JP2004325230A - Antenna positioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna positioner permitting wide-band EMI (electro-magnetic interference) measurement, without exchanging an antenna. <P>SOLUTION: Two masts 13 and 20 are erected on a base 12, and holders 16 and 21 capable of being lifted are attached to the masts 13 and 20, respectively. A sub-mast 35 extending in the lateral direction is attached to the holders 16 and 21, and the wide-band antenna 38 is mounted on the tip of the sub-mast 35. A gear wheel 14 meshing with a rack part 36 of the sub-mast 35 is provided to the mast 13 so that a lateral direction moving mechanism 43 is constituted by the rack part 36, the gear wheel 14, and so forth. Accordingly, the positional shift of a feeding point can be compensated using the lateral direction moving mechanism 43, even when the feeding point for the wide-band antenna 38 is laterally displaced according to the frequency. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an antenna positioner used for elevating and lowering an antenna, and more particularly to an antenna positioner suitable for measuring EMI (Electro-Magnetic Interference) generated from an electronic device or the like.
[0002]
[Prior art]
In general, as an antenna positioner, a vertical support provided vertically to a floor surface, a lift provided to be able to move up and down along the vertical support, and an antenna provided to the lift Is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-4-129301
[0004]
When performing EMI measurement using an antenna positioner according to the related art, an object to be measured (EUT: Equipment Under Test) is arranged on a turntable or the like, and the object to be measured and the antenna are separated by a predetermined distance defined by a standard. The antenna positioners are arranged so as to be separated from each other. In this state, the direction of the object to be measured is changed by rotating the turntable together with the object to be measured, and the height position of the antenna is changed by raising and lowering the antenna, so that all the electromagnetic waves radiated from the object to be measured are completely removed. It was measured over the circumference.
[0005]
[Problems to be solved by the invention]
By the way, in the above-described conventional technique, when performing EMI measurement using a wideband antenna having different feeding point positions according to the frequency, such as a log periodic antenna or a bilog antenna, the feeding point between the DUT and the antenna is required. Is different depending on the frequency, and there is a difference between this distance and a predetermined distance defined by the standard. At this time, in the EMI measurement, a combined wave of a direct wave from the object to be measured and a reflected wave from the floor surface or the like is measured. Therefore, the difference between the distance between the object to be measured and the feeding point of the antenna is equal to the difference in the spatial position. This causes a measurement error.
[0006]
For this reason, in the related art, it is not suitable to use the wideband antenna for the EMI measurement, and it is necessary to replace the antenna to be used according to the frequency band to be measured. As a result, the workability has deteriorated due to the replacement of the antenna and the like, and the measurement time has been long.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems of the related art, and an object of the present invention is to provide an antenna positioner capable of performing wideband EMI measurement without replacing an antenna.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a vertical support provided to extend upward and downward, an elevator provided to be able to move up and down along the vertical support, The present invention is applied to an antenna positioner including an antenna provided on a table.
[0009]
A feature of the configuration adopted by the invention of claim 1 is that the antenna comprises a broadband antenna in which a position of a feeding point is displaced in a horizontal direction orthogonal to the vertical support according to a frequency, and the vertical support and the broadband antenna are arranged. And a lateral moving means for moving the broadband antenna in the lateral direction.
[0010]
With this configuration, even when the position of the feed point of the broadband antenna is displaced in the horizontal direction according to the frequency, the displacement of the feed point can be corrected by using the lateral moving means. As a result, the distance between the feeding point of the broadband antenna and the device under test can be kept constant, and the accuracy of EMI measurement can be improved.
[0011]
In the invention according to claim 2, the broadband antenna is provided at a tip of a horizontal support extending in a direction orthogonal to the vertical support, and the horizontal support is configured to be supported by the elevator.
[0012]
Thus, by displacing the horizontal support in the length direction, the broadband antenna can be moved in the horizontal direction, and the displacement of the feeding point can be compensated.
[0013]
According to the third aspect of the present invention, another vertical support is provided at a position separated from the vertical support in the horizontal direction, and the other vertical support is supported along the other vertical support while supporting the horizontal support. , And another lifting platform that can be raised and lowered in the downward direction is provided.
[0014]
Thus, since the horizontal support can be supported by using two vertical supports, the horizontal support can be prevented from tilting downward due to the weight of the broadband antenna. Therefore, even when a broadband antenna having high directivity is used, EMI measurement can be accurately performed.
[0015]
In the invention of claim 4, the length of the vertical support extending in the horizontal direction is set to a larger value than the width of the vertical support in a direction orthogonal to the moving direction of the broadband antenna.
[0016]
Thus, the horizontal support can be supported by using the vertical support having a large horizontal length, so that the horizontal support can be prevented from tilting downward due to the weight of the broadband antenna. Therefore, even when a broadband antenna having high directivity is used, EMI measurement can be accurately performed. Further, since the horizontal support is supported by using one vertical support, the horizontal support can be easily attached and detached as compared with the case where a plurality of vertical supports are used.
[0017]
In the invention of claim 5, the lateral direction moving means is constituted by a gear provided on the vertical support and a rack provided on the horizontal support and meshing with the gear.
[0018]
Thus, by rotating the gear provided on the vertical support, the rack provided on the horizontal support can be moved in the horizontal direction together with the horizontal support and the broadband antenna, and the displacement of the feeding point of the wideband antenna is corrected. can do.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an antenna positioner according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0020]
First, FIGS. 1 to 5 show a first embodiment. In the drawings, reference numeral 1 denotes an anechoic chamber, and the anechoic chamber 1 has a radio wave absorber (shown in FIG. 1) on front, rear, left, right wall surfaces and a ceiling surface. And a rotary table 3 rotatable about a rotation axis OO on the floor 2. An object to be measured 4 (EUT) such as an electronic device is mounted on the turntable 3.
[0021]
Reference numeral 11 denotes an antenna positioner provided in the radio wave anechoic chamber 1 at a position separated from the rotary table 3, and the antenna positioner 11 includes masts 13, 20, holders 16, 21, a sub mast 35, a broadband antenna 38, and the like, which will be described later. I have.
[0022]
Reference numeral 12 denotes a base provided on the floor surface 2. Masts 13 and 20 are erected on the base 12, and an elevating motor 29 for elevating and lowering the broadband antenna 38 and a polarization plane are switched therein. For switching the polarization is accommodated.
[0023]
Reference numeral 13 denotes a first mast as a vertical support provided on the base 12 so as to extend perpendicularly to the floor 2, and the mast 13 has a hollow, substantially square cross-section, and extends from the floor 2 to the ceiling. It extends upward and downward toward. In the mast 13, a sub-mast 35 is provided on a lateral movement gear 14 for moving the sub-mast 35 in the lateral direction (the direction indicated by the arrow A in FIG. 2). The gear 14 has a star-shaped cross section, extends upward and downward, and is mounted in a state where a part thereof projects to the front side of the mast 13 so as to be able to contact the sub-mast 35. The gear 14 is connected to an output shaft 15 </ b> A of a lateral movement motor 15 provided on the base end side of the mast 13, and is configured to be rotated by the motor 15.
[0024]
Reference numeral 16 denotes a first holder serving as a lifting table provided to be able to move up and down (in the direction of arrow B in FIG. 2) along the first mast 13, and the holder 16 surrounds the mast 13. A circular insertion hole 16 </ b> A extending in the horizontal direction (left and right directions) is formed to have a rectangular frame shape and to insert a sub-mast 35 described later.
[0025]
The holder 16 is connected to an elevating belt 17, and the elevating belt 17 is wound around gears 18, 19 provided on both ends in the longitudinal direction of the mast 13. The holder 16 is moved up and down by driving the belt 17 upward and downward by using a lifting motor 29 described later.
[0026]
Reference numeral 20 denotes a second mast as another vertical support provided in the lateral direction apart from the first mast 13, and the mast 20 is arranged at a position closer to the DUT 4 than the mast 13, for example. At the same time, it is attached to the base 12 so as to extend perpendicular to the floor surface 2. The second mast 20 has a substantially rectangular hollow cross section substantially in the same manner as the first mast 13, and extends upward and downward from the floor 2 toward the ceiling.
[0027]
Reference numeral 21 denotes a second holder as another elevating table provided so as to be able to move up and down along the second mast 20. The holder 21 has a square shape surrounding the mast 20 in substantially the same manner as the holder 16. And a circular insertion hole 21A extending in the lateral direction for inserting a sub-mast 35 to be described later.
[0028]
One end of the holder 21 in the horizontal direction is connected to an elevating belt 22, and the elevating belt 22 is wound around gears 23 and 24 provided on both ends of the mast 20 in the vertical direction. The holder 21 is moved up and down by driving the belt 22 upward and downward by using an elevator motor 29 described later.
[0029]
The other end of the holder 21 in the horizontal direction is provided with another insertion hole 21B extending in the vertical direction for inserting the polarization switching rack 25, and the insertion hole 21B communicates with the insertion hole 21A. ing. The polarization switching rack 25 connected to the polarization switching belt 26 is inserted into the insertion hole 21B, and the polarization switching belt 26 is provided with gears provided on both ends of the mast 20 in the vertical direction. 27 and 28. The rack 25 is moved up and down by driving the belt 26 up and down using a polarization switching motor 34 described later.
[0030]
Reference numeral 29 denotes an elevating motor housed in the base 12. The elevating motor 29 drives a connecting shaft 32 through gears 30 and 31, and gears 19 and 24 are connected to the connecting shaft 32. . Thus, the elevating motor 29 drives the elevating belts 17 and 22 upward and downward to move the holders 16 and 21 together. The connecting shaft 32 is connected to a polarization switching gear 28 via an electromagnetic clutch 33. The electromagnetic clutch 33 is connected when the holders 16 and 21 are moved up and down, and is disconnected when the polarization plane of the broadband antenna 38 is switched.
[0031]
Numeral 34 denotes a polarization switching motor located in the base 12 and connected to the gear 28. The polarization switching motor 34 moves the rack 25 up and down with respect to the holder 21 through the polarization switching belt 26. The polarization direction of the broadband antenna 38 is switched between, for example, vertical polarization and horizontal polarization.
[0032]
Reference numeral 35 denotes a sub-mast as a horizontal support inserted through the insertion holes 16A and 21A of the holders 16 and 21. The sub-mast 35 has a rod-like shape with a circular cross section, and its distal end extends toward the DUT 4 and has a length. An intermediate portion in the vertical direction is supported by masts 13 and 20 using holders 16 and 21.
[0033]
On the base end side of the sub mast 35, there is provided a rack portion 36 composed of a plurality of arc grooves 36A provided along the circumferential direction. 14 meshed. Further, a gear 37 composed of a plurality of horizontal grooves 37A extending in the lateral direction is provided at an intermediate position in the length direction (lateral direction) of the sub mast 35, and the gear 37 is located in the holder 21 and is provided with a polarization switching rack. 25.
[0034]
Reference numeral 38 denotes a broadband antenna attached to the distal end of the sub mast 35. The broadband antenna 38 includes, for example, a log periodic antenna 39 including a plurality of elements 39A having different lengths and a proximal end of the log periodic antenna 39. It is constituted by a bilog antenna in combination with an arranged biconical antenna 40, and the element 39A of the log periodic antenna 39 gradually increases from the base end to the tip end (the DUT 4 side) of the broadband antenna 38. Has become shorter.
[0035]
The log periodic antenna 39 can receive signals from, for example, 100 MHz to 1 GHz, and the biconical antenna 40 can receive signals from 30 MHz to 100 MHz. As a result, the broadband antenna 38 can receive a signal in a frequency band from 30 MHz to 1 GHz, and the feeding point of the wideband antenna 38 is shifted from the base end in the lateral direction to the distal end as the received signal changes from low frequency to high frequency. It is displaced to the side.
[0036]
The broadband antenna 38 is connected to an EMI receiver (neither is shown) via a cable, a preamplifier, or the like. Then, the EMI receiver measures and records the maximum electric field intensity received by the broadband antenna 38 for each frequency of, for example, 30 MHz, 100 MHz, 200 MHz, 300 MHz, 500 MHz, 700 MHz, and 1 GHz.
[0037]
Reference numeral 41 denotes an elevating mechanism for elevating and lowering the broadband antenna 38 in an upward and downward direction (vertical direction). The elevating mechanism 41 includes the elevating belts 17 and 22, the elevating motor 29, and the like. Then, the elevating mechanism 41 drives the elevating motor 29 to rotate in the forward or reverse direction, thereby sending the belts 17 and 22 together in the forward or reverse direction, and connecting with the sub mast 35 attached to the holders 16 and 21. The broadband antenna 38 is raised and lowered.
[0038]
Reference numeral 42 denotes a polarization switching mechanism that switches the polarization plane of the broadband antenna 38 between horizontal polarization and vertical polarization. The polarization switching mechanism 42 includes the polarization switching rack 25, the polarization switching belt 26, and the polarization switching. It is constituted by a motor 34 and the like. Then, the polarization switching mechanism 42 rotates the polarization switching motor 34 in the forward or reverse direction, thereby moving the rack 25 upward and downward, and moving the sub mast 35 in the circumferential direction (the arrow in FIG. 2). (C direction), the polarization plane of the broadband antenna 38 is switched.
[0039]
Reference numeral 43 denotes a lateral moving mechanism (lateral moving means) for moving the broadband antenna 38 in the left and right directions (lateral direction). The lateral moving mechanism 43 includes a lateral moving gear 14 provided on the mast 13, It is constituted by a lateral movement motor 15 and a rack 36 provided on the sub mast 35 and meshing with the gear 14. The lateral moving mechanism 43 drives the lateral moving motor 15 in the forward or reverse direction to move the rack 36 of the sub-mast 35 to the left or right, and moves the broadband antenna 38 to the device under test. They are moving back and forth towards 4.
[0040]
The antenna positioner according to the present embodiment is configured as described above, and its operation will be described next.
[0041]
When performing the EMI measurement of the DUT 4, first, the DUT 4 is placed on the rotary table 3, and the rotation axis OO and the feeding point on the base end side of the broadband antenna 38 (the feeding point of the biconical antenna 40, for example) are measured. The distance dimension L0 from the point (point) is set to a value (3 m or 10 m) defined by the standard.
[0042]
Next, with the electromagnetic clutch 33 disconnected, the polarization switching mechanism 42 (the polarization switching motor 34) is driven to change the polarization plane of the broadband antenna 38 to either horizontal polarization or vertical polarization (for example, horizontal polarization). ). Thereafter, with the electromagnetic clutch 33 connected, the elevating mechanism 41 (elevating motor 29) is driven to move and fix the broadband antenna 38 to a height of about 1 m from the floor 2. In this state, the maximum electric field strength from 30 MHz to 100 MHz is measured using an EMI receiver connected to the wideband antenna 38.
[0043]
Next, the lateral movement mechanism 43 (the lateral movement motor 15) is driven to move the wideband antenna 38 in the lateral direction so as to move away from the device under test 4. Then, the broadband antenna 38 is fixed at a position where the distance dimension L0 between the power feeding point of the log periodic antenna 39 for 200 MHz and the rotation axis OO matches the standard value. In this state, the maximum electric field strength at 200 MHz is measured using the EMI receiver. Thereafter, the broadband antenna 38 is gradually moved away from the device under test 4 in the same procedure, and measurement is performed on signals of 200 MHz, 300 MHz, 500 MHz, 700 MHz, and 1 GHz.
[0044]
In this way, when the measurement for the signal from 30 MHz to 1 GHz is completed at one height position, the height of the wideband antenna 38 is gradually increased from 1 m to 4 m using the lifting mechanism 41, and the height is reduced. Measurements for signals from 30 MHz to 1 GHz are similarly made at different locations. When the measurement at the highest position (4 m) is completed, the rotary table 3 is rotated to change the orientation of the DUT 4 and the broadband antenna 38, and again for the height dimension from 1 m to 4 m. Perform EMI measurements. The measurement for the vertically polarized wave can be performed in the same procedure.
[0045]
Thus, in the present embodiment, since the lateral movement mechanism 43 for moving the broadband antenna 38 in the lateral direction is provided, even when the feed point of the broadband antenna 38 is displaced in the lateral direction according to the frequency of the received signal, , The wideband antenna 38 can be moved in the horizontal direction, and the distance dimension L0 between the DUT 4 (rotation axis OO) and the wideband antenna 38 can be maintained at a constant value regardless of the frequency. For this reason, the displacement of the feed point of the broadband antenna 38 can be compensated for using the lateral movement mechanism 43, so that the accuracy of the EMI measurement can be improved.
[0046]
As an example, when the horizontal position of the wideband antenna 38 is fixed, a maximum deviation of 3.7 dB occurs as compared with the case where the measurement is performed using the half-wavelength dipole antenna corresponding to each frequency. On the other hand, in the present embodiment, the distance dimension L0 between the DUT 4 and the broadband antenna 38 is maintained at a constant value by moving the feed point position determined for each frequency, and thus a half-wavelength dipole antenna is used. The maximum deviation from the case could be reduced to 0.7 dB or less, confirming that the measurement accuracy was improved.
[0047]
As a result, highly accurate EMI measurement can be performed using the broadband antenna 38, so that the DUT 4 can take EMI countermeasures with a small margin relative to the standard value. In addition, since EMI measurement in a frequency range from 30 MHz to 1 GHz can be performed using only the broadband antenna 38, it is not necessary to replace the antenna according to the frequency band, so that the burden of the measurement operation can be reduced and the measurement time can be reduced. It can be greatly reduced.
[0048]
Further, since the sub mast 35 to which the broadband antenna 38 is attached is supported by using the two masts 13 and 20, it is possible to reduce the downward inclination of the distal end side of the sub mast 35 due to the weight of the broadband antenna 38. Therefore, even when the broadband antenna 38 composed of a bilog antenna having directivity is used, the EMI measurement can be accurately performed.
[0049]
In particular, in the prior art, when performing EMI measurement using a broadband antenna, in order to prevent the broadband antenna from tilting downward, the base end side of the sub mast (opposite to the wideband antenna) extends greatly beyond the mast. Thus, the weight balance between the broadband antenna and the base end side of the submast was obtained. For this reason, the submast 35 becomes unnecessarily long, and there is a problem that it is difficult to use the submast 35 in the small anechoic chamber 1.
[0050]
On the other hand, in the present embodiment, since the broadband antenna 38 is supported using the two masts 13 and 20, the length of the base end side of the sub mast 35 extending beyond the mast 13 can be reduced. it can. As a result, the distance between the broadband antenna 38 and the masts 13 and 20 can be kept long even in the small anechoic chamber 1, so that the reflected waves from the masts 13 and 20 can be reduced and the measurement accuracy can be increased. be able to.
[0051]
Further, since the broadband antenna 38 is supported using the two masts 13 and 20, the overall rigidity of the masts 13 and 20 is increased. For this reason, since each mast 13, 20 can have a smaller diameter (width), the cross-sectional area of the masts 13, 20 viewed from the measured object 4 can be reduced, and the masts 13, 20 can be reduced. The reflected wave from the antenna to the broadband antenna 38 is reduced, and accurate measurement can be performed.
[0052]
Next, FIGS. 6 and 7 show an antenna positioner according to a second embodiment. The feature of the present embodiment is that a wide band width is obtained by using a single mast whose lateral length is larger than its width. The configuration is such that the antenna is supported. Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0053]
Reference numeral 51 denotes a mast as a vertical support disposed on the base 12 in a state of extending vertically to the floor surface 2. The mast 51 has a hollow rectangular cross section as shown in FIG. The length L in the horizontal direction, which is the direction in which the antenna 38 moves, is set to a value larger than the width W orthogonal to the horizontal direction. In the mast 51, a lateral movement gear 52 for moving the sub mast 35 in the lateral direction is provided, and the gear 52 is provided on the front surface of the mast 51 in substantially the same manner as the gear 14 according to the first embodiment. The sub-mast 35 is attached to the sub-mast 35 in a protruding state. As shown in FIG. 6, the gear 52 is connected to an output shaft 53A of a lateral movement motor 53 provided on the base end side of the mast 51, and is configured to be rotated by the motor 53.
[0054]
Numeral 54 denotes a holder as a lift which is provided so as to be movable upward and downward along the mast 51. The holder 54 has a rectangular frame shape surrounding the mast 51, and is used for inserting the sub mast 35. A circular insertion hole 54A extending in the lateral direction is formed.
[0055]
One end of the holder 54 in the horizontal direction is connected to an elevating belt 55, and the elevating belt 55 is wound around gears 56, 57 provided on both ends in the vertical direction of the mast 51. On the other hand, another insertion hole 54B extending in the vertical direction is provided on the other end in the horizontal direction of the holder 54 to insert the polarization switching rack 58, and the insertion hole 54B communicates with the insertion hole 54A. ing. A polarization switching rack 58 connected to a polarization switching belt 59 is inserted into the insertion hole 54B, and the polarization switching belt 59 is provided with gears provided on both ends of the mast 51 in the vertical direction. 60 and 61 are wound.
[0056]
Reference numeral 62 denotes a lifting / lowering motor housed in the base 12. The lifting / lowering motor 62 drives a connecting shaft 65 to rotate through gears 63 and 64, and a gear 57 is connected to the connecting shaft 65. Thus, the lifting / lowering motor 62 drives the lifting / lowering belt 55 upward and downward, and raises / lowers the holder 54. The connection shaft 65 is connected to a polarization switching gear 61 via an electromagnetic clutch 66. The electromagnetic clutch 66 is connected when the holder 54 is moved up and down, and is disconnected when the polarization plane of the broadband antenna 38 is switched.
[0057]
A polarization switching motor 67 is located in the base 12 and connected to the gear 61. The polarization switching motor 67 moves the rack 58 up and down with respect to the holder 54 through a polarization switching belt 59. The polarization direction of the broadband antenna 38 is switched between, for example, vertical polarization and horizontal polarization.
[0058]
Reference numeral 68 denotes an elevating mechanism for elevating and lowering the broadband antenna 38 in the upward and downward directions (vertical direction). The elevating mechanism 68 includes the elevating belt 55, the elevating motor 62, and the like. The elevating mechanism 68 raises and lowers the holder 54, the sub mast 35, and the broadband antenna 38 by rotating and driving the elevating motor 62.
[0059]
A polarization switching mechanism 69 switches the polarization plane of the broadband antenna 38 between horizontal polarization and vertical polarization. The polarization switching mechanism 69 includes a polarization switching rack 58, a polarization switching belt 59, and a polarization switching switch. It is constituted by a motor 67 and the like. The polarization switching mechanism 69 rotates the sub-mast 35 by 90 degrees in the circumferential direction by rotating the polarization switching motor 67 to switch the polarization plane of the broadband antenna 38.
[0060]
Reference numeral 70 denotes a lateral movement mechanism (lateral movement means) for moving the wideband antenna 38 in the left and right directions (lateral direction). The lateral movement mechanism 70 includes a lateral movement gear 52 provided on the mast 51, It is constituted by a lateral movement motor 53 and a rack 36 provided on the sub mast 35 and meshing with the gear 52. The lateral movement mechanism 70 drives the lateral movement motor 53 in the forward or reverse direction to move the rack 36 of the sub-mast 35 left and right, and moves the broadband antenna 38 to the device under test. 4 is advanced and retreated.
[0061]
Thus, in the present embodiment configured as described above, substantially the same operation and effect as those in the first embodiment can be obtained. In particular, in the present embodiment, the broadband antenna 38 (sub-mast 35) is supported by using the mast 51 whose length L is larger than the width W, so that even when one mast 51 is used. By increasing the length L, the broadband antenna 38 can be prevented from tilting downward.
[0062]
Further, in the present embodiment, since the sub-mast 35 is supported by using one mast 51, even if the sub-mast 35 is replaced in order to use the sub-mast 35 having a different length dimension, for example, Detachability can be improved, and work efficiency can be improved.
[0063]
In each of the above embodiments, the lateral movement mechanisms 43 and 70 are configured to engage the gears 14 and 52 with the rack 36 of the sub mast 35. However, the present invention is not limited to this, and the lateral movement mechanism 82 may be configured by engaging a rotatable grooved belt 81 with the rack portion 36 as in a modified example shown in FIG. In this case, the area where the grooved belt 81 and the rack portion 36 mesh with each other is increased as compared with the case where the gears 14 and 52 are used, so that the positioning accuracy of the sub mast 35 can be improved. As a result, the position of the feeding point of the broadband antenna 38 can be precisely controlled, and the accuracy of EMI measurement can be improved.
[0064]
Further, in each of the above embodiments, a bilog antenna composed of a log periodic antenna 39 and a biconical antenna 40 is used as the wide band antenna 38, but a single log periodic antenna may be used as the wide band antenna. .
[0065]
Further, in each of the above embodiments, the masts 13, 20, 51 are formed in a square cross section, but may be formed in a circular cross section, an elliptical cross section, or the like.
[0066]
【The invention's effect】
As described in detail above, according to the first aspect of the present invention, the horizontal moving means for moving the wide band antenna in the horizontal direction is provided between the vertical support and the wide band antenna. Even when the position of the feed point of the antenna is displaced in the lateral direction, the displacement of the feed point can be corrected using the lateral moving means. As a result, the distance between the feeding point of the broadband antenna and the device under test can be kept constant, and the accuracy of EMI measurement can be improved. Further, since wideband EMI measurement can be performed using a single wideband antenna, there is no need to exchange antennas according to the band, so that work efficiency can be improved and measurement time can be shortened.
[0067]
According to the second aspect of the present invention, since the wide-band antenna is provided at the tip of the horizontal support and the horizontal support is supported on the elevating platform, the wide-band antenna can be displaced in the length direction to thereby realize the wide-band antenna. It can be moved in the length direction to compensate for the displacement of the feeding point.
[0068]
According to the third aspect of the present invention, since the horizontal column is supported using the two vertical columns, the horizontal column can be prevented from tilting downward due to the weight of the broadband antenna. Therefore, even when a broadband antenna having high directivity is used, EMI measurement can be accurately performed.
[0069]
According to the fourth aspect of the present invention, since the length of the vertical support extending in the horizontal direction is set to a large value compared to the width, the horizontal support can be supported using the vertical support having a large length. In addition, it is possible to reduce the inclination of the horizontal support column due to the weight of the broadband antenna. Therefore, even when a broadband antenna having high directivity is used, EMI measurement can be accurately performed. Further, since the horizontal support is supported by using one vertical support, the horizontal support can be easily attached and detached as compared with the case where a plurality of vertical supports are used. For this reason, work efficiency can be improved even when performing EMI measurement using horizontal supports having different length dimensions.
[0070]
According to the fifth aspect of the present invention, since the horizontal movement means is constituted by the gear provided on the vertical support and the rack portion provided on the horizontal support and meshing with the gear, the gear provided on the vertical support is rotated. By doing so, the rack portion provided on the horizontal support can be moved in the horizontal direction together with the horizontal support and the broadband antenna, and the displacement of the feed point of the wideband antenna can be corrected.
[Brief description of the drawings]
FIG. 1 is a front view showing a state in which an antenna positioner according to a first embodiment of the present invention is disposed in an anechoic chamber.
FIG. 2 is a front view showing the antenna positioner in FIG. 1 alone;
FIG. 3 is a cross-sectional view showing a mast, a holder, and the like as viewed from a direction indicated by arrows III-III in FIG.
FIG. 4 is a cross-sectional view showing a rack portion of the sub-mast viewed from a direction indicated by arrows IV-IV in FIG.
FIG. 5 is a cross-sectional view showing a mast, a holder, a rack, and the like as viewed from a direction indicated by arrows VV in FIG.
FIG. 6 is a front view showing an antenna positioner according to a second embodiment.
FIG. 7 is a cross-sectional view showing a mast, a holder, and the like as viewed in a direction indicated by arrows VII-VII in FIG.
FIG. 8 is a cross-sectional view showing a lateral movement mechanism and the like according to a modification of the present invention at the same position as in FIG. 3;
[Explanation of symbols]
11 Antenna positioner
13 First mast (vertical support)
14,52 Gears for lateral movement
15,53 Motor for lateral movement
16 First holder (elevating platform)
20 Second mast (vertical support)
21 Second holder (elevator)
35 sub mast (horizontal support)
36 Rack part
38 Broadband Antenna
43, 70, 82 Lateral moving mechanism (lateral moving means)
51 mast (vertical support)
54 Holder (elevator)
81 grooved belt

Claims (5)

In an antenna positioner including a vertical column extending upward and downward, a vertical column provided to be able to move up and down along the vertical column, and an antenna provided on the vertical column,
The antenna includes a wideband antenna in which a position of a feeding point is displaced in a horizontal direction orthogonal to the vertical support in accordance with a frequency. Between the vertical support and the wideband antenna, a horizontal movement of the wideband antenna is performed. An antenna positioner comprising a direction moving means. 2. The antenna positioner according to claim 1, wherein the broadband antenna is provided at an end of a horizontal support extending in a horizontal direction orthogonal to the vertical support, and the horizontal support is configured to be supported by the elevator. 3. Another vertical strut is provided at a position horizontally separated from the vertical strut, and the other vertical strut can be moved up and down along the other vertical strut while supporting the horizontal strut. 3. The antenna positioner according to claim 2, further comprising another lifting platform. 3. The antenna positioner according to claim 2, wherein a length dimension of the vertical support extending in a lateral direction is set to be larger than a width dimension orthogonal to a moving direction of the broadband antenna. 4. 5. The antenna positioner according to claim 2, wherein the lateral movement means comprises a gear provided on the vertical support, and a rack provided on the horizontal support and meshing with the gear. 6.

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