JP2024039494A - Test equipment and test method - Google Patents

Abstract

[Problem] Test equipment that can move a test antenna for RRM measurement without repeatedly bending and stretching the RF cable, and can avoid deterioration of frequency characteristics, disconnection of the RF cable, and decrease in space efficiency due to cable length. and test methods. A test device 1 is placed in a quiet zone (QZ) in an internal space of an anechoic box 50, and transmits a wireless signal to the DUT 100 to measure the transmission characteristics or reception characteristics of the DUT 100 whose attitude is sequentially changed. The first test antenna 6a and the second test antenna 6b that transmit or receive data from the test antenna are moved, and the positions of the second test antenna 6b are moved. and an antenna moving mechanism 60 that moves the converters 45 and 46 connected by the RF cables 47a and 47b while maintaining a constant positional relationship with the second test antenna 6b. [Selection diagram] Figure 7

Description

The present invention relates to a test device and a test method for measuring transmission characteristics or reception characteristics of a test object using an anechoic box in an OTA (Over The Air) environment.

In recent years, with the development of multimedia, wireless terminals (smartphones, etc.) equipped with antennas for wireless communication such as cellular and wireless LAN have been actively produced. In the future, there will be a particular need for wireless terminals that can transmit and receive wireless signals compatible with IEEE802.11ad, 5G cellular, etc., which use wideband signals in the millimeter wave band.

Wireless terminal design and development companies or their manufacturing factories measure the output level and reception sensitivity of the transmitted radio waves stipulated for each communication standard for the wireless communication antenna equipped on the wireless terminal, and measure these RF (Radio A performance test is conducted to determine whether the frequency characteristics meet predetermined standards. Furthermore, in the performance test, RRM (Radio Resource Management) characteristics are also measured. Measurement of RRM characteristics is performed to confirm whether radio resource control between a base station and a wireless terminal, for example, handover between adjacent base stations, etc., operates correctly.

With the generation transition from 4G or 4G Advanced to 5G, the test methods for the above-mentioned performance tests are also changing. For example, in a performance test that uses a wireless terminal for a 5G NR (New Radio) system as the device under test (DUT), the antenna terminal of the DUT and the test equipment, which are the mainstream in tests such as 4G and 4G Advanced, are used. The method of connecting by wire is that attaching an antenna terminal to the high-frequency circuit degrades the characteristics, and because the number of elements in the array antenna is large, attaching an antenna terminal to every element is impractical due to space and cost considerations. It cannot be used for other reasons. For this reason, the DUT is housed together with the test antenna in an anechoic box that is not affected by the surrounding radio wave environment. A so-called OTA test, in which reception with an antenna is performed by wireless communication, is being conducted (for example, see Patent Document 1).

In the OTA test, a test antenna placed in an anechoic box forms, for example, a spherical quiet zone, and the DUT is placed within the quiet zone. Here, the quiet zone is a concept representing the range of a spatial region in which the DUT is irradiated with radio waves of approximately uniform amplitude and phase from the test antenna in the anechoic box that constitutes the OTA test environment (for example, non-patent (See Reference 1). By arranging the DUT in such a quiet zone, it becomes possible to perform an OTA test while suppressing the influence of scattered waves from the surroundings.

JP2020-085784A

3GPP (registered trademark) TR 38.810

Conventional test equipment capable of performing OTA tests includes two types of test antennas placed in an anechoic box: a reflector-type test antenna that transmits and receives radio waves to and from the DUT via a reflector; Among the multiple test antennas for RRM measurement that transmit and receive radio waves to and from the DUT, one test for RRM characteristic measurement was conducted in order to reduce the number of test antennas for RRM measurement and to keep equipment costs and installation costs low. In some cases, the test antenna for RRM measurement is movably arranged through the arrangement positions of the plurality of test antennas for RRM measurement.

FIG. 14 shows the arrangement of a test antenna and mirror for RRM measurement in an anechoic box of a conventional test device. As shown in FIG. 14, according to the conventional test apparatus, the mirror M and one test antenna AT1 for measuring RRM characteristics are held by an antenna holding part 650, and the antenna movable mechanism (not shown) This enables rotational movement in the θ direction about the y-axis passing through the center of the quiet zone (QZ) (origin O).

Here, the test antenna AT1 is arranged below the horizontal plane HP that includes the reflection point P0 on the reflector 7 and the origin O, and the mirror M is arranged so that the reflection point P5 of the radio wave beam on the mirror surface is located on the horizontal plane HP. It is arranged as follows. The radio beam radiated from the test antenna AT1 is reflected by the mirror M and sent to the origin O where the DUT is placed. Further, the radio beam radiated from the antenna of the DUT is reflected by the mirror M and sent to the test antenna AT1. By bending the propagation path of the radio beam with the mirror M, it is possible to arrange the test antenna AT1 in the anechoic box and to secure the distance between the antennas necessary for far field measurement.

In the conventional test apparatus having the above-described configuration, the antenna holding section 650 holds the test antenna AT1 and is rotated together with the mirror M within a predetermined range (eg, 30° to 150°) in the θ direction. On the other hand, a frequency converter (hereinafter referred to as a converter) that converts the frequency of a signal sent to the test antenna AT1 or a signal received is fixedly arranged at a different position from the antenna holding part 650, and the antenna holding part 650 is rotationally driven. The test antenna AT1, which moves in conjunction with the test antenna AT1, is connected via an RF cable. Therefore, in the conventional test device, the RF cable connecting the test antenna AT1, which moves in conjunction with the movement of the antenna holding part 650, and the fixedly arranged converter moves in accordance with the reciprocating movement of the test antenna AT1. I had to repeat bending and stretching.

As a result, in the conventional test apparatus, there was a problem in that the frequency characteristics changed due to bending of the RF cable connecting the test antenna AT1 and the converter, making it impossible to obtain accurate measurement results. In addition, repeated bending and stretching of the RF cable causes metal fatigue in the metal used in the RF cable, resulting in deterioration of frequency characteristics due to breakage of the outer conductor, deterioration of shielding performance, and disconnection of the inner conductor. There was also. Furthermore, the cable length of the RF cable connecting the test antenna AT1 and the converter has to be long, and there are other problems such as the cable movable range cannot be used effectively.

The present invention was made to solve such conventional problems, and it is possible to move a test antenna for RRM measurement without repeating bending and stretching of the RF cable, thereby preventing deterioration of frequency characteristics and RF The purpose of the present invention is to provide a test device and a test method that can avoid cable breakage and a decrease in space efficiency due to cable length.

In order to solve the above problems, a test device according to the present invention is a test device (1) that measures the transmission characteristics or reception characteristics of a target under test (100) having an antenna under test (110). a radio anechoic box (50) having an internal space (51) that is unaffected by the radio wave environment; and a posture variable mechanism (56) that sequentially changes the posture of the test object placed within a quiet zone (QZ) in the internal space. , a first test antenna (6a) and a second test antenna that are housed in the internal space and transmit or receive a wireless signal from the antenna under test for measuring the transmission characteristics or reception characteristics of the object under test. a test antenna (6b), a reflector (7) that reflects the radio signal emitted by the first test antenna and converts it into a plane wave radio signal, and a radio wave arrival direction from the first test antenna. The position of the second test antenna is moved so that radio signals can be transmitted or received at a plurality of angles of arrival to the target under test installed in a far field, and Antenna movable to move the frequency converter (45, 46) connected to the second test antenna by an RF cable (47a, 47b) while maintaining a constant positional relationship with the second test antenna. A mechanism (60).

As described above, the test device according to the present invention moves the position of the second test antenna and also connects the frequency converter (45, 46) to the second test antenna by an RF cable. It includes an antenna moving mechanism (60) that moves the antenna while maintaining a constant positional relationship with the second test antenna. With this configuration, in the test apparatus according to the present invention, when performing far-field measurement of transmission and reception characteristics such as RRM characteristics of the object under test, the second test antenna for far-field measurement is set at a frequency that moves together with the second test antenna for far-field measurement. It is connected to the converter with a short RF cable and can be moved without bending or stretching the RF cable. Since the RF cable does not undergo repeated bending and stretching, the frequency characteristics do not change due to bending of the RF cable.Furthermore, the metal used in the RF cable causes metal fatigue, and the frequency decreases due to damage to the outer conductor. Deterioration of characteristics, deterioration of shielding performance, and disconnection of the inner conductor will no longer occur. Furthermore, the cable length of the RF cable connecting the second test antenna and the converter has been changed from the conventional configuration in which a long RF cable is used to connect the second test antenna and the fixedly placed converter. It can be made much shorter than the conventional RF cable, and it becomes possible to effectively utilize the movable range of the conventional RF cable.

Furthermore, in the test device according to the present invention, the antenna movable mechanism includes an antenna holding part (610) that holds the second test antenna, and a frequency converter housing part (620) that houses the frequency converter. , a moving mechanism (700) that moves the antenna holding section and the frequency converter accommodating section on a circle.

With this configuration, the test apparatus according to the present invention moves the antenna holding part and the frequency converter accommodating part on a circle using the antenna moving mechanism, thereby moving the second test antenna held by the antenna holding part and the frequency The frequency converter accommodated in the converter accommodating portion can be moved while maintaining a constant positional relationship at all times, and the movement can be easily controlled.

Furthermore, in the test device according to the present invention, the second test antenna includes a horizontally polarized antenna (6bH) that transmits and receives horizontally polarized waves, and a vertically polarized antenna (6bV) that transmits and receives vertically polarized waves; The frequency converter accommodating section is provided separately for each of the horizontally polarized wave and the vertically polarized wave, and is configured to accommodate the converter having the functions of an up-converter, a down-converter, or both. There may be.

With this configuration, the test apparatus according to the present invention connects the frequency converter connected to the horizontally polarized antenna and the vertically polarized antenna of the second test antenna by the respective RF cables to the horizontally polarized antenna and the vertically polarized antenna of the second test antenna. It can be moved together with the polarized antenna, and the RF cable will not be bent or stretched during movement.

Further, the test device according to the present invention reflects the radio signal radiated from the second test antenna and sends it to the antenna under test, and also reflects the radio signal radiated from the antenna under test and sends it to the antenna under test. The antenna may further include a mirror (9) for sending data to the second test antenna, and the antenna holding section may be configured to hold the second test antenna and the mirror at intervals in the longitudinal direction.

With this configuration, the test device according to the present invention can change the route of the wireless signal transmitted and received between the second test antenna and the antenna under test using the mirror, and can operate in the limited internal space of the anechoic box. It is also possible to secure the distance between antennas necessary for far-field measurements.

Further, in the test device according to the present invention, the antenna holding section includes a columnar support (61) that holds the second test antenna and the mirror, and a columnar support (61) that holds the second test antenna and the mirror, and the second further comprising an electromagnetic wave shielding mechanism (611) provided so as to surround the test antenna, the electromagnetic wave shielding mechanism including a first shield provided between the second test antenna and the quiet zone. A configuration including a plate (612) and a second shielding plate (613) provided between the second test antenna and the reflector may be used.

With this configuration, the test apparatus according to the present invention can shield direct waves (spherical waves) radiated from the second test antenna with the first shield plate provided between the test antenna and the quiet zone. This prevents direct wave interference with the reflected wave (plane wave) that is radiated from the second test antenna, is reflected by the mirror, and reaches the object under test, and improves the frequency characteristics of the RRM characteristics of the object under test. can. Furthermore, in the test apparatus according to the present invention, direct waves (spherical waves) radiated from the second test antenna can be shielded by the second shielding plate provided between the test antenna and the reflector. This prevents the direct wave (spherical wave) radiated from the second test antenna from interfering with the reflected wave (plane wave) radiated from the first test antenna, reflected by the reflector, and reaching the test object. The frequency characteristics of the RF characteristics of the object under test can be improved.

Further, a test method according to the present invention is a test method using any of the test devices described above, and includes a step (S2) of selecting one arrival angle from the plurality of arrival angles; The position of the second test antenna is moved by the antenna movable mechanism so that the arrival angle is the same, and the frequency conversion is connected to the second test antenna by an RF cable (47a, 47b). a step (S3) of moving the device (45, 46) while maintaining a constant positional relationship with the second test antenna; and sequentially changing the posture of the test object placed in the quiet zone. step (S5), each time the posture of the object under test is changed, measuring the transmission characteristics or reception characteristics of the object under test using the first test antenna and the second test antenna; (S8).

As described above, the test apparatus used in the test method according to the present invention moves the position of the second test antenna, and also moves the frequency converter (45) connected to the second test antenna by an RF cable. , 46) while maintaining a fixed positional relationship with the second test antenna. Then, in this test method, the position of the second test antenna is moved by the antenna movable mechanism so that the arrival angle is selected, and the second test antenna is connected to the second test antenna by an RF cable. It includes a step (S3) of moving the frequency converter (45, 46) while maintaining a constant positional relationship with the second test antenna. As a result, in this test method, when performing far-field measurements on the transmission and reception characteristics such as RRM characteristics of the object under test, the second test antenna for far-field measurement is connected to a frequency converter that moves together with the antenna. It can be connected with an RF cable and moved without bending or stretching the RF cable. Since the RF cable does not undergo repeated bending and stretching, the frequency characteristics do not change due to bending of the RF cable.Also, as the RF cable is repeatedly bent, the metal used in the RF cable becomes metal. This eliminates fatigue, deterioration of frequency characteristics due to breakage of the outer conductor, deterioration of shielding performance, and disconnection of the inner conductor. Furthermore, the cable length of the RF cable connecting the second test antenna and the converter has been changed from the conventional configuration in which a long RF cable is used to connect the second test antenna and the fixedly placed converter. It can be made much shorter than the conventional RF cable, and it becomes possible to effectively utilize the movable range of the conventional RF cable.

According to the present invention, a test antenna for RRM measurement can be moved without repeatedly bending and stretching the RF cable, and it is possible to avoid deterioration of frequency characteristics, disconnection of the RF cable, and decrease in space efficiency due to cable length. We can provide testing equipment and testing methods.

1 is a diagram showing a schematic configuration of an entire test apparatus according to an embodiment of the present invention. FIG. 1 is a block diagram showing the functional configuration of a test device according to an embodiment of the present invention. 1 is a block diagram showing a functional configuration of an integrated control device of a test device according to an embodiment of the present invention. FIG. FIG. 2 is a block diagram showing the functional configuration of the NR system simulator of the test device according to the embodiment of the present invention. FIG. 2 is a plan view of the anechoic box of the test device according to the embodiment of the present invention, viewed from above with the top plate removed. FIG. 3 is a front view of the anechoic box as seen from the front side with the side plate on the front side removed. FIG. 2 is a schematic diagram showing the arrangement of a test antenna, a mirror, and a converter in an anechoic box of a test device according to an embodiment of the present invention. It is a figure showing the structure seen from the back side of the movable object accommodating part of the antenna movable mechanism in the test device concerning an embodiment of the present invention. 1 is a flowchart showing an outline of a test method performed using a test device according to an embodiment of the present invention. FIG. 2 is a plan view showing the structure of the anechoic box of the test device according to the embodiment of the present invention, when viewed from above with the top plate removed. (a) is a schematic diagram for explaining the radio wave shielding function by the shielding plate 1 between the test antenna and the quiet zone of the test device according to the embodiment of the present invention, and (b) is a schematic diagram without the shielding plate 1. FIG. 3 is a schematic diagram for explaining the radio wave interference situation in the same section in the device of the reference example. 1A is a schematic diagram for explaining the radio wave shielding function of a shielding plate 2 between a test antenna and a reflector of a test device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram for explaining the radio wave interference situation in the same section of a reference example device that does not have a shielding plate 2. FIG. 3 is a front view showing the configuration of a mirror held by the antenna holding section of the test device according to the embodiment of the present invention. FIG. 2 is a schematic diagram showing the arrangement of a test antenna and a mirror in an anechoic box of a conventional test device.

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

A test apparatus 1 according to an embodiment of the present invention measures the transmission characteristics or reception characteristics of a DUT 100 having an antenna 110, and is configured to measure, for example, the RF characteristics or RRM characteristics of the DUT 100. For this purpose, the test apparatus 1 includes an anechoic box (also referred to as an OTA chamber) 50, two test antennas 6a and 6b (hereinafter sometimes collectively referred to as the test antenna 6), a variable attitude mechanism 56, It includes an integrated control device 10, an NR system simulator 20, and a signal processing section 40. The integrated control device 10, the NR system simulator 20, and the signal processing section 40 constitute the measuring device 2.

FIG. 1 shows the external structure of the test device 1, and FIG. 2 shows the functional blocks of the test device 1. However, FIG. 1 shows the arrangement of each component when the anechoic box 50 is viewed from the front.

As shown in FIGS. 1 and 2, the anechoic box 50 has an internal space 51 that is not affected by the surrounding radio wave environment. The test antenna 6 is installed in the internal space 51 of the anechoic box 50, and is adapted to transmit or receive a wireless signal to/from the antenna 110 for measuring the transmission characteristics or reception characteristics of the DUT 100. The attitude variable mechanism 56 is configured to change the attitude of the DUT 100 placed within a quiet zone (QZ) in the internal space 51 of the anechoic box 50. The integrated control device 10, the NR system simulator 20, and the signal processing unit 40 use one or two test antennas 6 for the DUT 100 whose attitude has been changed by the attitude change mechanism 56, and measure the transmission characteristics or reception characteristics of the DUT 100. It is now possible to take measurements.

The test apparatus 1 is used, for example, with a rack structure 90 having a plurality of rack storage parts 90a as shown in FIG. 1, and is operated with each component placed in each rack storage part 90a. FIG. 1 shows an example in which an integrated control device 10, an NR system simulator 20, and an anechoic box 50 are placed in three rack storage sections 90a of a rack structure 90, respectively. Each component will be explained below.

(anechoic box)
The anechoic box 50 is used to measure the transmission or reception characteristics of a wireless terminal, and provides an OTA test environment for performance testing of a 5G wireless terminal, for example. As shown in FIGS. 1 and 2, the anechoic box 50 includes, for example, a metal housing main body 52 having an internal space 51 in the shape of a rectangular parallelepiped. The anechoic box 50 accommodates the DUT 100 and two test antennas 6 directly or indirectly facing the antenna 110 of the DUT 100 in an internal space 51 in a state that prevents radio waves from entering from the outside and radio waves from radiating to the outside. It is supposed to be done.

In addition, a radio wave absorber 55 is attached to the entire inner surface of the anechoic box 50, that is, the entire bottom surface 52a, side surface 52b, and top surface 52c of the housing body 52, to ensure the anechoic characteristics of the internal space 51. The function of regulating the radiation of radio waves to the outside has been strengthened. In this way, the anechoic box 50 forms an internal space 51 that is not affected by the surrounding radio wave environment. The anechoic box 50 used in this embodiment is, for example, a CATR (Compact Antenna Test Range) type anechoic chamber.

(DUT)
The DUT 100 to be tested is, for example, a wireless terminal such as a smartphone. Communication standards for 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/n/ac/ad, etc.), Bluetooth (registered trademark), GNSS (GPS, Galileo, GLONASS, BeiDou, etc.), FM, and digital broadcasting (DVB-H, ISDB-T, etc.). Further, the DUT 100 may be a wireless terminal that transmits and receives wireless signals in the millimeter wave band compatible with 5G cellular and the like.

In this embodiment, the DUT 100 is, for example, a 5G NR wireless terminal. For 5G NR wireless terminals, the 5G NR standard stipulates that the communicable frequency range is a predetermined frequency band that includes other frequency bands used in LTE, etc. in addition to the millimeter wave band. Therefore, the antenna 110 of the DUT 100 transmits or receives a radio signal in a predetermined frequency band (5G NR band), which is the object of measurement of the transmission characteristics or reception characteristics of the DUT 100. The antenna 110 is, for example, an array antenna such as a Massive-MIMO antenna, and corresponds to the antenna under test in the present invention.

In this embodiment, the DUT 100 is configured to be able to transmit and receive test signals and signals under test via the test antenna 6 and, if necessary, the reflector 7 or mirror 9 during measurements regarding transmission and reception characteristics within the anechoic box 50. There is.

(Posture variable mechanism)
Next, the attitude variable mechanism 56 provided in the internal space 51 of the anechoic box 50 will be explained. As shown in FIG. 1, a posture variable mechanism 56 for changing the posture of the DUT 100 placed in the quiet zone is provided on the bottom surface 52a (floor) of the housing body 52 of the anechoic box 50 on the internal space 51 side. ing. The posture variable mechanism 56 is, for example, a two-axis positioner that includes a rotation mechanism that rotates around two axes. The attitude variable mechanism 56 constitutes an OTA test system (Combined-axes system) that rotates the DUT 100 with rotational degrees of freedom around two axes with the test antenna 6 set. Specifically, the posture variable mechanism 56 includes a drive section 56a, a turntable 56b, a support 56c, and a DUT mounting section 56d as a test object mounting section.

The drive unit 56a is composed of a drive motor such as a stepping motor that generates rotational driving force, and is installed on the bottom surface 52a, for example. The turntable 56b is configured to rotate by a predetermined angle around one of two axes orthogonal to each other by the rotational driving force of the drive unit 56a. The support column 56c is connected to the turntable 56b, extends from the turntable 56b in the direction of one axis, and rotates together with the turntable 56b by the rotational driving force of the drive section 56a. The DUT mounting section 56d extends from the side surface of the support column 56c in the direction of the other of the two axes, and is rotated by a predetermined angle around the other axis by the rotational driving force of the driving section 56a. The DUT 100 is placed on the DUT placement section 56d.

Note that one of the above-mentioned axes is, for example, an axis (Y axis in the figure) extending in a direction perpendicular to the bottom surface 52a. Further, the other axis mentioned above is, for example, an axis extending in the horizontal direction from the side surface of the support column 56c. The posture variable mechanism 56 configured as described above rotates the DUT 100 held on the DUT mounting portion 56d in all three-dimensional directions with respect to the test antenna 6 and the reflector 7, for example, with the center of the DUT 100 as the rotation center. The antenna 110 can be rotated so as to sequentially change its attitude to a state where the antenna 110 is facing.

In the OTA test system, the center of the DUT 100 or the center of the antenna 110 is arranged at the rotation center (also referred to as the origin O), which is the intersection of the two rotation axes of the variable attitude mechanism 56. The position where the DUT 100 is placed is the origin O of the OTA test system, which is the center of the DUT 100 placed in the anechoic box 50 or the center of the antenna 110. That is, the origin O corresponds to an immovable center of rotation when the DUT 100 is rotated around two axes by the variable attitude mechanism 56.

(link antenna)
In the anechoic box 50, two types of link antennas 5 and 8 for establishing or maintaining a link (call) with the DUT 100 are mounted at predetermined positions in the main body part 52 using holders 57 and 59, respectively. installed. The link antenna 5 is a link antenna for LTE, and is used in non-standalone mode. On the other hand, the link antenna 8 is a 5G link antenna and is used to maintain 5G calls. The link antennas 5 and 8 are held by holders 57 and 59, respectively, so as to have directivity with respect to the DUT 100 held by the variable attitude mechanism 56. Note that instead of using the above-mentioned link antennas 5 and 8, it is also possible to use the test antenna 6 as a link antenna. Therefore, in the following, the test antenna 6 will be described as having the function of a link antenna. do.

(Near field and far field)
Next, the near field and far field will be explained. A case in which radio waves are transmitted directly from the antenna to the DUT 100 is called a DFF (Direct Far Field) method, and a case in which radio waves are transmitted from the antenna to the DUT 100 after being reflected by a reflector 7 having a paraboloid of revolution is called an IFF (Indirect Far Field) method.

Radio waves with an antenna as a radiation source have the property of propagating while a surface (wavefront) connecting points of the same phase spreads out in a spherical shape with the radiation source as the center. At a short distance from the radiation source, the wavefront is a curved spherical surface (spherical wave), but as it moves away from the radiation source, the wavefront becomes close to a plane (plane wave). Generally, the region where the wavefront needs to be considered as a spherical surface is called the near field (NEAR FIELD), and the region where the wavefront can be considered as a plane is called the far field (FAR FIELD). In order to perform accurate measurements, it is preferable for the DUT 100 to receive a plane wave rather than a spherical wave.

In order to receive plane waves, the DUT 100 needs to be installed in the far field. When the location and antenna size of antenna 110 within DUT 100 are not known, the far field is the region beyond 2D2/λ from the antenna. Here, D is the maximum linear size of the DUT 100, and λ is the wavelength of the radio wave. Note that when the position and antenna size of the antenna 110 within the DUT 100 are known, D is the antenna size.

In this embodiment, a CATR method is used in which the radio waves from the test antenna 6a are reflected by the paraboloid of revolution of the reflector 7 and the reflected waves reach the position of the DUT 100. According to this method, the distance between the test antenna 6a and the DUT 100 can be shortened, and since the plane wave region expands from the distance immediately after reflection on the reflective mirror surface of the reflector 7, propagation loss can also be reduced. The degree of plane waves can be expressed by the phase difference between waves of the same phase. An acceptable phase difference in terms of plane waves is, for example, λ/16. The phase difference can be evaluated with a vector network analyzer (VNA), for example.

(Test antenna)
Next, the test antenna 6 will be explained.
FIG. 5 is a plan view of the anechoic box 50 of the test apparatus 1 according to the present embodiment, viewed from above with the top plate removed, and FIG. It is a front view seen from the front side with side plates removed.

The test antenna 6 includes one reflector-type test antenna 6a as a first test antenna, and one mirror-reflector test antenna 6b (see FIG. 6) as a second test antenna. Contains. The test antenna 6a of the reflector type transmits or receives a radio signal (hereinafter also referred to as a measurement radio signal) for measuring the transmission characteristics or reception characteristics of the DUT 100 between it and the antenna 110 via the reflector 7. It is supposed to be done. The mirror reflection type test antenna 6b is configured to transmit or receive a radio signal for measuring the transmission characteristics or reception characteristics of the DUT 100 between the mirror reflection type test antenna 6b and the antenna 110 included in the DUT 100 via the mirror 9. .

(Reflector type test antenna)
The test antenna 6a of the reflector type is used together with the reflector 7 and functions as a primary radiator. As the test antenna 6a, for example, a directional millimeter wave antenna such as a horn antenna can be used. The reflector 7 has a curved reflective surface made of aluminum, for example, and reflects the radio waves of the wireless signal for measurement, and is an offset formed by cutting out a part of the paraboloid of revolution of a perfect circular parabola. It has a parabolic structure. As shown in FIG. 1, the reflector 7 is attached to a predetermined position on the side surface 52b of the anechoic box 50 using a reflector holder 58.

The reflector 7 receives, on its paraboloid of revolution, radio waves of a test signal radiated from the test antenna 6a as a primary radiator, which is placed at a focal point determined by the paraboloid of revolution, and is held by the attitude variable mechanism 56. reflected toward the DUT 100 (during transmission). Further, the reflector 7 receives the radio wave of the signal to be measured emitted from the antenna 110 by the DUT 100 that has received the test signal on a paraboloid of revolution, and reflects it toward the test antenna 6a (during reception). The reflector 7 is placed in a position and attitude that allows for simultaneous transmission and reception. That is, the reflector 7 is configured to reflect radio waves of a wireless signal transmitted and received between the test antenna 6a and the antenna 110 of the DUT 100 on a paraboloid of revolution.

With this configuration, the radio waves radiated from the test antenna 6a (for example, a test signal for the DUT 100) are reflected by the paraboloid of revolution in a direction parallel to the axial direction of the paraboloid of revolution, and the axis of the paraboloid of revolution is A radio wave (for example, a signal to be measured transmitted from the DUT 100) that is incident on the paraboloid of revolution in a direction parallel to the paraboloid of revolution can be reflected by the paraboloid of revolution and guided to the test antenna 6a. In other words, the reflector 7 converts the spherical wave radio waves radiated from the test antenna 6a into plane wave radio waves and sends them to the DUT 100, and also converts the plane wave radio waves radiated from the DUT 100 and incident on the reflector 7 to the test antenna 6a. 6a. In the offset parabola, the reflector 7 itself can be smaller than the parabolic type, and it can be arranged so that the mirror surface is close to vertical, so the structure of the anechoic box 50 can be made smaller.

As shown in FIG. 6, the test antenna 6a of the reflector type is arranged below the horizontal plane HP passing through the arrangement position (origin O) of the DUT 100. The radio wave beam radiated from the test antenna 6a and reflected by the reflector 7 is propagated in the negative direction of the Z-axis to form a quiet zone with a required radius r1 (FIG. 5). The test antenna 6a of the reflector type includes a horizontally polarized antenna 6aH and a vertically polarized antenna 6aV (see FIG. 2).

(Mirror reflection type test antenna)
Similar to the reflector reflection type test antenna 6a, the mirror reflection type test antenna 6b is capable of transmitting and receiving horizontally polarized waves and vertically polarized waves. It has a wave antenna 6bV (see FIG. 2). The mirror reflection type test antenna 6b is configured to transmit or receive a wireless signal to/from the antenna 110 of the DUT 100 via a flat mirror 9 that reflects the radio waves of the wireless signal for measurement. (See Figure 6). The mirror 9 is made of aluminum, for example, and has a flat mirror surface.

As shown in FIG. 6, the radio wave beam radiated from the mirror reflection type test antenna 6b is specularly reflected by the mirror 9 and radiated to the quiet zone. Furthermore, the radio wave beam radiated from the antenna 110 of the DUT 100 placed in the quiet zone is specularly reflected by the mirror 9 and received by the mirror reflection type test antenna 6b.

(mirror)
The mirror 9 is arranged so that its reflective surface intersects the horizontal plane HP passing through the arrangement position P0 of the DUT 100 (see FIG. 6). Specifically, the mirror 9 is arranged on a virtual spherical surface S having a radius r2 centered on the arrangement position P0 of the DUT 100 and on a horizontal plane HP (see FIG. 5). According to FIGS. 5 and 6, the reflection points P2, P3, P4, P5, and P6 on the reflection surface of the mirror 9 where the center of the radio wave beam is reflected are located on the virtual spherical surface S and on the horizontal plane HP. I can understand.

(Overview of antenna movable mechanism)
As shown in FIG. 6, the mirror reflection type test antenna 6b and the mirror 9 are held by an antenna holding section 610 in a state in which they maintain a constant positional relationship. The antenna holding section 610 constitutes the moving object holding section 600 together with the converter housing section 620 (shown by a solid line in FIG. 5 and shown by a dotted line in FIG. 6).

Converter accommodating portion 620 accommodates converters 45 and 46 (see FIG. 8). The converters 45 and 46 are functional units that perform frequency conversion processing on signals transmitted and received between each of the horizontally polarized antenna 6bH and vertically polarized antenna 6bV of the test antenna 6b and the NR system simulator 20, as described later. be. Converter accommodating section 620 corresponds to the frequency converter accommodating section of the present invention.

As shown in FIGS. 5 and 6, the moving object holding unit 600 is placed on a movable table 77 that constitutes a moving mechanism 700, and is moved along with the movable table 77 from position P1 in FIGS. 5 and 6 by the moving mechanism 700. It is possible to reciprocate in the direction D1 indicated by the arrow in the area including position P5. In FIGS. 5 and 6, the movable base 77 is drawn with a solid line when it is at that position (for example, position P5), and when it is moved and is not at that position (for example, positions P4, P3, P2, P1). is drawn with a dotted line. According to FIGS. 5 and 6, the movable table 77 is movable in the direction D1 on a circle within the range of positions P5 to P1.

In FIGS. 5 and 6, a moving target holding unit 600 loaded on a movable table 77 includes an antenna holding unit 610 that holds a mirror reflection type test antenna 6b and a mirror 9, and a converter housing that stores converters 45 and 46. 620. As described above, in the test apparatus 1 according to the present embodiment, the movable object holding section 600 that is placed on the movable table 77 and includes the antenna holding section 610 and the converter accommodating section 620, and the moving mechanism 700 that moves the movable table 77. An antenna movable mechanism 60 is configured.

The antenna movable mechanism 60 reciprocates the moving object holding section 600 along the arcuate trajectory of the moving mechanism 700 in the direction D1 while passing through positions P1, P2, P3, P4, and P5 shown in FIGS. 5 and 6. It is now possible to move it. During this movement, the test antenna 6b held by the antenna holding part 601 and the mirror 9 are both at positions P1 and P2, as shown in FIG. 5, when the internal space 51 of the anechoic box 50 is viewed from above. , P3, P4, and P5, and can be stopped. At this time, when looking at the internal space 51 from the side, the test antenna 6b follows the movement of the mirror 9 to any measurement position including positions P11, P12, P13, P14, and P15, as shown in FIG. It is designed to move horizontally and can be stopped. Thereby, communication via the mirror 9 between the test antenna 6b and the DUT 100 is maintained no matter where the test antenna 6b is located in the above-described arc shape.

To move the test antenna 6b and the mirror 9 (that is, the antenna holding section 610) to arbitrary positions by the antenna moving mechanism 60, the moving mechanism 700 of the antenna moving mechanism 60 is moved from the antenna position control section 18 of the integrated control device 10. This is done by controlling the drive.

FIG. 7 shows the arrangement of the mirror 9, the test antenna 6b, and the converters 45 and 46 in the anechoic box 50 having the antenna movable mechanism 60 configured as described above.

As shown in FIG. 7, the antenna movable mechanism 60 includes a moving object holding section 600 and a moving mechanism 700, and the moving object holding section 600 further includes an antenna holding section 610 and a converter accommodating section 620. In the antenna holding unit 600, the mirror 9 and the test antenna 6b are held in a predetermined positional relationship (see FIG. 6), and the antenna movable mechanism 60 moves the antenna in the θ direction around the y-axis passing through the origin O. It can be rotated and moved. The test antenna 6b is arranged below the horizontal plane HP, and the mirror 9 is arranged so that the reflection point P5 of the radio wave beam on the mirror surface is located on the horizontal plane HP.

The radio wave beam radiated from the test antenna 6b is reflected by the mirror 9 and sent to the origin O where the DUT 100 is placed. Further, the radio wave beam radiated from the antenna 110 of the DUT 100 is reflected by the mirror 9 and sent to the test antenna 6b. If the mirror 9 were not provided, the test antenna 6A would be placed outside the anechoic box 50, making it impossible to secure the inter-antenna distance (O-PA distance) required for far-field measurement. By bending the propagation path of the radio wave beam with the mirror 9, it is possible to arrange the test antenna 6b inside the anechoic box 50 and to secure the distance between the antennas necessary for far field measurement.

Specifically, in FIG. 7, the sum of the O-P5 distance and the P5-P15 distance is equal to the O-PA distance, which is the inter-antenna distance required for far-field measurement. P5 indicates a reflection point where the radio wave beam radiated from the test antenna 6b is reflected on the mirror 9, P15 is the aperture center of the test antenna 6b, and PA is the aperture center of the virtual test antenna 6A. It is. The propagation path between O and P5 is on the horizontal plane HP. The radio wave beam radiated from the reflector test antenna 6a is reflected at the reflection point P0 on the reflector 7 and sent to the origin O where the DUT 100 is placed, and the propagation path between P0 and O is also on the horizontal plane. It's on the website.

The test antenna 6a of the reflector type forms a so-called indirect far field (IFF), and the test antenna 6b of the mirror reflection type forms a direct far field (DFF). Indirect far field refers to the far field formed by a reflective antenna that uses a reflector that converts spherical waves into plane waves, and direct far field refers to the far field formed directly by an antenna that does not use such a reflector. Refers to the far field. Note that although the mirror reflection type test antenna 6b uses a mirror 9 to reflect the radio wave beam, the distance that the radio wave beam travels from the test antenna 6b to the far field is the same as when there is no mirror. Therefore, it can be considered a DEF type antenna.

For example, when the antenna size D of the antenna 110 is known, the distance from the mirror reflection type test antenna 6b to the antenna 110 of the DUT 100 via the corresponding mirror 9 is preferably larger 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 test antenna 6. Thereby, far field measurement of the DUT 100 can be performed.

The mirror reflection type test antenna 6b and the mirror 9 are arranged outside the path of the radio wave beam that reflects the reflector 7 of the reflector reflection type test antenna 6a and passes through the quiet zone. With this configuration, the test apparatus 1 according to the present embodiment can form a good quiet zone.

Further, in this embodiment, the quiet zone formed by the mirror reflection type test antenna 6b is the same as the quiet zone formed by the reflector reflection type test antenna 6a, but the present invention is not limited thereto. The quiet zone formed by the mirror reflection type test antenna 6b and the quiet zone formed by the reflector reflection type test antenna 6a may be different. For example, if the quiet zone formed by the reflector-reflection test antenna 6a is made wider, when measuring RF characteristics etc. using the reflector-reflection test antenna 6a alone, the quiet zone will be wider. can be used.

(Arrival angle)
As shown in FIGS. 5 and 6, the antenna movable mechanism 60 transmits or receives radio signals at a plurality of different arrival angles to the DUT 100 based on the radio wave arrival direction (Z-axis negative direction) from the test antenna 6a. The positions of the test antenna 6b and the mirror 9 are each moved on a circle so that the test antenna 6b and the mirror 9 can be moved in a circle. The plurality of arrival angles are, for example, 30°, 60°, 90°, 120°, and 150°. In this way, since measurements can be made evenly and without omission within a predetermined angular range, far-field measurements of transmission and reception characteristics such as RRM characteristics of the DUT 100 can be performed with high accuracy. Thereby, for example, the RRM characteristics specified in the standard 3GPP TR 38.810 V16.2.0 (2019-03) can be measured with high accuracy.

Here, "AoA (Angle of Arrival)" refers to the angle of arrival from the test antenna 6 to the origin O with respect to a specific straight line (for example, the Z axis) passing through the origin O where the DUT 100 is placed. Refers to a radio wave beam or the angle formed by the center of the radio wave beam. The angle of arrival can also be defined by two test antennas. In this case, the angle formed by the radio wave beam arriving at the origin O from the other test antenna or the center of the radio wave beam is based on the radio wave arrival direction, which is the direction of the radio wave beam arriving at the origin O from one test antenna. is called the "angle of arrival" or "relative angle of arrival."

(Antenna movable mechanism)
Next, the antenna movable mechanism 60 will be explained in detail.

The antenna movable mechanism 60 is designed to directly transmit or receive wireless signals at a plurality of arrival angles to the DUT 100 installed in the far field based on the radio wave arrival direction from the test antenna 6a. The position of the antenna 6b is moved on a circle. Further, the antenna movable mechanism 60 is configured to move the converters 45 and 46, which perform frequency conversion processing on signals transmitted and received by the test antenna 6b, on the above-mentioned circle together with the test antenna 6b.

In order to realize this, the antenna movable mechanism 60 includes a moving object holding section 600 that holds moving objects such as the test antenna 6b, mirror 9, converters 45 and 46, and a moving object holding section as shown in FIG. A moving mechanism 700 that performs 600 movements is provided.

The moving object holding section 600 is moved by the moving mechanism 700 by moving the movable table 77 in an arc shape along the guide rail 73 that constitutes the circular motion section 701. The object holder 600 is also based on the principle of moving along the arcuate trajectory.

(Moving object holding part)
The moving object holding section 600 holds the moving object moved by the antenna movable mechanism 60, and includes an antenna holding section 610 and a converter accommodating section 620, as shown in FIG.

The antenna holding part 610 and the converter accommodating part 620 are placed on a movable base 77 that is reciprocated in a circle by a moving mechanism 700, and are moved together with the movable base 77 along the arcuate trajectory described above. It is designed to be able to move back and forth in direction D1.

(antenna holding part)
The antenna holding section 610 holds the test antenna 6b and the planar mirror 9, as shown in FIG. The test antenna 6b and the mirror 9 are held by an antenna holding part 610 with a required spacing between them. The mirror 9 reflects the radio waves of the radio signal radiated from the test antenna 6b and sends them to the antenna 110 of the DUT 100, and also reflects the radio waves of the radio signal radiated from the antenna 110 of the DUT 100 and sends them to the test antenna 6b. It looks like this. The antenna movable mechanism 60 moves the position of the planar mirror 9 together with the test antenna 6b.

With this configuration, the path of the wireless signal transmitted and received between the test antenna 6b and the antenna 110 of the DUT 100 can be changed by the mirror 9, so even if the radio signal is transmitted and received in the narrow internal space 51 of the anechoic box 50, it can be It is possible to secure the distance between antennas necessary for field measurements.

As shown in FIG. 8, the antenna holding section 610 has a long and thin bar-shaped or columnar support 61 that holds the test antenna 6b and the mirror 9 at intervals in the longitudinal direction. Specifically, a mirror attachment part 62 is provided at one end of the support column 61 and extends in a direction perpendicular to the longitudinal direction of the support column 61, and the mirror 9 is attached to the end of the mirror attachment part 62 while tilting at a predetermined angle. It is being Further, as shown in FIG. 8, an antenna mounting part 63 extending in a direction perpendicular to the longitudinal direction is provided at the middle of the longitudinal direction of the support column 61, and an angle adjustment table 64 is mounted at the end of the antenna mounting part 63. The test antenna 6b is attached to the angle adjustment table 64 at a predetermined angle. The other end of the support column 61 is attached to the upper surface of a support plate 65, and the support plate 65 is fixed to a movable base 77 that constitutes a moving mechanism 700 by a fixture 65a. The column 61 is configured such that the longitudinal direction of the column 61 is the vertical direction.

The angle of the test antenna 6b and the angle of the mirror 9 are set so that the radio wave beam of the wireless signal radiated from the test antenna 6b is reflected by the mirror 9 and sent to the DUT 100.

In this embodiment, the support plate 65 is used to support the column 61 of the antenna holding part 610, but the end of the column 61 may be directly fixed to the movable table 77.

As shown in FIG. 8, the antenna holder 610 having the above-described configuration holds the test antenna 6b sideways (antenna It further includes an electromagnetic wave shielding mechanism 611 that surrounds it from three sides (excluding the mounting part 63 side). In addition, in the antenna holding portion 610, the mirror 9 has a notch portion 9a that is a portion of the mirror area, as shown in FIG. The configuration of the electromagnetic wave shielding mechanism 611 and the mirror 9 having the notch 9a will be described in detail later with reference to FIGS. 10 to 13.

(Converter housing)
Converter housing section 620 is attached to a position adjacent to antenna holding section 610 on movable base 77, as shown in FIG. In the example of FIG. 8, the converter accommodating part 620 is attached, for example, at a position to the left of the antenna holding part 610 when the antenna movable mechanism 60 is viewed from the back side of the movable object accommodating part 600.

Converter accommodating portion 620 is composed of a metal box 621 having a rectangular parallelepiped appearance. The bottom of the box 621 is fixed to the mounting surface 77a of the movable table 77 by a predetermined fixture. A radio wave absorber is attached to the box 621 on the surface corresponding to the quiet zone, that is, on the entire back side in the state shown in FIG.

The box 621 has an internal space partitioned into, for example, two levels, upper and lower, with the converter 45 placed in the upper internal space and the converter 46 placed in the lower internal space.

The converters 45 and 46 are components of the second signal processing unit 40b of the signal processing unit 40 (see FIG. 4) provided between the test antenna 6b and the NR system simulator 20, and each It is connected to horizontally polarized antenna 6bH and vertically polarized antenna 6bV of 6b. The converter 45 is, for example, an up converter that performs frequency conversion (up conversion) of a signal transmitted to the horizontal polarization antenna 6bH of the test antenna 6b, and a frequency conversion (down conversion) of a signal received by the horizontal polarization antenna 6bH. It also has the function of a down converter. On the other hand, the converter 46 has the function of, for example, an up-converter that up-converts the signal transmitted to the water vertically polarized antenna 6bV of the test antenna 6b, and a down-converter that down-converts the signal received by the vertically polarized antenna 6bH. It combines the following.

As shown in FIG. 8, the converters 45 and 46 have one input/output end connected to the test antenna 6b, for example, a horizontally polarized antenna 6bH and a vertically polarized antenna 6bV, by RF cables 47a and 47b, respectively. . In addition, the other input/output ends of the converters 45 and 46 (the side opposite to the side where the test antenna 6b is connected to the horizontally polarized antenna 6bH and the vertically polarized antenna 6bV) are connected, for example, to RF cables 48a and 48b, respectively. , and can be electrically connected to the NR system simulator 20.

The converters 45 and 46 correspond to, for example, a functional circuit part in the second signal processing section 40b (see FIG. 4) shown in FIG. 4, and can be controlled from the NR system simulator 20 side. In the configuration of the other input/output end side of the converters 45 and 46 shown in FIG. Various controls can be performed. Similarly, the converter 46 can also be controlled, such as switching between an up-converter and a down-converter, from the NR system simulator 20 via the other control cable 49a. Converters 45 and 46 can receive power supply via power cables 49b and 49b, respectively.

With the above-described configuration, in the test apparatus 1 according to the present embodiment, the signal sent from the NR system simulator 20 toward the horizontally polarized antenna 6bH of the test antenna 6b is transmitted through the RF cable 48a, the converter 45, and the RF cable 47a. The signal is then sent to the horizontally polarized antenna 6bH and radiated as a radio wave. Further, the signal sent from the NR system simulator 20 toward the vertically polarized antenna 6bV of the test antenna 6b is sent to the vertically polarized antenna 6bH through the RF cable 48b, converter 46, and RF cable 47b, and is converted into a radio wave. radiated.

On the other hand, the signal input from the horizontally polarized antenna 6bH of the test antenna 6b is taken in as a signal under test by the NR system simulator 20 through the RF cable 47a, converter 45, and RF cable 48a. Further, a signal input from the vertically polarized antenna 6bV of the test antenna 6b is taken in as a signal under test by the NR system simulator 20 through the RF cable 47b, the converter 46, and the RF cable 48b.

In FIG. 8, the second signal processing section 40b (see FIG. 4) of the signal processing section 40 converts converters 45 and 46 (one for each horizontally polarized antenna 6bH and vertically polarized antenna 6bV of the test antenna 6b) In both cases, a housing form for the converter housing section 620 is mentioned in the case where the converter housing section 620 has both an up-converter function and a down-converter function. The present invention is not limited to this. For example, a configuration may be adopted in which two up-converters and two down-converters are provided separately (four in total) for each horizontally polarized antenna 6bH and vertically polarized antenna 6bV. In short, in the present invention, the converters 45 and 46 are provided separately for each horizontally polarized wave and vertically polarized wave, and a converter having the functions of an up converter, a down converter, or both is installed in the converter accommodating section 620. The structure can be arranged as appropriate.

(Moving mechanism)
As shown in FIG. 8, the moving mechanism 700 includes a circular motion section 701 and a drive section 702.

(Circular motion part)
The circular motion section 701 has a guide rail 73, a drive rail 74, and a movable base 77. The circular motion unit 701 is configured to be able to move the movable base 77 in the direction D1 along the guide rail 73. The drive rail 74 is, for example, a mechanism that engages with a gear rotationally driven by a drive source such as a motor to move the movable base 77 in the direction D1.

(Drive part)
The drive section 702 includes a drive gear that meshes with a gear provided on the drive rail 74 that forms the circular motion section 701 together with the guide rail 73, and a drive source such as a motor that rotationally drives the drive gear.

According to the test apparatus 1 according to the present embodiment having the antenna movable mechanism 60 having the above-described configuration, the movable base 77 is moved by the drive source such as a motor in the direction D1 (see FIG. 8) corresponding to the direction of rotation of the drive source. Moving. It is possible to move the movable table 77 in the direction D1 using a drive source such as a motor so that the test antenna 6b is at the position shown, for example, at P5 in FIGS. 5 and 6. In this case, the test antenna 6b can radiate a radio wave beam at an arrival angle of 150°, for example, based on the direction of the radio wave beam arriving at the DUT 100 from the test antenna 6a.

Similarly, the movable base 77 rotates the driving source by the antenna position control unit 18, and moves the test antenna 6b to the positions shown in P4, P3, P2, and P1 in FIGS. 5 and 6, respectively. By moving in the direction D1, the test antenna 6b can emit radio wave beams at arrival angles of 120°, 90°, 60°, and 30°, for example, based on the direction of the radio wave beam arriving at the DUT 100 from the test antenna 6a. becomes able to radiate.

In accordance with the control to move the test antenna 6b to the positions P5, P4, P3, P2, and P1 corresponding to the arrival angles of 150°, 120°, 90°, 60°, and 30°, the test antenna 6b and the antenna The mirrors 9 held by the holding part 610 will move to positions P15, P14, P13, P12, and P11, respectively, as shown in FIG.

In the test apparatus 1 according to the present embodiment, the antenna position control unit 18 stops the test antenna 6b at any of the above angles of arrival of 150°, 120°, 90°, 60°, and 30°. In addition, the antenna movable mechanism 60 can be driven and controlled so that the arrival angle is any angle within the range of 150° to 30°.

With the above-described configuration, the test apparatus 1 according to the present embodiment does not need to provide test antennas equal to the number of arrival angles to be tested, and can reduce the number of antennas. Further, the test antenna 6b can be moved so that an arbitrary arrival angle is formed within a predetermined range. Furthermore, the antenna movable mechanism 60 can be installed around the central attitude variable mechanism 56 where the DUT 100 is held, and the area and space (volume) occupied by the antenna movable mechanism 60 can be kept small. Therefore, the limited internal space 51 of the anechoic box 50 can be used efficiently.

In this embodiment, the antenna movable mechanism 60 is placed on the bottom surface 52a (see FIG. 8) of the anechoic box 50, but the placement location is not limited to this, and it may be placed on the ceiling or horizontally. Alternatively, they may be arranged vertically or at an angle.

(Electromagnetic wave shielding mechanism)
Next, the electromagnetic wave shielding mechanism 611 of the antenna holding section 610 will be described in more detail with reference to FIGS. 10 to 12. FIG. 10 is a plan view of the anechoic box 50 of the test apparatus 1 according to the present embodiment, viewed from above with the top plate removed, and shows a more detailed structure with respect to the structure shown in FIG. 5.

As shown in FIG. 10, in the test apparatus 1 according to the present embodiment, in the internal space 51 of the anechoic box 50, the antenna holding part 610 is placed on the guide rail 73 (on a circle) in the direction D1 centering on the origin O. ) is attached to a movable table 77 that moves the The movement range of the movable table 77 is, for example, within the range from the angle of arrival of 30° to the angle of arrival of 150° in FIG.

The antenna holding part 610 is attached to the mirror 9 and the test antenna 6b (for convenience, indicated by a dotted line) located directly below the mirror 9 in the vertical direction (on the back side of the page when FIG. 10 is viewed from directly above the page). ) and reflect the electron beam emitted from the test antenna 6b in the direction of the origin O by the mirror 9. 0 position) is reflected by mirror 9 and guided to test antenna 6b. In FIG. 10, a path for transmitting and receiving such an electron beam is shown by a dotted line extending from the origin O to the test antenna 6b, and is designated by the symbol R1.

The antenna holding unit 610, which enables transmission and reception of electron beams using the mirror reflection method between the DUT 100 and the path R1, has a quiet zone for the test antenna 6b (existing directly below the mirror 9 in the vertical direction) in the anechoic box 50. , or the reflector 7 as shown in FIG. 10, the electron beam from the test antenna 6b does not pass through the mirror 9 and is transmitted to the quiet zone or the reflector 7 as a so-called direct wave. A situation is assumed in which the radio waves are radiated and cause radio wave interference.

As a countermeasure for this, in the test apparatus 1 according to the present embodiment, the antenna holding part 610 is provided with an electromagnetic wave for blocking the electron beam (direct wave) between the test antenna 6b and the origin O or the reflector 7. A shielding mechanism 611 is provided.

Specifically, as shown in FIG. 8, the electromagnetic wave shielding mechanism 611 includes, for example, a shielding plate 1 (reference numeral 612) arranged to surround the test antenna 6b on three sides up to a predetermined height toward the top in the vertical direction. (hereinafter sometimes referred to as shielding plate 612), shielding plate 2 (hereinafter referred to as 613), shielding plate 3 (hereinafter referred to as 614), shielding plate 3 (hereinafter referred to as 614; hereinafter referred to as shielding plate). (also referred to as a plate 614). The shielding plate 1 and the shielding plate 2 constitute a first shielding plate and a second shielding plate of the present invention, respectively.

Here, the shielding plates 612, 613, and 614 are connected so that the cross-sectional shape when the electromagnetic wave shielding mechanism 611 is cut horizontally is, for example, a U-shape with the side where the test antenna 6b is placed open. There is. As shown in FIG. 8, the shielding plate 612 is placed in a position to block the direct wave radiation path from the test antenna 6b to the quiet zone. Moreover, the shielding plate 613 is arranged at a position to block the radiation path of the direct wave from the test antenna 6b to the reflector 7. The shielding plate 614 is attached to a position facing the shielding plate 612 so as to be connected to an end of the shielding plate 613. The shielding plate 614 performs an electromagnetic wave shielding function to prevent electromagnetic waves from being radiated from the test antenna 6b to the region on the opposite side of the quiet zone.

Next, the radio wave blocking function of the electromagnetic wave shielding mechanism 611 will be explained. First, the radio wave blocking function of the shielding plate 1 will be explained with reference to FIG. 11. In FIG. 11, (a) is a schematic diagram for explaining the radio wave shielding function of the shielding plate 1 (shielding plate 612) between the test antenna 6b and the quiet zone of the test apparatus 1 according to the present embodiment, and ( b) is a schematic diagram for explaining the radio wave interference situation in the same section in a reference example device (for example, a conventional device) that does not have the shielding plate 1.

As shown in FIG. 11(b), according to the configuration of the device of the reference example without the shielding plate 1, the radio waves (spherical waves) radiated from the mirror reflection type test antenna 6b are reflected by the mirror 9. When the reflected wave reaches the DUT 100 (and is radiated from the DUT 100 and reaches the test antenna 6b on the opposite path), the direct wave (spherical wave) radiated from the test antenna 6b is It is conceivable that the reflected wave (plane wave) reflected by the mirror 9 and reaching the DUT 100 may be interfered with. At this time, the RRM characteristics of the DUT 100 based on the signal received by the mirror reflection type test antenna 6b may deteriorate in frequency characteristics depending on the degree of interference described above.

On the other hand, since the antenna holding part 610 of the test apparatus 1 according to the present embodiment has a configuration in which a shielding plate 612 is provided as shown in FIG. The direct waves (spherical waves) that occur are blocked by the shielding plate 612 and do not reach the DUT 100. As a result, in the antenna holding unit 610 of the test device 1 according to the present embodiment, the direct wave (spherical wave) radiated from the test antenna 6b interferes with the reflected wave (plane wave) that is reflected by the mirror 9 and reaches the DUT 100. Therefore, the frequency characteristics of the RRM characteristics of the DUT 100 can be improved.

Next, the radio wave blocking function of the shielding mechanism 613 will be explained with reference to FIG. 12. In FIG. 12, (a) is a schematic diagram for explaining the radio wave shielding function of the shielding plate 2 (shielding plate 613) between the test antenna 6b and the reflector 7 of the test apparatus 1 according to the present embodiment, and ( b) is a schematic diagram for explaining the radio wave interference situation in the same section in a reference example device (for example, a conventional device) that does not have the shielding plate 2;

As shown in FIG. 12(b), according to the configuration of the antenna holding mechanism of the device of the reference example that does not have the shielding plate 2, radiation is emitted from the test antenna 6a of the reflector type, reflected by the reflector 7, and the The operation in which the wave (plane wave) reaches the DUT 100 (and the operation in which it is radiated from the DUT 100 and reaches the test antenna 6a on the opposite path) and the radio wave (spherical wave) radiated from the mirror reflection type test antenna 6b. When the operation of being reflected by the mirror 9 and reaching the DUT 100 as a DFF desired wave (and the operation of being radiated from the DUT 100 and reaching the test antenna 6b on the opposite path) is performed, the mirror reflection type It is conceivable that a situation may occur in which the radio waves (direct waves) radiated from the test antenna 6b interfere with the reflected waves from the reflector 7. In this case, depending on the degree of interference, the frequency characteristics of the RF characteristics of the DUT 100 based on the signal received by the test antenna 6a will deteriorate.

On the other hand, since the antenna holding section 610 of the test apparatus 1 according to the present embodiment has a configuration including a shielding plate 613 (shielding plate 2) as shown in FIG. Direct waves (spherical waves) radiated from the antenna 6b are shielded by a shielding plate 613 provided between the antenna 6b and the reflector 7, and do not reach the DUT 100. As a result, in the antenna holding unit 610 of the test device 1 according to the present embodiment, the direct wave (spherical wave) radiated from the test antenna 6b interferes with the reflected wave (plane wave) that is reflected by the reflector 7 and reaches the DUT 100. Therefore, the frequency characteristics of the RF characteristics of the DUT 100 can be improved.

(Partial cutout structure of mirror)
Next, the configuration of mirror 9 held by antenna holding section 610 will be described in more detail with reference to FIG. 13.

In the test apparatus 1 according to the present embodiment, in order to measure the RF characteristics of the DUT 100 with higher accuracy, the antenna holding section 610 holds the reflector 7 so that the area that protrudes to hide a part of the reflector 7 is as small as possible. The shape of the mirror 9 has been devised.

FIG. 13 is a front view showing the configuration of the mirror 9 held by the antenna holding section 610 of the testing apparatus 1 according to this embodiment. As shown in FIG. 13, in this embodiment, the mirror 9 held by the antenna holder 610 has a basic planar shape of a rectangle, and among the four corners of the rectangle, the reflector 7 is It has a configuration in which a notch portion 9a is partially cut out at a corner corresponding to a region that protrudes so as to cover a portion thereof. The present invention is not limited to this, and it is possible to appropriately use the rectangular mirror 9 and the mirror 9 provided with the cutout portion 9a, depending on the content of measurement of the RF characteristics of the DUT 100.

According to the configuration of the mirror 9 having the cutout portion 9a described above, in the internal structure of the anechoic box 50, the reflector 7 is located further beyond the end of the mirror attachment portion 62 extending from the support 61 of the antenna holding portion 610. You can reduce the size of the hidden area that covers part of the image. That is, the notch 9a provided in the mirror 9 reduces the area that partially covers the reflector 7 when viewed from the front (increases the area that is not covered). Thereby, fluctuations in the reception status of the reflected wave from the reflector 7 at the DUT 100 can be suppressed to a small level, and it is possible to improve the measurement results of the RF characteristics of the DUT 100 using the test antenna 6a.

In FIG. 13, as an example, a structure of the mirror 9 having a notch 9a in which one corner of a rectangular shape is cut out into a triangular shape is shown, but the present invention is not limited to this, and the basic shape of the mirror 9 , various modifications or applications can be made to the shape of the cutout portion 9a, etc. In either configuration, by employing the mirror 9 having the notch 9a, it is possible to suppress fluctuations in the reception status of the reflected wave from the reflector 7 by the DUT 100 to a small extent, and improve the measurement results of the RF characteristics of the DUT 100. Effects can be expected.

Next, the integrated control device 10, NR system simulator 20, and signal processing unit 40 that constitute the measuring device 2 of the testing device 1 according to this embodiment will be explained with reference to FIGS. 2 to 4.

(integrated control device)
The integrated control device 10, as described below, controls the NR system simulator 20, the attitude variable mechanism 56, and the antenna movable mechanism 60 in an integrated manner. For this purpose, the integrated control device 10 is connected to the NR system simulator 20, the attitude variable mechanism 56, and the antenna movable mechanism 60 so as to be able to communicate with each other via a network 19 such as, for example, Ethernet (registered trademark).

FIG. 3 is a block diagram showing the functional configuration of the integrated control device 10. As shown in FIG. As shown in FIG. 3, the integrated control device 10 includes a control section 11, an operation section 12, and a display section 13. The control unit 11 is configured by, for example, a computer device. For example, as shown in FIG. 3, this computer device includes a CPU (Central Processing Unit) 11a, a ROM (Read Only Memory) 11b, a RAM (Random Access Memory) 11c, and an external interface (I/F) section 11d. , a non-volatile storage medium such as an SSD (Solid State Drive) or a hard disk device (not shown), and various input/output ports.

The CPU 11a is configured to perform overall control over the NR system simulator 20 and the like. The ROM 11b stores an OS (Operating System) for starting up the CPU 11a, other programs, control parameters, and the like. The RAM 11c is configured to store execution codes, data, etc. of the OS and applications used by the CPU 11a. The external interface (I/F) section 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 communicably connected to the NR system simulator 20 via the network 19. The external I/F unit 11d is also connected to the attitude variable mechanism 56 and the antenna movable mechanism 60 in the anechoic box 50 via the network 19. An operation section 12 and a display section 13 are connected to the input/output port. 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 input screens for the various information and various information such as measurement results.

The computer device described above functions as the control unit 11 by the CPU 11a executing a program stored in the ROM 11b using the RAM 11c as a work area. As shown in FIG. 3, the control section 11 includes a call connection control section 14, a signal transmission/reception control section 15, a DUT attitude control section 17, and an antenna position control section 18. The call connection control section 14, the signal transmission/reception control section 15, the DUT attitude control section 17, and the antenna position control section 18 are also realized by the CPU 11a executing a predetermined program stored in the ROM 11b in the work area of the RAM 11c. It is.

The call connection control unit 14 drives the test antenna 6 to transmit and receive control signals (wireless signals) to and from the DUT 100, thereby establishing a call (capable of transmitting and receiving wireless signals) between the NR system simulator 20 and the DUT 100. control to establish the state).

The signal transmission/reception control unit 15 monitors user operations on the operation unit 12, and when the user performs a predetermined measurement start operation related to measurement of the transmission characteristics and reception characteristics of the DUT 100, the signal transmission/reception control unit 15 performs a function in the call connection control unit 14. After the call connection control, a signal transmission command is transmitted to the NR system simulator 20. Further, the signal transmission/reception control unit 15 controls the NR system simulator 20 to transmit a test signal via the test antenna 6, and also transmits a signal reception command to the NR system simulator 20, and transmits a signal reception command to the test antenna 6. Controls the reception of the signal under test via the

Further, the signal transmission/reception control unit 15 is configured to set the angle of arrival in a test of transmission/reception characteristics such as RRM characteristics using the two test antennas 6. Specifically, one arrival angle is selected from a plurality of predetermined arrival angles (for example, 30°, 60°, 90°, 120°, 150°) and set as the measurement condition (stored in the RAM 11c, etc.). . The arrival angle may be selected by the user or may be automatically selected by the control unit 11 or the like.

The antenna position control unit 18 controls the position of the test antenna 6b based on the set arrival angle. As shown in FIGS. 5 and 6, for example, when the set arrival angle is 30 degrees, the test antenna 6b is controlled to be moved to position P11, and the mirror 9 is controlled to be moved to position P1. Similarly, when the set arrival angles are 60°, 90°, 120°, and 150°, the test antenna 6b is moved to positions P12, P13, P14, and P15, respectively, and the mirror 9 is moved to positions P2, P3, and P4, respectively. , P5. For this reason, for example, the ROM 11b stores in advance an arrival angle-antenna position correspondence table 18a indicating the correspondence between the arrival angle and the position of the test antenna 6b. The arrival angle-antenna position correspondence table 18a is expanded and used in the work area of the RAM 11c during control execution. Note that the setting of the arrival angle and the control of the position of the test antenna 6b may be performed by the control unit 22 of the NR system simulator 20.

Note that the antenna position control unit 18 is not limited to controlling the position of the test antenna 6b so that the position corresponds to each of the arrival angles of 30°, 60°, 90°, 120°, and 150°. , the arrival angle can be controlled to any position. In this control, for example, the antenna position control unit 18 recognizes the position of the movable base 77 based on the detection output of the position detection sensor 79, and the position of the movable base 77 is set at an arbitrary arrival angle set by the user. This can be achieved by rotating the drive source 82 in either the forward or reverse direction so as to achieve the desired position.

In the test apparatus 1 according to the present embodiment, the test antenna 6b of the antenna holding section 610 placed on the movable base 77 and the mirror 9 are moved while maintaining a predetermined distance by controlling the movable base 77 to move. It can be moved to any position within the angle of arrival mentioned above, for example, within the range of 30° to 150°.

A converter accommodating part 620 is placed on the movable base 77 together with the antenna holding part 610 (see FIG. 8). As a result, in the test apparatus 1 according to the present embodiment, the converters 45 and 46 accommodated in the converter accommodating section 620 are also moved in accordance with the movement of the test antenna 6b held in the antenna holding section 610 and the mirror 9. They can be moved together (while maintaining a fixed positional relationship with respect to the test antenna 6b and mirror 9).

Between the antenna holding part 610 and the converter accommodating part 620, the horizontally polarized antenna (6bH) and vertically polarized antenna (6bV) of the test antenna 6b and the converters 45 and 46 are connected to the cable 47a, 47b (see FIG. 8). According to the configuration of the antenna movable mechanism 60 according to the present embodiment in which the test antenna 6b and the converters 45, 46 move together, the cable 47a connecting the horizontally polarized antenna 6bH of the test antenna 6b and the converter 45, the test The cable 47b connecting the vertically polarized antenna 6bV of the test antenna 6b and the converter 46 does not move at all even when the test antenna 6b and the mirror 9 are moved, and there is no chance of bending or twisting due to the movement. do not have.

Further, converters 45 and 46 are electrically connected to NR system simulator 20 via a group of cables housed in cable support guide section 704. Therefore, in the test apparatus 1 according to the present embodiment, when the moving object holding section 600 having the antenna holding section 610 and the converter accommodating section 620 moves in the direction D1, the above-mentioned cable group is protected by the cable support guide section 704. This avoids bending, twisting, etc. caused by the movement. According to the configuration of the antenna movable mechanism 60 having such a cable support guide section 704, when moving the moving object holding section 600 in the direction D1, a path for electrically connecting the test antenna 6b and the NR system simulator 20 is provided. This greatly reduces the possibility of cable group breakage, etc.

The explanation will be continued by returning to FIG. 3 again. The DUT attitude control unit 17 controls the attitude of the DUT 100 held by the attitude variable mechanism 56 during measurement. In order to realize this control, for example, a DUT attitude control table 17a is stored in advance in the ROM 11b. For example, when a stepping motor is used as the drive unit 56a, the DUT posture control table 17a stores the number of drive pulses (number of driving pulses) that determines the rotational drive of the stepping motor as control data.

The DUT attitude control unit 17 develops the DUT attitude control table 17a in the work area of the RAM 11c, and, based on the DUT attitude control table 17a, controls the DUT 100 so that the antenna 110 sequentially faces in all three-dimensional directions, as described above. The posture variable mechanism 56 is drive-controlled to change the posture.

(NR system simulator)
As shown in FIG. 4, the NR system simulator 20 of the test apparatus 1 according to this embodiment includes a signal measurement section 21, a control section 22, an operation section 23, and a display section 24. The signal measurement unit 21 includes a signal generation function unit including a signal generation unit 21a, a digital/analog converter (DAC) 21b, a modulation unit 21c, and a transmission unit 21e of the RF unit 21d; a reception unit 21f of the RF unit 21d; It has a signal analysis function section composed of an analog/digital converter (ADC) 21g and an analysis processing section 21h. Note that two sets of signal measurement units 21 may be provided so as to correspond to the two test antennas 6a and 6b used.

In the signal generation function section of the signal measurement section 21, the signal generation section 21a generates waveform data having a reference waveform, specifically, for example, an I component baseband signal and a Q component baseband signal that is an orthogonal component signal thereof. generate. The DAC 21b converts the waveform data (I component baseband signal and Q component baseband signal) having the reference waveform output from the signal generating section 21a from a digital signal to an analog signal, and outputs the analog signal to the modulating section 21c. The modulation unit 21c performs a modulation process of mixing local signals for each of the I component baseband signal and the Q component baseband signal, and further synthesizing the two to output a digital modulated signal. The RF section 21d generates a test signal corresponding to the frequency of each communication standard from the digital modulated signal output from the modulation section 21c, and outputs the generated test signal to the signal processing section 40 by the transmission section 21e.

The signal processing section 40 performs signal processing such as frequency conversion of signals transmitted and received between the first test antenna 6a to be used and the other test antenna 6b to be used. The second signal processing unit 40b performs signal processing such as frequency conversion of signals to be transmitted and received. The first signal processing unit 40a performs signal processing on the test signal to be transmitted to the one test antenna 6a to be used, and outputs the signal to the test antenna 6a. The second signal processing unit 40b performs signal processing on the test signal to be transmitted to the other test antenna 6b to be used, and outputs the signal to the test antenna 6b.

Further, in the signal analysis function section of the signal measurement section 21, the RF section 21d receives the signal under test transmitted from the DUT 100, which has received the test signal through the antenna 110, at the reception section 21f via the signal processing section 40. After that, the measured signal is mixed with a local signal to convert it into an intermediate frequency band signal (IF signal). The ADC 21g converts the signal under measurement converted into an IF signal by the receiving section 21f of the RF section 21d from an analog signal to a digital signal, and outputs the digital signal to the analysis processing section 21h.

The analysis processing unit 21h digitally processes the signal under test, which is a digital signal output from the ADC 21g, to generate waveform data corresponding to an I component baseband signal and a Q component baseband signal, and then converts the waveform data into Processing is performed to analyze the I-component baseband signal and the Q-component baseband signal based on the following. In measuring the transmission characteristics (RF characteristics) of the DUT 100, the analysis processing unit 21h measures, for example, equivalent isotropically radiated power (EIRP), total radiated power (TRP), spurious radiation, and modulation accuracy. (EVM), transmission power, constellation, spectrum, etc. can be measured. Furthermore, in measuring the reception characteristics (RF characteristics) of the DUT 100, the analysis processing unit 21h can measure reception sensitivity, bit error rate (BER), packet error rate (PER), etc., for example. Here, EIRP is the radio signal strength of the antenna 110 of the DUT 100 in the main beam direction. Moreover, TRP is the total value of the power radiated into space from the antenna 110 of the DUT 100.

The analysis processing unit 21h is also capable of analyzing the RRM characteristics of the DUT 100, such as whether or not a handover operation from one test antenna to another test antenna is performed normally. .

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

The operating section 23 and the display section 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 an input screen for the various information and measurement results.

In this embodiment, the integrated control device 10 and the NR system simulator 20 are separate devices, but they may be configured as one 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 into one computer device.

(Signal processing section)
Next, the signal processing section 40 will be explained.

The signal processing unit 40 is a first signal processing unit that is provided between the NR system simulator 20 and the test antenna 6, and performs signal processing such as frequency conversion of signals transmitted and received between the one test antenna 6a to be used. 40a, and a second signal processing unit 40b that performs signal processing such as frequency conversion of signals transmitted and received between the test antenna 6b and the other test antenna 6b used.

The first signal processing unit 40a includes an upconverter, a downconverter, an amplifier, a frequency filter, etc., and performs frequency conversion (upconversion), amplification, and frequency selection for the test signal to be transmitted to the one test antenna 6a used. The signal is subjected to signal processing such as the following and output to the test antenna 6a. Further, the first signal processing section 40a performs signal processing such as frequency conversion (down conversion), amplification, and frequency selection on the signal under test inputted from the one test antenna 6a to be used, and the signal processing section 40a performs signal processing such as frequency conversion (down conversion), amplification, and frequency selection. 21.

The second signal processing unit 40b includes an upconverter, a downconverter, an amplifier, a frequency filter, etc., and performs frequency conversion (upconversion), amplification, and frequency selection for the test signal to be transmitted to the other test antenna 6b to be used. etc., and outputs it to the test antenna 6b. Further, the second signal processing section 40b performs signal processing such as frequency conversion (down conversion), amplification, and frequency selection on the signal under test inputted from the other test antenna 6b to be used, and performs signal processing such as frequency conversion (down conversion), amplification, and frequency selection. 21.

The above-mentioned up-conversion and down-conversion are performed for each signal transmitted to the horizontally polarized antenna 6bH or vertically polarized antenna 6bV constituting the test antenna 6b, and for each signal input from the flat polarized antenna 6bH or vertically polarized antenna 6bV. Implemented. Therefore, the converters 45 and 46 shown in FIG. 10 are, for example, an up-converter that converts a signal to be transmitted to the horizontally polarized antenna 6bH or the vertically polarized antenna 6bV into a high frequency, It may also be configured to be installed as a down converter that converts the signal input from the polarized antenna 6bV to a lower frequency.

(Test method)
Next, a test method performed using the test apparatus 1 according to this embodiment will be described with reference to the flowchart in FIG. The following describes a test (for example, measurement of transmission and reception characteristics such as RRM characteristics) using two test antennas, but this is just an example of a test method, and the specific test method may differ depending on the type of test. Of course.

First, the user sets the DUT 100 to be tested on the DUT mounting section 56d of the variable attitude mechanism 56 provided in the internal space 51 of the anechoic box 50 (step S1).

Next, the user uses the operation unit 12 of the integrated control device 10 to perform a measurement start operation that instructs the control unit 11 to start measuring the transmission characteristics and reception characteristics of the DUT 100. This measurement start operation may be performed using the operation section 23 of the NR system simulator 20.

The control unit 11 sets one of the predetermined angles of arrival (step S2). For example, when the predetermined arrival angles are 30°, 60°, 90°, 120°, and 150°, the control unit 11 selects one of the arrival angles (for example, 30°) and Set it as an angle (for example, store it in the RAM 11c). The arrival angle may be set by the user.

Next, the control unit 11 moves the position of the test antenna 6b so that the arrival angle is set in step S2 (step S3). For example, when the set arrival angle is 30 degrees, the test antenna 6b is moved to position P11 and the mirror 9 is moved to position P1, and when the arrival angle is 60 degrees, the test antenna 6b is moved to position P12, and the mirror 9 is moved to position P1. is moved to position P2, and when the angle of arrival is 90°, the test antenna 6b is moved to position P13, the mirror 9 is moved to position P3, and when the angle of arrival is 120°, the test antenna 6b is moved to position P14, When the mirror 9 is moved to the position P4 and the arrival angle is 150°, the test antenna 6b is controlled to be moved to the position P15 and the mirror 9 is controlled to be moved to the position P5.

To move the test antenna 6b and mirror 9 in step S3, the antenna position control unit 18 operates the drive source 82 until the movable base 77 on which the antenna holding unit 610 and converter accommodating unit 620 are mounted reaches the target position. This can be done by rotationally driving. As a result, in step S3, by moving the position of the second test antenna 6b, the converters 45 and 46 connected to the second test antenna 6b by the RF cables 47a and 47b are connected to the second test antenna 6b. It can be moved while maintaining a constant positional relationship with the test antenna 6b.

Subsequently, the call connection control unit 14 of the control unit 11 uses the test antenna 6 to perform call connection control by transmitting and receiving control signals (wireless signals) to and from the DUT 100 (step S4). Specifically, the NR system simulator 20 wirelessly transmits a control signal (call connection request signal) having a predetermined frequency to the DUT 100 via the test antenna 6. On the other hand, the DUT 100 that has received the call connection request signal sets the connection requested frequency and returns a control signal (call connection response signal). The NR system simulator 20 receives this call connection response signal and confirms that the response has been made normally. A series of these processes is call connection control. Through this call connection control, a state is established between the NR system simulator 20 and the DUT 100 in which a radio signal of a predetermined frequency can be transmitted and received via the test antenna 6.

Note that the process in which the DUT 100 receives a wireless signal sent from the NR system simulator 20 via the test antenna 6 is called downlink (DL) process. Conversely, the process of transmitting a wireless signal by the DUT 100 to the NR system simulator 20 via the test antenna 6 is called uplink (UL) process. The test antenna 6 is used to perform link (call) establishment processing and downlink (DL) and uplink (UL) processing after link establishment, and also functions as a link antenna. ing.

After establishing the call connection in step S4, the DUT attitude control unit 17 of the integrated control device 10 controls the attitude of the DUT 100 placed within the quiet zone to a predetermined attitude using the attitude variable mechanism 56 (step S5).

After the DUT 100 is controlled to a predetermined attitude by the attitude variable 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. Based on this signal transmission command, the NR system simulator 20 transmits a test signal to the DUT 100 via the selected test antenna 6 (step S6).

Test signal transmission control by the NR system simulator 20 is performed as follows. In the NR system simulator 20 (see FIG. 4), the signal generating section 21a generates a signal for generating a test signal under the control of the control section 22 which has received the signal transmission command. Next, the DAC 21b performs digital/analog conversion processing on the signal generated by the signal generator. Next, the modulation section 21c performs modulation processing on the analog signal obtained by digital/analog conversion. Next, the RF section 21d generates a test signal corresponding to the frequency of each communication standard from the modulated signal, and the transmitting section 21e sends this test signal (DL data) to the signal processing section 40.

The signal processing unit 40 is provided inside or outside the anechoic box 50, performs signal processing such as frequency conversion (up-conversion), amplification, and frequency selection, and sends the signal to the test antenna 6, so that the test antenna 6 receives the signal. is output toward the DUT 100. Note that in order to process the signals of the two test antennas, the signal processing unit 40 can process a plurality of signals in parallel.

The signal transmission/reception control unit 15 controls the test signal to be transmitted at an appropriate timing after starting the test signal transmission control in step S6 until the measurement of the transmission characteristics and reception characteristics of the DUT 100 is completed. .

On the other hand, the DUT 100 receives the test signal (DL data) sent via the test antenna 6 with the antenna 110 in different postures that sequentially change based on the attitude control in step S5, and A signal to be measured, which is a response signal to the signal, is transmitted.

After starting the transmission of the test signal in step S6, reception processing is subsequently performed under the control of the signal transmission and reception control section 15 (step S7). In this reception process, the test antenna 6 receives the signal under test transmitted from the DUT 100 that has received the test signal, and outputs it to the signal processing section 40. The signal processing unit 40 performs signal processing such as frequency conversion (down conversion), amplification, and frequency selection, and outputs the signal to the NR system simulator 20.

The NR system simulator 20 executes a measurement process of measuring the signal under test whose frequency has been converted by the signal processing unit 40 (step S8).

Specifically, the receiving section 21f of the RF section 21d of the NR system simulator 20 receives the signal under measurement processed by the signal processing section 40 as input. Under the control of the control section 22, the RF section 21d converts the signal under measurement input to the reception section 21f into an IF signal with a lower frequency. Next, under the control of the control section 22, the ADC 21g converts the IF signal from an analog signal to a digital signal and outputs it to the analysis processing section 21h. The analysis processing unit 21h generates waveform data corresponding to the I component baseband signal and the Q component baseband signal, respectively. Further, the analysis processing section 21h analyzes the signal under measurement under the control of the control section 22 based on the generated waveform data. Note that in order to process the signals of the two test antennas, the signal processing unit 40 can process a plurality of signals in parallel.

More specifically, in the NR system simulator 20, the analysis processing section 21h measures the transmission characteristics and reception characteristics of the DUT 100 under the control of the control section 22 based on the analysis result of the signal under test.

For example, the transmission characteristics (RF characteristics) of the DUT 100 are determined as follows. First, under the control of the control unit 22, the NR system simulator 20 transmits a request frame for uplink signal transmission as a test signal. In response to the uplink signal transmission request frame, the DUT 100 transmits an uplink signal frame as a signal under measurement to the NR system simulator 20. The analysis processing unit 21h performs processing to evaluate the transmission characteristics of the DUT 100 based on this uplink signal frame.

Further, the reception characteristics (RF characteristics) of the DUT 100 are determined as follows, for example. The analysis processing unit 21h, under the control of the control unit 22, calculates the number of transmissions of the measurement frame transmitted as a test signal from the NR system simulator 20, and the ACK and NACK transmitted from the DUT 100 as a signal under measurement in response to the measurement frame. The ratio of the number of receptions is calculated as the error rate (PER).

Regarding the RRM characteristics of the DUT 100, for example, the analysis processing unit 21h, under the control of the control unit 22, determines whether or not the handover operation from one test antenna to another test antenna is performed normally. The test may be performed by changing the position of the

In step S8, the analysis processing unit 21h stores the measurement results of the transmission characteristics and reception characteristics of the DUT 100 in a storage area such as a RAM (not shown) under the control of the control unit 22. This measurement result may be displayed on the display section 24 or the display section 13.

Next, the control unit 11 of the integrated control device 10 determines whether the measurement of the transmission characteristics and reception characteristics of the DUT 100 for all desired postures has been completed (step S9). Here, 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.

If it is determined that the measurement has been completed for all orientations (YES in step S9), the control unit 11 determines whether or not the measurement has been completed for all angles of arrival (step S10).

If it is determined that the measurement has not been completed for all angles of arrival (NO in step S10), the control unit 11 returns to step S2 and continues the process. If it is determined that the measurements have been completed for all angles of arrival (YES in step S10), the control unit 11 ends the test.

(action/effect)
As described above, the test apparatus 1 according to the present embodiment is a test apparatus 1 that measures the transmission characteristics or reception characteristics of a DUT 100 having an antenna 110, and has an internal space 51 that is not affected by the surrounding radio wave environment. A dark box 50 , an attitude variable mechanism 56 that sequentially changes the attitude of the DUT 100 placed in a quiet zone (QZ) in the interior space 51 , and an attitude change mechanism 56 that is housed in the interior space 51 and is used to measure the transmission characteristics or reception characteristics of the DUT 100 . A test antenna 6a and a test antenna 6b that transmit or receive radio signals to/from the antenna 110, a reflector 7 that reflects the radio signal radiated by the test antenna 6a and converts it into a plane wave radio signal, The position of the mirror reflection test antenna 6b is moved so that radio signals can be transmitted or received at multiple angles of arrival to the DUT 100 installed in the far field based on the radio wave arrival direction from the antenna 6a. Also, an antenna moving mechanism 60 that moves converters 45 and 46 connected to the second test antenna 6b by RF cables 47a and 47b while maintaining a constant positional relationship with the second test antenna 6b. , is configured with.

The test apparatus 1 according to the present embodiment moves the position of the test antenna 6b, and also moves the converters 45 and 46 connected to the test antenna 6b by RF cables 47a and 47b to a fixed position with respect to the test antenna 6b. An antenna moving mechanism 60 is provided to move the antenna while maintaining the relationship. With this configuration, in the test apparatus 1 according to the present embodiment, when performing far-field measurement of transmission and reception characteristics such as RRM characteristics of the DUT 100, the test antenna 6b for far-field measurement is connected to the converter 45 that moves together, 46 with short RF cables 47a, 47b, and can be moved without bending or stretching the RF cables 47a, 47b. Since the RF cables 47a, 47b do not repeat bending and stretching, the frequency characteristics do not change due to bending of the RF cables 47a, 47b, and the metal used for the RF cables 47a, 47b is metal. This eliminates fatigue, deterioration of frequency characteristics due to breakage of the outer conductor, deterioration of shielding performance, and disconnection of the inner conductor. Furthermore, the cable length of the RF cables 47a and 47b connecting the test antenna 6b and the converters 45 and 46 has been reduced compared to the conventional method in which long RF cables were used to connect the test antenna 6b and a fixedly arranged converter. It can be significantly shorter than the conventional RF cable configuration, and it becomes possible to effectively utilize the portion corresponding to the movable range of a conventional RF cable.

In the test apparatus 1 according to the present embodiment, the antenna movable mechanism 60 includes an antenna holding part 610 that holds the test antenna 6b, a converter housing part 620 that houses the converters 45 and 46, and an antenna holding part 610 and the converter. It has a configuration including a moving mechanism 700 that moves the housing section 620 on a circle.

With this configuration, the test apparatus 1 according to the present embodiment can move the test antenna 6b held by the antenna holding part 610 by moving the antenna holding part 610 and the converter housing part 620 on a circle using the antenna moving mechanism 60. , the converters 45 and 46 housed in the converter accommodating portion 620 can be moved while maintaining a fixed positional relationship at all times, and the movement can be easily controlled.

Furthermore, in the test apparatus 1 according to the present embodiment, the test antenna 6b includes a horizontally polarized antenna 6bH and a vertically polarized antenna 6bV, and the converter accommodating section 620 is provided separately for each horizontally polarized wave and vertically polarized wave. It is configured to accommodate converters 45 and 46 each having the functions of an up-converter, a down-converter, or both.

With this configuration, the test apparatus 1 according to the present embodiment has converters 45 and 46 connected to the horizontally polarized antenna 6bH and vertically polarized antenna 6bV of the test antenna 6b by the respective RF cables 47a and 47b. It can be moved together with the horizontally polarized antenna 6bH and the vertically polarized antenna 6bV, and the RF cables 47a and 47b are not bent or stretched during movement.

The test apparatus 1 according to the present embodiment also includes a mirror that reflects a radio signal radiated from the test antenna 6b and sends it to the antenna 110, and also reflects a radio signal radiated from the DUT 100 and sends it to the test antenna 6b. 9, and the antenna holding section 610 is configured to hold the test antenna 6b and the mirror 9 at intervals in the longitudinal direction.

With this configuration, the test apparatus 1 according to the present embodiment can change the route of wireless signals transmitted and received between the test antenna 6b and the antenna 110 using the mirror 9, and is 51, it is possible to ensure the distance between the antennas necessary for far field measurement.

Further, in the test apparatus 1 according to the present embodiment, the antenna holding section 610 surrounds the test antenna 6b from the columnar support 61 that holds the test antenna 6b and the mirror 9, and the surrounding side excluding the support 61 side. The electromagnetic wave shielding mechanism 611 further includes a first shielding plate 612 provided between the test antenna 6b and the quiet zone, and a first shielding plate 612 provided between the test antenna 6b and the reflector 7. This configuration includes a second shielding plate 613 provided between the two.

With this configuration, the test apparatus 1 according to the present embodiment can shield direct waves (spherical waves) radiated from the test antenna 6b with the first shielding plate 612 provided between the test antenna 6b and the quiet zone. This prevents direct wave interference with the reflected wave (plane wave) radiated from the test antenna 6b, reflected by the mirror 9, and reaches the DUT 100, and improves the frequency characteristics of the RRM characteristics of the DUT 100. Furthermore, in the test apparatus 1 according to the present embodiment, the direct wave (spherical wave) radiated from the test antenna 6b can be shielded by the second shielding plate 613 provided between the test antenna 6b and the reflector 7. This prevents the direct wave (spherical wave) radiated from the test antenna 6b from interfering with the reflected wave (plane wave) that is radiated from the test antenna 6a, is reflected by the reflector 7, and reaches the DUT 100, and Regarding characteristics, frequency characteristics can be improved.

Further, the test method according to the present embodiment is a test method using the test apparatus 1 described in any one of the above, and includes a step (S2) of selecting one arrival angle from a plurality of arrival angles; The antenna movable mechanism 60 moves the position of the test antenna 6b so that the arrival angle is the same, and the converters 45 and 46 connected to the second test antenna 6b by the RF cables 47a and 47b are moved to the second test antenna 6b. A step (S3) of moving the DUT 100 while maintaining a constant positional relationship with the test antenna 6b, and a step (S5) of sequentially changing the attitude of the DUT 100 placed in the quiet zone. The method is characterized in that it includes a step (S8) of measuring the transmission characteristics or reception characteristics of the DUT 100 using the test antenna 6a and the test antenna 6b.

As described above, the test apparatus 1 used in the test method according to the present embodiment moves the position of the test antenna 6b and connects the converter to the second test antenna 6b by the RF cables 47a, 47b. An antenna moving mechanism 60 is provided for moving the antennas 45 and 46 while maintaining a constant positional relationship with the second test antenna 6b. Then, in this test method, the position of the test antenna 6b is moved by the antenna movable mechanism 60 so that the angle of arrival is selected, and the RF cables 47a and 47b are connected to the second test antenna 6b. This includes a step (S3) of moving the connected converters 45 and 46 while maintaining a constant positional relationship with the second test antenna 6b.

As a result, in this test method, when performing far-field measurement of transmission and reception characteristics such as RRM characteristics of the DUT 100, the test antenna 6b for far-field measurement is connected to the converters 45 and 46 that move together and the short RF cable 47a. , 47b, and can be moved without bending or stretching the RF cables 47a, 47b. Since the RF cables 47a, 47b do not repeat bending and stretching, the frequency characteristics do not change due to bending of the RF cables 47a, 47b, and the metal used for the RF cables 47a, 47b is metal. This eliminates fatigue, deterioration of frequency characteristics due to breakage of the outer conductor, deterioration of shielding performance, and disconnection of the inner conductor. Furthermore, the cable length of the RF cables 47a and 47b connecting the test antenna 6b and the converters 45 and 46 has been reduced compared to the conventional method in which long RF cables were used to connect the test antenna 6b and a fixedly arranged converter. It can be significantly shorter than the conventional RF cable configuration, and it becomes possible to effectively utilize the portion corresponding to the movable range of a conventional RF cable.

As described above, the present invention makes it possible to move a test antenna for RRM measurement without repeatedly bending and stretching the RF cable, thereby reducing space efficiency caused by deterioration of frequency characteristics, RF cable breakage, and cable length. This has the effect that deterioration can be avoided, and is useful for all wireless terminal testing devices and testing methods.

1 Test device 2 Measurement device 6, 6a, 6b Test antenna 6bH Horizontal polarized antenna 6bV Vertical polarized antenna 7 Reflector 9 Mirror 9a Notch 10 Integrated control device 20 NR system simulator 40b Second signal processing section 45 Converter (frequency converter)
46 Converter (frequency converter)
50 Anechoic box 51 Internal space 52a Bottom surface 56 Posture variable mechanism
60 Antenna movable mechanism 73 Guide rail 74 Drive rail 77 Movable base 100 DUT (target under test)
110 Antenna (antenna under test)
600 Moving object holding part 610 Antenna holding part 611 Electromagnetic wave shielding mechanism 612 Shielding plate (first shielding plate)
613 Shielding plate (second shielding plate)
614 Shielding plate 620 Converter housing part (frequency converter housing part)
700 Moving mechanism 701 Circular motion part QZ Quiet zone D1 Moving direction of moving mechanism

Claims (6)

A test device (1) for measuring transmission characteristics or reception characteristics of a target under test (100) having an antenna under test (110),
an anechoic box (50) having an internal space (51) that is not affected by the surrounding radio wave environment;
a posture variable mechanism (56) that sequentially changes the posture of the test subject disposed within a quiet zone (QZ) in the internal space;
A first test antenna (6a) and a second test antenna that are housed in the internal space and transmit or receive a wireless signal from the antenna under test for measuring the transmission characteristics or reception characteristics of the object under test. A test antenna (6b),
a reflector (7) that reflects the radio signal radiated by the first test antenna and converts it into a plane wave radio signal;
The second test is conducted so that radio signals can be transmitted or received at a plurality of arrival angles to the test target installed in a far field based on the radio wave arrival direction from the first test antenna. At the same time, the frequency converter (45, 46) connected to the second test antenna by the RF cable (47a, 47b) is moved to a fixed position with the second test antenna. an antenna movable mechanism (60) that moves the antenna while maintaining the relationship;
A test device comprising: The antenna movable mechanism includes an antenna holding part (610) that holds the second test antenna, a frequency converter housing part (620) that houses the frequency converter, and the antenna holding part and the frequency converter. The test device according to claim 1, further comprising a moving mechanism (700) that moves the housing section in a circle. The second test antenna includes a horizontally polarized antenna (6bH) that transmits and receives horizontally polarized waves and a vertically polarized antenna (6bV) that transmits and receives vertically polarized waves,
The frequency converter accommodating section is provided separately for each of the horizontally polarized wave and the vertically polarized wave, and each accommodates the converter having the functions of an up-converter, a down-converter, or both. The test device according to claim 2. A mirror ( 9) further comprising;
4. The test apparatus according to claim 3, wherein the antenna holding section holds the second test antenna and the mirror at a distance from each other in the longitudinal direction. The antenna holding part is provided to surround the second test antenna from a side other than a columnar support (61) that holds the second test antenna and the mirror, and a side of the support. Further comprising an electromagnetic wave shielding mechanism (611),
The electromagnetic wave shielding mechanism includes a first shielding plate (612) provided between the second test antenna and the quiet zone, and a first shielding plate (612) provided between the second test antenna and the reflector. The test device according to claim 4, comprising: two shielding plates (613). A test method using the test device according to any one of claims 1 to 5, comprising:
selecting one arrival angle from the plurality of arrival angles (S2);
The position of the second test antenna is moved by the antenna movable mechanism so as to achieve the selected arrival angle, and the second test antenna is connected to the second test antenna by an RF cable (47a, 47b). a step (S3) of moving the frequency converters (45, 46) to be tested while maintaining a constant positional relationship with the second test antenna;
a step (S5) of sequentially changing the posture of the subject to be tested placed within the quiet zone;
a step (S8) of measuring the transmission characteristics or reception characteristics of the object under test using the first test antenna and the second test antenna each time the attitude of the object under test is changed; , including test methods.

Images