Radio wave measuring system

Abstract

To provide a radio wave measuring system with which it is possible to reduce manual work and measure a radio wave radiated from a measurement object device with good accuracy.SOLUTION: A radio wave measuring system 10 comprises: an anechoic chamber 20 having a measurement region 28 and a standby region 29 located behind the measurement region 28; rails 32; antenna support units 40 attached to the rails 32, respectively; antennas 50 supported by the antenna support parts 40, respectively; and a movable partition 60 that functions as a radio wave absorbing body. The rails 32 extend along a longitudinal direction between the standby region 29 and the measurement region 28. The antennas 50 are movable along the rails 32 together with the antenna support parts 40. The movable partition 60 is located between the measurement region 28 and the standby region 29, and capable of shifting between a closed state (state shown in Fig. 1) and an open state. In the closed state, the movable partition 60 covers from the back the whole of the antennas 50 having moved to the measurement region 28.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a radio wave measurement system that measures radio waves emitted from a device under test. [Background technology]

[0002] For example, Patent Document 1 discloses a radio wave measuring system of this type.

[0003] The radio wave measurement system disclosed in Patent Document 1 includes two or more antennas. Each of the antennas measures radio waves emitted from a device under test, such as an electronic device. In general, when measuring radio waves using two or more antennas, manual work such as replacing or installing the antennas is required to prevent each antenna from being affected by the other antennas. For example, it is necessary to install only the antenna to be measured inside the anechoic chamber and move the other antennas outside the anechoic chamber. On the other hand, the antennas in Patent Document 1 are arranged around a turntable on which the device under test is mounted, with angles of 30 degrees or more and 180 degrees or less between each other. This arrangement makes it possible to measure radio waves emitted from the device under test while reducing the influence of the antennas on each other. In other words, it is possible to measure electromagnetic noise emitted from the device under test while reducing manual work. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-116785 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to Patent Document 1, although the distance between the antennas can be increased, the antennas affect each other to a certain extent, and therefore there is a risk of the measurement accuracy decreasing due to the influence between the antennas.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a radio wave measurement system that can reduce the amount of manual work and can accurately measure radio waves emitted from a device under test. [Means for solving the problem]

[0007] The present invention provides a first radio wave measurement system, A radio wave measurement system for measuring radio waves emitted from a device under test, the radio wave measurement system includes an anechoic chamber, two or more rails, two or more antenna support parts respectively corresponding to the rails, two or more antennas respectively corresponding to the antenna support parts, and a movable partition functioning as a radio wave absorber; The anechoic chamber has a measurement area and a waiting area, The device to be measured is placed in the measurement area, The waiting area is located behind the measurement area in the front-rear direction, The rails are spaced apart from each other in a lateral direction perpendicular to the front-rear direction and extend along the front-rear direction so as to straddle the waiting area and the measurement area, Each of the antenna support parts is attached to the corresponding rail and is movable along the front-rear direction, Each of the antennas is supported by a corresponding one of the antenna support parts and is movable between the waiting area and the measurement area in accordance with the movement of the corresponding one of the antenna support parts; The movable partition is disposed between the measurement area and the standby area and is capable of transitioning between a closed state and an open state; An opening and a shielding portion are formed in the movable partition in the closed state, In the closed state, the rail extends through the opening; In the closed state, the shielding portion is located above the opening in a vertical direction perpendicular to both the front-rear direction and the lateral direction, and covers the entire antenna that has moved to the measurement area from behind. A radio wave measurement system is provided.

[0008] Further, the present invention provides a second radio wave measurement system, which is the first radio wave measurement system, The movable partition comprises two partial partitions, The two partition sections are movable in the lateral direction; When the movable partition is in the open state, the two partial partitions are open in the lateral direction; When the movable partition is in the closed state, the two partial partitions are closed in the lateral direction. A radio wave measurement system is provided.

[0009] Further, the present invention provides a third radio wave measurement system, which is the first or second radio wave measurement system, The distance in the vertical direction between the upper end of the opening and the upper end of the rail is within 30 mm. A radio wave measurement system is provided.

[0010] Further, the present invention provides a fourth radio wave measurement system, which is the first or second radio wave measurement system, A harness is connected to the device under test, The harness extends along the lateral direction, The two or more antennas include a high-frequency antenna and a low-frequency antenna, the high-frequency antenna is for measuring radio waves having a frequency of 1 GHz or more, and is positioned in front of the device under test when the device is moved to the measurement area; The low-frequency antenna is for measuring radio waves having a frequency of 1 GHz or less, and is located in front of the harness at a midpoint in the lateral direction when the harness is moved to the measurement area. A radio wave measurement system is provided.

[0011] the high frequency antenna includes a horn antenna, the rail corresponding to the horn antenna extends toward the device under test along the front-rear direction, The low frequency antenna includes a first antenna and a second antenna, one of the first antenna and the second antenna is a biconical antenna, and the other of the first antenna and the second antenna is a log periodic antenna; a first rail corresponding to the first antenna extends toward the intermediate position of the harness along the front-rear direction, a second rail corresponding to the second antenna is spaced apart from the first rail in the lateral direction; the antenna support portion corresponding to the second antenna has an antenna folding mechanism, The antenna tilting mechanism is capable of moving the second antenna to be positioned in front of the intermediate position of the harness. A radio wave measurement system is provided. Effect of the Invention

[0012] According to the present invention, when measuring radio waves emitted from a device under test, an antenna to be used for measurement can be positioned in a measurement area, and an antenna not used for measurement can be positioned in a waiting area. The antenna in the measurement area can be shielded from the antenna in the waiting area by the shielding portion of the movable partition (radio wave absorber) in the closed state. Therefore, it is possible to almost completely eliminate the influence of other antennas in the waiting area on the antenna in the measurement area. For example, it is possible to prevent the influence of other antennas reflecting radio waves emitted from the device under test and affecting the measurement of the antenna in the measurement area. In addition, the movement of the antenna between the measurement area and the waiting area, and the transition of the movable partition between the open state and the closed state can be automatically performed by remote control using the power of a motor or the like. That is, according to the present invention, it is possible to provide a radio wave measurement system that can reduce human work and accurately measure radio waves emitted from a device under test. [Brief description of the drawings]

[0013] [Figure 1]1 is a top view showing a radio wave measurement system according to an embodiment of the present invention. The ceiling of the anechoic chamber is not drawn. The movable partition is in a closed state. The second antenna is in the measurement area, and the first antenna and the third antenna are in the waiting area. [Diagram 2] This is a front view partially showing the inside of the anechoic chamber in Figure 1 along line II-II. All antennas are in the waiting area. The radio wave absorbing structure of the movable partition is not drawn. A part of the movable partition (area surrounded by a dashed line) is drawn in an enlarged manner. [Diagram 3] FIG. 3 is a front view of the interior of the anechoic chamber of FIG. 2. The movable partition is in the open position. The hidden polarization switching mechanism of the antenna is drawn in dashed lines. The outline of the movable partition in the closed position of FIG. 2 is drawn in dashed lines. [Figure 4] 4 is a rear view showing a part (a part surrounded by a dashed line A) of the first antenna and the first antenna support part in FIG 3. The outline of the first antenna when rotated is drawn by a dashed line. [Diagram 5] This is a side view partially showing the inside of the anechoic chamber in Figure 1. The first antenna is not drawn. The outline of the device under test, the outline of the hidden part of the belt, and the outline of the second antenna when it is moved to the front of the middle position of the harness are drawn with dashed lines. [Figure 6] 6 is a side view showing a part (a part surrounded by a dashed dotted line B) of the second antenna and the second antenna support part in FIG. 5. FIG. [Figure 7] 7 is a rear view partially showing the second antenna and the second antenna support part of Fig. 6. The outline of the second antenna when it is moved to the front of the intermediate position of the harness is drawn by a dashed line. [Figure 8] FIG. 2 is a top view partially showing the inside of the anechoic chamber of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Referring to FIG. 1, a radio wave measurement system 10 according to an embodiment of the present invention is a radio wave measurement system that measures radio waves emitted from a device under test (DUT) 80. The device under test 80 in this embodiment is an electronic device mounted on a vehicle. The radio wave measurement system 10 in this embodiment complies with the CISPR25 (Limits and Measurement Methods of Interference Waves for Vehicle Receiver Protection) standard, and measures radio waves (interference waves) emitted from the device under test 80. Based on the measurement results, it is evaluated whether the interference waves emitted by the device under test 80 are below a predetermined limit value. However, the present invention is not limited to this. For example, the radio wave measurement system 10 may be a radio wave measurement system that does not comply with the CISPR25 standard. In this case, the device under test 80 is not limited to an electronic device mounted on a vehicle.

[0015] The radio wave measurement system 10 of this embodiment includes an anechoic chamber 20, two or more bases 30, two or more rails 32, two or more antenna support parts 40 each corresponding to the rails 32, two or more antennas 50 each corresponding to the antenna support parts 40, a movable partition 60 functioning as a radio wave absorber, and two fixed partitions 69 functioning as radio wave absorbers. The radio wave measurement system 10 of this embodiment includes the above-mentioned members. However, the present invention is not limited to this. For example, as described later, the base 30 and the fixed partition 69 may be provided as necessary. Meanwhile, the radio wave measurement system 10 may further include other members in addition to the above-mentioned members.

[0016] The radio wave measurement system 10 of this embodiment includes three bases 30, three rails 32, three antenna support parts 40, and three antennas 50. The three antennas 50 can receive radio waves (jamming waves) in three bands radiated by the device under test 80, respectively, and thus the jamming waves can be measured more accurately. However, the present invention is not limited to this. For example, the number of antennas 50 may be two, or four or more. The number of rails 32 and the number of antenna support parts 40 may match the number of antennas 50.

[0017] The anechoic chamber 20 of this embodiment will now be described.

[0018] The anechoic chamber 20 of this embodiment includes a front wall 21, a rear wall 22, two side walls 23, a floor 25, and a ceiling (not shown). The internal space of the anechoic chamber 20 is surrounded by the front wall 21, the rear wall 22, the side walls 23, the floor 25, and the ceiling. A radio wave absorbing structure is provided on each of the front wall 21, the rear wall 22, the side walls 23, and the ceiling on a surface facing the internal space of the anechoic chamber 20. On the other hand, the floor 25 is not provided with a radio wave absorbing structure.

[0019] Floor 25 is located at the bottom end of anechoic chamber 20 in the vertical direction, and ceiling (not shown) is located at the top end of anechoic chamber 20 in the vertical direction. The height of the ceiling is, for example, 4 m. The vertical direction in this embodiment is the direction of gravity, or the Z direction. In this embodiment, "upper" is the +Z direction, and "lower" is the -Z direction.

[0020] The front wall 21 is located at the front end of the anechoic chamber 20 in the front-rear direction perpendicular to the up-down direction, and the rear wall 22 is located at the rear end of the anechoic chamber 20 in the front-rear direction. The distance in the front-rear direction between the front wall 21 and the rear wall 22 is, for example, 7 m. The front-rear direction in this embodiment is a relative direction when it is assumed that the device under test 80 is located in front of the rail 32. The front-rear direction in this embodiment is the X direction. In this embodiment, "front" is the +X direction, and "rear" is the -X direction.

[0021] The two side walls 23 are located on both sides of the anechoic chamber 20 in a horizontal direction perpendicular to both the up-down direction and the front-rear direction. The distance between the two side walls 23 in the horizontal direction is, for example, 6.5 m. The horizontal direction in this embodiment is the Y direction.

[0022] The anechoic chamber 20 of the present embodiment has a structure conforming to the CISPR25 standard. The anechoic chamber 20 shown in the figure is a sealed space with no gaps. However, the actual anechoic chamber 20 has parts such as an openable door (not shown) and a passage (not shown) for passing cables. The structure of the anechoic chamber 20 of the present invention is not limited to the structure conforming to the CISPR25 standard, and can be modified in various ways as needed. For example, the front wall 21, the rear wall 22, the side wall 23, and the ceiling may each be provided with a radio wave absorbing structure as needed. The specific shape and size of the radio wave absorbing structure are not particularly limited.

[0023] The anechoic chamber 20 of this embodiment has a measurement area 28 and a waiting area 29. The measurement area 28 is a space on the front side of the internal space of the anechoic chamber 20, and the waiting area 29 is a space on the rear side of the internal space of the anechoic chamber 20. In other words, the waiting area 29 is located behind the measurement area 28 in the front-to-rear direction.

[0024] In the measurement area 28 of this embodiment, a table 70 made of an insulating material is placed. The table 70 of this embodiment is located at the middle part in the lateral direction of the internal space of the anechoic chamber 20. The table 70 is placed on the floor 25. The height of the table 70 of this embodiment is matched to the height from the ground when the measured device 80 is mounted on the vehicle. More specifically, the height of the table 70 of this embodiment is about 90 cm. However, the present invention is not limited to this. For example, the height of the table 70 may be variable. Furthermore, the table 70 may be rotatable in a horizontal plane (XY plane) perpendicular to the up-down direction.

[0025] A metallic reference ground plane 72 is provided on the upper surface of the table 70. The reference ground plane 72 is connected to five ground straps 78 made of a conductor. The ground straps 78 extend above the floor 25 in the front-to-rear direction. The ground straps 78 are connected to the front wall 21 and are grounded. That is, the reference ground plane 72 has a ground potential.

[0026] When measuring radio waves, the device under test 80 is placed on the reference ground plane 72. That is, the device under test 80 is placed in the measurement area 28. In addition to the device under test 80, a harness 82 and a road simulator 86 are provided on the reference ground plane 72. The harness 82 is connected to the device under test 80. The harness 82 extends in the lateral direction and terminates at the road simulator 86. Electromagnetic noise generated by the device under test 80 is transmitted to the harness 82. As a result, for example, radio waves (interference waves) are emitted from a middle position 84 in the lateral direction of the harness 82.

[0027] As described above, the radio wave measurement system 10 of this embodiment complies with the CISPR25 standard. In addition to the above-mentioned components, components (not shown) such as a power supply for the device under test 80 are arranged in the measurement area 28 of this embodiment. However, the present invention is not limited to this. When measuring radio waves, there is no particular limitation on the components arranged in the measurement area 28 as long as the device under test 80 is arranged in the measurement area 28.

[0028] The base 30, rail 32, antenna support 40 and antenna 50 of this embodiment will be described below.

[0029] The base 30 in this embodiment is located at the middle in the lateral direction of the internal space of the anechoic chamber 20. The three bases 30 are installed on the floor 25. The bases 30 extend parallel to each other along the lateral direction. One of the bases 30 is located in the measurement area 28, and the other two of the bases 30 are located in the waiting area 29. Each of the rails 32 is attached on the three bases 30. That is, the bases 30 are a platform that supports the three rails 32.

[0030] 2 together with FIG. 1, each of the bases 30 is provided with casters. As can be seen from this structure, the three bases 30 are movable together with the three rails 32. For example, the bases 30 to which the rails 32 are attached can pass through a door (not shown) and be taken out of the anechoic chamber 20. In addition, the bases 30 disposed in the internal space of the anechoic chamber 20 can be temporarily fixed on the floor 25 by a stopper (not shown) to prevent them from moving.

[0031] However, the present invention is not limited to this embodiment. For example, the rails 32 may be fixed immovably on the floor 25. In this case, it is not necessary to provide the base 30. Each of the rails 32 may be provided with a caster (not shown) and a stopper (not shown). That is, each of the illustrated rails 32 may be temporarily fixed on the floor 25 without the base 30. In this case, it is also not necessary to provide the base 30. However, from the viewpoint of taking the three rails 32 in and out of the anechoic chamber 20 together, this embodiment is preferable.

[0032] 1, the rails 32 are located at the horizontal middle of the internal space of the anechoic chamber 20. The rails 32 are separated from each other in the horizontal direction, and extend in the front-rear direction so as to straddle the waiting area 29 and the measurement area 28. Each of the antenna supports 40 is attached to the corresponding rail 32 and is movable in the front-rear direction.

[0033] For more details, referring to Fig. 5 together with Fig. 1, a belt 34 is provided on each of the rails 32 in this embodiment. Each of the belts 34 forms an endless track that moves along the rail 32. Each of the belts 34 can rotate clockwise and counterclockwise by power supplied from outside the anechoic chamber 20 via a power cable (not shown). Each of the antenna supports 40 is fixed to the belt 34 of the corresponding rail 32, and can thereby move forward and backward.

[0034] Each of the antenna support parts 40 in this embodiment can be moved along the front-rear direction by the moving mechanism using the belt 34 described above. That is, each of the antenna support parts 40 in this embodiment is indirectly attached to the corresponding rail 32 via the belt 34 so as to be movable along the front-rear direction. The movement and stopping of the antenna support parts 40 can be controlled from outside the anechoic chamber 20 via a communication cable (not shown). However, as long as each of the antenna support parts 40 can move along the corresponding rail 32, the moving mechanism of the antenna support part 40 in the present invention is not particularly limited. For example, each of the antenna support parts 40 may have a moving mechanism including wheels. In this case, each of the antenna support parts 40 may be directly attached to the corresponding rail 32.

[0035] Referring to Fig. 1, each of the antennas 50 is supported by a corresponding antenna support 40. In detail, referring to Figs. 5 and 8, each of the antennas 50 has a metallic main portion 52 and a shaft portion 54 made of an insulating material. The shape of the main portion 52 varies depending on the antenna 50. Each of the shaft portions 54 has a round bar shape and extends straight rearward from the rear end of the main portion 52. Each of the shaft portions 54 is held by a corresponding antenna support 40.

[0036] According to this embodiment, a coaxial cable 58 is connected to each of the shafts 54. The coaxial cable 58 passes through a passage (not shown) formed in a wall such as the back wall 22 and is drawn out to the outside of the anechoic chamber 20. The radio waves received by the antenna 50 are transmitted to a measuring device (not shown) outside the anechoic chamber 20 via the coaxial cable 58. Each of the antennas 50 in this embodiment has the above-mentioned structure. However, the present invention is not limited to this. For example, the shafts 54 may be provided as necessary. The cable connected to the antenna 50 is not limited to the coaxial cable 58.

[0037] 1, as described above, each of the antennas 50 supported by the antenna support part 40 moves in the front-rear direction together with the antenna support part 40. In particular, each of the antennas 50 can move between the waiting area 29 and the measurement area 28 in association with the movement of the corresponding antenna support part 40. Each of the antennas 50 in this embodiment is located in the measurement area 28 when the corresponding antenna support part 40 has moved to the frontmost position, and is located in the waiting area 29 when the corresponding antenna support part 40 has moved to the rearmost position.

[0038] The movable partition 60 of this embodiment will now be described.

[0039] The movable partition 60 in this embodiment is disposed between the measurement area 28 and the waiting area 29. More specifically, the movable partition 60 is located on the boundary line between the measurement area 28 and the waiting area 29. In other words, the space located in front of the movable partition 60 within the internal space of the anechoic chamber 20 is the measurement area 28, and the space located behind the movable partition 60 within the internal space of the anechoic chamber 20 is the waiting area 29.

[0040] 2 and 3, the movable partition 60 of this embodiment includes two partial partitions 60P. Each of the partial partitions 60P has a rectangular flat plate shape parallel to a vertical plane (YZ plane) perpendicular to the front-rear direction. A radio wave absorbing structure is formed on the front surface of each of the partial partitions 60P.

[0041] 2 and 5, each of the partial partitions 60P is attached to a support base 67. Each of the support bases 67 is located behind the partial partitions 60P. Each of the partial partitions 60P attached to the support bases 67 is slightly spaced from the floor 25 and is located above the floor 25.

[0042] Each of the support bases 67 is provided with casters. As can be seen from this structure, each of the support bases 67 is movable together with the partial partition 60P. For example, the support base 67 to which the partial partition 60P is attached can be passed through a door (not shown) and taken out of the anechoic chamber 20. Furthermore, the support base 67 disposed in the internal space of the anechoic chamber 20 can be temporarily fixed onto the floor 25 by a stopper so as not to move. However, the present invention is not limited to this. For example, the support base 67 may be fixed onto the floor 25 so as not to move.

[0043] 2 together with FIG. 5, each of the partial partitions 60P in this embodiment is attached to a support base 67 so as to be slidable laterally. That is, each of the support bases 67 is provided with a slide mechanism 68 that slides the partial partition 60P relatively to the support base 67. Each of the slide mechanisms 68 slides the partial partition 60P laterally by power supplied from outside the anechoic chamber 20 via a power cable (not shown).

[0044] Each of the partial partitions 60P in this embodiment can slide in the horizontal direction by a slide mechanism 68. The movement and stopping of the partial partitions 60P can be controlled from outside the anechoic chamber 20 via a communication cable (not shown). Each of the slide mechanisms 68 in this embodiment is formed of a rod that rotates around an axis extending parallel to the horizontal direction, and a gear or other member that converts the rotation of the rod into horizontal movement. However, the present invention is not limited to this. For example, the structure of the slide mechanism 68 is not particularly limited.

[0045] 2 and 3, as described above, the two partial partitions 60P are movable in the lateral direction. More specifically, the two partial partitions 60P are movable between a closed position (see FIG. 2) and an open position (see FIG. 3). When the partial partition 60P is in the closed position, the movable partition 60 covers the lateral middle portion of the waiting area 29 from the front. Therefore, each of the antennas 50 cannot move between the measurement area 28 and the waiting area 29. On the other hand, when the partial partition 60P is in the open position, the movable partition 60 does not cover the lateral middle portion of the waiting area 29. Therefore, each of the antennas 50 can move between the measurement area 28 and the waiting area 29.

[0046] As can be understood from the above description, the movable partition 60 can transition between a closed state (the state in FIG. 2) and an open state (the state in FIG. 3). According to this embodiment, when the movable partition 60 is in the open state, the two partial partitions 60P are open in the horizontal direction, and when the movable partition 60 is in the closed state, the two partial partitions 60P are closed in the horizontal direction. However, the present invention is not limited to this. For example, the movable partition 60 may be a single member. In this case, the movable partition 60 may be movable up and down between a closed position that prohibits the movement of the antenna 50 and an open position that allows the movement of the antenna 50, like a fire shutter.

[0047] Referring to FIG. 2, each of the partial partitions 60P in this embodiment is provided with an elastically deformable cushioning material 66. Each of the cushioning materials 66 is provided on the inner edge of the partial partition 60P in the lateral direction, and extends between the upper end and the lower end of the partial partition 60P. When the movable partition 60 is in the closed state, the cushioning materials 66 of the two partial partitions 60P are in close contact with each other. As a result, the two partial partitions 60P in the closed state are completely closed in the lateral direction. However, the present invention is not limited to this. For example, the cushioning material 66 may be provided as necessary. The two partial partitions 60P in the open state may be slightly separated from each other in the lateral direction.

[0048] The lower end of each of the partial partitions 60P in the present embodiment is cut out in a rectangular shape on the inside in the lateral direction. As a result, the movable partition 60 in the closed state has an opening 62 and a shielding portion 64. In the closed state, the three rails 32 extend through the opening 62. Referring to FIG. 2 together with FIG. 5 and FIG. 8, in the closed state, the shielding portion 64 is located above the opening 62 in the vertical direction and covers the entire antenna 50 that has moved to the measurement area 28 from the rear. In detail, when the main portion 52 of the antenna 50 that has moved to the measurement area 28 is projected onto the shielding portion 64 along the front-rear direction, the projected image is located inside the two shielding portions 64. With this structure, when the movable partition 60 is in the closed state, the antenna 50 that has moved to the measurement area 28 can be isolated from the other antennas 50 that remain in the waiting area 29.

[0049] 2, according to this embodiment, the distance DT in the vertical direction between the upper end of the opening 62 and the upper end of the rail 32 is within 30 mm. The distance DT in this embodiment is set to a minimum value that allows the rail 32 and belt 34 (see FIG. 5) to pass through, taking into consideration tolerances and unevenness that may be formed on the floor 25. Therefore, when the movable partition 60 is in the closed state, the antenna 50 that has moved to the measurement area 28 can be more reliably isolated from the other antennas 50 remaining in the waiting area 29. However, the present invention is not limited to this. As long as the opening 62 is located at a sufficiently low position, the value of the distance DT may be set as necessary.

[0050] The fixed partition 69 (see FIG. 1) of this embodiment will be described below.

[0051] Referring to FIG. 1, the two fixed partitions 69 in this embodiment are provided corresponding to the two partial partitions 60P, respectively. Each of the fixed partitions 69 is disposed in front of the support base 67 of the corresponding partial partition 60P. Each of the fixed partitions 69 is provided with casters (not shown). As can be understood from this structure, each of the fixed partitions 69 can be passed through a door (not shown) and taken out of the anechoic chamber 20. In addition, each of the fixed partitions 69 disposed in the internal space of the anechoic chamber 20 can be temporarily fixed on the floor 25 by a stopper (not shown) so as not to move. However, the present invention is not limited to this. For example, each of the fixed partitions 69 may be fixed on the floor 25 so as not to move.

[0052] Even when each of the partial partitions 60P moves most inward in the lateral direction, no gap is formed between the corresponding fixed partition 69 and the partial partition 60P in the lateral direction. That is, when the movable partition 60 is in the closed state (see FIG. 1), the waiting area 29 is covered from the front over the area from the outer end of one of the two fixed partitions 69 to the outer end of the other of the two fixed partitions 69 in the lateral direction.

[0053] According to this embodiment, since the fixed partitions 69 are provided, the antennas 50 that have moved to the measurement area 28 can be more reliably isolated from the other antennas 50 that remain in the waiting area 29. However, the present invention is not limited to this. For example, the fixed partitions 69 may be provided as necessary. On the other hand, the size of each of the fixed partitions 69 in the lateral direction may be larger than that of this embodiment. For example, the outer edge of each of the fixed partitions 69 in the lateral direction may be connected to the side wall 23.

[0054] In the radio wave measurement system 10 of this embodiment, various components including the base 30, rails 32, movable partition 60, and fixed partition 69 can be taken in and out of the anechoic chamber 20. Therefore, the anechoic chamber 20 of this embodiment is not limited to the measurement of this embodiment described below, but can be used for various measurements. However, the present invention is not limited to this, and the anechoic chamber 20 may be equipment specialized for the measurement of this embodiment described below.

[0055] The antenna 50 of this embodiment will be described in more detail below.

[0056] The rail 32 of this embodiment includes a first rail 32F, a second rail 32S, and a third rail 32T. The antenna support 40 of this embodiment includes a first antenna support 40F, a second antenna support 40S, and a third antenna support 40T. The first antenna support 40F, the second antenna support 40S, and the third antenna support 40T are attached to the first rail 32F, the second rail 32S, and the third rail 32T, respectively.

[0057] The antenna 50 of the present embodiment includes a first antenna (antenna) 50F, a second antenna (antenna) 50S, and a third antenna (antenna) 50T. The first antenna 50F, the second antenna 50S, and the third antenna 50T are supported by the first antenna support part 40F, the second antenna support part 40S, and the third antenna support part 40T, respectively.

[0058] 1 and 3, the first antenna 50F of this embodiment is a biconical antenna, suitable for receiving radio waves of 30 to 300 MHz. Referring to FIG. 8, the first rail 32F, which is the rail 32 corresponding to the first antenna 50F, extends toward a middle position 84 in the lateral direction of the harness 82 along the front-rear direction. With this arrangement, the first antenna 50F of this embodiment is located in front of the middle position 84 when moved to the most forward position. As described above, the first antenna 50F located in front of the middle position 84 is located about 90 cm behind the middle position 84, and preferably receives radio waves (interference waves) radiated from the harness 82 due to electromagnetic noise transmitted from the measured device 80 to the harness 82.

[0059] 1 and 3, the second antenna 50S of this embodiment is a log periodic antenna, suitable for receiving radio waves of 300 MHz to 1 GHz. Referring to FIG. 8, the second rail 32S, which is the rail 32 corresponding to the second antenna 50S, is separated from the first rail 32F in the lateral direction. Due to this arrangement, the second antenna 50S of this embodiment is not located in front of the intermediate position 84 when moved to the most forward position. However, the antenna support part 40S corresponding to the second antenna 50S has an antenna tilting mechanism 48 (see FIG. 7). As described later, the antenna tilting mechanism 48 can move the second antenna 50S so that it is located in front of the intermediate position 84 of the harness 82. The second antenna 50S moved in this way is located about 90 cm behind the intermediate position 84, and appropriately receives radio waves (jamming waves) emitted from the harness 82.

[0060] 1 and 3, the third antenna 50T of this embodiment is a horn antenna, suitable for receiving radio waves of 1 to 6 GHz. Referring to FIG. 8, the third rail 32T, which is the rail 32 corresponding to the third antenna 50T, extends toward the device under test 80 along the front-rear direction. With this arrangement, the third antenna 50T of this embodiment is located in front of the device under test 80 when moved to the most forward position. As described above, the third antenna 50T located in front of the device under test 80 is located about 90 cm behind the device under test 80, and appropriately receives radio waves (jamming waves) emitted from the device under test 80 itself.

[0061] To summarize the above explanation, the two or more antennas 50 in this embodiment include a high-frequency antenna (third antenna 50T) and a low-frequency antenna (first antenna 50F and second antenna 50S). The high-frequency antenna is for measuring radio waves with a frequency of 1 GHz or more, and is located in front of the device under test 80 when moved to the measurement area 28. The low-frequency antenna is for measuring radio waves with a frequency of 1 GHz or less, and is located in front of a middle position 84 in the lateral direction of the harness 82 when moved to the measurement area 28.

[0062] In particular, the high frequency antenna of this embodiment includes a horn antenna (third antenna 50T). The low frequency antenna of this embodiment includes a biconical antenna (first antenna 50F) and a log periodic antenna (second antenna 50S). According to this embodiment, by using the above-mentioned three antennas 50, radio waves (jamming waves) in three bands radiated by the measured device 80 and the harness 82 can be received, respectively, and the jamming waves can be measured more accurately. However, the present invention is not limited to this. For example, the number and type of antennas 50 can be modified as necessary.

[0063] According to this embodiment, the first antenna 50F is a biconical antenna, and the second antenna 50S is a log periodic antenna. However, the present invention is not limited to this. For example, the first antenna 50F may be a log periodic antenna, and the second antenna 50S may be a biconical antenna. That is, one of the first antenna 50F and the second antenna 50S may be a biconical antenna, and the other of the first antenna 50F and the second antenna 50S may be a log periodic antenna.

[0064] Referring to FIG. 4 together with FIG. 3, each of the antennas 50 of this embodiment is provided with a polarization switching mechanism 46. In detail, each of the antenna support parts 40 has a support member 42. Each of the support members 42 is located near the upper end of the antenna support part 40. Each of the support members 42 has a bearing 44. Each of the bearings 44 is rotatable relative to the support member 42 around an axis extending parallel to the front-rear direction. Each of the bearings 44 has a hole penetrating the support member 42 in the front-rear direction. Each of the shaft parts 54 of the antennas 50 passes through the hole of the bearing 44 and extends along the front-rear direction, and is held by the bearing 44.

[0065] 4, the rear surface of the support member 42 is provided with a polarization switching mechanism 46 including a piston 462 and an operating arm 464. The piston 462 can be extended and retracted by the pressure of air supplied from a compressor (not shown) through an air tube (not shown) (see dashed line in FIG. 4). One of both ends of the operating arm 464 is connected to the piston 462, and the other of both ends of the operating arm 464 is fixed to the bearing 44 of the antenna support part 40. When the piston 462 extends, the operating arm 464 rotates, and the shaft part 54 of the antenna 50 rotates 90° together with the bearing 44. As a result, the antenna 50 rotates 90° around the shaft part 54 (see dashed line in FIG. 4). When the piston 462 contracts and returns to its initial shape (see solid line in FIG. 4), the antenna 50 returns to its initial shape (see solid line in FIG. 4).

[0066] 3, each of the antennas 50 of this embodiment can be rotated between an initial position (see FIG. 3) suitable for receiving vertically polarized waves and a rotational position (see dashed line in FIG. 4) suitable for receiving horizontally polarized waves by the polarization switching mechanism 46 functioning as described above. The compressor (not shown) of this embodiment is located outside the anechoic chamber 20. However, the present invention is not limited to this. For example, the structure of the polarization switching mechanism 46 is not particularly limited. Moreover, the polarization switching mechanism 46 may be provided as necessary.

[0067] 7 together with FIG. 6, the second antenna 50S of the present embodiment is provided with an antenna tilting mechanism 48 in addition to the polarization switching mechanism 46. In detail, referring to FIG. 7, the second antenna support part 40S is provided with the antenna tilting mechanism 48 including a movable part 482, a piston 484, an operated part 486, and a movable shaft 488. The movable part 482 is an upper part of the second antenna support part 40S. The movable part 482 is connected to the lower part of the second antenna support part 40S at the movable shaft 488, and is rotatable around the movable shaft 488.

[0068] The piston 484 can expand and contract by the pressure of air supplied from a compressor (not shown) through an air tube (not shown) (see dashed line in FIG. 7). One of both ends of the operated part 486 is connected to the piston 484, and the other of both ends of the operated part 486 is connected to the movable part 482. When the piston 484 contracts, the operated part 486 pulls the movable part 482, and the movable part 482 rotates 90° around the movable shaft 488. As a result, the second antenna 50S rotates 90° around the movable shaft 488. When the piston 484 expands and returns to its initial shape (see solid line in FIG. 7), the second antenna 50S returns to its initial shape (see solid line in FIG. 4).

[0069] The compressor (not shown) in this embodiment is located outside the anechoic chamber 20. However, the present invention is not limited to the above-described embodiment. For example, the structure of the antenna tilting mechanism 48 is not particularly limited. Moreover, the antenna tilting mechanism 48 may be provided as necessary.

[0070] Referring to Figures 3, 4 and 8 together with Figure 7, the second antenna 50S of this embodiment can transition between a waiting posture (see Figure 3) when located in the waiting area 29 and a measurement posture (see Figure 8) when located in the measurement area 28 by the antenna folding mechanism 48 that functions as described above.

[0071] 3, when the second antenna 50S is in the standby position, the main part 52 of the second antenna 50S is located in a predetermined plane (XZ plane). This arrangement can shorten the lateral distance between the first antenna 50F and the second antenna 50S. According to this embodiment, the lateral size of the internal space of the anechoic chamber 20 can be reduced.

[0072] 5 and 8, when the second antenna 50S is in the measurement position, the horizontal position of the second antenna 50S coincides with the center position of the harness 82, and the vertical position of the second antenna 50S coincides with the vertical positions of the first antenna 50F and the third antenna 50T. More specifically, in this embodiment, the height of the shaft 54 ​​of the first antenna 50F and the shaft 54 ​​of the third antenna 50T from the floor 25 is set to match the height of the intermediate position 84 of the measured device 80 and the harness 82 from the floor 25, which is about 1 m. When the second antenna 50S is in the measurement position, the height of the shaft 54 ​​of the second antenna 50S from the floor 25 is about 1 m.

[0073] An example of a procedure for measuring radio waves according to this embodiment will be described below. The following measurement procedure can be modified as necessary.

[0074] Referring to FIG. 2, first, the three antennas 50 are positioned in the waiting area 29 (see FIG. 1). At this time, the movable partition 60 is in a closed state. Referring to FIG. 3, next, the movable partition 60 is opened. Next, the first antenna 50F is moved to the measurement area 28. Next, the movable partition 60 is closed. Next, the first antenna 50F measures the vertical polarization of the radio wave radiated from the harness 82 (see FIG. 1). Referring to FIG. 4, next, the polarization switching mechanism 46 rotates the first antenna 50F 90° around the shaft 54. Next, the first antenna 50F measures the horizontal polarization of the radio wave radiated from the harness 82 (see FIG. 1). Next, the first antenna 50F is returned to its initial position. Referring to FIG. 3, next, the movable partition 60 is opened. Next, the first antenna 50F is returned to the waiting area 29.

[0075] Next, the second antenna 50S is moved to the measurement area 28. Referring to FIG. 8, the movable partition 60 is then closed. Referring to FIG. 8 together with FIG. 6 and FIG. 7, the antenna tilt mechanism 48 is then used to change the attitude of the second antenna 50S to a measurement attitude. Next, the second antenna 50S measures the horizontal polarization of the radio waves radiated from the harness 82. Next, the polarization switching mechanism 46 rotates the second antenna 50S 90° around the shaft 54. Next, the second antenna 50S measures the vertical polarization of the radio waves radiated from the harness 82. Next, the second antenna 50S is returned to its initial position. Next, the attitude of the second antenna 50S is returned to its standby attitude. Referring to FIG. 3, the movable partition 60 is then opened. Next, the second antenna 50S is returned to the standby area 29.

[0076] Next, the third antenna 50T is moved to the measurement area 28. Next, the movable partition 60 is closed. Next, the vertical polarization of the radio waves emitted from the device under test 80 is measured by the third antenna 50T. Referring to FIG. 3 together with FIG. 4, next, the polarization switching mechanism 46 rotates the third antenna 50T 90° around the axis 54. Next, the horizontal polarization of the radio waves emitted from the device under test 80 is measured by the third antenna 50T. Next, the third antenna 50T is returned to its initial position. Next, the movable partition 60 is opened. Next, the third antenna 50T is returned to the waiting area 29.

[0077] To summarise the above explanation with reference to Fig. 8, according to this embodiment, when measuring radio waves radiated from the device under test 80 or harness 82, the antenna 50 used for measurement can be positioned in the measurement area 28, and the antenna 50 not used for measurement can be positioned in the waiting area 29. The antenna 50 in the measurement area 28 can be shielded from the antenna 50 in the waiting area 29 by the shielding portion 64 (see Fig. 2) of the movable partition 60 (radio wave absorber) in the closed state. The antenna 50 in the measurement area 28 is positioned in front of the movable partition 60 in the closed state, and is 1 m or more away from the movable partition 60 in the closed state.

[0078] The above-mentioned arrangement can almost completely eliminate the influence of other antennas 50 in the waiting area 29 on the antenna 50 in the measurement area 28. For example, it can prevent the other antennas 50 from reflecting radio waves emitted from the device under test 80, thereby affecting the measurement of the antenna 50 in the measurement area 28.

[0079] Furthermore, according to this embodiment, the movement of the antenna 50 between the measurement area 28 and the waiting area 29, the transition of the movable partition 60 between the open state and the closed state, the movement of the antenna 50 between the initial position and the rotation position, and the transition of the second antenna 50S between the waiting position and the measurement position can be automatically performed by an operator using the power of a motor or the like by remote control. If these tasks (hereinafter referred to as "tasks associated with measurement") were performed by a human, it would require a huge amount of work and would not necessarily be performed accurately. Even if the antenna 50 used for measurement were to be placed in the anechoic chamber 20 for each measurement, it would require a lot of work and would not necessarily be placed accurately.

[0080] On the other hand, according to this embodiment, the work involved in the measurement can be performed accurately without the help of humans. As a result, the accuracy of the radio wave measurement can be improved. That is, according to this embodiment, it is possible to provide a radio wave measurement system 10 that can reduce the amount of work required by humans and can accurately measure the radio waves emitted from the device under test 80.

[0081] In addition to the various modifications already described, the radio wave measurement system 10 of this embodiment can be modified in various other ways.

[0082] 8, the measurement positions in this embodiment are two positions: the same position as the measured device 80 in the lateral direction, and the same position as the middle position 84 of the harness 82 in the lateral direction. However, the present invention is not limited to this. For example, the measurement positions may be only one position, or may be three or more positions.

[0083] The two partial partitions 60P of this embodiment are slidable independently of each other. Therefore, the boundary position between the two partial partitions 60P in the closed position can be adjusted to match the lateral position of the coaxial cable 58 connected to the antenna 50 located in the measurement area 28. As a result, even if any one of the three antennas 50 is located in the measurement area 28, the coaxial cable 58 can pass straight backward between the two partial partitions 60P without applying a large stress to the coaxial cable 58. However, the present invention is not limited to this. For example, only one of the two partial partitions 60P may be slidable.

[0084] 8 together with FIG. 2, according to this embodiment, the coaxial cable 58 connected to the antenna 50 located in the measurement area 28 is sandwiched between soft cushioning materials 66 made of a material such as sponge. This structure allows the two partial partitions 60P in the closed position to be in close contact with each other with almost no stress applied to the coaxial cable 58. However, the present invention is not limited to this. For example, the material of the cushioning materials 66 is not particularly limited.

[0085] According to this embodiment, each shaft 54 ​​of the antennas 50 is separated from the rail 32 in the lateral direction. Each coaxial cable 58 extends in the front-rear direction along a cable guide (not shown) adjacent to the rail 32 in the lateral direction. With this structure, each antenna 50 can move in the front-rear direction while retracting the coaxial cable 58 so as not to bend. However, the present invention is not limited to this. For example, each shaft 54 ​​of the antennas 50 may be located at the same position as the rail 32 in the lateral direction. Also, a cable guide may be provided as necessary.

[0086] According to this embodiment, the coaxial cable 58, the power cable (not shown), and the communication cable (not shown) are each connected to the necessary locations via a connector (not shown). This makes it easy to take various members such as the partial partition 60P into and out of the anechoic chamber 20. However, the present invention is not limited to this, and the method of connecting the cables can be modified as necessary.

[0087] According to this embodiment, the coaxial cable 58 and the power cable (not shown) are each electromagnetically shielded, thereby suppressing radiation of electromagnetic noise. Furthermore, each of the communication cables (not shown) is an optical cable, which generates substantially no electromagnetic noise. Therefore, these members do not substantially affect the measurement of radio waves. However, the present invention is not limited to this, and the structures of the coaxial cable 58 and the power cable (not shown) can be modified as necessary.

[0088] 1, various members of this embodiment, including the base 30, rail 32, antenna support 40, movable partition 60, and fixed partition 69, are made of non-metallic materials. Therefore, these members do not substantially affect the measurement of radio waves. However, the present invention is not limited to this, and the materials of the above-mentioned members may be selected as necessary. [Explanation of symbols]

[0089] 10 Radio wave measurement system 20 Radio-Anechoic Chamber 21 Front wall 22 Back wall 23 Side wall 25 beds 28 Measuring area 29 Standby area 30 base 32 Rail 32F 1st Rail (Rail) 32S 2nd rail (rail) 32T 3rd rail (rail) 34 Belt 40 Antenna support 40F First antenna support (antenna support) 40S Second antenna support (antenna support) 40T 3rd antenna support (antenna support) 42 Support member 44 Bearings 46 Polarization switching mechanism 462 Piston 464 Operating Arm 48 Antenna folding mechanism 482 Moving parts 484 Piston 486 Operated part 488 Movable axis 50 Antenna 50F 1st Antenna (Antenna) 50S Second Antenna (Antenna) 50T 3rd Antenna (Antenna) 52 Main part 54 Shaft 58 Coaxial Cable 60 Movable partition 60P Partition 62 Opening 64 Shielding part 66 Cushioning material 67 Support stand 68 Slide mechanism 69 Fixed Partition 70 Table 72 Reference Ground Plane 78 Grounding Strap 80 Device under test (DUT) 82 Harness 84 Intermediate position 86 Road Simulator

Claims

1. A radio wave measurement system for measuring radio waves emitted from a device under test, the radio wave measurement system includes an anechoic chamber, two or more rails, two or more antenna support parts respectively corresponding to the rails, two or more antennas respectively corresponding to the antenna support parts, and a movable partition functioning as a radio wave absorber; The anechoic chamber has a measurement area and a waiting area, The device to be measured is placed in the measurement area, The waiting area is located behind the measurement area in the front-rear direction, The rails are spaced apart from each other in a lateral direction perpendicular to the front-rear direction and extend along the front-rear direction so as to straddle the waiting area and the measurement area, Each of the antenna support parts is attached to the corresponding rail and is movable along the front-rear direction, Each of the antennas is supported by a corresponding one of the antenna support parts and is movable between the waiting area and the measurement area in accordance with the movement of the corresponding one of the antenna support parts; The movable partition is disposed between the measurement area and the standby area and is capable of transitioning between a closed state and an open state; An opening and a shielding portion are formed in the movable partition in the closed state, In the closed state, the rail extends through the opening; In the closed state, the shielding portion is located above the opening in a vertical direction perpendicular to both the front-rear direction and the lateral direction, and covers the entire antenna that has moved to the measurement area from behind. Radio wave measurement system.

2. 2. The radio wave measurement system according to claim 1, The movable partition comprises two partial partitions, The two partition sections are movable in the lateral direction; When the movable partition is in the open state, the two partial partitions are open in the lateral direction; When the movable partition is in the closed state, the two partial partitions are closed in the lateral direction. Radio wave measurement system.

3. 3. The radio wave measurement system according to claim 1, The distance in the vertical direction between the upper end of the opening and the upper end of the rail is within 30 mm. Radio wave measurement system.

4. 3. The radio wave measurement system according to claim 1, A harness is connected to the device under test, The harness extends along the lateral direction, The two or more antennas include a high frequency antenna and a low frequency antenna, the high-frequency antenna is for measuring radio waves having a frequency of 1 GHz or more, and is positioned in front of the device under test when the device is moved to the measurement area; The low-frequency antenna is for measuring radio waves having a frequency of 1 GHz or less, and is located in front of the harness at a midpoint in the lateral direction when the harness is moved to the measurement area. Radio wave measurement system.

5. 5. The radio wave measurement system according to claim 4, the high frequency antenna includes a horn antenna, the rail corresponding to the horn antenna extends toward the device under test along the front-rear direction, The low frequency antenna includes a first antenna and a second antenna, one of the first antenna and the second antenna is a biconical antenna, and the other of the first antenna and the second antenna is a log periodic antenna; a first rail corresponding to the first antenna extends toward the intermediate position of the harness along the front-rear direction, a second rail corresponding to the second antenna is spaced apart from the first rail in the lateral direction; the antenna support portion corresponding to the second antenna has an antenna tilting mechanism, The antenna tilting mechanism is capable of moving the second antenna to be positioned in front of the intermediate position of the harness. Radio wave measurement system.

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