JP6974411B2 - Antenna device and measurement method - Google Patents

Description

The present invention relates to an antenna device and a measuring method for performing spurious measurement on a radio signal transmitted and received from an antenna to be tested by 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 is a particular demand for wireless terminals that transmit and receive wireless signals compatible with IEEE802.11ad and 5G cellular, which use wideband signals in the millimeter wave band.

At a wireless terminal design / development company or its manufacturing plant, the output level and reception sensitivity of the transmitted radio waves specified for each communication standard are measured for the wireless communication antenna provided in the wireless terminal, and meet the specified standards. A performance test is performed to determine whether or not it is.

With the generation shift from 4G or 4G advance to 5G, the test method of the above-mentioned performance test is also changing. For example, in a performance test in which a wireless terminal for a 5G NR system (New Radio System) (hereinafter referred to as a 5G wireless terminal) is a subject to be tested (Device Under Test: DUT), tests such as 4G and 4G advance are the mainstream. As for the method of connecting the antenna terminal of the DUT and the test device by wire, it is necessary to attach the antenna terminal to the high frequency circuit to deteriorate the characteristics, or to attach the antenna terminal to all the elements due to the large number of elements of the array antenna. It cannot be used because it is not realistic in consideration of the aspect. Therefore, the DUT is housed together with the test antenna in an anechoic box that is not affected by the surrounding radio wave environment, and the test signal is transmitted from the test antenna to the DUT and the test signal from the DUT that receives the test signal is tested. A so-called OTA test is performed in which reception by an antenna is performed by wireless communication (see, for example, Patent Document 1).

Furthermore, for 5G wireless terminals, the revision of the 5G NR standard has made it mandatory to measure spurious in addition to the performance tests described above. Spurious measurement is a technique for measuring how much unnecessary radio waves, that is, spurious waves, are radiated in other bands during communication at a target oscillation frequency of a 5G radio terminal.

In the performance test of a 5G wireless terminal, a compact antenna test range (hereinafter referred to as CATR) is known as a test equipment for realizing the above-mentioned OTA test environment and spurious measurement environment. The CATR consists of an anechoic box called an OTA chamber, which houses a DUT, a test antenna, and multiple receiving antennas for spurious measurement so as to prevent the intrusion of radio waves from the outside and the radiation of radio waves to the outside. ing. Further, in the CATR, a reflector having a rotating parabolic surface is arranged in the radio wave propagation path between the DUT antenna and the test antenna, so that the radio wave propagation path is compared with the one without the reflector. The feature is that it can be shortened and is literally more compact than the OTA test in a general parabolic environment.

In the OTA chamber, the measuring device using the CATR transmits a test signal from the test antenna and causes the DUT to receive the test signal, and the DUT receiving the test signal receives the measured signal transmitted by the test antenna to perform the above performance. Conduct the test. Further, this measuring device receives the radio waves of the out-of-band region and the spurious region radiated by the DUT together with the radio waves of the signal to be measured by a plurality of receiving antennas, and analyzes each frequency band corresponding to each receiving antenna. It has become. In the following, the out-of-band region and the spurious region are collectively referred to as a “spurious frequency band”.

Japanese Patent Application No. 2018-193996

3GPP TR 38.810 V16.2.0 (2019-03)

In a general CATR, one receiving antenna for spurious measurement is arranged at the focal position of the above-mentioned reflector in an internal space (radio wave anechoic box) that is not affected by the surrounding radio wave environment, and is emitted from the DUT antenna together with the measured signal. It is possible to measure radio signals in the spurious frequency band. In order to perform spurious measurement in a wide frequency band specified by the 5G NR standard, the spurious frequency band is divided into a plurality of divided frequency bands, and a plurality of receiving antennas corresponding to each divided frequency band are required. Further, in spurious measurement of all divided frequency bands, it is necessary to install each receiving antenna at the focal position of the reflector one by one.

Therefore, in a measuring device using a conventional CATR as disclosed in Patent Document 1, complicated work or mechanism for switching a plurality of receiving antennas is required in order to perform spurious measurement. At the same time, the measurement process had to be complicated. Further, in the conventional measuring device, there is a problem that various cables connecting the measuring unit and a plurality of receiving antennas move with the switching of a plurality of receiving antennas, resulting in wear and deterioration. there were.

The present invention has been made to solve such a conventional problem, and when performing spurious measurement by CATR, it is necessary to sequentially arrange a plurality of receiving antennas for spurious measurement at the focal position of the reflector. The purpose is to provide an antenna device and a measurement method capable of achieving efficient spurious measurement over a wide frequency band for a DUT that transmits and receives radio signals in the millimeter wave band while increasing the durability of the device. do.

In order to solve the above problems, the antenna device according to the present invention has an anechoic box having an internal space that is not affected by the surrounding radio wave environment, and radio signals in a plurality of preset divided frequency bands housed in the internal space. An antenna device comprising a plurality of receiving antennas, each of which receives a plurality of receiving antennas, and a reflector accommodated in the internal space and having a predetermined rotating parabolic surface, wherein the reflector is interposed via the rotating parabolic surface. The radio wave of the radio signal of the specified frequency band transmitted or received by the antenna under test possessed by the object under test arranged in the quiet zone in the internal space is reflected, and each of the above-mentioned divided frequency bands is of the above-mentioned specified frequency band. The frequency band from the frequency lower than the lower limit frequency to the frequency higher than the upper limit frequency of the specified frequency band is divided, and the plurality of receiving antennas are outside the focal position determined from the rotating parabolic surface. It is an arranged configuration.

With this configuration, since a plurality of receiving antennas are arranged outside the focal position determined by the rotating paraboloid of the reflector, the antenna device according to the present invention sequentially places the plurality of receiving antennas for spurious measurement at the focal position of the reflector. It is not necessary to arrange them, and the durability of the device can be improved. Further, since the antenna device according to the present invention can continuously perform spurious measurement in each divided frequency band for a DUT that transmits and receives a radio signal in the millimeter wave band, efficient spurious measurement can be performed over a wide frequency band. It can be carried out.

Further, the antenna device according to the present invention is arranged at the focal position in the internal space, and is the subject to be tested via the test antenna for transmitting or receiving a radio signal in the specified frequency band and the test antenna. In addition to outputting the test signal to, the test signal output from the test object to which the test signal is input is received by the test antenna, and the radio in the specified frequency band is received based on the received signal. A transmission / reception characteristic measuring device that measures a signal and a radio signal of the plurality of divided frequency bands output together with the measured signal from the subject to be tested to which the test signal is input correspond to each of the divided frequency bands. The configuration may further include a signal analysis device that receives signals via the respective reception antennas and analyzes the frequency distribution and power of the received radio signals in the divided frequency bands.

With this configuration, the antenna device according to the present invention facilitates spurious signals in a plurality of divided frequency bands different from the specified frequency band for a DUT having an antenna under test for transmitting or receiving a radio signal in the specified frequency band. Can be measured.

Further, the antenna device according to the present invention holds the plurality of receiving antennas so that the center of the opening surface of the plurality of receiving antennas is arranged within a distance corresponding to the size of the quiet zone from the focal position. It may be configured to further include an antenna holding portion.

With this configuration, in the antenna device according to the present invention, for example, when the diameter Φ of the quiet zone is 33 cm, the amplitude deviation in the quiet zone when the radio wave of the radio signal is emitted from each receiving antenna is 0.6 dB. Within a distance (eg, within 60 mm) from the focal position that is less than, the center of the open surface of the receiving antenna is located. As a result, the antenna device according to the present invention can obtain spurious measurement results of substantially the same quality as when a plurality of receiving antennas are arranged at focal positions.

Further, in the antenna device according to the present invention, in the antenna holding portion, the opening surface of the test antenna and the opening surface of the plurality of receiving antennas are transmitted from the antenna under test and reflected by the reflector. The test antenna and the plurality of receiving antennas may be held so as to be arranged on the same plane perpendicular to the traveling direction of the radio wave of the radio signal.

With this configuration, the antenna device according to the present invention can easily arrange a plurality of receiving antennas at positions outside the focal position where good quality spurious measurement results can be obtained.

Further, the measuring method according to the present invention is a measuring method using any of the above-mentioned antenna devices, and includes a holding step of holding the test target in the test target mounting portion in the anechoic box, and the above-mentioned. A test signal output step that outputs a test signal to the subject to be tested via a test antenna, and radio waves in the plurality of divided frequency bands that are output together with the signal to be measured from the subject to be tested to which the test signal is input. The frequency distribution and power of the spurious signal receiving step of receiving the signal via the respective receiving antenna corresponding to each of the divided frequency bands and the radio signal of each of the divided frequency bands received in the spurious signal receiving step are analyzed. It is a configuration including an analysis step to be performed.

With this configuration, the measurement method according to the present invention can continuously measure spurious in each divided frequency band for a DUT that transmits and receives a radio signal in the millimeter wave band, and thus efficient spurious over a wide frequency band. Measurements can be made.

The present invention eliminates the need to sequentially arrange a plurality of receiving antennas for spurious measurement at the focal position of the reflector when performing spurious measurement with CATR, thereby improving the durability of the device and transmitting a radio signal in the millimeter wave band. It provides an antenna device and a measurement method capable of realizing efficient spurious measurement over a wide frequency band for transmission / reception DUT.

It is a figure which shows the schematic structure of the whole measuring apparatus which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the measuring apparatus which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the integrated control apparatus of the measuring apparatus which concerns on embodiment of this invention. (A) is a block diagram showing the functional configuration of the NR system simulator in the measuring device according to the embodiment of the present invention, and (b) is a block showing the functional configuration of the signal analysis device in the measuring device according to the embodiment of the present invention. It is a figure. It is a schematic diagram for demonstrating the near field and the distant field in the radio wave propagation between an antenna AT and a radio terminal, (a) shows an example of a direct fur field, and (b) shows an example of a CATR. It is a schematic diagram which shows the signal path structure of the parabola which has the same rotating paraboloid as the reflector adopted in the OTA chamber of the measuring apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the signal path structure of the offset parabola which has the same rotating paraboloid as the reflector adopted in the OTA chamber of the measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the use frequency classification of a plurality of receiving antennas for spurious measurement adopted in the OTA chamber of the measuring apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the arrangement of the test antenna and a plurality of receiving antennas in the antenna holding part of the measuring apparatus which concerns on embodiment of this invention. It is a figure which shows the measurement result of the amplitude characteristic of the receiving antenna (for 6GHz to 20GHz) in the measuring apparatus which concerns on embodiment of this invention, (a) shows the measurement result when the receiving antenna is arranged in the focal position, and shows the measurement result. (B) shows the measurement result when the receiving antenna is arranged outside the focal position. It is a figure which shows the measurement result of the amplitude characteristic of the receiving antenna (for 20GHz to 40GHz) in the measuring apparatus which concerns on embodiment of this invention, (a) shows the measurement result when the receiving antenna is arranged in the focal position, and shows the measurement result. (B) shows the measurement result when the receiving antenna is arranged outside the focal position. It is a figure which shows the measurement result of the amplitude characteristic of the receiving antenna (for 40GHz to 60GHz) in the measuring apparatus which concerns on embodiment of this invention, (a) shows the measurement result when the receiving antenna is arranged in the focal position, and shows the measurement result. (B) shows the measurement result when the receiving antenna is arranged outside the focal position. It is a figure which shows the measurement result of the amplitude characteristic of the receiving antenna (for 60GHz-87GHz) in the measuring apparatus which concerns on embodiment of this invention, and (a) shows the measurement result when the receiving antenna is arranged in the focal position, and shows the measurement result. (B) shows the measurement result when the receiving antenna is arranged outside the focal position. It is a flowchart which shows the spurious measurement process of DUT in the measuring apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the antenna device and the measuring method according to the present invention will be described with reference to the drawings. The dimensional ratio of each component on each drawing does not always match the actual dimensional ratio.

The measuring device 1 according to the present embodiment corresponds to the antenna device of the present invention. The measuring device 1 has an external structure as shown in FIG. 1 as a whole, and is configured by a functional block as shown in FIG. However, FIG. 1 shows an arrangement mode of each component of the OTA chamber 50 in a state of being seen through from the side surface.

As shown in FIGS. 1 and 2, the measuring device 1 according to the present embodiment includes an integrated control device 10, an NR system simulator 20, a signal analysis device 30, signal processing units 40a and 40b, a spurious signal processing unit 41, and an OTA. It has a chamber 50.

The integrated control device 10 is communicably connected to the NR system simulator 20 and the signal analysis device 30 via a network 19 such as Ethernet (registered trademark). Further, the integrated control device 10 is also connected to a control means for controlling the components arranged in the OTA chamber 50 via the network 19. The measuring device 1 has, for example, a DUT attitude control unit 17 as a control means for the OTA chamber 50.

The integrated control device 10 comprehensively controls the control means for the NR system simulator 20, the signal analysis device 30, and the OTA chamber 50 via the network 19, and is configured by, for example, a personal computer (PC). NS. The DUT attitude control unit 17 may be provided in the integrated control device 10 as shown in FIG. 3, for example. Hereinafter, the integrated control device 10 will be described as having the configuration shown in FIG.

The measuring device 1 is operated, for example, by using a rack structure 90 having a plurality of racks 90a as shown in FIG. 1 and mounting each component on each rack 90a. In FIG. 1, an example in which an integrated control device 10, an NR system simulator 20, a signal analysis device 30, and an OTA chamber 50 are mounted on each rack 90a of the rack structure 90 is given.

Here, for convenience, the configuration of the OTA chamber 50 will be described first. The OTA chamber 50 realizes an OTA test environment and a spurious measurement environment for a performance test of a wireless terminal for 5G, and is used as an example of the above-mentioned CATR.

As shown in FIGS. 1 and 2, the OTA chamber 50 is composed of, for example, a metal housing body 52 having a rectangular parallelepiped-shaped internal space 51. The OTA chamber 50 has a DUT 100, a test antenna 5 facing the antenna 110 (antenna to be tested) of the DUT 100, and a plurality of receiving antennas 6 for spurious measurement in the internal space 51. It is housed in a state that prevents the radiation of radio waves to the outside. As the test antenna 5 and the plurality of receiving antennas 6, a directional antenna for millimeter waves such as a horn antenna can be used. The test antenna 5 transmits or receives a radio signal for measuring the transmission characteristic or the reception characteristic of the DUT 100 and the spurious measurement with the antenna 110.

The internal space 51 of the OTA chamber 50 further accommodates a reflector 7 that realizes a radio wave path that returns the radio wave of the radio signal radiated from the antenna 110 of the DUT 100 to the opening surfaces of the test antenna 5 and the plurality of receiving antennas 6. Has been done. Further, the radio wave absorber 55 is attached to the entire inner surface of the OTA chamber 50, that is, the entire surface of the bottom surface 52a, the side surface 52b, and the top surface 52c of the housing body 52, and the function of restricting the radiation of radio waves to the outside is strengthened. There is. As described above, the OTA chamber 50 realizes an anechoic box having an internal space 51 that is not affected by the surrounding radio wave environment. The anechoic chamber used in this embodiment is, for example, an Anechoic type.

The DUT 100 to be tested is a wireless terminal such as a smartphone. Communication standards for DUT100 include cellular (LTE, LTE-A, W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, 1xEV-DO, TD-SCDMA, etc.), wireless LAN (IEEE802.11b / g / g / (A / n / ac / ad, etc.), Bluetooth (registered trademark), GNSS (GPS, Galileo, CDMASS, BeiDou, etc.), FM, and digital broadcasting (DVB-H, ISDB-T, etc.). Further, the DUT 100 may be a wireless terminal that transmits / receives a radio signal in a millimeter wave band corresponding to 5G cellular or the like.

In the present embodiment, for example, the DUT 100 is a 5G NR radio terminal, and the antenna 110 of the DUT 100 transmits or receives a radio signal within a specified frequency band (millimeter wave band) conforming to the 5G NR standard. .. The antenna 110 is an array antenna such as a Massive-MIMO antenna, and corresponds to the antenna under test in the present invention. The test antenna 5 arranged in the OTA chamber 50 transmits or receives a radio signal in the same specified frequency band as the antenna 110 of the DUT 100. On the other hand, the plurality of receiving antennas 6 receive radio signals of a plurality of preset divided frequency bands different from the above-mentioned defined frequency bands. Here, each divided frequency band is a frequency band (spurious frequency band) divided from a frequency lower than the lower limit frequency of the specified frequency band to a frequency higher than the upper limit frequency of the specified frequency band. be. In the following, the radio signal of each division frequency band is also referred to as a “spurious signal”.

FIG. 8 is a table showing the usable frequency band classification of the plurality of receiving antennas 6 arranged in the OTA chamber 50 in the present embodiment. In FIG. 8, the entire frequency band of 6 GHz to 87 GHz used by the plurality of receiving antennas 6 corresponds to, for example, numbers 1, 2, 3, 4, ..., 6 GHz to 20 GHz, 20 GHz to 40 GHz, 40 GHz. It is divided into a plurality of bands (divided frequency bands) such as ~ 60 GHz, 60 GHz to 87 GHz, and so on.

In the present embodiment, for example, in the frequency band classification in FIG. 8, the OTA chamber 50 arranges four receiving antennas 6 using the divided frequency bands corresponding to the numbers 1, 2, 3, and 4 in the internal space 51. It is something to do. Further, the OTA chamber 50 may be configured to adopt an antenna that uses a frequency band of 24.65 GHz to 45.1 GHz as a default frequency band as the test antenna 5.

Next, an arrangement mode of the posture variable mechanism 56, the test antenna 5, the receiving antenna 6, and the reflector 7 in the internal space 51 of the OTA chamber 50 will be described. As shown in FIG. 1, in the OTA chamber 50, the housing body 52 in the internal space 51 is provided with a posture variable mechanism 56 that sequentially changes the posture of the DUT 100 arranged in the quiet zone QZ. ing. Here, the quiet zone QZ represents a range of a spatial region in which the DUT 100 is irradiated from the test antenna 5 with a substantially uniform amplitude and phase (see, for example, Non-Patent Document 1). The shape of the quiet zone is usually spherical. By arranging the DUT 100 in such a quiet zone QZ, it becomes possible to perform the OTA test in a state where the influence of scattered waves from the surroundings is suppressed.

The attitude variable mechanism 56 is, for example, a two-axis positioner provided with a rotation mechanism that rotates in two axes, and the test antenna 5 and the plurality of receiving antennas 6 are fixed in positions by an antenna holding portion 61 described later. An OTA test system (Combined-axes system) that rotates the DUT 100 with two degrees of freedom is configured. Specifically, the posture variable mechanism 56 includes drive portions 56a and 56b, a turntable 56c, a support column 56d, and a DUT mounting portion 56e as a mounting portion to be tested.

The drive units 56a and 56b are composed of a drive motor such as a stepping motor that generates a rotary drive force. The turntable 56c is adapted to rotate by a predetermined angle around one of the two axes orthogonal to each other by the rotational driving force of the driving unit 56a. The support column 56d is connected to the turntable 56c, extends from the turntable 56c in the direction of one axis, and rotates together with the turntable 56c by the rotational driving force of the drive unit 56a. The DUT mounting portion 56e extends from the side surface of the support column 56d in the direction of the other axis of the two axes, and is rotated by a predetermined angle around the other axis by the rotational driving force of the drive unit 56b. The DUT 100 is mounted on the DUT mounting unit 56e.

The above-mentioned one axis is, for example, an axis extending in the vertical direction with respect to the bottom surface 52a (x-axis in the figure). Further, the other axis described above is, for example, an axis extending in the horizontal direction from the side surface of the support column 56d. The attitude variable mechanism 56 configured in this way sequentially positions the DUT 100 held in the DUT mounting portion 56e so that the antenna 110 faces in all directions in three dimensions, for example, with the center of the DUT 100 as the center of rotation. It is possible to rotate it so that it can be changed. That is, the measuring device 1 of the present embodiment can be tested by the "black-box approach" by the posture variable mechanism 56 as described above.

In the OTA chamber 50, two types of link antennas 8, 9a and 9b for establishing or holding a link (call) with the DUT 100 are provided at a required position of the housing body 52, respectively. The link antenna 8 is a link antenna for LTE and is used in a non-standalone mode. On the other hand, the link antennas 9a and 9b are link antennas for 5G and are used in a stand-alone mode. The link antennas 8, 9a, and 9b are installed so as to have directivity with respect to the DUT 100 held by the posture variable mechanism 56.

The spurious measurement is performed by measuring the total radiated power (TRP). Therefore, during the spurious measurement, it is necessary to maintain the state in which the antenna 110 of the DUT 100 emits a beam in a fixed direction when viewed from the housing, regardless of the rotation by the attitude variable mechanism 56. First, before starting the spurious measurement, the test antenna 5 establishes a call connection between the DUT 100 and the NR system simulator 20. After that, in order to prevent the call connection from being disconnected due to the rotation of the DUT 100, the call connection between the DUT 100 and the NR system simulator 20 is maintained by the link antennas 9a and 9b provided in the vicinity of the DUT 100. It is desirable that the two link antennas 9a and 9b are arranged at positions that are point-symmetrical with respect to the center of the DUT100.

Further, in the OTA chamber 50, an antenna holding portion 61 is provided at a position below the housing main body portion 52, and the antenna holding portion 61 holds the test antenna 5 and the plurality of receiving antennas 6 in a state of being separated from each other. ing.

In the OTA chamber 50, the reflector 7 has an offset parabolic (see FIG. 7) type structure described later. As shown in FIG. 1, the reflector 7 is attached to a required position on the side surface 52b of the OTA chamber 50 by using the reflector holder 58. The reflector 7 receives a radio wave of a test signal radiated from one test antenna 5 arranged at a focal position F determined from the rotating paraboloid on the rotating paraboloid, and is held by the attitude variable mechanism 56. While reflecting toward the DUT 100, the DUT 100 that has received the test signal receives the radio wave of the measured signal radiated from the antenna 110 on the rotating paraboloid and reflects it toward the test antenna 5 that radiates the radio wave of the test signal. It is arranged in a position and posture that can be made to move. That is, the reflector 7 is adapted to reflect the radio wave of the radio signal transmitted and received between the test antenna 5 and the antenna 110 through the rotating paraboloid.

Here, the merits of mounting the reflector 7 on the OTA chamber 50 and a preferable form of the reflector 7 will be described with reference to FIGS. 5 to 7. FIG. 5 is a schematic diagram showing, for example, how radio waves radiated from an antenna AT equivalent to the test antenna 5 are transmitted to the radio terminal 100A. The wireless terminal 100A is equivalent to the DUT100. In FIG. 5, (a) shows an example of the case where the radio wave is directly transmitted from the antenna AT to the wireless terminal 100A (Direct Far Field), and (b) shows the rotating paraboloid surface from the antenna AT. An example of the case where the radio wave is transmitted to the radio terminal 100A via the reflecting mirror 7A (CATR) is shown.

As shown in FIG. 5A, a radio wave having an antenna AT as a radiation source has a property that a surface (wavefront) connecting points having the same phase spreads in a spherical shape around the radiation source and propagates. At this time, interference waves generated by disturbances such as scattering, refraction, and reflection as shown by the broken line are also generated. In addition, the wavefront is a curved spherical surface (spherical wave) at a distance close to the radiation source, but the wavefront becomes close to a plane (plane wave) at a distance from the radiation source. 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 regarded as a plane is called the far field (FAR FIELD). In the propagation of the radio wave shown in FIG. 5A, it is preferable that the wireless terminal 100A receives a plane wave rather than a spherical wave in order to perform an accurate measurement.

In order to receive a plane wave, the wireless terminal 100A needs to be installed in a distant field. Here, when the maximum linear size of the wireless terminal 100A is D and the wavelength of the radio wave is λ, the far field is ^{a distance of 2D 2} / λ or more from the antenna AT. Specifically, when D = 0.4 m (meter) and wavelength λ = 0.01 m (corresponding to a radio signal in the 28 GHz band), the position approximately 30 m from the antenna AT is the boundary between the near field and the far field. Therefore, it becomes necessary to place the wireless terminal 100A at a position farther than that. In this embodiment, it is assumed that the maximum linear size D is, for example, a measurement of DUT100 of about 5 cm (centimeter) to 33 cm.

As described above, the direct far field method shown in FIG. 5A has a characteristic that the propagation distance between the antenna AT and the wireless terminal 100A is large and the propagation loss is large. Therefore, as a countermeasure, for example, as shown in FIG. 5B, reflection having a rotating paraboloid so as to reflect the radio wave of the antenna AT so that the reflected wave reaches the position of the wireless terminal 100A. There is a method of arranging the mirror 7A. According to this method, not only the distance between the antenna AT and the wireless terminal 100A can be shortened, but also the plane wave region is expanded from the distance immediately after the reflection on the mirror surface of the reflecting mirror 7A, so that the effect of reducing the propagation loss is expected. be able to. The degree of a plane wave can be expressed by the phase difference of waves of the same phase. The acceptable phase difference as the degree of plane wave is, for example, λ / 16. The phase difference can be evaluated, for example, with a vector network analyzer (VNA).

Examples of the reflector 7A shown in FIG. 5 (b) include a parabola (see FIG. 6) and an offset parabola (see FIG. 7). As shown in FIG. 6, the parabola has a mirror surface (rotating paraboloid) symmetric with respect to the axis passing through the center O of the antenna, and is in the direction of the rotating paraboloid at the focal position F determined from the rotating paraboloid. By installing a directional primary radiator, it has a function of reflecting radio waves radiated from the primary radiator in a direction parallel to the axial direction. On the contrary, the parabola is transmitted by a radio wave (for example, the DUT 100) incident on the rotating paraboloid in a direction parallel to the axial direction by arranging the test antenna 5 in the present embodiment at the focal position F, for example. The radio signal) can be reflected and guided to the test antenna 5. However, the parabola has a perfect circular shape when viewed from the front (z direction) and has a large structure, and is not suitable for arrangement as the reflector 7 of the OTA chamber 50.

On the other hand, as shown in FIG. 7, the offset paraboloid has a shape obtained by cutting out a part of the rotating paraboloid of a mirror surface (a perfect circular paraboloid (see FIG. 6)) that is asymmetric with respect to the axis of the rotating paraboloid. ), And by installing the primary radiator with its beam axis tilted at an angle α, for example, with respect to the axis of the rotating paraboloid, the radio waves radiated from the primary radiator can be transmitted to the rotating paraboloid. It has a function of reflecting in a direction parallel to the axial direction of. In this offset paraboloid, for example, by arranging the test antenna 5 in the present embodiment at the focal position F, the radio wave radiated from the test antenna 5 (for example, the radio wave of the test signal for the DUT 100) is radiated on a rotating paraboloid. A radio wave (for example, a signal to be measured transmitted from the DUT 100) that is reflected in a direction parallel to the axial direction of the rotating paraboloid and is incident on the rotating paraboloid in a direction parallel to the axial direction of the rotating paraboloid. ) Can be reflected by the rotating paraboloid and guided to the test antenna 5. The offset parabola can be arranged so that the mirror surface approaches vertically, and the structure can be significantly smaller than that of the parabola (see FIG. 6).

Based on the above findings, in the OTA chamber 50 of the present embodiment, as shown in FIG. 1, a reflector 7 using an offset parabola (see FIG. 7) is provided with a DUT 100, a test antenna 5, and a plurality of receiving antennas 6. It is placed in the radio wave propagation path between them. The reflector 7 is attached to the side surface 52b of the housing body 52 so that the center of the opening surface of the test antenna 5 is the focal position.

The traveling direction of the radio wave of the radio signal transmitted from the antenna 110 of the DUT 100 and reflected by the reflector 7 (hereinafter, also referred to as “beam axis BS1”) with respect to the axis RS1 of the reflector 7 is tilted by a predetermined angle α. .. That is, the reflector 7 and the test antenna 5 (located at the focal position) held by the antenna holding portion 61 are in an offset state in which the beam axis BS1 is tilted by a predetermined angle α with respect to the axis RS1 of the reflector 7. ing. The reflector 7 has a focal position F on the beam axis BS1 of the test antenna 5.

As shown in FIG. 9, the antenna holding portion 61 includes an opening surface 5a of the test antenna 5 and an opening surface 6-of a plurality of receiving antennas 6 (6-1, 6-2, 6-3, 6-4). Hold the test antenna 5 and the plurality of receiving antennas 6 so that 1a, 6-2a, 6-3a, 6-4a are arranged on the same plane 61a perpendicular to the beam axis BS1. It has become. Here, "vertical" means that the plane 61a forms an angle of about 90 ± 10 degrees with respect to the beam axis BS1. The plane 61a is composed of, for example, one surface of a rectangular parallelepiped-shaped radio wave absorber having a hollowed-out opening corresponding to the opening surface of the test antenna 5 and the plurality of receiving antennas 6. The numbers 1, 2, 3 and 4 in FIG. 8 correspond to the receiving antennas 6-1 and 6-2, 6-3 and 6-4, respectively.

That is, the antenna holding portion 61 holds the test antenna 5 for in-band at the focal position of the reflector 7, and holds the four receiving antennas 6 for out-band outside the focal position F of the reflector 7. Here, in the arrangement of the four receiving antennas 6, the quality of quiet zone (QoQZ) is measured by the measurement method described in "Annex D: Quality of the quiet zone validation" of Non-Patent Document 1. It suffices if the result of evaluation of the receiving antenna 6 satisfies, for example, QoQZ ≦ 1 dB. The lower limit of the size of the reflector 7 and the size of the internal space 51 is determined according to the size of the desired quiet zone QZ. For example, when the diameter Φ of the quiet zone QZ is 33 cm, the center of the opening surfaces 6-1a, 6-2a, 6-3a, 6-4a of the four receiving antennas 6 is the focal position F in the plane 61a. It is desirable to arrange it so that it is within 60 mm from the distance.

The tilt angle α described above can be set to, for example, 30 degrees. In this case, the opening surfaces of the test antenna 5 and the plurality of receiving antennas 6 are perpendicular to the beam axis BS1 so that the test antenna 5 and the plurality of receiving antennas 6 face the reflector 7 at an elevation angle of 30 degrees. It will be held by the antenna holding portion 61 at an angle. By adopting the offset parabolic reflector 7, the reflector 7 itself can be made small, and the mirror surface can be arranged in a posture close to vertical, which has the advantage that the structure of the OTA chamber 50 can be reduced. ..

10 to 13 show a measurement plane provided in the internal space 51 in the case where radio waves of radio signals are radiated from a plurality of receiving antennas 6-1, 6-2, 6-3, 6-4, respectively. The results of actual measurement of the amplitude characteristics by the near field measurement system are shown. Here, the above-mentioned measurement plane is a plane parallel to the xy plane of FIG. 1 and is provided at a position passing through the center of the quiet zone QZ. The range of the white circles in FIGS. 10 to 13 represents the size of the quiet zone QZ (Φ = 33 cm).

FIG. 10A is a measurement result of the amplitude characteristic when the receiving antenna 6-1 is arranged at the focal position F and emits a radio wave of a radio signal of 15 GHz. On the other hand, FIG. 10B is a measurement result of the amplitude characteristic when the receiving antenna 6-1 is arranged outside the focal position F in the plane 61a shown in FIG. 9 and emits a radio wave of a radio signal of 15 GHz. Further, FIG. 11A is a measurement result of the amplitude characteristic when the receiving antenna 6-2 is arranged at the focal position F and emits a radio wave of a radio signal of 30 GHz. On the other hand, FIG. 11B is a measurement result of the amplitude characteristic when the receiving antenna 6-2 is arranged outside the focal position F in the plane 61a shown in FIG. 9 and emits a radio wave of a radio signal of 30 GHz.

Further, FIG. 12A is a measurement result of the amplitude characteristic when the receiving antenna 6-3 is arranged at the focal position F and emits a radio wave of a radio signal of 50 GHz. On the other hand, FIG. 12B is a measurement result of the amplitude characteristic when the receiving antenna 6-3 is arranged outside the focal position F in the plane 61a shown in FIG. 9 and emits a radio wave of a radio signal of 50 GHz. Further, FIG. 13A is a measurement result of the amplitude characteristic when the receiving antenna 6-4 is arranged at the focal position F and emits a radio wave of a radio signal of 80 GHz. On the other hand, FIG. 13B is a measurement result of the amplitude characteristic when the receiving antenna 6-4 is arranged outside the focal position F in the plane 61a shown in FIG. 9 and emits a radio wave of an 80 GHz radio signal.

As shown in FIGS. 10 to 13, each receiving antenna 6 is substantially the same in the quiet zone QZ when it is arranged outside the focal position F and when it is arranged at the focal position F satisfying QoQZ ≦ 1 dB. They showed fairly uniform amplitude characteristics, and their amplitude deviations were generally less than 0.6 dB. From these measurement results, it is considered that a plurality of receiving antennas 6 arranged outside the focal position F in the plane 61a also satisfy QoQZ ≦ 1 dB and can contribute to good spurious measurement.

Here, with reference to FIGS. 2 to 4, the functional configuration of the measuring device 1 according to the present embodiment will be described in more detail. In the measuring device 1 (see FIG. 2) according to the present embodiment, the integrated control device 10 has, for example, the functional configuration as shown in FIG. 3, and the NR system simulator 20 and the signal analysis device 30 are, for example, FIG. It has a functional configuration as shown in. The NR system simulator 20 constitutes the transmission / reception characteristic measuring device of the present invention.

As shown in FIG. 3, the integrated control device 10 has a control unit 11, an operation unit 12, and a display unit 13. The control unit 11 is configured by, for example, a computer device. As shown in FIG. 3, this computer device is, for example, a CPU that performs predetermined information processing for realizing the function of the measuring device 1 and comprehensive control for the NR system simulator 20 and the signal analysis device 30. (Central Processing Unit) 11a, ROM (Read Only Memory) 11b for storing OS (Operating System) for starting up CPU 11a, other programs, parameters for control, etc., and OS and applications used for operation by CPU 11a. A RAM (Random Access Memory) 11c for storing execution codes, data, etc., an external interface (I / F) unit 11d having an input interface function for inputting a predetermined signal and an output interface function for outputting a predetermined signal. It has a non-volatile storage medium such as a hard disk device (not shown) and various input / output ports.

The external I / F unit 11d is communicably connected to the NR system simulator 20 and the signal analysis device 30 via the network 19. Further, the external I / F unit 11d is also connected to the posture variable mechanism 56 in the OTA chamber 50 via the network 19. An operation unit 12 and a display unit 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 various information such as the input screen of the various information and the measurement result.

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

The call connection control unit 14 drives the test antenna 5 arranged at the focal position F of the reflector 7 and the link antennas 9a and 9b to transmit and receive a control signal (wireless signal) between the DUT 100 and the test antenna 5. Control is performed to establish or maintain a call (a state in which radio signals can be transmitted and received) between the NR system simulator 20 and the DUT 100.

The signal transmission / reception control unit 15 monitors the user operation in the operation unit 12, and when the user performs a predetermined spurious measurement start operation, the call connection control unit 14 performs the call connection control, and then the NR system simulator. A signal transmission command is transmitted to 20. Further, the signal transmission / reception control unit 15 controls to transmit a test signal via the test antenna 5, transmits a signal reception command, and controls to receive a spurious signal via a plurality of reception antennas 6.

Further, the signal transmission / reception control unit 15 monitors the user operation in the operation unit 12, and the call connection is triggered by the user performing a predetermined transmission / reception characteristic measurement start operation related to the measurement of the transmission characteristic and the reception characteristic of the DUT 100. A signal transmission command is transmitted to the NR system simulator 20 via the call connection control by the control unit 14. Further, the signal transmission / reception control unit 15 controls the transmission of the test signal via the test antenna 5, transmits the signal reception command, and controls the reception of the measured signal via the test antenna 5.

The DUT posture control unit 17 controls the posture at the time of measurement of the DUT 100 held by the posture variable mechanism 56. In order to realize this control, for example, the DUT attitude control table 17a is stored in advance in the ROM 11b. For example, when a stepping motor is used as the drive units 56a and 56b, the DUT attitude control table 17a stores the number of drive pulses (number of operation pulses) that determine the rotational drive of the stepping motor as control data. There is.

The DUT attitude control unit 17 expands the DUT attitude control table 17a into the work area of the RAM 11c, and based on the DUT attitude control table 17a, as described above, the DUT 100 causes the antenna 110 to sequentially face in all directions in three dimensions. The attitude variable mechanism 56 is driven and controlled so as to change the attitude.

Further, in the measuring device 1 according to the present embodiment, the NR system simulator 20 has, for example, the functional configuration as shown in FIG. 4 (a), and the signal analysis device 30 has, for example, shown in FIG. 4 (b). It has such a functional configuration.

As shown in FIG. 4A, the NR system simulator 20 has, for example, a signal measurement unit 21, a control unit 22, an operation unit 23, and a display unit 24, and the posture of the DUT 100 is changed by the posture variable mechanism 56. The transmission characteristic or the reception characteristic of the DUT 100 is measured each time. The signal measurement unit 21 includes a signal generation function unit composed of a signal generation unit 21a, a digital / analog converter (DAC) 21b, a modulation unit 21c, a transmission unit 21e of the RF unit 21d, and a reception unit 21f of the RF unit 21d. It has an analog / digital converter (ADC) 21g and a signal analysis function unit composed of an analysis processing unit 21h.

In the signal generation function unit of the signal measurement unit 21, the signal generation unit 21a transmits waveform data having a reference waveform, specifically, for example, an I component baseband signal and a Q component baseband signal which is an orthogonal component signal thereof. Generate. The DAC 21b converts waveform data (I component baseband signal and Q component baseband signal) having a reference waveform output from the signal generation unit 21a from a digital signal to an analog signal and outputs the waveform data to the modulation unit 21c. The modulation unit 21c mixes a local signal with each of the I component baseband signal and the Q component baseband signal, further synthesizes the two, and outputs a digitally modulated signal. The RF unit 21d generates a test signal corresponding to the frequency of each communication standard from the digital modulation signal output from the modulation unit 21c, and the generated test signal is directed to the DUT 100 by the transmission unit 21e via the test antenna 5. Output.

Further, in the signal analysis function unit of the signal measurement unit 21, the RF unit 21d uses the test antenna 5 and the test signal in the specified frequency band output from the DUT 100 to which the test signal is input via the antenna 110. After being received by the receiving unit 21f via the signal processing unit 40b, the measured signal is mixed with the local signal to be converted into a signal (IF signal) in the intermediate frequency band. The ADC 21g converts the measured signal converted into an IF signal by the receiving unit 21f of the RF unit 21d into a digital signal and outputs it to the analysis processing unit 21h. The signal processing unit 40b is composed of a down converter, an amplifier, a frequency filter, and the like, and frequency conversion (down conversion), amplification, and frequency selection are performed with respect to the signal to be measured input from the test antenna 5. It is designed to be processed.

The analysis processing unit 21h generates waveform data corresponding to the I component baseband signal and the Q component baseband signal by digital processing the measured signal, which is a digital signal output by the ADC 21g, and then the waveform data. The process of analyzing the I component baseband signal and the Q component baseband signal is performed based on the above. In measuring the transmission characteristics for the DUT 100, the analysis processing unit 21h may, for example, measure equivalent isotropically radiated power (EIRP), total radiated power (TRP), modulation accuracy (EVM), transmission power, constellation, and spectrum. Etc. can be measured. Further, the analysis processing unit 21h can measure, for example, the reception sensitivity, the bit error rate (BER), the packet error rate (PER), and the like in the measurement of the reception characteristics for the DUT 100. Here, EIRP is the radio signal intensity in the main beam direction of the antenna under test. Further, TRP is the total value of the electric power radiated from the antenna under test into the space.

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

The operation unit 23 and the display unit 24 are connected to the 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 the input screen of the various information and the measurement result.

As shown in FIG. 4B, the signal analysis device 30 has a signal analysis unit 31, a control unit 32, an operation unit 33, and a display unit 34, and the posture of the DUT 100 is changed by the posture variable mechanism 56. The spurious measurement of the DUT 100 is performed for each. The signal analysis unit 31 has an RF unit 31a, an ADC 31b, and an analysis processing unit 31c, and has an analysis process related to spurious measurement for a spurious signal input from the spurious signal processing unit 41 and a signal analysis function of the NR system simulator 20. Performs the same analysis processing as the part. The spurious signal processing unit 41 transmits a radio signal (spurious signal) of a plurality of division frequency bands output from the DUT 100 to which the test signal is input together with the signal to be measured via each reception antenna 6 corresponding to each division frequency band. To receive. The spurious signal processing unit 41 has a down converter, an amplifier, and a frequency filter.

The spurious signal processing unit 41 performs frequency conversion (down-conversion), amplification, and frequency selection processing on the spurious signal received by each receiving antenna 6, and then converts the spurious signal into the signal analysis unit 31. It is designed to be transmitted to the RF unit 31a. The RF unit 31a converts the received spurious signal into an IF signal by mixing it with a local signal. The ADC 31b converts the spurious signal converted into the IF signal by the RF unit 31a into a digital signal and outputs the spurious signal to the analysis processing unit 31c. The analysis processing unit 31c analyzes the frequency distribution and power of the spurious signal in each divided frequency band received. The signal analysis device 30 may be configured to incorporate the spurious signal processing unit 41.

Next, the spurious measurement process of the DUT 100 using the measuring device 1 according to the present embodiment will be described with reference to the flowchart of FIG. In FIG. 14, four receiving antennas 6 that can use each of the divided frequency bands indicated by No. 1, No. 2, No. 3, and No. 4 in the spurious frequency band (see FIG. 8) are outside the focal position F, respectively. It is assumed that the spurious measurement is performed in the state of being placed in. Further, in FIG. 14, a case where the spurious measurement start operation for instructing the start of the spurious measurement process of the DUT 100 is performed by the operation unit 12 of the integrated control device 10 will be described. The spurious measurement start operation may be performed by the operation unit 33 of the signal analysis device 30.

In order to perform spurious measurement of the DUT 100 in the measuring device 1, it is first necessary to set the DUT 100 in the internal space 51 of the OTA chamber 50. As a result, in the measuring device 1, as the first process of spurious measurement, the user performs an operation of holding the DUT 100 to be tested in the DUT mounting portion 56e of the posture variable mechanism 56 of the OTA chamber 50 (holding step S1). ).

After the setting work of the DUT 100 is performed, the integrated control device 10 monitors, for example, whether or not the control unit 11 has performed the spurious measurement start operation in the operation unit 12 (step S2).

Here, when it is determined that the spurious measurement start operation has not been performed (NO in step S2), the control unit 11 continues the monitoring in step S2. On the other hand, when it is determined that the spurious measurement start operation has been performed (YES in step S2), the control unit 11 sets n indicating the order of the division frequency bands for performing spurious measurement to the first division frequency band. Set to the indicated n = 1 (step S3). In this example, the maximum value of n is 4.

Next, the call connection control unit 14 of the control unit 11 performs call connection control by transmitting and receiving a control signal (radio signal) to and from the DUT 100 using the test antenna 5 arranged at the focal position F. (Step S4). Here, the NR system simulator 20 wirelessly transmits a control signal (call connection request signal) to the DUT 100 via the test antenna 5, while the DUT 100 receiving the call connection request signal sets the frequency requested for connection. Call connection control is performed to receive the control signal (call connection answer signal) transmitted after setting. This call connection control establishes a state in which radio signals can be transmitted and received between the NR system simulator 20 and the DUT 100 via the test antenna 5 and the reflector 7 arranged at the focal position F of the reflector 7. ..

The process of receiving the radio signal transmitted from the NR system simulator 20 via the test antenna 5 and the reflector 7 by the DUT 100 is a downlink (DL) process. On the contrary, the process in which the DUT 100 transmits a radio signal to the NR system simulator 20 via the reflector 7 and the test antenna 5 is an uplink (UL) process. The test antenna 5 is used to perform a process of establishing a link (call) and a process of downlink (DL) and uplink (UL) after the link is established, and also has a function of 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 arranged in the quiet zone QZ to a predetermined attitude by the attitude variable mechanism 56 (attitude variable step S5). ).

After the attitude variable mechanism 56 controls the DUT 100 to a predetermined attitude in step S5, 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 the signal transmission command, the NR system simulator 20 controls the DUT 100 to output a test signal via the test antenna 5 arranged at the focal position F of the reflector 7 (test signal output step S6). ..

The test signal transmission control by the NR system simulator 20 is carried out as follows. In the NR system simulator 20 (see FIG. 4A), the control unit 22 that has received the signal transmission command controls the signal generation function unit, and the signal generation unit 21a generates a signal for generating a test signal. .. After that, this signal is digitally / analog-converted by the DAC 21b, further modulated by the modulation unit 21c, and then the RF unit 21d generates a test signal corresponding to the frequency of each communication standard from the digital modulation signal, and the test is performed. The signal (DL data) is output from the transmission unit 21e toward the DUT 100 via the test antenna 5.

A signal processing unit 40a is provided between the transmission unit 21e and the test antenna 5, and the signal processing unit 40a is composed of an upconverter, an amplifier, a frequency filter, and the like. The signal processing unit 40a performs frequency conversion (up-conversion), amplification, and frequency selection processing on the test signal output to the test antenna 5. The signal transmission / reception control unit 15 appropriately uses the test signal after starting the control of the test signal transmission in step S6 until the spurious measurement for all the divided frequency bands of the spurious frequency band to be measured is completed. Control to send at the timing.

On the other hand, the DUT 100 receives the test signal (DL data) transmitted via the test antenna 5 and the reflector 7 by the antenna 110 in different postures that are sequentially changed based on the posture control in step S5. At the same time, it operates to transmit a measured signal which is a response signal to the test signal.

After the transmission of the test signal is started in step S6, the signal analyzer 30 continues to process the reception of the spurious signal received by the nth receiving antenna 6-n arranged outside the focal position F of the reflector 7. (Spurious signal reception step S7). In this reception processing, the signal received by the receiving antenna 6-n is input to the spurious signal processing unit 41, and the spurious signal processing unit 41 performs each processing of frequency conversion (down-conversion), amplification, and frequency selection. After that, it is input to the signal analysis unit 31 of the signal analysis device 30.

Subsequently, the signal analysis device 30 analyzes the signal received and processed in step S7 (spurious signal received by the receiving antenna 6-n), and controls to store the analysis result (analysis step S8). At this time, in the signal analysis device 30, the control unit 32 controls the signal analysis unit 31, the spurious signal input from the spurious signal processing unit 41 is taken in via the RF units 31a and the ADC 31b, and the analysis processing unit 31c performs the spurious signal. Control is performed to analyze, for example, the frequency distribution and the power of the spurious signal. Further, the control unit 32 controls to store the analysis result of the spurious signal in a storage area such as a RAM (not shown).

Subsequently, in the integrated control device 10, for example, the DUT attitude control unit 17 determines whether or not the spurious measurement of the DUT 100 has been completed for all the desired attitudes in the nth division frequency band (step S9). Here, when it is determined that the spurious measurement for the nth divided frequency band has not been completed (NO in step S9), the processing after step S5 is continued.

On the other hand, when it is determined that the spurious measurement for the nth division frequency band is completed (YES in step S9), the control unit 11 indicates that n is the last division frequency band. It is determined whether or not 4 has been reached (step S10). Here, when it is determined that n = 4 has not been reached (NO in step S10), the control unit 11 increments the value of n (step S11) and continues the processing after step S5.

On the other hand, when it is determined that n = 4 has been reached (YES in step S10), the integrated control device 10 ends the series of spurious measurement processes shown in FIG.

In the measuring device 1 according to the present embodiment, after the test signal is transmitted from the NR system simulator 20 in step S6, the DUT 100 that receives the test signal by the control unit 22 in the NR system simulator 20 continues. Control may be performed to measure the measured signal transmitted from the antenna 110. Alternatively, the measurement process of the test signal by the NR system simulator 20 may be performed at an arbitrary timing independently of the spurious measurement process shown in FIG.

In the above embodiment, for example, an example in which a spurious frequency band of 6 GHz to 87 GHz (see FIG. 8) is covered by four receiving antennas 6 is given, but the present invention is not limited to this, and any spurious frequency is given. The band may be covered by an arbitrary number of receiving antennas 6. The present invention can be applied not only to an anechoic box but also to an anechoic chamber.

As described above, in the measuring device 1 according to the present embodiment, the plurality of receiving antennas 6 for spurious measurement are arranged outside the focal position F determined from the rotating paraboloid of the reflector 7. This eliminates the need to sequentially arrange a plurality of receiving antennas 6 for spurious measurement at the focal position F of the reflector 7, and enhances the durability of the measuring device 1. Further, since the measuring device 1 according to the present embodiment can continuously measure spurious in each division frequency band with respect to the DUT 100 that transmits and receives radio signals in the millimeter wave band, efficient spurious over a wide frequency band is performed. Measurements can be made.

Further, the measuring device 1 according to the present embodiment includes a signal analysis device 30, so that the DUT 100 having an antenna 110 that transmits or receives a radio signal in a specified frequency band has a plurality of DUTs that are different from the specified frequency band. The spurious signal in the divided frequency band can be easily measured.

Further, in the measuring device 1 according to the present embodiment, the center of the opening surfaces 6-1a, 6-2a, 6-3a, 6-4a of the plurality of receiving antennas 6 is changed from the focal position F to the size of the quiet zone QZ. Placed within the appropriate distance. For example, when the diameter Φ of the quiet zone QZ is 33 cm, the amplitude deviation in the quiet zone QZ when the radio wave of the radio signal is radiated from each receiving antenna 6 is less than 0.6 dB, and the distance from the focal position F. It is desirable that the centers of the opening surfaces 6-1a, 6-2a, 6-3a, 6-4a are arranged within (for example, within 60 mm). As a result, the measuring device 1 according to the present embodiment can obtain spurious measurement results having substantially the same quality as when a plurality of receiving antennas 6 are arranged at the focal position F.

Further, in the measuring device 1 according to the present embodiment, the opening surface 5a of the test antenna 5 and the opening surfaces 6-1a, 6-2a, 6-3a, 6-4a of the plurality of receiving antennas 6 are antennas. The radio signal transmitted from the 110 and reflected by the reflector 7 is arranged on the same plane 61a perpendicular to the traveling direction of the radio wave. As a result, the measuring device 1 according to the present embodiment can easily arrange a plurality of receiving antennas 6 at positions outside the focal position F where good quality spurious measurement results can be obtained.

1 Measuring device 5 Test antenna 5a Open surface 6,6-1, 6-2, 6-3, 6-4 Receiving antenna 6-1a, 6-2a, 6-3a, 6-4a Open surface 7 Reflector 8, 9a, 9b Link antenna 10 Integrated control device 20 NR system simulator 30 Signal analysis device 40a, 40b Signal processing unit 41 Spurious signal processing unit 50 OTA chamber 51 Internal space 56 Attitude variable mechanism 61 Antenna holding unit 61a Flat surface 100 DUT
110 Antenna F Reflector Focus Position QZ Quiet Zone

Claims (5)

An anechoic box (50) having an internal space (51) that is not affected by the surrounding radio wave environment,
A plurality of receiving antennas (6) housed in the internal space and receiving radio signals of a plurality of preset frequency bands, respectively.
An antenna device (1) including a reflector (7) housed in the internal space and having a predetermined rotating paraboloid.
The reflector has a specified frequency transmitted or received by a test antenna (110) included in a test target (100) arranged in a quiet zone (QZ) in the internal space through the rotating paraboloid. Reflects the radio waves of the radio signal in the band,
Each of the divided frequency bands is divided into a frequency band from a frequency lower than the lower limit frequency of the specified frequency band to a frequency higher than the upper limit frequency of the specified frequency band.
An antenna device characterized in that the plurality of receiving antennas are arranged outside a focal position (F) determined from the rotating paraboloid. A test antenna (5) arranged at the focal position in the internal space and transmitting or receiving a radio signal in the specified frequency band, and a test antenna (5).
The test signal is output to the subject to be tested via the test antenna, and the signal to be measured output from the subject to be tested to which the test signal is input is received by the test antenna and received. A transmission / reception characteristic measuring device (20) that measures a radio signal in the specified frequency band based on the measured signal, and a transmission / reception characteristic measuring device (20).
The radio signals of the plurality of divided frequency bands output together with the measured signal from the subject to be tested to which the test signal is input are received via the respective receiving antennas corresponding to the respective divided frequency bands. The antenna device according to claim 1, further comprising a signal analysis device (30) for analyzing the frequency distribution and power of the received radio signal in each of the divided frequency bands. The center of the opening surface (6-1a, 6-2a, 6-3a, 6-4a) of the plurality of receiving antennas is arranged within a distance corresponding to the size of the quiet zone from the focal position. wherein the plurality of antenna device according to請Motomeko 2 further comprising an antenna holding portion (61) for holding the receiving antenna. In the antenna holding portion, the opening surface (5a) of the test antenna and the opening surfaces of the plurality of receiving antennas are transmitted from the antenna under test and reflected by the reflector in the traveling direction of the radio wave. The antenna device according to claim 3, wherein the test antenna and the plurality of receiving antennas are held so as to be arranged on the same plane (61a) perpendicular to the antenna. The measuring method using the antenna device according to any one of claims 2 to 4.
A holding step (S1) for holding the test target in the test target mounting portion (56e) in the anechoic box, and a holding step (S1).
A test signal output step (S6) for outputting a test signal to the test object via the test antenna, and a test signal output step (S6).
A spurious that receives a radio signal of the plurality of divided frequency bands output together with the measured signal from the subject to be tested to which the test signal is input via the respective receiving antenna corresponding to each of the divided frequency bands. The signal reception step (S7) and
A measuring method comprising an analysis step (S8) for analyzing the frequency distribution and power of a radio signal in each of the divided frequency bands received in the spurious signal receiving step.

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