehumidifying unit 60 according to the present embodiment can circulate the dry air to the dry gas generating unit 61 through the dry gas discharge passage 63, and can adjust the humidity of the dry air. Specifically, as shown in fig. 5, the end of the dry gas discharge passage 63 opposite to the dry gas discharge port 63A is connected to the inlet of the dry gas generator 61. Accordingly, the dry air circulates between the dry gas generating part 61 and the outer space 22 through the dry gas supply passage 62 and the dry gas discharge passage 63.

The dry gas generator 61 in the present embodiment incorporates a mechanism for removing moisture from dry air (e.g., a cooling dehumidifier of a refrigeration apparatus, a desiccant type dehumidifier, etc.). Therefore, the dry air having absorbed moisture in the outer space 22 is dehumidified by the dry gas generating unit 61 and supplied to the outer space 22 again. The moisture removal mechanism operates based on the measurement value of the outside humidity sensor 26, operates until the humidity in the outside space 22 becomes equal to or lower than a predetermined target humidity, and stops when the humidity becomes equal to or lower than the target humidity. Then, if the humidity of the outer space 22 becomes higher than a predetermined target humidity, the moisture removing mechanism operates. In the present embodiment, the humidity of the outside space 22 can be more reliably adjusted by adjusting the humidity of the dry air and circulating the dry air.

The moisture removal means may operate based on the dew-point temperature calculated from the measurement values of outside temperature sensor 25 and outside humidity sensor 26. In this case, the moisture removal means is operated until the calculated dew point temperature becomes equal to or lower than a predetermined target temperature, and is stopped when the calculated dew point temperature becomes equal to or lower than the target temperature, and is operated if the calculated dew point temperature becomes higher than the predetermined target temperature.

(embodiment mode 4)

Next, the structure of the radio wave shielding room 4 according to embodiment 4 of the present invention will be described with reference to fig. 6. The radio wave shielding chamber 4 according to embodiment 4 has basically the same configuration as the radio wave shielding chamber 3 according to embodiment 3, but differs in that it further includes a gas guide plate 81 disposed in the outer space 22. Only the differences from embodiment 3 will be described below.

As shown in fig. 6, in the present embodiment, the dry gas supply path 62 and the dry gas discharge path 63 penetrate the same wall (wall 14) among the plurality of walls constituting the chamber 10, and the dry gas supply port 62A and the dry gas discharge port 63A are adjacent to each other. The gas guide plate 81 is disposed in the outer space 22 so as to be positioned between the dry gas supply port 62A and the dry gas discharge port 63A.

The gas guide plate 81 forms a flow of the dry air in such a manner that the dry air surrounds the outer space 22. Specifically, as shown by arrows in fig. 6, the dry air supplied from the dry gas supply port 62A to the outer space 22 flows through the outer space 22 in the order of the wall 14, the upper wall 16, the wall 15, and the lower wall 17 of the chamber 10, and is then sucked into the dry gas discharge passage 63 from the dry gas discharge port 63A.

Although the flow of the dry air in the outer space 22 in any cross section of the chamber 10 (including cross sections of the walls 14 and 15, the upper wall 16, and the lower wall 17) is described here, the gas guide plate 81 extends in the paper surface front direction and the paper surface depth direction in fig. 6. Therefore, the dry air supplied from the dry gas supply port 62A to the outer space 22 flows toward the upper wall 16 and also flows in the paper surface front direction and the paper surface depth direction in fig. 6 along the gas guide plate 81.

As described above, in embodiment 4, even when the dry gas supply port 62A and the dry gas discharge port 63A are close to each other, the dry air can be distributed over a wide range of the outer space 22. Therefore, the tube length of the dry gas discharge passage 63 can be made shorter as compared with the case where the dry gas supply port 62A and the dry gas discharge port 63A are located on the opposite sides to each other. The gas guide plate 81 is preferably made of a material that can transmit radio waves.

(embodiment 5)

Next, the structure of the radio wave shielding room 5 according to embodiment 5 of the present invention will be described with reference to fig. 7. The radio wave shielding chamber 5 according to embodiment 5 has basically the same configuration as the radio wave shielding chambers 1 according to embodiments 1 and 2 described above, but differs in that it further includes a heating unit 90 for heating dry air. Only the differences from embodiment 1 will be described below.

The heating unit 90 is constituted by a heater, for example. As shown in fig. 7, the heating unit 90 of the present embodiment is disposed in the dry gas supply passage 62. Accordingly, the dry air generated in the dry air unit (dry gas generating unit 61) is heated by the heating unit 90, and the heated dry air is introduced into the outer space 22. As a result, the outer space 22 and the first partition wall 30 are heated. That is, the heating part 90 in the present embodiment indirectly heats the first partition wall 30 by heating the dry air supplied to the outer space 22.

The control section 70 in the present embodiment further includes a heating control section 77 that controls the heating section 90. The heating control section 77 is a function of the CPU, and controls the heater output of the heating section 90. The heating control unit 77 in the present embodiment controls the heating unit 90 based on the set temperature and humidity of the inner space 21 and the temperature of the outer space 22. The control unit 70 also includes a calculation unit 74. The calculation unit 74 calculates the dew point temperatures of the inner space 21 and the outer space 22 based on the temperature and humidity data of the inner space 21 and the outer space 22.

Next, a radio wave test method according to the present embodiment, which is performed using the radio wave shielding room 5, will be described with reference to a flowchart of fig. 8. The radio wave test method evaluates the transmission/reception state of radio waves between the test object S1 and the antenna S2 while heating the first partition wall 30 while adjusting the temperature of the inner space 21 as follows.

First, similarly to embodiment 1, the test body S1 is provided in the inner space 21 and the antenna S2 is provided in the outer space 22 (step S13). Next, the temperature and humidity of the inner space 21 in the chamber 10 are set (step S23). In the present embodiment, the set temperature of the inner space 21 is 85 ℃ and the set humidity of the inner space 21 is 85% (relative humidity), for example.

Subsequently, the temperature control unit 50 is operated (step S33). The temperature control of the inner space 21 is as described in embodiment 1, but the humidity of the inner space 21 is also adjusted as follows in the present embodiment. Specifically, the humidity of the inside space 21 is measured by the inside humidity sensor 24, and when the measured humidity is higher than the set humidity, the temperature control unit 75 decreases the output of the heater. On the other hand, when the measured humidity of the inside space 21 is lower than the set humidity, the temperature regulation control part 75 increases the output of the heater.

On the other hand, after step S23, the temperature of outer space 22 is measured by outer temperature sensor 25 at all times or at predetermined time intervals. Then, in step S43, the determination unit 73 determines whether or not the measured temperature of the outer space 22 is equal to or lower than the set dew point temperature of the inner space 21. Here, the set dew point temperature is a temperature calculated by the calculation unit 74 based on the set temperature and humidity (85 ℃ and 85% in the present embodiment) of the inner space 21, and is, for example, 83 ℃ in the present embodiment.

In the present embodiment, immediately after the start of the test, the temperature of the outer space 22 is around room temperature. Therefore, it is determined that the measured temperature of the outer space 22 is equal to or lower than the set dew point temperature of the inner space 21 (yes in step S43), and the dry gas control unit 76 starts the operation of the dry air unit and the heating control unit 77 operates the heating unit 90 (step S53). Accordingly, the heated dry air is supplied to the outer space 22, and the outer space 22 and the first partition wall 30 are heated.

Then, if a certain amount of time has elapsed since the operation of the dry air unit and the operation of the heating unit 90 started, the measured temperature of the outer space 22 rises, and the measured temperature becomes higher than the set dew point temperature (83 ℃) of the inner space 21 (no at step S43). At this time, the dry gas control section 76 stops the operation of the dry air unit and the heating control section 77 stops the heating section 90 (step S73). Until the test end condition is satisfied, the determination of step S43 is repeated until the measured temperature of the outer space 22 exceeds the set dew point temperature of the inner space 21, and the operation of the dry air unit and the operation of the heating unit 90 are continued.

As described above, in the present embodiment, the heated dry air is supplied to the outer space 22, and the temperature of the first partition wall 30 can be increased. Therefore, even if the inner space 21 in the chamber 10 is in a high-temperature and high-humidity state (for example, 85 ℃ or 85%), the temperature of the inner surface of the first partition wall 30 can be suppressed from becoming equal to or lower than the dew point temperature of the inner space 21. This can suppress the occurrence of dew condensation water on the inner surface of the first partition wall 30, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber 10.

Here, a modification of the present embodiment will be described.

< modification 1>

In the present embodiment, the set dew point temperature is calculated based on the set temperature and humidity of the inner space 21, and the dry air unit and the heating unit 90 are controlled based on the comparison result between the set dew point temperature and the measured temperature of the outer space 22, but control based on the measured temperature and humidity of the inner space 21 (the measurement values of the inner temperature sensor 23 and the inner humidity sensor 24) may be performed. Specifically, the temperature and humidity of the inner space 21 may be measured at all times or at predetermined time intervals after step S23 in fig. 8, and the calculation unit 74 may calculate the actual dew point temperature of the inner space 21 based on the measured values. In step S43, it may be determined whether or not the measured temperature of the outer space 22 is equal to or lower than the actual dew point temperature of the inner space 21, and the dry air unit and the heating unit 90 may be controlled based on the determination result.

< modification 2>

It may be determined at step S43 in fig. 8 whether or not the measured temperature of the outer space 22 is equal to or lower than the measured temperature of the inner space 21. Further, when the measured temperature of the outer space 22 is equal to or lower than the measured temperature of the inner space 21, the operation of the dry air unit and the heating unit 90 may be started (or continued), and when the measured temperature of the outer space 22 is higher than the measured temperature of the inner space 21, the operation of the dry air unit and the heating unit 90 may be stopped (or continued). In modification 2, instead of the measured temperature of the inner space 21, the set temperature of the inner space 21 may be used.

< other modification >

In step S53 in fig. 8, the heating unit 90 may be operated in a state where the blowing function of the dry air unit is activated and the dehumidifying function is deactivated. At this time, the non-dehumidified air is heated by the heating portion 90 and supplied to the outer space 22, but the outer space 22 and the first partition wall 30 are heated similarly.

The heating unit 90 may have an air blowing function. At this time, in step S53, the blowing function and the dehumidifying function of the dry air unit are both stopped (operation is stopped), and the heating function and the blowing function of the heating portion 90 are activated, whereby the heated air is supplied to the outside space 22. At this time, the outer space 22 and the first partition wall 30 are also heated.

The heating unit 90 is not limited to the case of being disposed in the dry gas supply passage 62, and may be a heater incorporated in the dry air unit (dry air generating unit 61). A bypass passage (not shown) having both ends connected to the dry gas supply passage 62 may be provided, and the heating portion 90 may be disposed in the bypass passage.

The heating unit 90 described in this embodiment can be applied to the radio wave shielding rooms 3 and 4 according to embodiments 3 and 4 described above.

(embodiment mode 6)

Next, a radio wave shielding room according to embodiment 6 of the present invention will be described. The radio wave shielding compartment according to embodiment 6 has basically the same configuration as the radio wave shielding compartment 5 according to embodiment 5, but differs in that the dry air unit and the heating unit 90 are controlled based on the set temperature and humidity of the inner space 21 without using the measured temperature of the outer space 22. Only points different from embodiment 5 will be described below.

Fig. 9 shows a control flow of the dry air unit and the heating unit 90 in the present embodiment. Steps S14 to S34 in fig. 9 are the same as steps S13 to S33 in fig. 8.

In the present embodiment, in step S44, the determination unit 73 determines whether or not the set dew point temperature of the inner space 21 is equal to or higher than the heating reference temperature. The set dew point temperature is calculated based on the temperature and humidity set at step S24. The heating reference temperature is a reference temperature for determining whether or not to supply heated dry air, and is set to 30 ℃. The data of the heating reference temperature is stored in the storage unit 72.

When the set dew point temperature of the inner space 21 is equal to or higher than the heating reference temperature (yes at step S44), the dry gas control unit 76 starts the operation of the dry air unit, and the heating control unit 77 operates the heating unit 90 (step S54). On the other hand, when the set dew point temperature of the inner space 21 is lower than the heating reference temperature (no in step S44), the stop state of the dry air unit and the heating unit 90 is maintained. When the predetermined test termination condition is satisfied (yes at step S64), the radio wave test is terminated.

On the other hand, when the test end condition is not satisfied (no at step S64), the process returns to the judgment at step S44. Then, if the set temperature and humidity of the inner space 21 are changed during the test, it is determined whether or not the set dew point temperature of the inner space 21 calculated based on the changed set temperature and humidity is equal to or higher than the heating reference temperature. When the set dew-point temperature of the inside space 21 is equal to or higher than the heating reference temperature while the dry air unit and the heating unit 90 are operating, the operation of the dry air unit and the heating unit 90 is continued, and when the set dew-point temperature is lower than the heating reference temperature, the operation of the dry air unit and the heating unit 90 is stopped (step S74). When the set dew-point temperature of the inner space 21 is equal to or higher than the heating reference temperature while the dry air unit and the heating unit 90 are in the stop operation, the operation of the dry air unit and the heating unit 90 is started, and when the set dew-point temperature is lower than the heating reference temperature, the operation stop state of the dry air unit and the heating unit 90 is maintained.

< modification 1>

Fig. 10 shows a control flow of the dry air unit and the heating unit 90 in modification 1 of embodiment 6. The heating control unit 77 may control the heating unit 90 based on the measured temperature and humidity of the inner space 21 instead of the set temperature and humidity of the inner space 21.

Steps S15 to S35 in fig. 10 are the same as steps S14 to S34 in fig. 9. In the present modification, the temperature and humidity of the inner space 21 are measured at all times or at predetermined time intervals after step S25, and the calculation unit 74 calculates the actual dew point temperature of the inner space 21 based on the measurement result.

Then, in step S45, it is determined whether or not the actual dew point temperature of the inner space 21 is equal to or higher than the heating reference temperature. When the actual dew point temperature of the inner space 21 is equal to or higher than the heating reference temperature (yes at step S45), the dry gas control unit 76 starts the operation of the dry air unit, and the heating control unit 77 operates the heating unit 90 (step S55). On the other hand, when the actual dew-point temperature of the inner space 21 is lower than the heating reference temperature (no at step S45), the dry air unit and the heating unit 90 are brought into a stopped state (step S75).

In the present modification, the determination in step S45 is repeated until the test end condition is satisfied. The dry air unit and the heating unit 90 are stopped while the actual dew-point temperature of the inner space 21 is lower than the heating reference temperature, and the dry air unit and the heating unit 90 are constantly operated while the actual dew-point temperature is equal to or higher than the heating reference temperature.

< modification 2>

In step S44 in fig. 9, it may be determined whether or not the measured temperature of the inner space 21 is equal to or higher than the heating reference temperature. Then, when the measured temperature of the inner space 21 is equal to or higher than the heating reference temperature, the operation of the dry air unit and the heating unit 90 is started (or continued), and when the measured temperature of the inner space 21 is lower than the heating reference temperature, the operation of the dry air unit and the heating unit 90 is stopped (or continued). In modification 2, the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

(embodiment 7)

Next, a radio wave shielding room according to embodiment 7 of the present invention will be described. The radio wave shielding chamber according to embodiment 7 has basically the same configuration as the radio wave shielding chamber 5 according to embodiment 5, but is different in that it further includes a switching unit that switches between a dry state in which the outside space 22 is dehumidified and a heated state in which the dry air or the first partition wall 30 is heated by the heating unit 90. Only points different from embodiment 5 will be described below.

The switching unit switches between the drying state and the heating state based on at least the measured temperature of the inner space 21 or at least the set temperature of the inner space 21, and specifically performs each of the switching controls of the following modes (1) to (6).

First, in the aspect (1), the switching section switches between the dry state and the heating state based only on the measured temperature of the inner space 21. Specifically, when the measured temperature of the inner space 21 is equal to or higher than a predetermined reference temperature (e.g., 25 ℃), the switching unit transmits a control signal to each of the dry air unit and the heating unit 90 so that the dry air unit and the heating unit operate, respectively, to the dry gas control unit 76 and the heating control unit 77. On the other hand, when the measured temperature of the inner space 21 is lower than the reference temperature, the switching section transmits a control signal to each of the dry gas control section 76 and the heating control section 77 so that the dry air unit is activated and the heating section 90 is stopped.

The reference temperature may have a predetermined range, for example, from 15 ℃ to 35 ℃. At this time, the heating state is switched when the measured temperature of the inner space 21 becomes equal to or higher than the upper limit of the temperature range, and the drying state is switched when the measured temperature of the inner space 21 becomes equal to or lower than the lower limit of the temperature range. In the switching control of the mode (1), the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

Next, in the aspect (2), the switching section switches between the dry state and the heating state based on the measured temperature and the measured humidity of the inner space 21. Specifically, the calculation unit 74 calculates the dew point temperature of the inner space 21 based on the measured temperature and the measured humidity of the inner space 21, and when the dew point temperature is equal to or higher than a predetermined reference temperature, the switching unit transmits a control signal to each of the dry air control unit 76 and the heating control unit 77 so that the dry air unit and the heating unit 90 are operated. On the other hand, when the dew point temperature of the inner space 21 is lower than the predetermined reference temperature, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit is activated and the heating unit 90 is stopped. In the switching control of the method (2), the set temperature and humidity of the inner space 21 may be used instead of the measured temperature and humidity of the inner space 21.

Next, in the aspect (3), the switching unit switches between the drying state and the heating state based on the measured temperature of the inner space 21 and the measured temperature of the outer space 22. Specifically, when the measured temperature of the inner space 21 is higher than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit and the heating unit 90 are operated. On the other hand, when the measured temperature of the inner space 21 is lower than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit is activated and the heating unit 90 is stopped. In the switching control of the mode (3), the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

Next, in the aspect (4), the switching unit switches between the dry state and the heating state based on the measured temperature of the inner space 21, the measured humidity of the inner space 21, and the measured temperature of the outer space 22. Specifically, the calculation unit 74 calculates the dew point temperature of the inner space 21 based on the measured temperature and the measured humidity of the inner space 21, and when the dew point temperature is higher than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry air control unit 76 and the heating control unit 77 so that the dry air unit and the heating unit 90 are operated. On the other hand, when the measured temperature of the inner space 21 is lower than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit is activated and the heating unit 90 is stopped. In the switching control of the aspect (4), the set temperature and the set humidity of the inner space 21 may be used instead of the measured temperature and the measured humidity of the inner space 21. At this time, the switching unit switches between the dry state and the heated state based on a comparison between the set dew point temperature of the inner space 21 calculated based on the set temperature and humidity and the measured temperature of the outer space 22.

Next, in the aspect (5), the switching unit switches between the dry state and the heating state based on the measured temperature of the inner space 21, the measured temperature of the outer space 22, and the measured humidity of the outer space 22. Specifically, when the measured temperature of the inner space 21 is higher than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit and the heating unit 90 are operated. On the other hand, the calculation unit 74 calculates the dew point temperature of the outer space 22 based on the measured temperature and the measured humidity of the outer space 22, and when the dew point temperature is higher than the measured temperature of the inner space 21, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit is activated and the heating unit 90 is stopped. In the switching control of the mode (5), the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

Finally, in the aspect (6), the switching section switches between the dry state and the heating state based on the measured temperature of the inner space 21, the measured humidity of the inner space 21, the measured temperature of the outer space 22, and the measured humidity of the outer space 22. Specifically, the calculation unit 74 calculates the dew point temperature of the inner space 21 based on the measured temperature and the measured humidity of the inner space 21, and when the dew point temperature is higher than the measured temperature of the outer space 22, the switching unit transmits a control signal to each of the dry air control unit 76 and the heating control unit 77 so that the dry air unit and the heating unit 90 are operated. On the other hand, the calculation unit 74 calculates the dew point temperature of the outer space 22 based on the measured temperature and the measured humidity of the outer space 22, and when the dew point temperature is higher than the measured temperature of the inner space 21, the switching unit transmits a control signal to each of the dry gas control unit 76 and the heating control unit 77 so that the dry air unit is activated and the heating unit 90 is stopped. In the switching control of the aspect (6), the set temperature and the set humidity of the inner space 21 may be used instead of the measured temperature and the measured humidity of the inner space 21. At this time, the switching unit switches between the dry state and the heated state based on a comparison between the set dew point temperature of the inner space 21 calculated based on the set temperature and humidity and the measured temperature of the outer space 22.

In addition, in the present embodiment, the case where both the dry air unit and the heating unit 90 are operated in the heating state is described, but in the above-described aspects (1) to (6), the dry air unit may be stopped and the heating unit 90 may be operated. Specifically, as described in the modification of embodiment 5, the outer space 22 and the first partition wall 30 may be heated by the heating function and the blowing function of the heating unit 90. Further, the heating unit 90 that directly heats the first partition wall 30 without using air may be operated.

(embodiment mode 8)

Next, the structure of the radio wave shielding room 7 according to embodiment 8 of the present invention will be described with reference to fig. 11. The radio wave shielding compartment 7 according to embodiment 8 has basically the same configuration as the radio wave shielding compartment 5 according to embodiment 5, but differs in that it further includes a second partition wall 91 that partitions the outer space 22. Only points different from embodiment 5 will be described below.

The second partition wall 91 partitions the outer space 22 into a first outer space 22A surrounding the inner space 21 and a second outer space 22B in which the antenna S2 can be disposed. As shown in fig. 11, the dry gas supply port 62A and the dry gas discharge port 63A open to the first outer space 22A. Therefore, the dry air heated by the heating part 90 is supplied to the first outside space 22A, but is not supplied to the second outside space 22B. Further, the second partition wall 91 is formed of a material that can transmit an electric wave.

According to the above configuration, even when the inner space 21 is in a high-temperature and high-humidity state and heated dry air is supplied to the first outer space 22A in order to suppress dew condensation on the inner surface (the surface facing the inner space 21) of the first partition wall 30, the temperature of the second outer space 22B can be maintained lower than the temperature of the first outer space 22A. Accordingly, even when the antenna S2 having low heat resistance is disposed in the second outer space 22B, thermal damage to the antenna S2 can be suppressed. The second partition wall 91 described in this embodiment can be applied to embodiments 1 to 7 described above.

(embodiment mode 9)

Next, a radio wave shielding room 9 according to embodiment 9 of the present invention will be described with reference to fig. 12. The radio wave shielding chamber 9 according to embodiment 9 is basically the same as the radio wave shielding chambers 5 according to embodiments 5 and 6, but differs in that it has a structure in which the dry gas generating unit 61 is not provided and the heated gas is circulated.

The heating unit 90 includes an air blowing mechanism such as a fan and a heating mechanism such as a heater that heats gas (for example, air) sent from the air blowing mechanism. The heating control unit 77 controls the operations of the blowing mechanism and the heating mechanism, respectively.

The radio wave shielding chamber 9 includes a heated gas supply passage 92 for supplying a heated gas from the heating portion 90 to the outer space 22, and a heated gas discharge passage 93 for returning the heated gas discharged from the outer space 22 to the heating portion 90. As shown in fig. 12, the heated air supply passage 92 extends through the heat insulator 13, the outer box 11, and the inner box 12 to the outer space 22, and supplies heated air to the outer space 22 from the supply port 92A. On the other hand, the heated gas discharge passage 93 also extends to the outer space 22 through the heat insulator 13, the outer box 11, and the inner box 12, and the heated gas in the outer space 22 is discharged from the discharge port 93A to the heated gas discharge passage 93.

According to the above configuration, the heated gas circulates between the heating portion 90 and the outer space 22 through the heated gas supply passage 92 and the heated gas discharge passage 93. The outer space 22 and the first partition wall 30 are heated by the heating gas.

The heating portion 90 in the present embodiment is controlled by a flow substantially the same as that of fig. 8 to 10. That is, the fan and the heater of the heating unit 90 are operated at steps S53, S54, and S55 in fig. 8 to 10, and the fan and the heater of the heating unit 90 are stopped at steps S73, S74, and S75 in the figure.

< modification example >

In embodiment 9, the case where the heated gas is circulated has been described, but the heated gas discharged from the outer space 22 may be released into the atmosphere. That is, the end of the heated gas discharge passage 93 opposite the discharge port 93A may be open to the atmosphere.

The heating unit 90 is not limited to a configuration in which the first partition wall 30 and the outer space 22 are indirectly heated by heating the gas supplied to the outer space 22, and may be a heater or the like that directly heats the first partition wall 30.

The following modifications can be given as a control method of the heating unit 90.

In step S43 in fig. 8, it may be determined whether or not the measured temperature in the inner space 21 is equal to or higher than a predetermined reference temperature. Further, when the measured temperature of the inner space 21 is equal to or higher than the reference temperature, the operation of the fan and the heater of the heating unit 90 may be started (or continued), and when the measured temperature of the inner space 21 is lower than the reference temperature, the operation of the fan and the heater of the heating unit 90 may be stopped (or continued). In this case, the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

In step S43 in fig. 8, it may be determined whether or not the set dew point temperature in the inner space 21 is equal to or higher than a predetermined reference temperature. Further, the operation (or the continuous operation) of the fan and the heater of the heating unit 90 may be started (or continued) when the set dew point temperature of the inner space 21 is equal to or higher than the reference temperature, and the operation (or the continuous operation) of the fan and the heater of the heating unit 90 may be stopped (or continued) when the set dew point temperature of the inner space 21 is lower than the reference temperature. In this case, the actual dew point temperature of the inner space 21 calculated based on the measured temperature and the measured humidity of the inner space 21 may be used instead of the set dew point temperature of the inner space 21.

In step S43 in fig. 8, it may be determined whether or not the measured temperature of the inner space 21 is equal to or higher than the measured temperature of the outer space 22. Further, when the measured temperature of the inner space 21 is equal to or higher than the measured temperature of the outer space 22, the fan and the heater of the heating unit 90 may be started (or continued to be operated), and when the measured temperature of the inner space 21 is lower than the measured temperature of the outer space 22, the fan and the heater of the heating unit 90 may be stopped (or continued to be stopped). In this case, the set temperature of the inner space 21 may be used instead of the measured temperature of the inner space 21.

In step S43 in fig. 8, it may be determined whether or not the set dew point temperature of the inner space 21 is equal to or higher than the measured temperature of the outer space 22. Further, the operation (or the continuous operation) of the fan and the heater of the heating unit 90 may be started (or continued) when the set dew point temperature of the inner space 21 is equal to or higher than the measured temperature of the outer space 22, and the operation (or the continuous operation) of the fan and the heater of the heating unit 90 may be stopped (or continued) when the set dew point temperature of the inner space 21 is lower than the measured temperature of the outer space 22. In this case, the actual dew point temperature of the inner space 21 calculated based on the measured temperature and the measured humidity of the inner space 21 may be used instead of the set dew point temperature of the inner space 21.

The second partition wall 91 described in embodiment 8 can be applied to the radio wave shielding room 9 according to embodiment 9.

(other embodiments)

Here, another embodiment of the present invention will be described.

As another example of the dehumidifying part in the present invention, a moisture absorbent such as silica gel disposed in the outer space 22 can be given. In the above embodiment, the dry air is described as an example of the dry gas, but other types of dry gases such as an inert gas may be used.

In the radio wave shielding room according to each of the above embodiments, the radio wave absorber 40 may be omitted. Whether or not the radio wave absorber 40 is disposed in the chamber 10 may be determined according to the type of test to be performed using the radio wave shielding chamber.

The radio wave shielding room of the present invention includes not only a relatively small radio wave shielding room for performing a radio wave test on a smartphone or the like, but also a large radio wave shielding room (radio wave shielding room) capable of accommodating a vehicle on which a communication module is mounted.

The dew point temperatures of the inner space 21 and the outer space 22 are not limited to those calculated based on the measured temperature and humidity or the set temperature and humidity, and may be directly detected using a dew point meter.

The embodiments are described in general terms as follows.

The radio wave shielding room according to the embodiment includes: a chamber; a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate; a temperature adjusting unit for adjusting the temperature of the inner space; and a dehumidification section that dehumidifies the outer space.

According to the radio wave shielding chamber, the dehumidification section can reduce the humidity of the space outside the chamber. Therefore, even if the temperature of the inner space in the chamber is controlled to a low temperature by the temperature control means and the temperature of the outer surface of the first partition wall decreases, the temperature of the outer surface can be suppressed from becoming equal to or lower than the dew point temperature of the outer space. This can suppress the occurrence of dew condensation water on the outer surface of the first partition wall, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber.

In the radio wave shielding chamber, the dehumidifying unit may include: a dry gas generator disposed outside the chamber; and a dry gas supply path in which a dry gas supply port for supplying the dry gas generated in the dry gas generation unit to the outer space is formed.

According to this configuration, the outside space can be easily dehumidified by the dry gas. Further, in the case where the radio wave absorber is disposed in the outside space, deterioration of the performance of the radio wave absorber due to a high humidity environment and dew condensation water can be suppressed.

The radio wave shielding chamber may further include a dry gas control unit configured to control the dry gas generation unit based on a set temperature of the inner space or a measured temperature of the inner space.

According to this configuration, when the set temperature or the measured temperature of the inner space is low and the temperature of the outer surface of the first partition wall is likely to decrease, the generation of dew condensation on the outer surface of the first partition wall can be more reliably suppressed by supplying the dry gas to the outer space. Further, when the set temperature of the inner space or the measured temperature thereof is high, the supply of the dry gas to the outer space is stopped, thereby saving energy.

The radio wave shielding chamber may further include a dry gas control unit configured to control the dry gas generation unit to supply the dry gas to the outer space when the set temperature of the inner space or the measured temperature of the inner space is equal to or lower than the dew point temperature of the outer space.

According to this configuration, the timing of supplying the dry air to the outside space is adjusted in consideration of the dew point temperature of the outside space, and therefore, the generation of the dew condensation water can be more reliably suppressed.

In the radio wave shielding chamber, the dehumidifying section may further include a dry gas discharge passage for discharging the dry gas from the outer space to the outside of the chamber. The dry gas discharge passage may be provided with a dry gas discharge port that opens into the outer space and a dry gas discharge port that opens into an outer space of the chamber.

According to this configuration, since the dry gas can be discharged to the outside space of the chamber, the facility can be simplified as compared with a configuration in which the dry gas is circulated, and the cost can be reduced.

In the radio wave shielding chamber, the dehumidifying section may further include a dry gas discharge passage for discharging the dry gas from the outer space to the outside of the chamber. The dehumidifying unit may circulate the dry gas to the dry gas generating unit through the dry gas exhaust passage.

According to this configuration, the humidity of the outside space can be more reliably adjusted by circulating the dry gas.

The electric wave shielding chamber may further include a gas guide plate that forms a flow of the dry gas so that the dry gas surrounds the outer space.

According to this configuration, even when the dry gas supply port and the dry gas discharge port are close to each other, the dry gas can be distributed over a wide range in the outer space. Further, by making the dry gas supply port and the dry gas discharge port close to each other, the pipe length of the dry gas supply path and the dry gas discharge path can be suppressed when the circulating type dehumidifying section is used.

The electric wave shielding chamber may further include a shielding member installed at the dry gas supply port to allow the dry gas to pass therethrough but to reflect the electric wave.

According to this configuration, the dry gas can be supplied from the dry gas supply port to the outer space, and the leakage of the electric wave to the outside of the chamber through the dry gas supply port can be suppressed.

The radio wave shielding chamber may further include a heating unit configured to heat the dry gas or the first partition wall.

According to this configuration, the heated dry gas is supplied to the outside space or the first partition wall is heated, whereby the temperature of the first partition wall can be increased. Accordingly, even if the inner space is in a high-temperature and high-humidity state, dew condensation water can be prevented from being generated on the inner surface of the first partition wall.

The radio wave shielding chamber may further include a heating control unit that controls the heating unit based on at least a set temperature of the inner space or at least a measured temperature of the inner space and a measured temperature of the outer space.

According to this configuration, since the timing of heating the drying gas can be adjusted in consideration of the measured temperature of the outer space and at least the set temperature or at least the measured temperature of the inner space, even if the inner space is in a high-temperature and high-humidity state, dew condensation water can be more reliably suppressed from occurring on the inner surface of the first partition wall.

The radio wave shielding chamber may further include a heating control unit that controls the heating unit based on at least a set temperature of the inner space or at least a measured temperature of the inner space.

According to this configuration, the heating control can be further simplified as compared with the case where the heating of the dry gas is controlled in consideration of both the temperature of the outer space and at least the set temperature or at least the measured temperature of the inner space.

The radio wave shielding chamber may further include a switching unit configured to switch a drying state in which the outer space is dehumidified and a heating state in which the heating unit heats the drying gas or the first partition wall, based on at least a measured temperature of the inner space or at least a set temperature of the inner space.

According to this configuration, the dehumidification and heating in the chamber can be efficiently performed so that dew condensation water can be suppressed from occurring on both the inner surface and the outer surface of the first partition wall.

The radio wave shielding room according to the embodiment includes: a chamber; a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate; a temperature adjusting unit for adjusting the temperature of the inner space; and a heating unit that heats the first partition wall.

According to the radio wave shielding chamber, the temperature of the first partition wall can be increased by the heating unit. Therefore, even if the inner space in the chamber is in a high-temperature and high-humidity state, the inner surface temperature of the first partition wall can be suppressed from becoming equal to or lower than the dew point temperature of the inner space. This can suppress the occurrence of dew condensation water on the inner surface of the first partition wall, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber.

The radio wave shielding chamber may further include a second partition wall that partitions the outer space into a first outer space surrounding the inner space and a second outer space in which an antenna can be disposed, and the antenna may transmit and receive radio waves to and from the test object. An electric wave can penetrate the second partition wall.

According to this configuration, even when the inner space is in a high-temperature and high-humidity state and the temperature of the first outer space is increased to suppress dew condensation on the inner surface of the first partition wall, the temperature of the second outer space can be maintained lower than the temperature of the first outer space. Accordingly, even when an antenna having low heat resistance is disposed in the outside space, thermal damage to the antenna can be suppressed.

The radio wave test method according to the embodiment includes the steps of: a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and evaluating a transmission/reception state of the radio wave between the test object and the antenna while adjusting the temperature of the inner space and dehumidifying the outer space.

In this method, the transmission/reception state of radio waves between the test object and the antenna is evaluated while the temperature of the inner space in the chamber is adjusted and the outer space is dehumidified. Therefore, even if the temperature of the inner space is adjusted to a low temperature according to the test conditions and the outer surface temperature of the first partition wall is lowered, the outer surface temperature can be suppressed from becoming equal to or lower than the dew point temperature of the outer space. This can suppress the occurrence of dew condensation water on the outer surface of the first partition wall, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber.

The radio wave test method according to the embodiment includes the steps of: a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and evaluating a transmission/reception state of radio waves between the test object and the antenna while adjusting the temperature of the inner space and heating the first partition wall.

In this method, the transmission/reception state of radio waves between the test object and the antenna is evaluated while the temperature of the inner space in the chamber is adjusted and the first partition wall is heated. Therefore, even when a test is performed in a state where the inner space is at a high temperature and a high humidity, the inner surface temperature of the first partition wall can be suppressed from becoming equal to or lower than the dew point temperature of the inner space. This can suppress the occurrence of dew condensation water on the inner surface of the first partition wall, and can suppress the diffuse reflection of radio waves due to dew condensation water in the chamber.

The embodiments disclosed herein are illustrative in all respects and should not be construed as being limiting. The scope of the present invention is defined by the claims rather than the description given above, and includes all modifications equivalent in meaning and scope to the claims.

Claims (17)

1. An electric wave shielding room, characterized by comprising:

a chamber;

a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate;

a temperature adjusting unit for adjusting the temperature of the inner space; and the number of the first and second groups,

and a dehumidification section configured to dehumidify the outer space.

2. The radio wave shielding room according to claim 1, wherein the dehumidifying section includes:

a dry gas generator disposed outside the chamber; and the number of the first and second groups,

and a dry gas supply path in which a dry gas supply port for supplying the dry gas generated in the dry gas generation unit to the outer space is formed.

3. The radio wave shielding room according to claim 2, further comprising:

and a dry gas control unit that controls the dry gas generation unit based on a set temperature of the inner space or a measured temperature of the inner space.

4. The radio wave shielding room according to claim 2, further comprising:

and a dry gas control unit configured to control the dry gas generation unit to supply the dry gas to the outer space when the set temperature of the inner space or the measured temperature of the inner space is equal to or lower than the dew point temperature of the outer space.

5. The radio wave shielded room according to any of claims 2 to 4,

the dehumidifying part further includes a dry gas exhaust passage for exhausting the dry gas from the outer space to the outside of the chamber,

the dry gas discharge passage is formed with a dry gas discharge port that opens to the outer space and a dry gas discharge port that opens to an outer space of the chamber.

6. The radio wave shielded room according to any of claims 2 to 4,

the dehumidifying part further includes a dry gas exhaust passage for exhausting the dry gas from the outer space to the outside of the chamber,

the dehumidification section circulates the dry gas to the dry gas generation section through the dry gas discharge passage.

7. The radio wave shielded room according to any one of claims 2 to 4, further comprising:

a gas guide plate that forms a flow of the dry gas in such a manner that the dry gas surrounds the outer space.

8. The radio wave shielded room according to any one of claims 2 to 4, further comprising:

and a shielding member mounted at the dry gas supply port and allowing the dry gas to pass therethrough but reflecting an electric wave.

9. The radio wave shielded room according to any one of claims 1 to 4, further comprising:

and a heating unit that heats the dry gas or the first partition wall.

10. The radio wave shielding room according to claim 9, further comprising:

and a heating control unit that controls the heating unit based on at least a set temperature of the inner space or at least a measured temperature of the inner space and a measured temperature of the outer space.

11. The radio wave shielding room according to claim 9, further comprising:

and a heating control unit that controls the heating unit based on at least a set temperature of the inner space or at least a measured temperature of the inner space.

12. The radio wave shielding room according to claim 9, further comprising:

and a switching unit that switches between a drying state in which the outer space is dehumidified and a heating state in which the heating unit heats the drying gas or the first partition wall, based on at least the measured temperature of the inner space or at least the set temperature of the inner space.

13. The radio wave shielded room according to any one of claims 1 to 4, further comprising:

a second partition wall that partitions the outer space into a first outer space surrounding the inner space and a second outer space in which an antenna can be disposed, the antenna transmitting and receiving radio waves to and from the test object,

an electric wave can penetrate the second partition wall.

14. An electric wave shielding room, characterized by comprising:

a chamber;

a first partition wall that divides a space in the chamber into an inner space in which a test body is disposed and an outer space surrounding the inner space, and through which radio waves can penetrate;

a temperature adjusting unit for adjusting the temperature of the inner space; and the number of the first and second groups,

and a heating unit that heats the first partition wall.

15. The radio wave shielding room according to claim 14, further comprising:

a second partition wall that partitions the outer space into a first outer space surrounding the inner space and a second outer space in which an antenna can be disposed, the antenna transmitting and receiving radio waves to and from the test object,

an electric wave can penetrate the second partition wall.

16. An electric wave test method characterized by comprising the steps of:

a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and the number of the first and second groups,

the transmission/reception state of the radio wave between the test object and the antenna is evaluated while the temperature of the inner space is adjusted and the outer space is dehumidified.

17. An electric wave test method characterized by comprising the steps of:

a step of disposing at least one of a test body and an antenna in an inner space of an inner space partitioned by a first partition wall and an outer space surrounding the inner space in a chamber, the antenna transmitting and receiving radio waves to and from the test body; and the number of the first and second groups,

while the temperature of the inner space is adjusted and the first partition wall is heated, the transmission/reception state of the radio wave between the test object and the antenna is evaluated.

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