Measurement antenna and measurement system including same

Abstract

To provide a small, wideband measurement antenna that ensures a sufficient amount of power for transmission and reception to and from UE, and a measurement system equipped with the same. [Solution] The measurement antenna (10) includes a ground plate (11), a U-shaped antenna element (20), and radio wave absorbers (25, 26) loaded on the antenna element (20). The antenna element (20) has a first conductor plate (21) fed at a feed point (12), a second conductor plate (22) disposed at an angle of approximately 90 degrees relative to the first conductor plate (21), and a third conductor plate (23) facing the first conductor plate (21) and disposed at an angle of approximately 90 degrees relative to the second conductor plate (22). The radio wave absorber is loaded on at least an upper surface (23a) of the third conductor plate (23) facing the first conductor plate (21). The upper surface (21a) of the first conductor plate (21) opposite to the lower surface (21b) facing the radio wave absorber (25) is positioned close to the antenna of the UE, so that the antenna of the UE and the antenna element (20) are spatially coupled.

Description

[Technical Field]

[0001] The present invention relates to a measurement antenna and a measurement system including the same, and more particularly to a measurement antenna for the frequency band of a 5G wireless communication system and a measurement system including the same. [Background technology]

[0002] The wireless communication terminal (User Equipment: UE) used in the 5G wireless communication system is equipped with multiple antennas and uses a communication technology called MIMO (Multiple Input Multiple Output) that uses these multiple antennas simultaneously. Furthermore, the UE also uses a technology that increases the maximum transmission capacity by simultaneously transmitting and receiving signals of multiple frequencies.

[0003] Such UE functional tests have traditionally been conducted wired, but in recent years, there has been a demand for testing using so-called OTA (Over The Air) methods, in which the UE and the measurement antenna are housed in a shielded box that is not affected by the surrounding radio wave environment, and signals are sent and received between the UE and the test antenna via wireless communication.

[0004] To perform MIMO testing, signals with different amplitudes and phases must be transmitted and received from multiple antennas installed in a UE, such as a smartphone. Therefore, the measurement antenna must be placed close to the UE's built-in antenna. However, when the measurement frequency is low, the size of the measurement antenna becomes large, making it difficult to place multiple measurement antennas close to the UE's built-in antenna.

[0005] In addition to the millimeter wave band, 5G wireless communication systems also use the FR1 (Frequency Range 1) frequency band, which is between 600 MHz and 7.125 GHz. The wavelength of 600 MHz radio waves is 500 mm, so if a dipole antenna is used, for example, the corresponding antenna length is 250 mm. This means that measurement antennas must be compact enough to allow multiple antennas to be placed close to the UE. At the same time, measurement antennas must also have a wide bandwidth that can cover the frequency range required for measurement.

[0006] A typical method for miniaturizing an antenna element is shown in Fig. 5 of Non-Patent Document 1. Furthermore, as described in Non-Patent Document 2, it is empirically known that a monopole antenna can be made broadband by making the antenna plate-shaped.

[0007] For example, one method for achieving both miniaturization and broadband is a plate-shaped monopole antenna as shown in Fig. 14. A typical monopole antenna operates as an antenna by placing a conductive rod with a length of 1 / 4 wavelength on a ground plate. By changing this conductive rod to a conductive plate and bending it into a U-shape as shown in Fig. 14, it is possible to reduce the size of antenna element 20 to about the short side length of a smartphone (6 cm to 8 cm). [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Yoshio Koyanagi, "Design Issues and Solutions for Small Antennas for Mobile Communication Terminals," IEICE Transactions on Electronics, Information and Communication Engineers, Vol. J98-B, No. 9, pp. 842-852 (September 2015) [Non-patent document 2] Institute of Electronics, Information and Communication Engineers, "Forest of Knowledge" (http: / / www.ieice-hbkb.org / ), 4th Group, Part 2, Chapter 4, p.15 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the U-shaped antenna element 20 shown in Fig. 14 has the following problem. The arrows in Fig. 14 indicate the direction of current flowing through the antenna element 20 at a given moment. Of the three conductor plates 21 to 23 that make up the antenna element 20, the first conductor plate 21 that is close to the UE and the third conductor plate 23 that faces the first conductor plate 21 function to transmit and receive signals to and from the UE 200. The second conductor plate 22 that is perpendicular to the first conductor plate 21 and the third conductor plate 23 has little effect on the UE 200.

[0010] Here, since the directions of the currents I1 and I3 flowing through the first conductor plate 21 and the third conductor plate 23, respectively, are opposite to each other, if the length of the second conductor plate 22 is short compared to the wavelength, the electromagnetic waves emitted by the currents I1 and I3 may cancel each other out, resulting in a problem in that the amount of power that can be transmitted and received in the direction of the UE may be reduced.

[0011] The present invention has been made to solve these conventional problems, and aims to provide a small, wideband measurement antenna that ensures sufficient power to be transmitted and received to a UE, and a measurement system equipped with the same. [Means for solving the problem]

[0012] In order to solve the above problems, the measurement antenna according to the present invention comprises a ground plate (11), a U-shaped antenna element (20), and radio wave absorbers (25, 26) loaded on the antenna element, wherein the antenna element comprises a substantially rectangular first conductor plate (21) fed at a feeding point (12), a substantially rectangular second conductor plate (22) sharing one side in the width direction with the first conductor plate and disposed at an angle of approximately 90 degrees to the first conductor plate, and a substantially rectangular second conductor plate (22) facing the first conductor plate in a substantially parallel relationship. and a substantially rectangular third conductor plate (23) that shares one widthwise side with the plate and is arranged at an angle of approximately 90 degrees to the second conductor plate, the radio wave absorber is loaded on at least a surface (23a) of the third conductor plate that faces the first conductor plate, and a surface (21a) of the first conductor plate opposite a surface (21b) that faces the radio wave absorber is arranged close to an antenna (210) of the object to be measured (200), and the antenna of the object to be measured and the antenna element are spatially coupled.

[0013] For example, the measurement antenna according to the present invention has a configuration in which a plate-shaped monopole antenna is bent, and a radio wave absorber is loaded on the third conductor plate located farthest from the antenna of the device under test. The measurement antenna according to the present invention configured in this way achieves miniaturization and a wide bandwidth, and can ensure a sufficient amount of power that can be transmitted to and received from the device under test.

[0014] Furthermore, the measurement antenna according to the present invention may be configured such that the first conductor plate and the third conductor plate have a length of 6 cm, and the second conductor plate has a length of 3 cm.

[0015] With this configuration, the measurement antenna according to the present invention can use the FR1 frequency band of 600 MHz to 7.125 GHz as the operating frequency band.

[0016] Furthermore, the measurement system according to the present invention is a measurement system (100) that uses a plurality of any of the above-mentioned measurement antennas, and is configured to perform MIMO communication between each of the antenna elements of each of the measurement antennas and the plurality of antennas of the object to be measured.

[0017] With this configuration, the measurement system according to the present invention can perform MIMO communication in close proximity to the antenna of the device under test by using multiple small measurement antennas.

[0018] The measurement system according to the present invention may also be configured to include a shield box (50) that houses the plurality of measurement antennas and the object to be measured and blocks the intrusion of electromagnetic waves from the outside.

[0019] Furthermore, the measurement system according to the present invention may be configured such that an antenna installation section (63) for installing the plurality of measurement antennas and a measured object installation section (64) for installing the measured object, which is installed on the plurality of measurement antennas, are further housed within the shielding box, and grids are printed on the upper surface (63a) of the antenna installation section and the upper surface (64a) of the measured object installation section, respectively.

[0020] With this configuration, the measurement system of the present invention has grids printed on the top surface of the antenna installation section and the top surface of the object to be measured installation section, making it possible to easily install the measurement antenna and the object to be measured in the desired installation positions. [Effects of the Invention]

[0021] The present invention provides a small, wideband measurement antenna that ensures a sufficient amount of power for transmission and reception to and from a UE, and a measurement system that includes the same. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view showing an example of the basic configuration of a measurement antenna according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing the external structure of the measurement antenna. [Figure 3] FIG. 2 is a cross-sectional view of a measurement antenna. [Figure 4]FIG. 10 is a block diagram showing the configuration of a measurement system according to a second embodiment of the present invention. [Figure 5] 10A and 10B are diagrams showing the external structure of a shielding box provided in a measurement system according to a second embodiment of the present invention, where (a) is a perspective view seen from the front side, and (b) is a perspective view seen from the back side. [Figure 6] FIG. 2 is a perspective cross-sectional view showing the structure of a shielding box. [Figure 7] FIG. 10 is a top view of the shielding box with the lower partition plate provided. [Figure 8] FIG. 10 is a top view of the shielding box with the antenna tray provided therein. [Figure 9] FIG. 1 is a top view of a state in which multiple measurement antennas are installed on an antenna tray. [Figure 10] This is a top view of a UE tray placed on top of multiple measurement antennas. [Figure 11] This is a top view of a UE placed on a UE tray. [Figure 12] (a) is a diagram showing a schematic diagram of a situation where the UE and the measurement antenna are significantly misaligned, and (b) is a diagram showing a schematic diagram of a situation where a dummy antenna is placed between the UE antenna tray and the UE tray. [Figure 13] 10 is a flowchart showing the process of a measurement method using a measurement system according to a second embodiment of the present invention. [Figure 14] FIG. 1 is a side view showing an example of the basic configuration of a conventional planar monopole antenna. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of a measurement antenna and a measurement system including the same according to the present invention will be described with reference to the drawings. Note that the dimensional ratios of the components in the drawings do not necessarily match the actual dimensional ratios.

[0024] (First embodiment) FIG. 1 is a side view showing an example of the basic configuration of a measurement antenna 10 according to a first embodiment of the present invention.

[0025] The measurement antenna 10 comprises a ground plate 11 which is a flat conductor, a U-shaped antenna element 20 fed from a feed point 12, and radio wave absorbers 25 and 26 mounted on the antenna element 20. The ground plate 11, feed point 12, and antenna element 20 form a monopole antenna.

[0026] The antenna element 20 has a first conductor plate 21, a second conductor plate 22, and a third conductor plate 23. The first conductor plate 21, the second conductor plate 22, and the third conductor plate 23 are formed, for example, by bending a single metal plate into a U-shape.

[0027] The first conductor plate 21 is a flat conductor having a substantially rectangular shape, and is fed by a coaxial cable at a feeding point 12. The first conductor plate 21 and the second conductor plate 22 share one side in the width direction (y direction), and the second conductor plate 22 is disposed at an angle of approximately 90 degrees relative to the first conductor plate 21.

[0028] The second conductor plate 22 is a substantially rectangular flat conductor, and as described above, shares one widthwise side with the first conductor plate 21 and is disposed at an angle of approximately 90 degrees relative to the first conductor plate 21. The second conductor plate 22 faces the ground plate 11 in parallel.

[0029] The third conductor plate 23 is a substantially rectangular flat conductor that shares one of the two widthwise sides of the second conductor plate 22 that is not shared with the first conductor plate 21, and is disposed at an angle of approximately 90 degrees relative to the second conductor plate 22. The third conductor plate 23 faces the first conductor plate 21 in parallel.

[0030] If the operating frequency band of the measurement antenna 10 is, for example, FR1 600 MHz to 7.125 GHz, then a metal plate 2 cm wide, 15 cm long, and 0.5 mm thick can be bent so that the length of the first conductor plate 21 in the x direction is 6 cm, the length of the second conductor plate 22 in the z direction is 3 cm, and the length of the third conductor plate 23 in the x direction is 6 cm.

[0031] The radio wave absorber 25 is mounted on an upper surface 23a of the third conductor plate 23 facing the first conductor plate 21. The radio wave absorber 25 attenuates radiation waves due to the current I3 flowing through the third conductor plate 23, and suppresses interference with radiation waves due to the current I1 flowing through the first conductor plate 21.

[0032] However, it is desirable to provide a gap between the lower surface 21b of the first conductor plate 21 and the upper surface 25a of the radio wave absorber 25 in order to prevent the radiation wave due to the current I1 flowing through the first conductor plate 21 from being attenuated.

[0033] Furthermore, if a radio wave absorber 26 is mounted on the lower surface 23b of the third conductor plate 23 opposite to the upper surface 23a facing the first conductor plate 21, it is possible to more effectively attenuate the radiation waves due to the current I3 flowing through the third conductor plate 23. Alternatively, the entire periphery of the third conductor plate 23 may be covered with a radio wave absorber.

[0034] Here, upper surface 21a of first conductor plate 21 opposite to lower surface 21b facing radio wave absorber 25 is arranged close to antenna 210 of UE 200, which is the device under test. As a result, antenna 210 of UE 200 and antenna element 20 are spatially coupled.

[0035] 2 and 3 show a more detailed configuration example of the measurement antenna 10. Fig. 2 is a perspective view showing the external structure of the measurement antenna 10. Fig. 3 is a cross-sectional view of the measurement antenna 10.

[0036] As shown in Figures 2 and 3, the measurement antenna 10 is configured such that a ground plate 11, a feeding point 12, an antenna element 20, and radio wave absorbers 25 and 26 are housed in an antenna housing 30 made of a dielectric material.

[0037] The metal plates that form the first conductive plate 21, the second conductive plate 22, and the third conductive plate 23 are made of, for example, copper, aluminum, brass, or gold.

[0038] The ground plate 11 has a hole for inserting an SMA (Sub Miniature Type A) coaxial connector 13. The SMA coaxial connector 13 has a center conductor 14, a dielectric 15 surrounding the center conductor 14, and an outer conductor 16 surrounding the dielectric 15.

[0039] Dielectric 15 of SMA coaxial connector 13 is inserted into a hole provided in ground plate 11, and the tip portion of center conductor 14 is soldered to first conductive plate 21. The point where first conductive plate 21 and center conductor 14 are electrically connected by soldering forms feed point 12. Outer conductor 16 is electrically connected to ground plate 11.

[0040] A coaxial cable (not shown) is connected to the SMA coaxial connector 13, and power is supplied to the feeding point 12 of the first conductive plate 21 from a measuring device (described later) via this coaxial cable.

[0041] The radio wave absorbers 25 and 26 are adhered to the antenna element 20 and the antenna housing 30 surrounding the periphery of the antenna element 20 with double-sided tape or the like. The radio wave absorber 25 is placed so as to cover the entire upper surface 23a of the third conductor plate 23. The radio wave absorber 26 is placed in the space between the bottom surface of the antenna housing 30 and the lower surface 23b of the third conductor plate 23 so as to cover the entire lower surface 23b of the third conductor plate 23.

[0042] Spacers 27, 28 made of a low dielectric constant material such as polystyrene foam are inserted in the gap between the upper surface 21a of the first conductive plate 21 and the lower surface 31b of the upper wall 31 of the antenna housing 30, and in the gap between the lower surface 21b of the first conductive plate 21 and the upper surface 25a of the radio wave absorber 25. These spacers 27, 28 suppress vibration of the antenna element 20 due to external vibrations, etc., and prevent load from being applied to the soldered portion between the center conductor 14 of the SMA coaxial connector 13 and the first conductive plate 21.

[0043] As described above, the measurement antenna 10 according to this embodiment has a configuration in which a plate-shaped monopole antenna is bent, and the radio wave absorber 25 is loaded on the third conductor plate 23 located at the farthest position from the antenna 210 of the UE 200. The measurement antenna 10 according to this embodiment configured in this manner achieves miniaturization and a wide bandwidth, and can ensure a sufficient amount of power that can be transmitted to and received from the UE 200.

[0044] Furthermore, in the measurement antenna 10 of this embodiment, when the length of the first conductor plate 21 and the third conductor plate 23 is 6 cm and the length of the second conductor plate 22 is 3 cm, the FR1 frequency band of 600 MHz to 7.125 GHz can be used as the frequency band.

[0045] (Second embodiment) Next, a measurement system according to a second embodiment of the present invention will be described with reference to the drawings. Note that the same components as those in the first embodiment are denoted by the same reference numerals and their descriptions will be omitted as appropriate. Also, the same operations as those in the first embodiment will be omitted as appropriate.

[0046] FIG. 4 is a block diagram showing the configuration of a measurement system 100 of this embodiment that uses a plurality of measurement antennas 10 of the first embodiment.

[0047] 4, measurement system 100 of this embodiment inputs a test signal to UE 200 having multiple antennas 210, analyzes a signal under test output from UE 200, and performs various tests such as a protocol test and a throughput test. For example, measurement system 100 includes a measurement device 40, a display device 48, an operation device 49, and a shielding box 50.

[0048] The UE 200 is a wireless terminal such as a smartphone that can transmit and receive wireless signals in the FR1 frequency band, and is a UE that is capable of at least MIMO communication.

[0049] In Figure 4, the shield box 50 accommodates a UE 200 having, for example, four antennas 210 and, for example, four measurement antennas 10 inside the box (internal space) while blocking (shielding) the intrusion of electromagnetic waves into the internal space from the outside, and provides an OTA test environment through spatial coupling between each antenna 210 of the UE 200 and each measurement antenna 10.

[0050] As shown in FIG. 4, the measurement device 40 includes a signal transmitting unit 41, a signal receiving unit 42, an analysis processing unit 43, an input / output interface (I / F) unit 44, and a test control unit 45.

[0051] The signal transmitting unit 41 outputs a test signal to the UE 200 housed in the shield box 50 via the measurement antenna 10 and the antenna 210 of the UE 200 .

[0052] The signal receiving unit 42 receives the signal under measurement output from the UE 200 to which the test signal has been input, via the antenna 210 of the UE 200 and the measurement antenna 10.

[0053] The analysis processing unit 43 performs analysis processing on the signal under measurement received by the signal receiving unit 42 in accordance with various tests such as a protocol test and a throughput test.

[0054] The test signal includes a control signal for performing various controls corresponding to the communication standard of the UE 200, such as putting the UE 200 into a call connection state with respect to the measurement system 100 of this embodiment. The signal under measurement is a response signal from the UE 200 in response to the test signal output from the measurement system 100 of this embodiment, or a transmission signal output from the UE 200 regardless of the test signal.

[0055] The input / output I / F unit 44 is a wideband directional coupler that passes the output frequency of the test signal output from the signal transmitting unit 41, and is configured, for example, by a Wilkinson type splitter. The input / output I / F unit 44 is connected to a connector unit 56 (see FIG. 5) provided in the shielding box 50 via a coaxial cable 46.

[0056] Furthermore, the connector unit 56 is connected to the measurement antenna 10 installed in the shielding box 50 via a coaxial cable 57. That is, the input / output I / F unit 44 is capable of inputting the test signal output from the signal transmitting unit 41 to the measurement antenna 10 via the coaxial cable 46, the connector unit 56, and the coaxial cable 57, and inputting the signal under measurement from the UE 200 that has received the test signal at the antenna 210 to the signal receiving unit 42.

[0057] The test control unit 45 is composed of a control device such as a computer including, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field Programmable Gate Array), a ROM (Read Only Memory), a RAM, and an HDD (Hard Disk Drive), and controls the operation of each of the above-mentioned components that make up the measuring device 40.

[0058] The test control unit 45 controls the signal transmitting unit 41 and the signal receiving unit 42 to perform 4x4 MIMO communication between each antenna element 20 of the four measurement antennas 10 and the four antennas 210 of the UE 200.

[0059] The operation device 49 is used to accept operation inputs from the user, and is composed of user interfaces such as operation knobs, various keys, switches, buttons, and soft keys on the display screen of the display device 48. The operation device 49 also sets various settings related to various tests such as protocol tests and throughput tests, and various measurement conditions on the setting screen.

[0060] The display device 48 is configured with a display device such as an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube), and displays a setting screen, a measurement result screen, etc. based on a display control signal from the test control unit 45. The display device 48 may also have an operation function of an operation device 49 such as soft keys on the display screen.

[0061] Next, we will explain the configuration of the shielding box 50. Figures 5(a) and (b) are diagrams showing the external structure of the shielding box 50 in this embodiment, where Figure 5(a) is a perspective view seen from the front side and Figure 5(b) is a perspective view seen from the back side.

[0062] 5(a) and 5(b), the shielding box 50 has a rectangular parallelepiped shape with one side open, a housing main body 51 with an internal space, and a lid 53 that is supported on the housing main body 51 via a hinge 52 and can open and close the opening. A fastener 54 is provided on the outer surface of the housing main body 51 to prevent the closed lid 53 from opening. The housing main body 51 and the lid 53 are made of a conductive metal such as iron, stainless steel, aluminum, copper, brass, or an alloy of these.

[0063] Figures 6 to 11 are diagrams showing the internal structure of the shielding box 50. Figures 7 to 11 show the internal structure of the shielding box 50 with the lid 53 removed.

[0064] 6 and 7, etc., the shielding box 50 has a radio wave absorber 55 attached to the inner surface, i.e., the bottom surface 51a and side wall surfaces 51b of the housing main body 51, and the inner surface (not shown) of the lid 53. The radio wave absorber 55 absorbs electromagnetic waves generated by the antenna 210 of the UE 200 or the measurement antenna 10 when the lid 53 is closed, and prevents the waves from leaking to the outside.

[0065] 6 and 7, the shielding box 50 is provided with a plurality of support columns 60 and a UE tray installation member 61 on the bottom surface 51a of the housing main body 51. The shielding box 50 also has a lower partition plate 62 through which the support columns 60 pass and which is arranged horizontally relative to the bottom surface 51a of the housing main body 51.

[0066] The support columns 60 are made of cylindrical resin members, and are arranged vertically and horizontally at predetermined intervals on the bottom surface 51a of the housing main body 51. The lower partition plate 62 is arranged to cover the bottom surface 51a of the housing main body 51.

[0067] 6 and 8, an antenna tray 63 for installing multiple measurement antennas 10 is installed above the lower partition plate 62. The antenna tray 63 is fixed so that its upper surface 63a is horizontal with respect to the bottom surface 51a of the housing main body 51, with its lower surface 63b inserted into the tip of the support 60. The antenna tray 63 constitutes the antenna installation section of the present invention.

[0068] The antenna tray 63 is made of a foam material such as polystyrene foam to prevent electromagnetic waves emitted from the antenna 210 of the UE 200 and the measurement antenna 10 from being reflected inside the shield box 50 during an OTA test of the UE 200.

[0069] Furthermore, grids are printed on the top surface 63a of the antenna tray 63 to serve as a guide for the installation position of the measurement antenna 10. These grids make it easy to install the measurement antenna 10 in the desired installation position, and make it easy to reproduce tests under the same conditions.

[0070] As shown in FIGS. 6 and 9, the plurality of measurement antennas 10 are placed on an upper surface 63 a of an antenna tray 63 .

[0071] 9 to 11, the UE tray 64 is used to place the UE 200 in a horizontal position, and is placed so as to contact the upper surface 61a of the UE tray placement member 61 and the upper surface 31a of each measurement antenna 10 placed on the antenna tray 63. The UE tray 64 is made of a transparent material, such as acrylic, that has radio wave permeability so that the position of the measurement antenna 10 can be seen when the user places the UE 200. The UE tray 64 constitutes the DUT placement section of the present invention.

[0072] The UE tray installation member 61 is a cylindrical member made of resin. Five UE tray installation members 61 are provided along the surface of the radio wave absorber 55 in the internal space of the housing main body 51. A notch 61b is formed at the upper end of the UE tray installation member 61 to receive the UE tray 64 so that horizontal movement of the UE tray 64 is restricted.

[0073] 11, the UE 200 is placed on the upper surface 64a of the UE tray 64. The upper surface 64a of the UE tray 64 has a grid printed thereon similar to that of the antenna tray 63, in consideration of the reproducibility of the placement position of the UE 200.

[0074] Within the shielding box 50, the distance from the upper surface 21a of the first conductor plate 21 of the measurement antenna 10 to the lower surface of the UE 200 (i.e., the distance to the upper surface 64a of the UE tray 64) is 9 mm, for example, when the thickness of the spacer 27 is 3 mm, the thickness of the upper wall 31 of the antenna housing 30 is 3 mm, and the thickness of the UE tray 64 is 3 mm.

[0075] Ideally, the upper surface 61a of the UE tray mounting member 61 and the upper surface 31a of the measurement antenna 10 are all at the same height. However, in reality, due to manufacturing tolerances, the upper surface 31a of the measurement antenna 10 is often slightly higher than the upper surface 61a of the UE tray mounting member 61. In such cases, the UE tray 64 does not come into contact with the upper surface 61a of the UE tray mounting member 61, and the cutout portion 61b simply serves to position the UE tray 64.

[0076] 12(a), if the positions of the UE 200 and the measurement antenna 10 are significantly misaligned in the horizontal direction, the UE tray 64 may be distorted depending on the weight of the UE 200. In this way, if the weight of the UE 200 cannot be supported by the UE tray 64, a dummy antenna 220 can be installed between the antenna tray 63 and the UE tray 64 directly below the UE 200, as shown in FIGS.

[0077] The dummy antenna 220 is made of a foam material such as polystyrene foam and has the same height as the measurement antenna 10, so that the UE tray 64 can be prevented from being distorted by the weight of the UE 200.

[0078] Next, an example of the process of a measurement method using the measurement system 100 according to this embodiment will be described with reference to the flowchart of FIG.

[0079] First, as shown in FIG. 8, the antenna tray 63 is attached to the support 60 (step S1).

[0080] Next, as shown in Fig. 9, four measurement antennas 10 are placed on the upper surface 63a of the antenna tray 63 (step S2). At this time, although not shown in Fig. 9, the SMA coaxial connector 13 of each measurement antenna 10 is connected to the connector section 56 with a coaxial cable 57, and the connector section 56 is connected to the input / output I / F section 44 of the measurement device 40 with a coaxial cable 46.

[0081] 10, the UE tray 64 is placed on the upper surface 31a of the four measurement antennas 10 (step S3). At this time, the dummy antenna 220 is inserted between the antenna tray 63 and the UE tray 64 as needed.

[0082] Next, as shown in FIG. 11, the UE 200 is placed on the upper surface 64a of the UE tray 64 (step S4).

[0083] Next, the lid 53 is closed on the housing main body 51, and the lid 53 is fastened with the fastener 54 (step S5). As a result, the UE 200 and the multiple measurement antennas 10 are sealed in the shielding box 50 so as to block the intrusion of external electromagnetic waves into the internal space of the housing main body 51, and the UE 200 is ready for testing.

[0084] After the test preparation is complete, in response to a predetermined test start operation by the user, the signal transmitting unit 41 of the measuring device 40 outputs a test signal to the UE 200 via the measuring antenna 10 and the antenna 210 of the UE 200 (signal transmitting step S6).

[0085] Next, the signal receiving unit 42 of the measurement device 40 receives the signal under measurement output from the UE 200 to which the test signal has been input, via the antenna 210 of the UE 200 and the measurement antenna 10 (signal receiving step S7).

[0086] Next, the analysis processing unit 43 of the measurement device 40 performs an analysis process corresponding to the communication standard of the UE 200 on the signal under measurement received in the signal receiving step S7 (analysis process step S8).

[0087] As described above, the measurement system 100 according to this embodiment uses a plurality of small measurement antennas 10, and is therefore capable of performing MIMO communication in close proximity to the antenna 210 of the UE 200.

[0088] Furthermore, in the measurement system 100 of this embodiment, grids are printed on the upper surface 63a of the antenna tray 63 and the upper surface 64a of the UE tray 64, so that the measurement antenna 10 and the UE 200 can be easily installed in the desired installation positions. [Explanation of symbols]

[0089] 10 Measurement antenna 11 Ground plate 12 Power supply point 13 SMA coaxial connector 14 Center conductor 15 Dielectrics 16 Outer conductor 20 antenna elements 21 First conductor plate 21a Top side 21b Bottom side 22 Second conductor plate 23 Third conductor plate 23a Top side 25,26 Radio wave absorber 27,28 Spacer 30 Antenna housing 40 Measuring Equipment 50 Shield Box 60 pillars 61 UE tray installation material 61a Top side 61b Notch 63 Antenna tray 63a top surface 64 UE Tray 64a top surface 100 Measurement System 200 UE 210 Antenna

Claims

1. The antenna device comprises a ground plate (11), an antenna element (20) having a U-shape, and radio wave absorbers (25, 26) loaded on the antenna element, The antenna element is a substantially rectangular first conductor plate (21) fed at a feeding point (12); a second conductor plate (22) having a substantially rectangular shape, which shares one side in the width direction with the first conductor plate and is disposed at an angle of approximately 90 degrees to the first conductor plate; a third conductor plate (23) of a substantially rectangular shape that faces the first conductor plate substantially parallel to the first conductor plate, shares one side in the width direction with the second conductor plate, and is disposed at an angle of approximately 90 degrees to the second conductor plate; the wave absorber is mounted on at least a surface (23 a) of the third conductor plate facing the first conductor plate, A measurement antenna characterized in that a surface (21a) of the first conductor plate opposite to a surface (21b) facing the radio wave absorber is arranged close to an antenna (210) of an object to be measured (200), and the antenna of the object to be measured and the antenna element are spatially coupled.

2. 2. The measurement antenna according to claim 1, wherein the first and third conductor plates have a length of 6 cm, and the second conductor plate has a length of 3 cm.

3. A measurement system (100) using a plurality of measurement antennas according to claim 1 or 2, A measurement system characterized in that MIMO communication is performed between each of the antenna elements of each of the measurement antennas and a plurality of antennas of the device under test.

4. 4. The measurement system according to claim 3, further comprising a shield box (50) that houses the plurality of measurement antennas and the object to be measured and blocks electromagnetic waves from entering from outside.

5. an antenna installation section (63) for installing a plurality of the measurement antennas; a device under test (DUT) installation section (64) for installing the device under test, which is installed on the plurality of measurement antennas, is further accommodated in the shielding box; 5. The measurement system according to claim 4, wherein grids are printed on the upper surface (63a) of the antenna installation portion and the upper surface (64a) of the object to be measured installation portion.

Images