阅读说明：本技术 试验装置及试验方法 (Test apparatus and test method ) 是由 丸尾友彦 马场宽之 于 2021-05-20 设计创作，主要内容包括：本发明提供一种能够以高精度且低成本来执行关于被试验对象的RF特性或RRM特性等收发特性的远场测量的试验装置。一种试验装置,其具备：试验用天线,设置于OTA暗室(50)内,并且在与DUT(100)的天线(110)之间发送或接收无线信号；及测量装置,使用试验用天线对配置于空白区(QZ)内的DUT(100)进行DUT(100)的发送特性或接收特性的测量,试验用天线包含经由反射器(7)在与DUT的天线(110)之间发送或接收无线信号的反射器反射型试验用天线(6a)及经由反射镜(9b……9f)在与DUT的天线(110)之间发送或接收无线信号的反射镜反射型试验用天线(6b、6c、6d、6e、6f)。(The invention provides a test apparatus capable of performing far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object with high accuracy and low cost. A test apparatus is provided with: a test antenna which is provided in the OTA darkroom (50) and transmits or receives a wireless signal to or from an antenna (110) of the DUT (100); and a measuring device for measuring the transmission characteristics or reception characteristics of the DUT (100) placed in the blank space (QZ) using test antennas including a reflector reflection type test antenna (6a) for transmitting or receiving a radio signal to or from the antenna (110) of the DUT via a reflector (7) and mirror reflection type test antennas (6b, 6c, 6d, 6e, 6f) for transmitting or receiving a radio signal to or from the antenna (110) of the DUT via a mirror (9b … … 9 f).)

1. A test apparatus for measuring transmission characteristics or reception characteristics of a test object (100) having a test antenna (110), the test apparatus (1) comprising:

a anechoic box (50) having an internal space (51) that is not affected by the surrounding electric wave environment;

a test antenna (6) which is provided in the internal space and transmits or receives a radio signal to or from the antenna to be tested;

a reflector (7) disposed within the interior space and reflecting the wireless signal;

1 or more mirrors (9b, 9c, 9d, 9e, 9f) disposed in the internal space and reflecting the wireless signal; and

a measuring device (2) for measuring the transmission characteristic or the reception characteristic of the object to be tested, which is disposed in the blank space (QZ) of the internal space, by using the antenna for testing,

the test antenna includes a reflector reflection type test antenna (6a) for transmitting or receiving the radio signal to or from the test antenna via the reflector, and a mirror reflection type test antenna (6b, 6c, 6d, 6e, 6f) for transmitting or receiving the radio signal to or from the test antenna via at least 1 of the 1 or more mirrors.

2. The test device according to claim 1,

the plurality of mirrors that reflect the wireless signal from the mirror reflection type test antenna are arranged so as to form different arrival angles with reference to the arrival direction of the radio wave from the reflector reflection type test antenna at the arrangement position (P0) of the test object.

3. The test device according to claim 1,

there are a plurality of the mirrors arranged such that each mirror surface intersects with 1 plane passing through the arrangement position (P0) of the test object.

4. The test device according to claim 1,

the 1 or more mirrors include a 1 st mirror (9b), a2 nd mirror (9c), a 3 rd mirror (9d), a 4 th mirror (9e), and a 5 th mirror (9f), and the mirror reflection type test antenna includes a 1 st test antenna (6b) that transmits and receives the radio signal via the 1 st mirror, a2 nd test antenna (6c) that transmits and receives the radio signal via the 2 nd mirror, a 3 rd test antenna (6d) that transmits and receives the radio signal via the 3 rd mirror, a 4 th test antenna (6e) that transmits and receives the radio signal via the 4 th mirror, and a 5 th test antenna (6f) that transmits and receives the radio signal via the 5 th mirror.

5. The test device according to claim 1,

the test apparatus further includes a plurality of the reflecting mirrors: and a direction changing device (60) for changing the radio wave transmission direction of the reflecting type test antenna of the reflecting mirror in a manner of facing 1 of the plurality of reflecting mirrors.

6. The test device of claim 5,

the 1 or more mirrors include a 1 st mirror (9b), a2 nd mirror (9c), a 3 rd mirror (9d), a 4 th mirror (9e), and a 5 th mirror (9f), and the mirror reflection type test antenna includes a test antenna (6g) that transmits and receives the radio signal via 1 mirror selected from the plurality of mirrors by the direction changing device.

7. The test device according to claim 1,

the distance from the reflecting mirror type test antenna to the tested antenna through the corresponding reflecting mirror is larger than 2D²λ, where D is the antenna size of the antenna to be tested, and λ is for the test of reflection type from the reflectorThe wavelength of the radio wave transmitted by the antenna.

8. Testing device according to claim 1,

the reflector has a reflecting surface curved in a curved surface shape, and the reflecting mirror has a flat mirror surface.

9. Testing device according to any of claims 1 to 8,

the reflector-reflex test antenna is arranged at the focal position F of the reflector,

the test apparatus converts an electric wave of a spherical wave emitted from the reflector reflection type test antenna into an electric wave of a plane wave and transmits the electric wave to the test object, and converges an electric wave of a plane wave emitted from the test object and incident on the reflector on the test antenna.

10. A test method using a test apparatus (1) for measuring a transmission characteristic or a reception characteristic of a test object (100) having a test antenna (110),

the test device is provided with:

a anechoic box (50) having an internal space (51) that is not affected by the surrounding electric wave environment;

a test antenna (6) which is provided in the internal space and transmits or receives a radio signal to or from the antenna to be tested;

a reflector (7) disposed within the interior space and reflecting the wireless signal;

1 or more mirrors (9b, 9c, 9d, 9e, 9f) disposed in the internal space and reflecting the wireless signal; and

a measuring device (2) for measuring the transmission characteristic or the reception characteristic of the object to be tested, which is disposed in the blank space (QZ) of the internal space, by using the antenna for testing,

the antenna for test includes a reflector reflection type antenna for test (6a) for transmitting or receiving the radio signal between the antenna for test and the reflector and a mirror reflection type antenna for test (6b, 6c, 6d, 6e, 6f) for transmitting or receiving the radio signal between the antenna for test and the reflector for test through at least 1 of the 1 or more mirrors,

the trial comprises: selecting a test antenna to be used from the test antennas; sequentially changing the posture of the test object placed in the blank area; and a step of measuring the transmission characteristic or the reception characteristic of the object to be tested by using the selected antenna for testing every time the posture of the object to be tested changes.

Technical Field

The present invention relates to a test apparatus and a test method for measuring a transmission characteristic or a reception characteristic of a test object using an electric wave dark box in an OTA (Over The Air) environment.

Background

In recent years, with the development of multimedia, wireless terminals (smartphones and the like) equipped with antennas for wireless communication such as cellular and wireless LAN have been mass-produced. In the future, wireless terminals that transmit and receive wireless signals corresponding to ieee802.11ad, 5G cellular, and the like, which use wideband signals in the millimeter wave band, are particularly required.

In a design and development company of a wireless terminal or a manufacturing factory thereof, a performance test is performed in which an output level and a reception sensitivity of a transmission Radio wave set for each communication standard are measured for a wireless communication antenna provided in the wireless terminal, and whether or not these RF (Radio Frequency) characteristics satisfy a predetermined standard is determined. In the performance test, RRM (Radio Resource Management) characteristics are also measured. The RRM characteristics are measured to confirm whether or not radio resource control between the base station and the radio terminal, for example, handover between adjacent base stations, is operating normally.

The test methods of the above performance tests are also changing with 4G or the evolution from 4G to 5G. For example, in a performance Test in which a wireless terminal for a 5G NR (New Radio) system (hereinafter, referred to as a 5G wireless terminal) is a Device Under Test (DUT), a method of connecting an antenna terminal of a DUT and a Test apparatus by wire, which is mainstream in a Test of 4G or 4G evolution, cannot be used because of a characteristic deterioration due to mounting of the antenna terminal in a high-frequency circuit, a large number of elements of an array antenna, unrealistic mounting of the antenna terminal to all elements, and the like, from a space aspect and a cost aspect. Therefore, the DUT is housed in a radio-controlled box that is not affected by the surrounding radio environment together with the test antenna, and a so-called OTA test is performed by transmitting a test signal from the test antenna to the DUT and receiving a measurement signal from the DUT that has received the test signal by the test antenna through wireless communication (see, for example, patent documents 1 and 2).

In the OTA test, a blank area is formed by the test antenna, and the DUT is placed in the blank area. Here, the blank zone (quick zone) is a concept of a range in which a space region of the DUT is irradiated with a radio wave having a substantially uniform amplitude and phase from the test antenna in a radio wave bellows constituting the OTA test environment (for example, refer to non-patent document 1). Typically, the blank space is spherical in shape. By disposing the DUT in such a blank area, OTA testing can be performed while suppressing the influence of scattered waves from the surroundings.

Patent document 1: japanese patent application 2018-223942

Patent document 2: US2019/0302184

Non-patent document 1: 3GPP TR38.810 V16.2.0(2019-03)

In the test apparatus described in patent document 2, a plurality of test antennas capable of transmitting and receiving signals to and from the antennas to be tested of the DUT are provided in a radio wave box, and the RF characteristics or RRM characteristics of the DUT are measured. In the measurement of the RF characteristics or the RRM characteristics, far Field measurement (ffm) is generally used. In the test antenna of patent document 2, reflectors having curved reflecting surfaces are provided, and a radio wave emitted from the test antenna is reflected toward the DUT or a radio wave emitted from the DUT is reflected toward the test antenna. However, in the test apparatus described in patent document 2, since reflectors are provided in each of all the test antennas, the structure is complicated, and a mechanism for moving the test antennas is further provided. Therefore, a large anechoic chamber and a large installation area for installing the anechoic chamber are required.

Disclosure of Invention

The present invention has been made to solve the above conventional problems, and an object thereof is to provide a test apparatus and a test method capable of performing far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object with high accuracy and at low cost.

In order to solve the above problem, a test apparatus according to the present invention measures transmission characteristics or reception characteristics of a test object 100 having a test antenna 110, the test apparatus 1 including: a anechoic chamber 50 having an internal space 51 not affected by the surrounding radio wave environment; a test antenna 6 which is provided in the internal space and transmits or receives a radio signal to or from the antenna to be tested; a reflector 7 disposed in the inner space and reflecting the wireless signal; 1 or more reflection mirrors 9b, 9c, 9d, 9e, 9f provided in the internal space and reflecting the wireless signal; and a measuring device 2 for measuring a transmission characteristic or a reception characteristic of the object to be tested disposed in the blank space QZ of the internal space by using the test antenna including a reflector reflection type test antenna 6a for transmitting or receiving the radio signal to or from the object to be tested via the reflector and mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f for transmitting or receiving the radio signal to or from the object to be tested via at least 1 of the 1 or more mirrors.

As described above, the plurality of test antennas include a reflector reflection type test antenna that transmits or receives a radio signal to or from the antenna to be tested via the reflector, and a mirror reflection type test antenna that transmits or receives a radio signal to or from the antenna to be tested via the mirror. Since the direction of propagation of the electric wave can be changed by the mirror, the distance of propagation of the electric wave can be increased even in a small space limited in the anechoic chamber. This can ensure a distance between the test antenna and the antenna to be tested (hereinafter, also referred to as an inter-antenna distance) required for far-field measurement. Therefore, according to this configuration, the radio wave box can be made smaller and the cost of the test apparatus can be reduced as compared with an apparatus using an antenna of a conventional reflector.

The plurality of test antennas are a hybrid structure including a reflector-type test antenna that indirectly transmits and receives a radio signal using a reflector and a mirror-type test antenna that transmits and receives a radio signal via a mirror. This minimizes the number of reflector reflection type test antennas having a complicated structure, and allows a wider blank space to be used when a reflector reflection type test antenna is used alone, which allows the blank space to be formed relatively wider than a reflector reflection type test antenna. Therefore, the test apparatus according to the present invention can perform far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object with high accuracy and at low cost.

In the test apparatus according to the present invention, the plurality of mirrors that reflect the wireless signal from the mirror reflection type test antenna may be arranged so as to form different arrival angles with reference to the arrival direction of the radio wave from the reflector reflection type test antenna at the arrangement position P0 of the test object.

According to this configuration, since the arrival angle of the combination of the reflector reflection type test antenna and the reflector reflection type test antenna is different, the test apparatus according to the present invention can effectively perform the far-field measurement of the transmission/reception characteristics such as the RRM characteristics of the object to be tested by changing the arrival angle by switching the reflector reflection type test antenna used together with the reflector reflection type test antenna.

The test apparatus according to the present invention may be configured such that there are a plurality of the mirrors arranged such that the respective mirror surfaces intersect 1 plane passing through the arrangement position P0 of the test object.

With this configuration, the test apparatus according to the present invention can easily perform positioning work when the test apparatus is installed.

The test apparatus according to the present invention may be configured such that the 1 or more mirrors include a 1 st mirror 9b, a2 nd mirror 9c, a 3 rd mirror 9d, a 4 th mirror 9e, and a 5 th mirror 9f, and the mirror reflection type test antenna includes a 1 st test antenna 6b that transmits and receives the radio signal via the 1 st mirror, a2 nd test antenna 6c that transmits and receives the radio signal via the 2 nd mirror, a 3 rd test antenna 6d that transmits and receives the radio signal via the 3 rd mirror, a 4 th test antenna 6e that transmits and receives the radio signal via the 4 th mirror, and a 5 th test antenna 6f that transmits and receives the radio signal via the 5 th mirror.

With this configuration, the test apparatus according to the present invention can easily and individually adjust the distance between the test antenna and the antenna to be tested. Further, 5 arrival angles (for example, 30 °, 60 °, 90 °, 120 °, and 150 °) different from each other can be easily formed with reference to the arrival direction of the radio wave from the reflector reflection type test antenna.

Further, the test apparatus according to the present invention may be configured such that there are a plurality of the mirrors, and the test apparatus further includes: and a direction changing device 60 for changing the radio wave transmission direction of the reflecting type test antenna so as to face 1 of the plurality of mirrors.

With this configuration, the test apparatus according to the present invention can further reduce the cost by sharing 1 mirror reflection type test antenna for a plurality of mirrors and eliminating the need to provide a plurality of mirror reflection type test antennas.

The test apparatus according to the present invention may be configured such that the 1 or more mirrors include a 1 st mirror 9b, a2 nd mirror 9c, a 3 rd mirror 9d, a 4 th mirror 9e, and a 5 th mirror 9f, and the mirror reflection type test antenna includes a test antenna 6g that transmits and receives the radio signal via 1 mirror selected from the plurality of mirrors by the direction changing device.

With this configuration, the test apparatus according to the present invention can easily form 5 arrival angles (for example, 30 °, 60 °, 90 °, 120 °, and 150 °) different from each other with reference to the arrival direction of the radio wave from the reflector reflection type test antenna.

In the test apparatus according to the present invention, the distance from the mirror reflection type test antenna to the antenna under test via the corresponding mirror may be greater than 2D²And λ, where D is the antenna size of the antenna under test, and λ is the wavelength of the radio wave transmitted from the reflecting mirror type test antenna.

With this configuration, in the test apparatus according to the present invention, the antenna to be tested is disposed so as to be separated at least by 2D from the test antenna of the mirror reflection type via the mirror²Therefore, the far-field measurement of the test object can be reliably performed even in a radio wave dark box having a small internal space.

The test apparatus according to the present invention may be configured such that the reflector has a reflecting surface curved in a curved surface shape, and the reflecting mirror has a flat mirror surface.

According to this configuration, in the test apparatus according to the present invention, the direct test antenna is used for an apparatus capable of securing a distance between antennas necessary for far-field measurement, and the mirror reflection type test antenna can be used only for an apparatus incapable of securing a distance between antennas necessary for far-field measurement. This can reduce the number of mirrors.

The test apparatus according to the present invention may be configured such that the reflector-reflection test antenna is disposed at a focal position F of the reflector, converts a spherical wave radio wave emitted from the reflector-reflection test antenna into a plane wave radio wave and transmits the plane wave radio wave to the test object, and the plane wave radio wave emitted from the test object and incident on the reflector is converged on the test antenna.

Further, a test method according to the present invention uses a test apparatus 1 for measuring transmission characteristics or reception characteristics of a test object 100 having a test antenna 110, the test apparatus including: a anechoic chamber 50 having an internal space 51 not affected by the surrounding radio wave environment; a test antenna 6 which is provided in the internal space and transmits or receives a radio signal to or from the antenna to be tested; a reflector 7 disposed in the inner space and reflecting the wireless signal; 1 or more reflection mirrors 9b, 9c, 9d, 9e, 9f provided in the internal space and reflecting the wireless signal; and a measuring device 2 for measuring a transmission characteristic or a reception characteristic of the test object placed in the blank space QZ of the internal space using the test antenna including a reflector reflection type test antenna 6a for transmitting or receiving the radio signal to or from the test antenna via the reflector and mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f for transmitting or receiving the radio signal to or from the test antenna via at least 1 of the 1 or more mirrors, the testing method comprising: selecting a test antenna to be used from the test antennas; sequentially changing the posture of the test object placed in the blank area; and a step of measuring the transmission characteristic or the reception characteristic of the object to be tested by using the selected antenna for testing every time the posture of the object to be tested changes.

As described above, in the test apparatus using the test method according to the present invention, the plurality of test antennas include a reflector-reflection-type test antenna for transmitting or receiving a radio signal to or from the antenna to be tested via the reflector and a mirror-reflection-type test antenna for transmitting or receiving a radio signal to or from the antenna to be tested via the mirror. Since the propagation direction of the electric wave can be changed by the reflecting mirror, the propagation distance of the electric wave can be increased in a limited small space in the anechoic chamber, and thus the distance between the test antenna and the antenna to be tested, which is required for far-field measurement, can be secured. Therefore, a small-sized and low-cost anechoic chamber can be used.

In the test apparatus using the test method, the plurality of test antennas have a hybrid structure including a reflector-reflection-type test antenna that indirectly transmits and receives a radio signal using a reflector and a mirror-reflection-type test antenna that transmits and receives a radio signal via a mirror. This minimizes the number of reflector reflection type test antennas having a complicated structure, and allows a wider blank space to be used when a reflector reflection type test antenna is used alone, which allows the blank space to be formed relatively wider than a reflector reflection type test antenna. Therefore, the test method according to the present invention can perform far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object with high accuracy and at low cost.

Effects of the invention

According to the present invention, it is possible to provide a test apparatus and a test method capable of performing far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object with high accuracy and at low cost.

Drawings

Fig. 1 is a diagram showing a schematic configuration of the entire test apparatus according to embodiment 1 of the present invention.

Fig. 2 is a block diagram showing a functional configuration of a test apparatus according to embodiment 1 of the present invention.

Fig. 3 is a block diagram showing a functional configuration of an integrated control device of a test apparatus according to embodiment 1 of the present invention.

Fig. 4 is a block diagram showing a functional configuration of an NR system simulator of a test apparatus according to embodiment 1 of the present invention.

Fig. 5 is a schematic diagram for explaining the near field and the far field when radio waves propagate between the antenna AT and the wireless terminal.

Fig. 6 is a schematic diagram showing a configuration of a reflector used in the test apparatus according to embodiment 1 of the present invention.

Fig. 7 is a plan view of the test apparatus according to embodiment 1 of the present invention, as viewed from above, with a top plate of the OTA dark room removed.

Fig. 8 is a front view of the OTA darkroom viewed from the front side with the side panel removed.

Fig. 9 is a schematic diagram showing the arrangement of the mirror and the mirror reflection type test antenna in the OTA darkroom.

Fig. 10 is a flowchart schematically showing a test method performed using the test apparatus according to embodiment 1 of the present invention.

Fig. 11 is a front view of the test apparatus according to embodiment 2 of the present invention, viewed from the front side, with a side plate on the front side of the OTA darkroom removed.

Fig. 12 is a schematic diagram showing the arrangement of the mirror and the mirror reflection type test antenna in the OTA darkroom according to embodiment 2.

Fig. 13 is a schematic view showing a mirror and a mirror reflection type test antenna according to embodiment 2.

Fig. 14 is a plan view of the test apparatus according to embodiment 3 of the present invention, as viewed from above, with a top plate of the OTA dark room removed.

Fig. 15 is a front view of the test apparatus according to embodiment 3 of the present invention, viewed from the front side, with a side plate on the front side of the OTA darkroom removed.

Detailed Description

Hereinafter, a test apparatus and a test method according to an embodiment of the present invention will be described with reference to the drawings. The dimensional ratio of each component in each drawing does not necessarily match the actual dimensional ratio.

(embodiment 1)

The test apparatus 1 according to the present embodiment measures transmission characteristics or reception characteristics of the DUT100 having the antenna 110, for example, measures RF characteristics or RRM characteristics of the DUT 100. Therefore, the test apparatus 1 includes an OTA darkroom 50, a plurality of test antennas 6a, 6b, 6c, 6d, 6e, and 6f (hereinafter, sometimes referred to as test antennas 6), a posture varying mechanism 56, an integrated control apparatus 10, an NR system simulator 20, a signal processing unit 40, and a signal switching unit 41. The OTA darkroom 50 of the present embodiment corresponds to the anechoic chamber of the present invention, and the integrated control device 10, the NR system simulator 20, the signal processing unit 40, and the signal switching unit 41 of the present embodiment correspond to the measuring device 2 of the present invention.

Fig. 1 shows an external configuration of the test apparatus 1, and fig. 2 shows functional blocks of the test apparatus 1. Fig. 1 shows an arrangement of components in a state where the OTA darkroom 50 is seen from the front.

As shown in fig. 1 and 2, the OTA darkroom 50 has an internal space 51 that is not affected by the surrounding radio wave environment. The test antenna 6 is provided in the internal space 51 of the OTA darkroom 50, and transmits or receives a wireless signal for measuring a transmission characteristic or a reception characteristic of the DUT100 to or from the antenna 110. The attitude changing mechanism 56 changes the attitude of the DUT100 disposed in the blank area QZ of the internal space 51 of the OTA dark room 50. The integrated control apparatus 10, the NR system simulator 20, the signal processing unit 40, and the signal switching unit 41 measure the transmission characteristics or the reception characteristics of the DUT100 using 1 or 2 test antennas 6 with respect to the DUT100 whose posture has been changed by the posture changing mechanism 56.

The test apparatus 1 is used, for example, with a rack structure 90 having a plurality of racks 90a shown in fig. 1, and is operated such that each component is placed on each rack 90 a. Fig. 1 shows an example in which the integrated control device 10, the NR system simulator 20, and the OTA darkroom 50 are mounted on 3 racks 90a of a rack structure 90. Hereinafter, each constituent element will be described.

(OTA darkroom)

The OTA darkroom 50 realizes an OTA test environment for performing a performance test of the 5G wireless terminal, and is configured by, for example, a metal housing main body 52 having a rectangular parallelepiped inner space 51 as shown in fig. 1 and 2. The OTA darkroom 50 accommodates the DUT100 and the plurality of test antennas 6 facing the antenna 110 of the DUT100 in the internal space 51 in a state where the intrusion of the radio wave from the outside and the radiation of the radio wave to the outside are prevented. As the test antenna 6, a millimeter wave antenna having directivity such as a horn antenna can be used, for example, as will be described later.

Further, the radio wave absorber 55 is attached to the entire inner surface of the OTA darkroom 50, that is, the entire surfaces of the bottom surface 52a, the side surface 52b, and the upper surface 52c of the housing main body 52, thereby securing the noise cancellation property of the inner space and enhancing the radio wave emission limiting function to the outside. In this way, the OTA darkroom 50 realizes a bellows having an inner space 51 which is not affected by the surrounding radiowave environment. The Anechoic (non-reflective) Anechoic chamber is used in the present embodiment, for example.

(DUT)

The DUT100 to be tested is a wireless terminal such as a smartphone, for example. Examples of the communication standard of the DUT100 include cellular (LTE, LTE-A, W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, 1xEV-DO, TD-SCDMA, etc.), wireless LAN (IEEE802.11B/g/a/Wac/ad, etc.), B1 bluetooth (registered trademark), GNSS (GPS, Galileo, GLONASS, BeiDou, etc.), FM, and digital broadcasting (DVB-H, ISDB-T, etc.). The DUT100 may be a wireless terminal that transmits and receives wireless signals of a millimeter wave band corresponding to 5G cellular or the like.

In this embodiment, the DUT100 is a 5G NR wireless terminal. In the 5G NR wireless terminal, a predetermined frequency band including a frequency band used in LTE or the like in addition to the millimeter wave band is defined as a communicable frequency range according to the 5G NR standard. Therefore, the antenna 110 of the DUT100 transmits or receives a radio signal of a predetermined frequency band (5GNR band) as a measurement target of the transmission characteristic or the reception characteristic of the DUT 100. The antenna 110 is an array antenna such as a Massive-MIMO antenna, and corresponds to an antenna to be tested in the present invention.

In the present embodiment, the DUT100 can transmit and receive the test signal and the measured signal through 1 or 2 test antennas selected from the plurality of test antennas 6 in the measurement related to transmission and reception in the OTA darkroom 50.

(posture-variable mechanism)

Next, the posture changing mechanism 56 provided in the internal space 51 of the OTA darkroom 50 will be described. As shown in fig. 1, an attitude changing mechanism 56 for changing the attitude of the DUT100 disposed in the blank space QZ is provided on the bottom surface 52a of the housing main body 52 of the OTA dark room 50 on the side of the internal space 51. The attitude changing mechanism 56 is, for example, a biaxial positioner including a rotation mechanism that rotates about each of 2 axes. The attitude changing mechanism 56 constitutes an OTA test system (Combined-axes system) that rotates the DUT100 with 2 rotational degrees of freedom about the axes in a state in which the test antenna 6 is fixed. Specifically, the posture changing mechanism 56 includes a driving unit 56a, a turntable 56b, a support column 56c, and a DUT placement unit 56d as a test object placement unit.

The driving portion 56a is configured by a driving motor such as a stepping motor that generates rotational driving force, and is provided on the bottom surface 52a, for example. The turntable 56b is rotated by a predetermined angle about 1 of 2 axes orthogonal to each other by the rotational driving force of the driving section 56 a. The support column 56c is coupled to the turntable 56b, extends in the direction of 1 axis from the turntable 56b, and rotates together with the turntable 56b by the rotational driving force of the driving portion 56 a. The DUT placement section 56d extends from the side surface of the support column 56c in the direction of the other 1 of the 2 axes, and is rotated by a prescribed angle about the other 1 axis by the rotational driving force of the driving section 56 a. The DUT100 is placed on the DUT placing part 56 d.

The 1-axis is, for example, an axis (Y-axis in the drawing) extending in the vertical direction with respect to the bottom surface 52 a. The other 1 axis is, for example, an axis extending in the horizontal direction from the side surface of the pillar 56 c. The attitude changing mechanism 56 configured as described above can rotate the DUT100 held by the DUT mounting unit 56d such that, for example, the attitude of the antenna 110 can be sequentially changed in all three-dimensional directions with respect to the test antenna 6 and the reflector 7, with the center of the DUT100 as the center of rotation (also referred to as "arrangement position").

In the OTA test system, the center of the DUT100 or the center of the antenna 110 is arranged at the rotation center (also referred to as the origin) which is the intersection of the 2 rotation axes of the posture varying mechanism 56. The "configuration position P0" of the DUT100 is the origin of the OTA test system and is the position of the center of the DUT100 or the center of the antenna 110 disposed within the OTA darkroom 50. That is, the arrangement position P0 of the DUT100 corresponds to the stationary rotation center when the DUT100 is rotated around 2 axes by the posture varying mechanism 56. When the position and the antenna size of the antenna 110 in the DUT100 are known, the distance from the test antenna 6 to the antenna 110 required to form a far field can be significantly reduced by setting the placement position P0 of the DUT100 to the center of the antenna 110.

(Link antenna)

In the OTA darkroom 50, two kinds of link antennas 5, 8 for establishing or maintaining a link (call) with the DUT100 are mounted at desired positions of the frame body part 52 using holders 57, 59, respectively. The link antenna 5 is a link antenna for LTE and is used in a Non-Standalone mode (Non-standard mode). On the other hand, the link antenna 8 is a 5G link antenna for maintaining a 5G call. The link antennas 5 and 8 are held by the holders 57 and 59, respectively, so as to have directivity with respect to the DUT100 held by the posture varying mechanism 56. Note that, instead of using the link antennas 5 and 8, the test antenna 6 can also be used as a link antenna, and therefore, the following description will be given taking as an example a function in which the test antenna 6 also serves as a link antenna.

(near field and far field)

Next, the near field and the far field will be described. Fig. 5 is a schematic diagram showing a propagation system of radio waves emitted from the antenna AT toward the radio terminal 100A. The antenna AT is equal to the test antenna 6a or the mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f, which are primary radiators described later. The wireless terminal 100A is identical to the DUT 100. In fig. 5, fig. 5(a) shows a DFF (Direct Far Field) mode in which an electric wave directly propagates from the antenna AT to the wireless terminal 100A, and fig. 5(b) shows an IFF (Indirect Far Field) mode in which an electric wave propagates from the antenna AT to the wireless terminal 100A via the reflecting mirror 7A having a paraboloid of revolution.

As shown in fig. 5(a), the radio wave using the antenna AT as a radiation source has a property that a plane (wave surface) in which points of the same phase are connected spreads while being spherically around the radiation source. At this time, as shown by the broken line, an interference wave due to interference such as scattering, refraction, and reflection is also generated. Further, the wave surface is a curved spherical surface (spherical wave) at a short distance from the radiation source, but approaches a plane (plane wave) as the distance from the radiation source increases. In general, a region where the wave surface needs to be considered as a spherical surface is called a near FIELD (NEAR FIELD), and a region where the wave surface is not considered as a plane is called a FAR FIELD (FAR FIELD). In the propagation of the radio wave shown in fig. 5(a), the radio terminal 100A preferably receives the plane wave rather than the spherical wave in addition to performing accurate measurement.

To receive the plane wave, the wireless terminal 100A needs to be placed in the far field. When the position and size of the antenna 110 within the DUT100 are not known, the far field becomes more than 2D from the antenna AT₀ ²Region of/λ. Here, D₀λ is the wavelength of the radio wave, which is the maximum linear dimension of the wireless terminal 100A.

Specifically, for example, when the maximum linear dimension of the wireless terminal 100A is D₀When the frequency of the radio wave is 43.5GHz AT 0.2m, the position 11.6m from the antenna AT is a boundary between the near field and the far field, and the wireless terminal 100A needs to be placed AT a position farther than this.

On the other hand, when the position and the antenna size of the antenna 110 within the DUT100 are known, the far field becomes more than 2D from the antenna AT²Region of/λ. Here, D is the antenna size, and λ is the wavelength of the radio wave.

Specifically, for example, when the antenna size of the wireless terminal 100A is D0.03 m and the frequency of radio waves is 43.5GHz, the position 26.2cm from the antenna AT is a boundary between the near field and the far field, and the wireless terminal 100A needs to be placed AT a position farther than this. For example, when the antenna size D of the wireless terminal 100A is 0.04m and the frequency of radio waves is 43.5GHz, a position 46.5cm from the antenna AT is a boundary between the near field and the far field.

In the present embodiment, the maximum linear dimension D of the target DUT100 is, for example, about 20cm, and the frequency range used is assumed to be 24.25GHz to 43.5 GHz.

Fig. 5 b shows a method (castr (Compact Antenna Test Range) method) in which the reflector 7A having a paraboloid of revolution is disposed so as to reflect the radio wave of the Antenna AT and make the reflected wave reach the position of the wireless terminal 100A. According to this method, the distance between the antenna AT and the wireless terminal 100A can be shortened, and the area of the plane wave is expanded from the straight distance after reflection in the mirror surface of the mirror 7A, so the effect of reducing the propagation loss can also be expected. The degree of the plane wave can be expressed by the phase difference of the waves in the same phase. The allowable phase difference is λ/16, for example, as the degree of the plane wave. The phase difference can be evaluated by a Vector Network Analyzer (VNA), for example.

(test antenna)

Next, the test antenna 6 will be described.

Fig. 7 is a plan view of the test apparatus 1 according to the present embodiment, as viewed from above with the top plate of the OTA dark room 50 removed, and fig. 8 is a front view of the test apparatus 1 as viewed from the front side with the side plate on the front side (the lower side plate in fig. 7) removed from the OTA dark room 50.

As shown in fig. 7 and 8, the test antenna 6 includes 1 reflector reflection type test antenna 6a and 5 reflector reflection type test antennas 6b, 6c, 6d, 6e, and 6 f. The reflector reflection type test antenna 6a transmits or receives a radio signal (hereinafter, also referred to as a measurement radio signal) for measuring a transmission characteristic or a reception characteristic of the DUT100 to or from the antenna 110 via the reflector 7. The mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f transmit or receive radio signals for measuring transmission characteristics or reception characteristics of the DUT100 to/from the antenna 110 provided in the DUT100 via the mirrors 9b, 9c, 9d, 9e, and 9f, respectively. Each test antenna 6 includes a horizontally polarized antenna and a vertically polarized antenna (see fig. 2). Hereinafter, the mirrors 9b, 9c, 9d, 9e, and 9f may be referred to as the mirrors 9.

(Reflector reflection type test antenna)

First, the reflector reflection type test antenna 6a will be described.

The reflector reflection type test antenna 6a functions as a primary radiator, and includes a horizontally polarized antenna 6aH and a vertically polarized antenna 6aV (see fig. 2). The reflector 7 has a reflecting surface curved in a curved surface shape, reflects a radio wave of a radio signal for measurement, and has an offset paraboloid (see fig. 6) type structure described later. The reflector 7 is made of aluminum, for example. As shown in fig. 1, reflector 7 is mounted to side 52b of OTA chamber 50 at a desired location using reflector holder 58.

The reflector 7 receives, via the paraboloid of revolution, an electric wave of a test signal emitted from the test antenna 6a, which is a primary radiator, whose paraboloid of revolution is arranged at a predetermined focal position F, and reflects the electric wave toward the DUT100 held by the posture varying mechanism 56 (at the time of transmission). The reflector 7 receives the radio wave of the signal to be measured, which is emitted from the antenna 110 from the DUT100 that has received the test signal, through the paraboloid of revolution, and reflects the radio wave toward the test antenna 6a (at the time of reception). The reflector 7 is disposed in a position and a posture capable of performing these transmission and reception simultaneously. That is, the reflector 7 reflects the radio wave of the radio signal transmitted and received between the test antenna 6a and the antenna 110 of the DUT100 via the paraboloid of revolution.

Fig. 6 is a schematic diagram showing the structure of the reflector 7. The reflector 7 is of an offset parabolic type and has a mirror surface (a shape of a part of a paraboloid of revolution from which a perfect circular paraboloid is cut) asymmetrical with respect to the axis RS of the paraboloid of revolution. The test antenna 6a as a primary radiator is disposed at the focal point F of the offset paraboloid in a state where the beam axis BS thereof is offset by an angle α (e.g., 30 °) with respect to the axis RS of the paraboloid of revolution. In other words, the test antenna 6a is disposed so as to face the reflector 7 at the elevation angle α, and is held at an angle such that the receiving surface of the test antenna 6a is perpendicular to the beam axis BS of the radio signal.

According to this configuration, the paraboloid of revolution can reflect the radio wave (for example, a test signal to the DUT 100) emitted from the test antenna 6 in the direction parallel to the axial direction of the paraboloid of revolution, and the paraboloid of revolution can reflect the radio wave (for example, a measured signal transmitted from the DUT 100) incident on the paraboloid of revolution in the direction parallel to the axial direction of the paraboloid of revolution and guide the radio wave to the test antenna 6 a. In other words, the reflector 7 converts the spherical wave radio wave emitted from the test antenna 6a into the plane wave radio wave and transmits the plane wave radio wave to the DUT100, and the plane wave radio wave emitted from the DUT100 and incident on the reflector 7 is converged on the test antenna 6 a. The offset paraboloid can not only reduce the size of the reflector 7 itself, but also realize a configuration in which the mirror surfaces are vertically close to each other, as compared with the parabolic type, and thus the structure of the OTA darkroom 50 can be miniaturized.

As is clear from fig. 8, the reflector reflection type test antenna 6a is disposed below the plane HP passing through the disposition position P0 of the DUT 100. The electric wave beam emitted from the test antenna 6a and reflected by the reflector 7 propagates in the negative direction of the Z axis, and forms a blank space QZ of a radius r 2. The center of the electric beam reflected at the position P1 of the center of the opening of the reflector 7 propagates in the Z-axis negative direction and reaches the arrangement position P0 of the DUT 100.

(Reflector reflection type test antenna)

Next, the mirror reflection type test antenna 6 will be described.

The mirror reflection type test antenna 6 transmits or receives a radio signal to or from the antenna 110 of the DUT100 via the mirror 9 that reflects a radio wave of the radio signal for measurement. Specifically, the mirror reflection type test antenna 6 includes a 1 st test antenna 6b, a2 nd test antenna 6c, a 3 rd test antenna 6d, a 4 th test antenna 6e, and a 5 th test antenna 6 f. The mirror 9 includes a 1 st mirror 9b, a2 nd mirror 9c, a 3 rd mirror 9d, a 4 th mirror 9e, and a 5 th mirror 9 f. Each mirror 9 is made of, for example, aluminum and has a flat mirror surface.

Specifically, the 1 st test antenna 6b transmits and receives a radio signal to and from the antenna 110 of the DUT100 via the 1 st mirror 9b, the 2 nd test antenna 6c transmits and receives a radio signal via the 2 nd mirror 9c, the 3 rd test antenna 6d transmits and receives a radio signal via the 3 rd mirror 9d, the 4 th test antenna 6e transmits and receives a radio signal via the 4 th mirror 9e, and the 5 th test antenna 6f transmits and receives a radio signal via the 5 th mirror 9 f.

The reflecting mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f include horizontally polarized wave antennas 6bH, 6cH, 6dH, 6eH, and 6fH, respectively, and include vertically polarized wave antennas 6bV, 6cV, 6dV, 6eV, and 6fV, respectively (see fig. 2).

The mirrors 9 are arranged such that the reflection surfaces of the respective mirrors intersect a horizontal plane HP passing through the arrangement position P0 of the DUT 100. Specifically, the mirrors 9b, 9c, 9d, 9e, and 9f are arranged on the horizontal plane HP on the virtual spherical surface S having the radius r1 with the arrangement position P0 of the DUT100 as the center. The phrase "the mirrors are disposed on the virtual spherical surface S and on the horizontal plane HP" means that the reflection points P2, P3, P4, P5, and P6 reflected at the center of the electron beam on the reflection surfaces of the respective mirrors 9b, 9c, 9d, 9e, and 9f are located on the virtual spherical surface S and on the horizontal plane HP.

The arrangement of the reflection mirrors 9b, 9c, 9d, 9e, and 9f is not limited to the horizontal plane HP, and may be arranged on any plane passing through the arrangement position P0 of the DUT100, and need not necessarily be arranged on the same plane. The mirrors 9b, 9c, 9d, 9e, and 9f need not be arranged at the same distance from the DUT100, and may have different distances from the DUT100 for the mirrors 9b, 9c, 9d, 9e, and 9 f.

The mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f are disposed below a horizontal plane HP passing through the disposition position P0 of the DUT 100. The radio beam emitted from the mirror reflection type test antenna 6 is specularly reflected by the corresponding mirror 9. As long as the radio beam reflected by each mirror 9 reaches the DUT100, the incident angle and the reflection angle of the radio beam on each mirror 9 may be different or the same for each mirror. In the present embodiment, the reflecting mirror type test antennas 6b, 6c, 6d, 6e, and 6f are supported on the bottom surface 52a of the OTA dark room 50 by supports, but may be disposed above the horizontal plane HP or on the horizontal plane HP.

In the present embodiment, 1 mirror 9 is disposed in the propagation path of the radio wave between the mirror reflection type test antenna 6 and the DUT100, but a mirror of 2 or more may be disposed. That is, a plurality of mirror reflections may be performed during propagation of the radio wave to ensure a distance between the antennas necessary for far-field measurement.

In the present embodiment, the mirrors 9b, 9c, 9d, 9e, and 9f that reflect the radio signal from the mirror reflection type test antenna 6 are arranged at the arrangement position P0 of the DUT100 so as to form different arrival angles with reference to the arrival directions of the radio waves from the reflector reflection type test antenna 6a and the reflector 7. Accordingly, since the arrival angle differs depending on the combination of the reflector reflection type test antenna 6a and 1 of the mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f, it is possible to effectively perform far-field measurement of the transmission/reception characteristics such as the RRM characteristics of the DUT100 by changing the arrival angle by switching the mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6 f.

As shown in fig. 7, for example, a beam transmitted from the mirror reflection type test antenna 6b via the mirror 9b forms an arrival angle of 30 ° with reference to the arrival direction (Z axis) of a radio wave from the mirror reflection type test antenna 6a at the arrangement position P0 of the DUT 100. Similarly, the radio beams transmitted from the reflecting mirror reflection type test antennas 6c, 6d, 6e, and 6f via the reflecting mirrors 9c, 9d, 9e, and 9f form arrival angles of 60 °, 90 °, 120 °, and 150 °, respectively. That is, the 1 st to 5 th test antennas 6b, 6c, 6d, 6e, and 6f can realize the relative arrival angles of 30 °, 60 °, 90 °, 120 °, and 150 ° together with the reflector reflection type test antenna 6 a. In this way, since the measurement can be performed uniformly and without leakage within the predetermined angular range, the far-field measurement of the transmission/reception characteristics such as the RRM characteristics of the DUT100 can be performed with high accuracy. Thereby, RRM characteristics specified in the standard 3GPP TR38.810 V16.2.0(2019-03) can be measured with high accuracy.

Here, the "arrival angle (AoA)" is an angle formed by the center of the radio beam or radio wave beam that arrives at the arrangement position P0 from the test antenna 6 with respect to a specific straight line (for example, Z axis) passing through the arrangement position P0 of the DUT 100. The arrival angle can be specified by 2 test antennas. In this case, an angle formed by the electric beam or the center of the electric beam coming from the other 1 test antenna to the arrangement position P0 with reference to the direction of the electric wave coming from the electric beam coming from the 1 test antenna to the arrangement position P0, that is, the arrival direction of the electric wave is referred to as "arrival angle" or "relative arrival angle".

When the antenna size D of the antenna 110 is known, the distance from the mirror reflection type test antennas 6b, 6c, 6D, 6e, and 6f to the antenna 110 of the DUT100 via the corresponding mirrors 9b, 9c, 9D, 9e, and 9f may be set to be greater than 2D2/λ. D is the antenna size of the antenna 110, and λ is the wavelength of the radio wave transmitted from the mirror reflection type test antenna 6, whereby the far field measurement of the DUT100 can be performed.

Fig. 9 is a schematic diagram showing the arrangement of the mirror 9f and the mirror reflection type test antenna 6f in the OTA darkroom 50. In fig. 9, illustration of other reflecting mirrors and the test antenna is omitted. The test antenna 6f is disposed below the horizontal plane HP, and the reflecting mirror 9f is disposed such that a reflection point P6 of the radio beam on the reflecting mirror surface is located on the horizontal plane HP. The radio wave beam emitted from the test antenna 6f is reflected by the mirror 9f and transmitted to the arrangement position P0 of the DUT 100. The radio beam emitted from the antenna 110 of the DUT100 is reflected by the mirror 9f and transmitted to the test antenna 6 f. If the mirror 9f is not provided, the test antenna 6A is disposed outside the OTA darkroom 50, and the distance between the antennas (P0-PA) required for the far-field measurement cannot be secured. By bending the propagation path of the electric beam by the mirror 9f, the test antenna 6f can be disposed in the OTA darkroom 50, and the distance between the antennas required for far-field measurement can be secured.

Specifically, in fig. 9, the distance obtained by adding the distance between P0-P6 and the distance between P6-P16 is equal to the distance between antennas required for far-field measurement, i.e., the distance between P0-PA. P6 represents a reflection point at which a radio wave beam emitted from the test antenna 6f is reflected by the mirror 9f, P16 represents the center of the opening of the test antenna 6f, and PA represents the center of the opening of the virtual test antenna 6A. The propagation path between P0-P6 lies on the horizontal plane HP. The radio wave beam emitted from the reflector reflection type test antenna 6a is reflected by the reflection point P1 on the reflector 7 and transmitted to the arrangement position P0 of the DUT100, and the propagation path between P1 and P0 is also located on the horizontal plane HP.

The reflector reflection type test antenna 6a forms a so-called Indirect Far Field (IFF), and the mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f form a Direct Far Field (DFF). The indirect far field refers to a far field formed by a reflection type antenna using a reflector that converts a spherical wave into a plane wave, and the direct far field refers to a far field formed by an antenna not using such a reflector. The mirror reflection type test antenna 6 reflects a beam using a mirror, but the distance from the test antenna to the far field is the same as in the case without a mirror, and therefore can be regarded as a DEF type antenna.

The reflector reflection type test antennas 6b, 6c, 6d, 6e, and 6f and the reflectors 9b, 9c, 9d, 9e, and 9f are disposed outside the path of the beam reflected by the reflector 7 of the reflector reflection type test antenna 6a and passing through the blank area QZ. With this configuration, the test apparatus 1 according to the present embodiment can form the blank space QZ satisfactorily.

In the present embodiment, each of the 5 mirror reflection antennas 6 and the mirrors 9 is provided, but the number is not limited thereto, and the respective numbers can be set to arbitrary numbers according to the contents of the test.

In the present embodiment, the blank space formed by the test antennas 6b, 6c, 6d, 6e, and 6f of the mirror reflection type is the same as the blank space QZ formed by the reflector reflection type test antenna 6a, but the present invention is not limited thereto. The blank space QZ formed by the reflector-reflection type test antennas 6b, 6c, 6d, 6e, and 6f may be different from the blank space QZ formed by the reflector-reflection type test antenna 6 a. For example, if the blank space QZ formed by the reflector-reflection-type test antenna 6a is expanded, a wider blank space can be used when the reflector-reflection-type test antenna 6a alone is used to measure RF characteristics and the like.

Next, the integrated control device 10 and the NR system simulator 20 of the test apparatus 1 according to the present embodiment will be described with reference to fig. 2 to 4.

(Integrated control device)

As described below, the integrated control apparatus 10 centrally controls the NR system simulator 20 or the posture variable mechanism 56. Therefore, the integrated control apparatus 10 is connected to the NR system simulator 20 or the posture changing mechanism 56 via the network 19 such as ethernet (registered trademark) so as to be able to communicate with each other.

Fig. 3 is a block diagram showing a functional configuration of the integrated control device 10. As shown in fig. 3, the integrated control device 10 includes a control unit 11, an operation unit 12, and a display unit 13. The control unit 11 is constituted by a computer device, for example. As shown in fig. 3, the computer device includes, for example, a nonvolatile storage medium such as a CPU (Central Processing Unit) 11a, a ROM (Read Only Memory) 11b, a RAM (Random Access Memory) 11c, an external interface (I/F) 11d, and a hard disk drive device (not shown), and various input/output ports.

The CPU11a performs centralized control targeting the NR system simulator 20. The ROM11b stores an OS (Operating System) for starting the CPU11a, other programs, control parameters, and the like. The RAM11c stores an OS used by the CPU11a in operation, execution codes of application programs, data, and the like. The external interface (I/F) unit 11d has an input interface function for inputting a predetermined signal and an output interface function for outputting a predetermined signal.

The external I/F unit 11d is connected to the NR system simulator 20 via a network 19 so as to be able to communicate. The external I/F unit 11d is also connected to the posture changing mechanism 56 in the OTA darkroom 50 via the network 19. The input/output port is connected to an operation unit 12 and a display unit 13. The operation unit 12 is a functional unit for inputting various information such as commands, and the display unit 13 is a functional unit for displaying various information such as input screens of the various information and measurement results.

The CPU11a of the computer device functions as the control unit 11 by executing a program stored in the ROM11b using the RAM11c as a work area. As shown in fig. 3, the control unit 11 includes a call connection control unit 14, a signal transmission/reception control unit 15, and a DUT posture control unit 17. The call connection controller 14, the signal transmission/reception controller 15, and the DUT posture controller 17 are also realized by the CPU11a executing a predetermined program stored in the ROM11b in the work area of the RAM11 c.

The call connection control unit 14 drives the test antenna 6 to transmit and receive a control signal (radio signal) to and from the DUT100, thereby controlling the NR system simulator 20 to establish a call (a state in which the radio signal can be transmitted and received) to and from the DUT 100.

The signal transmission/reception control unit 15 monitors the user operation in the operation unit 12, and transmits a signal transmission command to the NR system simulator 20 via the call connection control in the call connection control unit 14 when a predetermined measurement start operation related to measurement of the transmission characteristic and the reception characteristic of the DUT100 is performed by the user. The signal transmission/reception control unit 15 performs control for transmitting a test signal to the NR system simulator 20 via the test antenna 6, and also performs control for transmitting a signal reception command to the NR system simulator 20 and receiving a signal to be measured via the test antenna 6.

The signal transmission/reception control unit 15 sets the arrival angle and selects the test antenna to be used in the test of the transmission/reception characteristics such as the RRM characteristics using the 2 test antennas. Specifically, 1 of a plurality of predetermined arrival angles (for example, 30 °, 60 °, 90 °, 120 °, and 150 °) is selected and set as the measurement condition (stored in the RAM11c, or the like). The arrival angle may be selected by the user or may be automatically selected by the control unit 11 or the like. The signal transmission/reception control unit 15 selects a test antenna to be used from the plurality of test antennas 6 based on the set arrival angle. For example, when the set arrival angle is 30 °, the signal transmission/reception control unit 15 selects the reflector-reflection type test antenna 6a and the mirror-reflection type 1 st test antenna 6b as the test antennas to be used. Therefore, for example, the ROM11b stores in advance an arrival angle-test antenna correspondence table 17b indicating the correspondence between the arrival angle and the test antenna. The setting of the arrival angle or the selection of the test antenna to be used may be performed by the control unit 11 or the control unit 22 of the NR system simulator 20.

The DUT posture control unit 17 controls the posture when the DUT100 held by the posture varying mechanism 56 is measured. To realize this control, for example, the ROM11b stores in advance the DUT attitude control table 17 a. For example, when a stepping motor is used as the driving unit 56a, the DUT posture control table 17a stores, as control data, the number of driving pulses (the number of operation pulses) for determining the rotational driving of the stepping motor.

The DUT attitude control unit 17 drives and controls the attitude changing mechanism 56 such that the DUT attitude control table 17a is expanded into the work area of the RAM11c, and the attitude of the DUT100 is changed so that the antenna 110 is sequentially oriented in all three-dimensional directions in accordance with the DUT attitude control table 17a, as described above.

(NR System simulator)

As shown in fig. 4, the NR system simulator 20 of the test apparatus 1 according to the present embodiment includes a signal measurement unit 21, a control unit 22, an operation unit 23, and a display unit 24. The signal measuring unit 21 includes a signal generating function unit including a signal generating unit 21a, a digital-to-analog converter (DAC)21b, a modulating unit 21c, and a transmitting unit 21e of the RF unit 21d, and a signal analyzing function unit including a receiving unit 21f of the RF unit 21d, an analog-to-digital converter (ADC)21g, and an analyzing unit 21 h. In addition, the signal measuring unit 21 may be provided with 2 sets so as to be compatible with 2 test antennas to be used.

In the signal generation function unit of the signal measurement unit 21, the signal generation unit 21a generates waveform data having a reference waveform, specifically, for example, generates an I-component baseband signal and a Q-component baseband signal which is a quadrature component signal thereof. The DAC21b converts the waveform data (I-component baseband signal and Q-component baseband signal) having the reference waveform output from the signal generation unit 21a from a digital signal to an analog signal and outputs the analog signal to the modulation unit 21 c. The modulation unit 21c performs a modulation process of mixing local signals with the I-component baseband signal and the Q-component baseband signal, respectively, and combining the two signals to output a digital modulation signal. The RF unit 21d generates a test signal corresponding to a frequency of each communication standard from the digital modulation signal output from the modulation unit 21c, and outputs the generated test signal to the signal processing unit 40 via the transmission unit 21 e.

The signal processing unit 40 includes a 1 st signal processing unit 40a that performs signal processing such as frequency conversion of signals transmitted and received to and from the 1 used test antenna, and a2 nd signal processing unit 40b that performs signal processing such as frequency conversion of signals transmitted and received to and from the other 1 used test antenna. The 1 st signal processing unit 40a performs signal processing on the test signal transmitted to the 1 test antenna used and outputs the signal to the signal switching unit 41. The 2 nd signal processing unit 40b performs signal processing on the test signal transmitted to the other 1 test antenna used and outputs the signal to the signal switching unit 41. The signal switching unit 41 switches the signal path such that the 1 st signal processing unit 40a is connected to 1 test antenna used and the 2 nd signal processing unit 40b is connected to the other 1 test antenna used under the control of the control unit 22. Therefore, the test signal output from the 1 st signal processing unit 40a is transmitted to the 1 test antenna used via the signal switching unit 41, and is output from the test antenna toward the DUT 100. The test signal output from the 2 nd signal processing unit 40b is transmitted to another 1 test antenna to be used via the signal switching unit 41, and is output from the test antenna toward the DUT 100.

In the signal analysis function unit of the signal measurement unit 21, the RF unit 21d receives the signal to be measured transmitted from the DUT100 that has received the test signal via the antenna 110, by the reception unit 21f via the signal switching unit 41 and the signal processing unit 40, and then mixes the signal to be measured with the local signal to convert the signal to a signal (IF signal) of an intermediate frequency band. The ADC21g converts the measured signal converted into the IF signal by the receiving unit 21f of the RF unit 21d from an analog signal to a digital signal and outputs the converted signal to the analysis processing unit 21 h.

The analysis processing unit 21h performs processing for generating waveform data corresponding to the I-component baseband signal and the Q-component baseband signal by digitally processing the measured signal, which is the digital signal output from the ADC21g, and analyzing the I-component baseband signal and the Q-component baseband signal based on the waveform data. The analysis processor 21h can measure, for example, Equivalent Isotropic Radiated Power (EIRP), Total Radiated Power (TRP), stray radiation, modulation accuracy (EVM), transmission Power, a constellation, a spectrum, and the like in the measurement of the transmission characteristics (RF characteristics) of the DUT 100. The analysis processing unit 21h can measure, for example, reception sensitivity, Bit Error Rate (BER), Packet Error Rate (PER), and the like in the measurement of the reception characteristics (RF characteristics) of the DUT 100. Here, the EIRP is the wireless signal strength in the main beam direction of the antenna 110 of the DUT 100. And, TRP is a total value of power transmitted to the space from the antenna 110 of the DUT 100.

The analysis processor 21h can analyze whether or not the switching operation from the selected 1 test antenna to the other 1 test antenna is normally performed, for example, with respect to the RRM characteristics of the DUT 100.

The control unit 22 is constituted by a computer device including a CPU, a RAM, a ROM, and various input/output interfaces, for example, as in the control unit 11 of the integrated control device 10 described above. The CPU performs predetermined information processing and control for realizing the functions of the signal generation function section, the signal analysis function section, the operation section 23, and the display section 24.

The operation unit 23 and the display unit 24 are connected to an input/output interface of the computer device. The operation unit 23 is a functional unit for inputting various information such as commands, and the display unit 24 is a functional unit for displaying various information such as input screens of the various information and measurement results.

In the present embodiment, the integrated control device 10 and the NR system simulator 20 are separate devices, but may be configured by 1 device. In this case, the control unit 11 of the integrated control device 10 and the control unit 22 of the NR system simulator 20 may be integrated and realized by 1 computer device.

(Signal processing section)

Next, the signal processing unit 40 will be explained.

The signal processing unit 40 is provided between the NR system simulator 20 and the signal switching unit 41, and includes a 1 st signal processing unit 40a that performs signal processing such as frequency conversion of signals transmitted and received to and from the 1 used test antenna, and a2 nd signal processing unit 40b that performs signal processing such as frequency conversion of signals transmitted and received to and from the other 1 used test antenna.

The 1 st signal processing unit 40a includes an up-converter, a down-converter, an amplifier, a frequency filter, and the like, and performs signal processing such as frequency conversion (up-conversion), amplification, and frequency selection on the test signal transmitted to the 1 test antenna used, and outputs the signal to the signal switching unit 41. The 1 st signal processing unit 40a performs signal processing such as frequency conversion (down-conversion), amplification, and frequency selection on the signal to be measured input from the 1 test antenna used via the signal switching unit 41, and outputs the signal to the signal measuring unit 21.

The 2 nd signal processing unit 40b includes an up-converter, a down-converter, an amplifier, a frequency filter, and the like, and performs signal processing such as frequency conversion (up-conversion), amplification, and frequency selection on the test signal transmitted to the other 1 test antenna used, and outputs the signal to the signal switching unit 41. The 2 nd signal processing unit 40b performs signal processing such as frequency conversion (down-conversion), amplification, and frequency selection on the signal to be measured input from another 1 test antenna to be used via the signal switching unit 41, and outputs the signal to the signal measuring unit 21.

The signal switching unit 41 is provided between the signal processing unit 40 and the test antenna 6, and switches the signal path such that the 1 st signal processing unit 40a is connected to 1 test antenna to be used and/or the 2 nd signal processing unit 40b is connected to another 1 test antenna to be used under the control of the control unit 22. The signal switching unit 41 may be included in the signal processing unit 40.

(test method)

Next, a test method using the test apparatus 1 according to the present embodiment will be described with reference to a flowchart of fig. 10. Hereinafter, a test (for example, measurement of transmission/reception characteristics such as RRM characteristics) using 2 test antennas will be described, but this is an example of a test method, and it is obvious that the specific test method differs depending on the type of test.

First, the user sets the DUT100 to be tested on the DUT placement unit 56d of the posture changing mechanism 56 provided in the internal space 51 of the OTA chamber 50 (step S1).

Next, the user uses the operation unit 12 of the integrated control device 10 to perform a measurement start operation for instructing the control unit 11 to start measurement of the transmission characteristic and the reception characteristic of the DUT 100. This measurement start operation may be performed by the operation section 23 of the NR system simulator 20.

The control unit 11 sets 1 of the preset arrival angles (step S2). For example, when the preset arrival angles are 30 °, 60 °, 90 °, 120 °, and 150 °, the control unit 11 selects 1 of the arrival angles (for example, 30 °) and sets the selected arrival angle as the arrival angle to be measured (for example, stored in the RAM11 c). The setting of the angle of arrival may also be performed by the user.

Next, the control unit 11 selects 2 test antennas 6 realizing the arrival angle based on the arrival angle set in step S2. For example, when the set arrival angle is 30 °, the test antenna 6a and the test antenna 6b are selected, when the set arrival angle is 60 °, the test antenna 6a and the test antenna 6c are selected, when the set arrival angle is 90 °, the test antenna 6a and the test antenna 6d are selected, when the set arrival angle is 120 °, the test antenna 6a and the test antenna 6e are selected, and when the set arrival angle is 150 °, the test antenna 6a and the test antenna 6f are selected.

Next, the control unit 22 of the NR system simulator 20 performs control for switching the signal path to the selected antenna 6 for test. Specifically, the control unit 22 of the NR system simulator acquires information on the selected 2 test antennas from the control unit 11, and transmits a switching signal to the signal switching unit 41. The signal switching unit 41 switches the signal path so that the selected test antenna 6 is connected to the signal processing unit 40 in accordance with the switching signal.

The call connection controller 14 of the controller 11 performs call connection control by transmitting and receiving a control signal (radio signal) to and from the DUT100 using the selected test antenna 6 (step S4). Specifically, the NR system simulator 20 wirelessly transmits a control signal (call connection request signal) having a predetermined frequency to the DUT100 via the test antenna 6. On the other hand, the DUT100 that has received the call connection request signal returns a control signal (call connection response signal) after setting the frequency of the requested connection. The NR system simulator 20 receives the call connection response signal and confirms that the response has been made normally. These series of processes are call connection control. By this call connection control, a state is established in which a radio signal of a predetermined frequency can be transmitted and received between the NR system simulator 20 and the DUT100 via the selected test antenna 6.

The process of receiving the radio signal transmitted from the NR system simulator 20 via the test antenna 6 by the DUT100 is referred to as Downlink (DL) processing. In contrast, the processing of the radio signal transmitted by the NR system simulator 20 via the test antenna 6 by the DUT100 is referred to as Uplink (UL) processing. The test antenna 6 is used for performing a process of establishing a link (call) and a process of establishing a Downlink (DL) and an Uplink (UL) after the link is established, and has a function of a link antenna.

After the call connection in step S4 is established, the DUT posture control unit 17 of the integrated control apparatus 10 controls the posture of the DUT100 placed in the blank space QZ to a predetermined posture by the posture varying mechanism 56 (step S5).

After the DUT100 is controlled to a predetermined posture by the posture varying mechanism 56, the signal transmission/reception control unit 15 of the integrated control device 10 transmits a signal transmission command to the NR system simulator 20. The NR system simulator 20 transmits a test signal to the DUT100 via the selected test antenna 6 in accordance with the signal transmission command (step S6).

With regard to the trial signal transmission control based on the NR system simulator 20, the following is implemented. In the NR system simulator 20 (see fig. 4), the signal generation unit 21a generates a signal for generating a test signal under the control of the control unit 22 that has received the signal transmission command. Next, the DAC21b performs digital-to-analog conversion processing on the signal generated by the signal generation section. Next, the modulation unit 21c performs modulation processing on the analog signal obtained by digital-to-analog conversion. Next, the RF unit 21d generates a test signal corresponding to the frequency of each communication standard from the modulated signal, and the transmission unit 21e transmits the test signal (DL data) to the signal processing unit 40.

The signal processing unit 40 is installed in the OTA darkroom 50, performs signal processing such as frequency conversion (up-conversion), amplification, and frequency selection, and outputs the signal to the switching unit 140. The switching unit 140 transmits the signal processed by the signal processing unit 40 to the selected test antenna 6, and the test antenna 6 outputs the signal to the DUT 100. In addition, the signal processing unit 40 may perform processing of a plurality of signals in order to perform signal processing of 2 test antennas corresponding to selection of the test antenna 6 by the control unit 11. In this case, a switching mechanism for switching the connection between the test antennas 6a, 6b, 6c, 6d, 6e, and 6f and the 2 signal processing units 40 is provided to perform signal processing of the plurality of test signals.

After the start of the control of the test signal transmission in step S6, the signal transmission/reception control unit 15 transmits the test signal at an appropriate timing until the end of the measurement of the transmission characteristic and the reception characteristic of the DUT 100.

On the other hand, the DUT100 receives the test signal (DL data) transmitted via the test antenna 6 via the antenna 110 in a state of different postures sequentially changed in accordance with the posture control performed in step S5, and transmits a measured signal that is a response signal to the test signal.

After the transmission of the test signal is started in step S6, the reception process is continued under the control of the transmission/reception control unit 15 (step S7). In this reception process, the test antenna 6 receives the signal to be measured transmitted from the DUT100 that has received the test signal, and outputs the signal to the signal switching unit 41. The signal switching unit 41 switches the signal path and outputs the signal to be measured to the signal processing unit 40. The signal processing unit 40 performs signal processing such as frequency conversion (down-conversion), amplification, and frequency selection, and outputs the result to the NR system simulator 20.

The NR system simulator 20 performs a measurement process of measuring the measured signal frequency-converted by the signal processing section 40 (step S8).

Specifically, the receiving unit 21f of the RF unit 21d of the NR system simulator 20 receives the measured signal subjected to the signal processing by the signal processing unit 40. The RF unit 21d converts the signal to be measured input to the receiving unit 21f into an IF signal of a lower frequency under the control of the control unit 22. Then, the ADC21g converts the IF signal from an analog signal to a digital signal under the control of the control unit 22, and outputs the converted signal to the analysis processing unit 21 h. The analysis processing unit 21h generates waveform data corresponding to the I-component baseband signal and the Q-component baseband signal, respectively. The analysis processing unit 21h analyzes the measured signal based on the generated waveform data under the control of the control unit 22. The signal processing unit 40 may process a plurality of signals in order to perform signal processing of 2 test antennas corresponding to the selection of the test antenna 6 by the control unit 11. In this case, a switching mechanism for switching the connection between the test antennas 6a, 6b, 6c, 6d, 6e, and 6f and the signal processing unit 40 is provided to process the plurality of test signals.

More specifically, in the NR system simulator 20, the analysis processing unit 21h measures the transmission characteristics and reception characteristics of the DUT100 based on the analysis result of the signal to be measured under the control of the control unit 22.

For example, the transmission characteristics (RF characteristics) of the DUT100 are performed as follows. First, the NR system simulator 20 transmits a request frame for uplink signal transmission as a test signal under the control of the control section 22. The DUT100 transmits an uplink signal frame as a measured signal to the NR system simulator 20 in response to the request frame for uplink signal transmission. The analysis processing unit 21h performs processing for evaluating the transmission characteristics of the DUT100 based on the uplink signal frame.

The reception characteristics (RF characteristics) of the DUT100 are performed, for example, as follows. The analysis processing unit 21h calculates, as an error rate (PER), a ratio of the number of times of transmission of the measurement frame transmitted as the test signal from the NR system simulator 20 and the number of times of reception of ACK and NACK transmitted as the measurement signal from the DUT100 for the measurement frame, under the control of the control unit 22.

Further, as for the RRM characteristics of the DUT100, for example, the analysis processing unit 21h may test whether or not the switching operation from the selected 1 test antenna to the selected other 1 test antenna is normally performed by changing the posture of the DUT100 under the control of the control unit 22.

In step S8, the analysis processing unit 21h stores the measurement results of the transmission characteristics and reception characteristics of the DUT100 in a storage area such as a RAM, not shown, under the control of the control unit 22. The measurement result may be displayed on the display unit 24 or the display unit 13.

Next, the control unit 11 of the integrated control device 10 determines whether or not the measurement of the transmission characteristic and the reception characteristic of the DUT100 is completed for all the desired postures (step S9). If it is determined that the measurement has not been completed (no in step S9), the process returns to step S5 to continue the process.

When determining that the measurement is ended for all the postures (yes in step S9), the control unit 11 determines whether the measurement is ended for all the arrival angles (step S10).

When determining that the measurement has not been completed for all the arrival angles (no in step S10), the control unit 11 returns to step S2 and continues the processing. When determining that the measurement has been completed for all the arrival angles (yes in step S10), the control unit 11 ends the test.

As described above, the test apparatus 1 according to the present embodiment includes the reflector reflection type test antenna 6a that transmits or receives a radio signal to or from the antenna 110 of the DUT100 via the reflector 7, and the mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f that transmits or receives a radio signal to or from the antenna 110 via the mirror 9. The direction of propagation of the electric wave can be changed by the mirror 9, and therefore the distance of propagation of the electric wave can be lengthened in a limited small space within the OTA darkroom 50. This ensures the distance between the test antenna 6 and the antenna 110 of the DUT100 required for far-field measurement. With this configuration, the OTA darkroom 50 can be made smaller and the cost of the test apparatus 1 can be reduced as compared with an apparatus using a conventional DFF antenna.

The test antenna 6 has a hybrid structure including a reflector reflection type test antenna 6a for indirectly transmitting and receiving a radio signal by using a reflector 7 and mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6f for transmitting and receiving a radio signal via a mirror 9. This minimizes the number of reflector reflection type test antennas having a complicated structure, and allows a wider blank space to be used when the reflector reflection type test antenna 6a is used alone, which allows a wider blank space to be formed than when a reflector reflection type test antenna is used alone. Therefore, the test apparatus 1 according to the present embodiment can perform far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of the DUT100 with high accuracy and at low cost.

(embodiment 2)

Next, a test apparatus according to embodiment 2 of the present invention will be described.

The test apparatus according to embodiment 2 differs from embodiment 1 in that it uses 1 mirror reflection type test antenna 6g and direction changing means 60, and it uses 5 mirror reflection type test antennas 6b, 6c, 6d, 6e, and 6 f. Other constituent elements are the same, and the same constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

Fig. 11 is a front view of the OTA darkroom 50A, with a front side plate removed, and fig. 12 is a schematic view showing the arrangement of the mirrors 9b, 9c, 9d, 9e, and 9f and the mirror reflection type test antenna 6g in the OTA darkroom 50A. As shown in fig. 11 and 12, the OTA darkroom 50A according to the present embodiment is provided with a 1 st mirror 9b, a2 nd mirror 9c, a 3 rd mirror 9d, a 4 th mirror 9e, and a 5 th mirror 9 f. Further, the OTA darkroom 50A is provided with a test antenna 6g for transmitting and receiving a radio signal via 1 mirror selected from the plurality of mirrors 9b, 9c, 9d, 9e, and 9 f. The test antenna 6g includes a horizontally polarized antenna and a vertically polarized antenna.

As in embodiment 1, the reflection mirrors 9b, 9c, 9d, 9e, and 9f are arranged such that the reflection mirrors intersect the horizontal plane HP passing through the arrangement position P0 of the DUT 100. The point of difference from embodiment 1 is that each mirror 9 is disposed in a posture of reflecting a radio wave beam emitted from 1 mirror reflection type test antenna 6g toward the DUT 100.

The test apparatus according to the present embodiment further includes a direction changing mechanism 60 that changes the radio wave transmission direction of the mirror reflection type test antenna 6g so as to be directed to 1 of the plurality of mirrors 9b, 9c, 9d, 9e, and 9 f. The direction changing device 60 of the present embodiment corresponds to the direction changing mechanism of the present invention.

As shown in fig. 13, the test antenna 6g is disposed below the horizontal plane HP passing through the placement position P0 of the DUT 100. The mirrors 9b, 9c, 9d, 9e, 9f are arranged such that the reflection points P2, P3, P4, P5, P6 of the electron beam on the mirror surface lie on the horizontal plane HP. The test antenna 6g can set the direction to 1 of the reflectors 9b, 9c, 9d, 9e, and 9f by the direction changing mechanism 60.

For example, when the test antenna 6g is directed toward the mirror 9f, the radio beam emitted from the test antenna 6g is reflected by the mirror 9f and transmitted to the placement position P0 of the DUT 100. The radio beam emitted from the antenna 110 of the DUT100 is reflected by the mirror 9f and transmitted to the test antenna 6 g. At this time, if the mirror 9f is not provided, the test antenna 6A is disposed outside the OTA darkroom 50A, and the distance between the antennas (P0-PA distance) necessary for the far-field measurement cannot be secured. By bending the propagation path of the electric beam by the reflecting mirror 9f, the test antenna 6f can be disposed in the OTA darkroom 50A, and the distance between the antennas required for far-field measurement can be secured.

Specifically, in fig. 12, the distance obtained by adding the distance between P0 and P6 and the distance between P6 and P7 is equal to the distance between antennas required for far-field measurement, i.e., the distance between P0 and PA. P7 is the center of the opening of the test antenna 6g, and the propagation path between P0-P6 is located on the horizontal plane HP.

The same applies to the case where the test antenna 6g is directed to the mirror other than the mirror 9 f. For example, when the test antenna 6g is directed toward the mirror 9b, the radio beam emitted from the test antenna 6g is reflected by the mirror 9b and transmitted to the arrangement position P0 of the DUT 100. The radio beam emitted from the antenna 110 of the DUT100 is reflected by the mirror 9b and transmitted to the test antenna 6 g. The distance obtained by adding the distance between P0 and P2 and the distance between P2 and P7 is set to be equal to or more than the shortest distance between antennas required for far-field measurement.

Fig. 13 is a schematic diagram showing the mirror 9b and the mirror reflection type test antenna 6g according to embodiment 2. As shown in fig. 13, the test antenna 6g is attached to the direction changing mechanism 60 provided on the bottom surface 52a of the OTA darkroom 50A. The direction changing mechanism 60 can rotate the test antenna 6g about a rotation shaft 61 parallel to the bottom surface 52a, and can rotate the test antenna 6g about a rotation shaft 62 perpendicular to the rotation shaft 61. Thus, the test antenna 6g can freely change the radiation direction of the radio beam to the direction of 1 selected one of the mirrors 9b, 9c, 9d, 9e, and 9 f. The direction changing mechanism 60 is a biaxial positioner, but may be a uniaxial positioner depending on the arrangement of the mirror 9.

As shown in fig. 13, the mirror 9b is mounted on a mirror holder 70 provided on the bottom surface 52a of the OTA darkroom 50A. The mirror holder 70 has a stay 71 and a mounting portion 74 for mounting the mirror 9 b. The mounting portion 74 is rotatable about a rotation shaft portion 72 perpendicular to the bottom surface 52a, and is rotatable about a rotation shaft portion 73 perpendicular to the rotation shaft portion 72. Thus, the posture of the mirror 9b attached to the mounting portion 74 can be freely adjusted, and the posture of the mirror 9b is adjusted so that the radio beam emitted from the test antenna 6g is reflected by the mirror 9b and directed to the DUT 100.

In the present embodiment, 1 mirror reflection antenna 6g and 5 mirrors 9b, 9c, 9d, 9e, and 9f are used, but the number is not limited thereto, and any number may be used depending on the test contents.

(embodiment 3)

Next, a test apparatus according to embodiment 3 of the present invention will be described.

The test apparatus according to embodiment 3 differs from embodiment 1 in that it uses 1 mirror 9d and 5 mirrors 9b, 9c, 9d, 9e, and 9 f. The same components are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

Fig. 14 is a plan view of the OTA dark room 50B according to the present embodiment as viewed from above with the top plate removed, and fig. 15 is a front view of the OTA dark room 50B as viewed from the front side with the side plate on the front side removed. As shown in fig. 14 and 15, the OTA darkroom 50B is provided with a reflector reflection type test antenna 6a, a reflector 7 corresponding thereto, a mirror reflection type test antenna 6d, and a mirror 9d corresponding thereto. In the present embodiment, direct test antennas 6h, 6i, 6j, and 6k for directly transmitting or receiving wireless signals to and from the antenna 110 of the DUT100 are also provided in the OTA darkroom 50B. Each test antenna 6 has a horizontally polarized antenna and a vertically polarized antenna.

The mirror 9d is configured such that a reflection point P4 of the electron beam on the mirror surface exists on a horizontal plane HP passing through the configuration position P0 of the DUT 100. The mirror reflection type test antenna 6d is disposed below a horizontal plane HP passing through the placement position P0 of the DUT 100.

The radio wave beam emitted from the mirror reflection type test antenna 6d is reflected by the mirror 9d and transmitted to the arrangement position P0 of the DUT 100. The radio beam emitted from the antenna 110 of the DUT100 is reflected by the mirror 9d and transmitted to the test antenna 6 d. The distance obtained by adding the distance between P0 and P4 and the distance between P4 and P14 is set to be equal to or more than the shortest distance between antennas required for far-field measurement.

In the present embodiment, the direct test antennas 6h, 6i, 6j, and 6k are arranged on the horizontal plane HP on the virtual spherical surface S having the radius r1 with the arrangement position P0 of the DUT100 as the center. Specifically, the reflection points P22, P23, P25, and P26 of the radio beam on the reflection surfaces of the direct test antennas 6h, 6i, 6j, and 6k are located on the horizontal plane HP. The direct test antennas 6h, 6i, 6j, and 6k do not need to be arranged at the same distance from the DUT100, and may have different distances from the DUT100 for the test antennas 6h, 6i, and 6k, respectively.

As described above, the test apparatus according to the present embodiment is suitable for an apparatus capable of securing a distance between antennas necessary for far-field measurement by a linear distance, using the direct type test antennas 6h, 6i, 6j, and 6k, and for an apparatus incapable of securing a distance between antennas necessary for far-field measurement by a linear distance, using the mirror reflection type test antenna 6 d. This makes it possible to minimize the number of mirrors.

In the present embodiment, 4 direct-type test antennas 6h, 6i, 6j, and 6k and 1 mirror reflection-type test antenna 6d are used, but the number is not limited thereto, and any number may be used depending on the test contents.

The present invention is applicable not only to an anechoic chamber but also to an anechoic chamber.

As described above, the present invention has an effect that far-field measurement of transmission/reception characteristics such as RF characteristics and RRM characteristics of a test object can be performed with high accuracy and at low cost, and is useful for a test apparatus and a test method for all wireless terminals.

Description of the symbols

1-test device, 2-measurement device, 5, 8-link antenna, 6-test antenna, 6 a-reflector reflection test antenna, 6b, 6c, 6d, 6e, 6 f-mirror reflection test antenna (1 st to 5 th test antennas), 6 g-mirror reflection test antenna, 6h, 6i, 6j, 6 k-direct test antenna, 7-reflector, 7A-mirror, 9b, 9c, 9d, 9e, 9 f-mirror (1 st to 5 th mirrors), 10-integrated control device, 11, 22-control section, 11a-CPU, 11b-ROM, 11 c-RAM, 11 d-external interface section, 12, 23-operation section, 13, 24-display section, 14-call connection control section, 15-signal transmission/reception control unit, 17-DUT attitude control unit, 17a-DUT attitude control table, 17 b-arrival angle-antenna correspondence table for test, 19-network, 20-NR system simulator, 21-signal measurement unit, 21 a-signal generation unit, 21b-DAC, 21 c-modulation unit, 21d-RF unit, 21 e-transmission unit, 21 f-reception unit, 21g-ADC, 21 h-analysis processing unit, 40-signal processing unit, 40 a-1 st signal processing unit, 40 b-2 nd signal processing unit, 41-signal switching unit, 50-dark OTA chamber (anechoic chamber), 51-internal space, 52-frame body unit, 52 a-bottom surface, 52 b-side surface, 52 c-top surface, 55-radio wave absorber, 56-attitude changing mechanism, 56 a-driving section, 56 b-turntable, 56 c-support, 56d-DUT mounting section, 57, 59-holder, 58-reflector holder, 60-direction changing mechanism (direction changing device), 61, 62, 72, 73-rotating shaft section, 70-mirror holder, 71-support, 74-mounting section, 90-rack structure, 90A-racks, 100-DUT (test object), 100A-wireless terminal, 110-antenna (test antenna), focal position of F-reflector, QZ-blank space, S-virtual spherical surface, HP-horizontal surface.