JP7136942B2 - Antenna and antenna device provided with the same - Google Patents

Description

The present invention relates to an antenna and an antenna apparatus having the same for measuring transmission characteristics or reception characteristics of a test object and spurious measurements using an anechoic box in an OTA (Over The Air) environment.

2. Description of the Related Art 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, wireless terminals that transmit and receive wireless signals compatible with IEEE 802.11ad, 5G cellular, and the like, which use broadband signals in the millimeter wave band, will be particularly required.

A wireless terminal design and development company or its manufacturing factory measures the output level and reception sensitivity of the transmission radio waves stipulated for each communication standard for the wireless communication antenna equipped with the wireless terminal, and meets the prescribed standards. A performance test is performed to determine whether

With the generation shift from 4G or 4G Advanced to 5G, the test method for the performance test described above is also changing. For example, in a performance test in which a wireless terminal for a 5G NR system (New Radio System) (hereafter referred to as a 5G wireless terminal) is a device under test (DUT), 4G and 4G advanced tests are the mainstream. The method of connecting the antenna terminal of the DUT and the test equipment with a wire is due to the deterioration of the characteristics due to attaching the antenna terminal to the high frequency circuit, or the number of elements of the array antenna is large and attaching the antenna terminal to all elements is space and cost. It cannot be used for reasons such as being impractical considering the aspect. 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 by an antenna is performed by wireless communication, is now being conducted.

In OTA tests, for example, radiated power measurements such as Total Radiated Power (TRP) and Equivalent Isotropically Radiated Power (EIRP) and 5G call connections are transmitted to 5G wireless terminals via test antennas. is carried out against A conventional test antenna is, for example, a Double-Ridged Horn Antenna (DRHA) or a Quad-Ridged Horn Antenna (QRHA) as shown in FIG. 17 (for example, Patent Document 1 reference).

FIG. 17 is a cross-sectional view of conventional antenna 300 taken along a plane including center axis 330 of horn 301. As shown in FIG. Antenna 300 has a pair of ridges 305 and 306 on the inner wall surface of horn 301 to extend the operating frequency range over a normal horn antenna. A pair of ridges 305 and 306 form a tapered shape symmetrical with respect to the central axis 330 of horn 301 . If the antenna 300 is a QRHA, a pair of ridges perpendicular to the pair of ridges 305 and 306 are formed on the inner wall surface of the horn 301 . In the case of QRHA, the four ridges are shaped like roofs to fit into each other.

Antenna 300 also has an input terminal 303 for supplying power to a pair of ridges 305 and 306 from outside horn 301 . The input terminal 303 has a center conductor 310 that protrudes through the ridge 305 and into the interior of the ridge 306 .

Further, the antenna 300 has a hollow portion 302 that is continuous with the end portion of the horn 301 opposite to the opening surface 301a. Cavity 302 has a rectangular parallelepiped shape and is provided to prevent radio wave energy from being radiated from behind antenna 300 .

Japanese Patent No. 5036772

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

However, in the conventional antenna 300 as shown in FIG. 17, of the pair of ridges 305 and 306, stronger power is supplied to the ridge 305 closer to the flange 313 of the input terminal 303 for feeding. There is a problem that the radiation pattern in the far field becomes asymmetrical.

The present invention has been made to solve such conventional problems, and provides an antenna capable of making the far-field radiation pattern more symmetrical than the conventional double-ridged or quad-ridged horn antenna, and the antenna provided therewith. An object of the present invention is to provide an antenna device with

In order to solve the above problems, an antenna according to the present invention includes a horn tapered with respect to a central axis, and arranged on an inner wall surface of the horn so as to face each other with the central axis interposed therebetween. a first input terminal having a first center conductor for supplying power to the first ridge pair from outside the horn; a hollow portion continuous with the end portion of the horn opposite to the opening surface and located farther from the opening surface than the first center conductor, wherein the first center conductor includes the first ridge pair. The hollow portion is arranged such that a tip thereof projects through one of the pair of ridges constituting the ridge and into the interior of the other ridge of the pair of ridges constituting the first ridge pair. , narrowing along the direction from the side far from the tip of the first central conductor toward the tip of the first central conductor.

As described above, the antenna according to the present invention has a cavity that narrows along the direction from the side farther from the tip of the first central conductor toward the tip of the first central conductor. can also make the far-field radiation pattern symmetrical.

Moreover, in the antenna according to the present invention, the hollow portion may have a rear wall including a surface inclined with respect to the central axis.

As described above, in the antenna according to the present invention, by providing the rear wall of the hollow portion with a surface that is inclined with respect to the central axis of the horn, the tip of the first central conductor can reach the tip of the first central conductor from the side far from the tip of the first central conductor. It is possible to easily form a cavity that narrows along the direction of travel.

Further, the antenna according to the present invention is arranged on the inner wall surface of the horn so as to face each other with the central axis interposed therebetween, and a second ridge pair comprising a pair of ridges tapered with respect to the central axis; a second input terminal having a second center conductor for powering the second ridge pair from outside the horn, the second ridge pair being orthogonal to the first ridge pair; The second center conductor passes through one ridge of the pair of ridges forming the second ridge pair and enters the inside of the other ridge of the pair of ridges forming the second ridge pair. The hollow portion is located on the side farther from the opening surface than the second center conductor, and extends from the side far from the tip of the second center conductor to the tip of the second center conductor. It may be a configuration that narrows along the facing direction.

As described above, in the antenna according to the present invention, since the cavity narrows along the direction from the side farther from the tip of the second central conductor toward the tip of the second central conductor, the antenna is farther than the conventional QRHA. The field radiation pattern can be symmetrical.

Further, an antenna device according to the present invention includes a radio wave anechoic box having an inner space that is not affected by the surrounding radio wave environment, and a plurality of anechoic boxes accommodated in the inner space for receiving radio signals of a plurality of preset divided frequency bands. A receiving antenna, a reflector having a predetermined paraboloid of revolution housed in the internal space, and a focal position determined by the paraboloid of revolution in the internal space to transmit or receive a radio signal in a specified frequency band. and a test antenna for outputting a test signal to a device under test via the test antenna, and receiving a signal under test output from the device under test to which the test signal is input by the test antenna. a transmitting/receiving characteristic measuring device for measuring a radio signal in the prescribed frequency band based on the received signal under measurement; a signal analysis device for receiving radio signals in the divided frequency bands via the receiving antennas corresponding to the respective divided frequency bands, and analyzing the frequency distribution and power of the received radio signals in the divided frequency bands; wherein the reflector is transmitted or received via the paraboloid of revolution by an antenna under test possessed by the object under test arranged within a quiet zone in the internal space. Radio waves of radio signals in frequency bands are reflected, and each of the divided frequency bands is 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. are divided, the plurality of receiving antennas are arranged outside the focal position, and either the test antenna or the plurality of receiving antennas is any of the above antennas.

With this configuration, since the plurality of receiving antennas are arranged outside the focal position determined by the paraboloid of revolution 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. The need for placement is eliminated, and the durability of the device can be enhanced. Furthermore, the antenna device according to the present invention can continuously measure spurious emissions in each frequency band for a DUT that transmits and receives radio signals in the millimeter wave band. It can be carried out.

Also, with this configuration, the antenna device according to the present invention uses any one of the above antennas as the test antenna or at least one of the plurality of receiving antennas, thereby reducing the cost of the entire device.

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 that transmits or receives radio signals in a specified frequency band. can be measured to Further, the antenna device according to the present invention uses any one of the above antennas as a test antenna or a plurality of receiving antennas, so that radio signals with symmetrical radiation patterns can be transmitted and received to perform high-quality measurement. can.

Further, the antenna apparatus according to the present invention holds the plurality of reception antennas so that the centers of the aperture planes of the plurality of reception antennas are arranged within a distance from the focal position according to the size of the quiet zone. The configuration may be further provided with an antenna holding portion that holds the antenna.

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 radio waves of radio signals are radiated from each receiving antenna is 0.6 dB. The center of the aperture plane of the receiving antenna is placed within a distance (for example, within 60 mm) from the focal position that is less than . As a result, the antenna apparatus according to the present invention can obtain spurious measurement results with substantially the same quality as when a plurality of receiving antennas are arranged at the focal positions.

Further, in the antenna device according to the present invention, the antenna holding section is configured such that the aperture plane of the test antenna and the aperture planes 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 propagation direction of the radio wave of the radio signal.

With this configuration, the antenna apparatus according to the present invention can easily place multiple receiving antennas at off-focus positions where good quality spurious measurement results can be obtained.

SUMMARY OF THE INVENTION The present invention provides an antenna and an antenna apparatus having the same that can make the far-field radiation pattern more symmetrical than conventional double-ridge or quad-ridge horn antennas.

1 is a perspective view showing the configuration of an antenna according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view of the antenna shown in FIG. 1 taken along a plane including the central axis of the horn; FIG. 2 is a diagram for explaining a tapered shape of a first ridge pair of the antenna shown in FIG. 1; FIG. FIG. 2 is a cross-sectional view of the cavity of the antenna shown in FIG. 1, where (a) shows the case where the back wall of the cavity includes an inclined surface, and (b) shows the case where the back wall of the cavity includes a curved surface; and (c) the case where the back wall of the cavity includes a stepped surface. (a) is a graph showing a radiation pattern when power is supplied to a conventional antenna having a cavity having a rectangular parallelepiped shape, and (b) is an antenna having a cavity with an inclined rear wall according to the present embodiment. is a graph showing the radiation pattern when power is supplied to the; 7 is a graph showing far-field radiation patterns when a test signal of 22.65 GHz is input to the conventional antenna and the antenna according to the first embodiment; It is a figure showing a schematic structure of the whole measuring device concerning a 2nd embodiment of the present invention. 8 is a block diagram showing the functional configuration of the measuring device shown in FIG. 7; FIG. 8 is a block diagram showing the functional configuration of an integrated control device of the measuring device shown in FIG. 7; FIG. 8A is a block diagram showing the functional configuration of an NR system simulator in the measuring device shown in FIG. 7, and FIG. 8B is a block diagram showing the functional configuration of a signal analysis device in the measuring device shown in FIG. 7; FIG. 2 is a schematic diagram for explaining the near field and far field in radio wave propagation between an antenna AT and a wireless terminal, (a) showing an example of direct far field, and (b) showing an example of CATR. FIG. 8 is a schematic diagram showing the signal path structure of a parabolic paraboloid of revolution similar to the reflector employed in the OTA chamber of the measurement apparatus shown in FIG. 7; FIG. 8 is a schematic diagram showing the signal path structure of an offset parabola with a paraboloid of revolution similar to the reflector employed in the OTA chamber of the measurement apparatus shown in FIG. 7; FIG. 8 is a table showing the operating frequency classification of a plurality of receiving antennas for spurious measurement adopted in the OTA chamber of the measuring apparatus shown in FIG. 7; FIG. 8 is a schematic diagram showing the arrangement of a test antenna and a plurality of receiving antennas in the antenna holding section of the measuring device shown in FIG. 7; FIG. 8 is a flowchart showing DUT spurious measurement processing in the measurement apparatus shown in FIG. 7 ; FIG. FIG. 4 is a cross-sectional view of a conventional antenna cut along a plane including the central axis of the horn;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an antenna and an antenna device including the antenna according to the present invention will be described below with reference to the drawings. Note that the dimensional ratio of each component on each drawing does not necessarily match the actual dimensional ratio. The antenna according to the invention is for example DRHA or QRHA.

(First embodiment)
As shown in FIGS. 1 and 2, the antenna 200 according to the first embodiment of the present invention includes a horn 201, a cavity 202, a first ridge pair, a second ridge pair, and a first input terminal 203. and a second input terminal 204, and uses the millimeter wave frequency band (eg, approximately 20 GHz to 46 GHz). Note that FIG. 1 illustrates a case where the antenna 200 is QRHA. If the antenna 200 is a DRHA, the second ridge pair and the second input terminal 204 are omitted.

The horn 201 has a rectangular cross-sectional shape perpendicular to its central axis 230 and is tapered with respect to the central axis 230 . That is, the horn 201 is configured to taper from the opening surface 201a toward the end portion on the hollow portion 202 side.

The first ridge pair is for extending the frequency band that can be transmitted and received by the antenna 200 with respect to linearly polarized radio waves whose plane of polarization is parallel to the XY plane. The first ridge pair consists of a pair of ridges 205 and 206 which are arranged on the inner wall surface of horn 201 so as to face each other across center axis 230 of horn 201 and form a tapered shape symmetrical with respect to center axis 230 .

The second ridge pair extends the frequency band in which the antenna 200 can transmit and receive linearly polarized radio waves that are orthogonal to the first ridge pair and whose plane of polarization is parallel to the XZ plane. The second ridge pair consists of a pair of ridges 207 and 208 that are arranged on the inner wall surface of horn 201 so as to face each other across center axis 230 of horn 201 and form a symmetrical tapered shape with respect to center axis 230 .

The horn 201, the cavity 202, the first ridge pair, and the second ridge pair are made of the same metal member 209, for example. Note that the horn 201 , the hollow portion 202 , the first ridge pair, and the second ridge pair may be integrally formed of the same metal member 209 . A conductive material such as brass, aluminum, or copper can be used as the metal member 209 . The metal member 209 has a rectangular parallelepiped shape as a whole from the viewpoint of cutting costs and assembly.

A first input terminal 203 is a terminal for supplying power to the first ridge pair from the outside of the horn 201 . The first input terminal 203 is, for example, a first central conductor 210 , an insulator 211 surrounding the first central conductor 210 , an outer conductor 212 surrounding the insulator 211 , and electrically connected to the outer conductor 212 . , a coaxial connector having a flange 213 that is The first central conductor 210, the outer conductor 212, and the flange 213 are made of, for example, stainless steel plated with gold or passivated. Passivation treatment is treatment for forming an oxide film (passive film) by chromium, which is a constituent element of stainless steel.

The first center conductor 210 extends in the Y-axis direction, passes through one ridge 205 of the pair of ridges forming the first ridge pair, and extends to the other of the pair of ridges forming the first ridge pair. It is arranged so that the tip protrudes inside the ridge 206 . A region near the tip of the first central conductor 210 that functions as a power feeding portion is referred to as a first power feeding region 215 . When a test signal is fed to the first central conductor 210 from the signal processing unit 40a to be described later via a coaxial cable (not shown), a high-frequency voltage is applied between the first central conductor 210 and the metal member 209 . As a result, the antenna 200 radiates to the outside a radio wave of the test signal whose plane of polarization is parallel to the XY plane. Further, when the first central conductor 210 receives an electric wave whose plane of polarization is parallel to the XY plane from the outside, the first central conductor 210 outputs the received electric wave within the first feeding region 215 toward a coaxial cable (not shown).

The flange 213 is for attaching the first input terminal 203 to the metal member 209, and has, for example, two screw holes 213a and 213b. Flange 213 is fixed in electrical connection with metal member 209 by two screws 214a and 214b inserted through two screw holes 213a and 213b.

A second input terminal 204 is a terminal for supplying power from the outside of the horn 201 to the second ridge pair. The second input terminal 204 has the same configuration as the first input terminal 203, and includes a second central conductor 220, an insulator 221 surrounding the second central conductor 220, and an outer conductor surrounding the insulator 221. 222 and a flange 223 electrically connected to the outer conductor 222.

The second center conductor 220 extends in the Z-axis direction, passes through one ridge 207 of the pair of ridges forming the second ridge pair, and extends to the other of the pair of ridges forming the second ridge pair. It is arranged so that the tip protrudes inside the ridge 208 . Although illustration is omitted, a region near the tip of the second central conductor 220 that functions as a power feeding portion is referred to as a second power feeding region. When a test signal is supplied to the second central conductor 220 from the signal processing unit 40a to be described later via a coaxial cable (not shown), a high-frequency voltage is applied between the second central conductor 220 and the metal member 209 . As a result, the antenna 200 radiates to the outside a radio wave of the test signal whose plane of polarization is parallel to the XZ plane. Further, when the second central conductor 220 receives an electric wave whose plane of polarization is parallel to the XZ plane from the outside, the second central conductor 220 outputs the received electric wave within the second feeding area toward a coaxial cable (not shown).

FIG. 3 is a diagram for explaining the tapered shape of the first ridge pair. FIG. 3 illustrates the shape of the ridge 205 closer to the flange 213 of the first input terminal 203 of the pair of ridges 205 and 206 forming the first ridge pair. The shape of the ridge 206 can also be shown by turning the figure upside down, but the illustration is omitted here to avoid complication.

The shape of each of the ridges 205 and 206 can be expressed by the sum of an exponential function term and a linear function term, as shown in Equation (1) below, for example. Here, the point where X=0 and Y=0 is the starting point of the tapered shape of the first ridge pair, and is closer to the first central conductor 210 than the opening surface 201a on the central axis 230 of the horn 201. To position.

In the curve of formula (1), if the value of Y at X= ₀ is Y0, then A= _Y0 . Let L be the length of the tapered shape of the ridges 205 and 206 in the X-axis direction, and YL be the value of Y when X= _L . B is a parameter that defines the tapered bulge of ridges 205 and 206 toward central axis 230 of horn 201 . Equation (1) indicates that the greater the value of B, the greater the linearity of the tapered shape, and the smaller the value of B, the greater the bulge of the tapered shape toward the central axis 230 of the horn 201 .

k in equation (1) is a function of B, A, _L , and YL, as shown in equation (2) below.

Similarly, the tapered shape of the second ridge pair can be represented by equations (1) and (2).

The hollow portion 202 is continuous with the end portion of the horn 201 opposite to the opening surface 201a, and is located farther from the opening surface 201a than the first central conductor 210 is. Cavity 202 is provided to prevent radio wave energy from being radiated from behind antenna 200 . The cavity 202 narrows along the direction from the side far from the tip of the first central conductor 210 toward the tip of the first central conductor 210 . In other words, the cavity 202 is configured such that the cross-sectional area parallel to the XZ plane decreases along the direction from the side far from the tip of the first central conductor 210 toward the tip of the first central conductor 210 . there is

Furthermore, when the antenna 200 is a QRHA, the cavity 202 is located farther from the opening surface 201a than the first central conductor 210 and the second central conductor 220 are. The hollow portion 202 narrows along the direction from the side far from the tip of the first center conductor 210 toward the tip of the first center conductor 210 , and narrows along the direction from the side far from the tip of the second center conductor 220 to the second center conductor. It narrows along the direction towards the tip of 220 . In other words, the cavity 202 is configured such that the cross-sectional area parallel to the XY plane decreases along the direction from the side far from the tip of the second central conductor 220 toward the tip of the second central conductor 220 . there is

4A to 4C are cross-sectional views in the XY plane showing examples of the shape of the cavity 202. FIG. FIG. 4(a) shows an example in which the rear wall 202a of the hollow portion 202 includes a surface inclined with respect to the central axis 230 of the horn 201. FIG. Also, FIG. 4(b) shows an example in which the rear wall 202a of the hollow portion 202 includes a curved surface. Also, FIG. 4C shows an example in which the rear wall 202a of the hollow portion 202 includes a stepped surface.

FIG. 5(a) is a simulation result of a radiation pattern when power is supplied to a conventional antenna 300 having a cavity 302 having a rectangular parallelepiped shape. A dashed line in the figure is an auxiliary line indicating the inclination of the wavefront with respect to the central axis 330 of the horn 301 . The lengths of the cavity 302 in FIG. 5A in the X-axis direction and the Y-axis direction are 1.1 mm and 4.4 mm, respectively.

FIG. 5(b) is a simulation result of the radiation pattern when power is supplied to the antenna 200 having the hollow portion 202 with the rear wall 202a inclined according to the present embodiment. A dashed line in the figure is an auxiliary line indicating the inclination of the wavefront with respect to the central axis 230 of the horn 201 . The length in the Y-axis direction of the hollow portion 202 in FIG. 5B is 4.4 mm, and the length in the X-axis direction of the hollow portion 202 varies from 1.1 mm to 0 mm in the negative direction of the Y-axis. .

As shown in FIGS. 5(a) and 5(b), compared with the conventional antenna 300 having a rectangular parallelepiped cavity 302, the antenna of this embodiment has a cavity 202 with an inclined rear wall 202a. In 200, it has been found that the wavefront becomes symmetrical with respect to the central axis 230 of the horn 201 as it goes toward the aperture surface 201a.

FIG. 6 is a graph showing far-field radiation patterns when a test signal of 22.65 GHz is input to the input terminal 303 of the conventional antenna 300 and the first input terminal 203 of the antenna 200 of this embodiment. . The radiation pattern of the conventional antenna 300 indicated by the dashed line has an asymmetry with a gain difference of about 3 dB between −30 degrees and +30 degrees from the front. On the other hand, in the radiation pattern of the antenna 200 of the present embodiment shown by the solid line, the difference in gain between −30 degrees and +30 degrees from the front is about 0.5 dB, indicating that the asymmetry is suppressed. I understand. That is, by inclining the rear wall 202a of the cavity 202, the symmetry of the radiation pattern is improved by 2.5 dB.

In this way, the space of the cavity 202 on the side closer to the flange 213 of the first input terminal 203 is relatively widened, and the space of the cavity 202 on the side closer to the tip of the first center conductor 210 is relatively narrowed. , the asymmetry of the far-field radiation pattern (XY plane) due to the arrangement of the first input terminal 203 for feeding can be canceled. Similarly, by relatively widening the space of the cavity 202 on the side closer to the flange 223 of the second input terminal 204 and relatively narrowing the space of the cavity 202 on the side closer to the tip of the second center conductor 220 , the asymmetry of the far-field radiation pattern (XZ plane) due to the arrangement of the second input terminal 204 for feeding can be canceled.

As described above, the antenna 200 according to this embodiment includes the cavity 202 that narrows along the direction from the side far from the tip of the first central conductor 210 toward the tip of the first central conductor 210 . Thereby, the antenna 200 according to this embodiment can make the far-field radiation pattern more symmetrical than the conventional DRHA or QRHA.

Further, in the antenna 200 according to the present embodiment, the rear wall 202a of the hollow portion 202 is provided with a surface that is inclined with respect to the center axis 230 of the horn 201, so that the first center conductor 210 extends from the side far from the tip of the first center conductor 210. A cavity 202 that narrows along the direction toward the tip of the conductor 210 can be easily formed.

In addition, in the antenna 200 according to this embodiment, the cavity 202 narrows along the direction from the side far from the tip of the second central conductor 202 toward the tip of the second central conductor 220 . Thereby, the antenna 200 according to this embodiment can make the far-field radiation pattern more symmetrical than the conventional QRHA.

(Second embodiment)
Next, an antenna device according to a second embodiment of the present invention will be described with reference to the drawings. It should be noted that the same reference numerals are assigned to the same configurations as in the first embodiment, and the description thereof will be omitted as appropriate. Also, descriptions of operations similar to those of the first embodiment will be omitted as appropriate.

The measuring device 1 according to this embodiment corresponds to the antenna device of the present invention. The measuring apparatus 1 has an external structure as shown in FIG. 7 as a whole, and is composed of functional blocks as shown in FIG. However, FIG. 7 shows the layout of each component when the OTA chamber 50 is seen through from the side.

As shown in FIGS. 7 and 8, the measurement apparatus 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 connected to the NR system simulator 20 and the signal analysis device 30 via a network 19 such as Ethernet (registered trademark) so as to be able to communicate with each other. The integrated controller 10 is also connected via a network 19 to control means for controlling the components arranged in the OTA chamber 50 . The measurement apparatus 1 has, for example, a DUT attitude control section 17 as 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 composed of, for example, a personal computer (PC). be. Note that the DUT attitude control section 17 may be provided in the integrated control device 10 as shown in FIG. 9, for example. In the following description, it is assumed that the integrated control device 10 has the configuration shown in FIG.

For example, the measuring apparatus 1 uses a rack structure 90 having a plurality of racks 90a as shown in FIG. 7, and is operated in a manner in which each component is placed on each rack 90a. 7 shows an example in which the integrated control device 10, the NR system simulator 20, the signal analysis device 30, and the OTA chamber 50 are mounted on each rack 90a of the rack structure 90, respectively.

Here, for the sake of 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 performance testing of 5G wireless terminals, and is used as an example of a compact antenna test range (hereinafter referred to as CATR). . Spurious measurement is a technique for measuring how much unnecessary radio waves, that is, spurious waves are radiated in other bands during communication at the target oscillation frequency of a 5G wireless terminal.

As shown in FIGS. 7 and 8, the OTA chamber 50 is composed of, for example, a metallic casing main body 52 having a rectangular parallelepiped internal space 51 . The OTA chamber 50 accommodates the DUT 100 , the test antenna 5 facing the antenna under test 110 of the DUT 100 , and a plurality of receiving antennas 6 for spurious measurement in this internal space 51 to prevent the intrusion of radio waves from the outside and to the outside. Store in a state that prevents radiation of radio waves. As the test antenna 5 and the plurality of receiving antennas 6, for example, an antenna for millimeter waves having directivity such as a horn antenna can be used. For example, the test antenna 5 may be the antenna 200 of the first embodiment. Also, the opening surface 5a of the test antenna 5, which will be described later, may be the opening surface 201a. The test antenna 5 transmits or receives radio signals to and from the antenna under test 110 for measuring the transmission characteristics or reception characteristics of the DUT 100 and spurious measurements.

The internal space 51 of the OTA chamber 50 further includes a reflector 7 that realizes a radio wave path for returning the radio wave of the radio signal radiated from the antenna under test 110 of the DUT 100 to the opening planes of the test antenna 5 and the plurality of receiving antennas 6. is accommodated. Further, a radio wave absorber 55 is attached to the entire inner surface of the OTA chamber 50, that is, the entire bottom surface 52a, side surface 52b, and upper surface 52c of the housing body 52, thereby enhancing the function of restricting the emission of radio waves to the outside. there is Thus, the OTA chamber 50 realizes an anechoic box having an inner space 51 that is not affected by the surrounding radio wave environment. The anechoic box used in this embodiment is, for example, of the Anechoic type.

The DUT 100 to be tested is, for example, a wireless terminal such as a smart phone. Communication standards for the DUT 100 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®, GNSS (GPS, Galileo, GLONASS, BeiDou, etc.), FM, and digital broadcasting (DVB-H, ISDB-T, etc.). Also, the DUT 100 may be a wireless terminal that transmits and receives wireless signals in the millimeter waveband compatible with 5G cellular or the like.

In this embodiment, for example, the DUT 100 is a 5G NR wireless terminal, and the antenna under test 110 of the DUT 100 transmits or receives wireless signals within a prescribed frequency band (millimeter wave band) conforming to the 5G NR standard. is. The antenna under test 110 is, for example, an array antenna such as a Massive-MIMO antenna, and corresponds to the antenna under test in the present invention. The test antenna 5 placed in the OTA chamber 50 transmits or receives radio signals in the same prescribed frequency band as the antenna under test 110 of the DUT 100 . On the other hand, the plurality of receiving antennas 6 each receive radio signals in a plurality of preset divided frequency bands different from the prescribed frequency band described above. Here, each divided frequency band is divided into a frequency band (out-of-band area and spurious area) 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. It is a thing. In addition, hereinafter, the out-of-band region and the spurious region are also collectively referred to as "spurious frequency band", and the radio signal of each divided frequency band is also referred to as "spurious signal".

FIG. 14 is a table showing usable frequency band classifications of the plurality of receiving antennas 6 arranged in the OTA chamber 50 in this embodiment. In FIG. 14, all frequency bands from 6 GHz to 87 GHz used by the plurality of receiving antennas 6 are 6 GHz to 20 GHz, 20 GHz to 40 GHz, 40 GHz corresponding to numbers 1, 2, 3, 4, . It is divided into a plurality of bands (divided frequency bands) of ~60 GHz, 60 GHz to 87 GHz, .

In this embodiment, the OTA chamber 50 has, for example, four receiving antennas 6 in the internal space 51 that use partitioned frequency bands respectively corresponding to numbers 1, 2, 3, and 4 during the frequency band classification in FIG. It is something to do. Further, the OTA chamber 50 may be configured to employ an antenna that uses a millimeter wave frequency band (for example, approximately 20 GHz to 46 GHz) as a predetermined frequency band as the test antenna 5 .

Next, the layout of the attitude varying 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. 7, in the OTA chamber 50, the housing main body 52 in the internal space 51 is provided with an attitude variable mechanism 56 that sequentially changes the attitude of the DUT 100 placed in the quiet zone QZ. ing. Here, the quiet zone QZ represents the range of the spatial region where the DUT 100 is irradiated with substantially uniform amplitude and phase from the test antenna 5 (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 an OTA test while suppressing the influence of scattered waves from the surroundings.

The attitude variable mechanism 56 is, for example, a biaxial positioner having a rotation mechanism that rotates in biaxial directions. An OTA test system (Combined-axes system) is constructed in which the DUT 100 is rotated with two degrees of freedom. Specifically, the posture varying mechanism 56 has driving units 56a and 56b, a turntable 56c, a support 56d, and a DUT mounting portion 56e as a test target mounting portion.

The driving units 56a and 56b are composed of driving motors such as stepping motors that generate rotational driving force. The turntable 56c is rotated by a predetermined angle around one of two axes orthogonal to each other by the rotational driving force of the driving portion 56a. The post 56d is connected to the turntable 56c, extends in one axial direction from the turntable 56c, and rotates together with the turntable 56c by the rotational driving force of the driving portion 56a. The DUT mounting portion 56e extends from the side surface of the column 56d in the direction of the other of the two axes, and rotates about the other axis by a predetermined angle due to the rotational driving force of the driving portion 56b. The DUT 100 is placed on the DUT placement section 56e.

Note that the above one axis is, for example, an axis (x-axis in the figure) extending in a direction perpendicular to the bottom surface 52a. Also, the other axis mentioned above is, for example, an axis extending horizontally from the side surface of the column 56d. The posture varying mechanism 56 configured in this manner sequentially rotates the DUT 100 held on the DUT mounting portion 56e to a state in which the antenna under test 110 is directed in all three-dimensional directions around the center of the DUT 100, for example, as the rotation center. It can be rotated to change its posture. That is, the measuring apparatus 1 of the present embodiment can be tested with a "black-box approach" by the posture changing mechanism 56 as described above.

In the OTA chamber 50 , two types of link antennas 8 , 9 a and 9 b for establishing or maintaining a link (call) with the DUT 100 are provided at required positions on the housing main body 52 . A 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 standalone mode. The link antennas 8 , 9 a and 9 b are installed so as to have directivity with respect to the DUT 100 held by the attitude variable mechanism 56 .

Spurious measurement is performed by measuring total radiated power (TRP). For this reason, it is necessary to maintain the state in which the antenna under test 110 of the DUT 100 emits a beam in a fixed direction when viewed from the housing, regardless of the rotation by the attitude varying mechanism 56 during the spurious measurement. First, before starting spurious measurement, a call connection is established between the DUT 100 and the NR system simulator 20 by the test antenna 5 . After that, the call connection between the DUT 100 and the NR system simulator 20 is maintained by the link antennas 9a and 9b provided near the DUT 100 so that the call connection is not cut off due to the rotation of the DUT 100. FIG. The two link antennas 9a and 9b are desirably arranged at points symmetrical with respect to the center of the DUT 100. FIG.

In addition, in the OTA chamber 50, an antenna holding portion 61 is provided 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 separated from each other. ing.

In the OTA chamber 50, the reflector 7 has an offset parabolic (see FIG. 13) type structure, which will be described later. The reflector 7 is mounted at a desired position on the side surface 52b of the OTA chamber 50 using a reflector holder 58, as shown in FIG. The reflector 7 receives the radio wave of the test signal radiated from one test antenna 5 arranged at the focal position F determined by the paraboloid of rotation, and is held by the attitude variable mechanism 56. While reflecting toward the DUT 100, the DUT 100 that received the test signal receives the radio wave of the signal under test radiated from the antenna under test 110 on the paraboloid of revolution, and directs the radio wave of the test signal toward the test antenna 5 that radiated the radio wave. It is arranged in a position and posture that allows it to be reflected by That is, the reflector 7 reflects radio waves of radio signals transmitted and received between the test antenna 5 and the antenna under test 110 via the paraboloid of revolution.

Here, the advantages of mounting the reflector 7 on the OTA chamber 50 and the preferred form of the reflector 7 will be described with reference to FIGS. 11 to 13. FIG. FIG. 11 is a schematic diagram showing, for example, how radio waves radiated from an antenna AT equivalent to the test antenna 5 propagate to the wireless terminal 100A. The radio terminal 100A is equivalent to the DUT 100. FIG. In FIG. 11, (a) shows an example in which radio waves are transmitted directly from the antenna AT to the wireless terminal 100A (Direct Far Field), and (b) shows an example in which radio waves travel from the antenna AT through a paraboloid of revolution. An example of the case (CATR) of transmission to the wireless terminal 100A via the reflector 7A is shown.

As shown in FIG. 11(a), radio waves emitted from the antenna AT as a radiation source have the property of propagating while a plane (wavefront) connecting points of the same phase spreads spherically around the radiation source. At this time, interference waves caused by disturbances such as scattering, refraction, and reflection are also generated as indicated by broken lines. Further, the wavefront is a curved spherical surface (spherical wave) at a short distance from the radiation source, but the wavefront becomes closer to a plane (plane wave) at a distance from the radiation source. In general, the area where the wavefront should be considered as a spherical surface is called the near field (NEAR FIELD), and the area where the wavefront can be considered as a plane is called the far field (FAR FIELD). In the radio wave propagation shown in FIG. 11(a), the radio terminal 100A preferably receives plane waves rather than spherical waves in order to perform accurate measurement.

In order to receive plane waves, the wireless terminal 100A needs to be placed in the far field. Here, when the maximum linear size of the radio terminal 100A is D and the wavelength of the radio wave is λ, the far field is at a distance of 2D ² /λ or more from the antenna AT. Specifically, when D = 0.4 m (meters) and wavelength λ = 0.01 m (equivalent 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 DUT 100 having a maximum linear size D of, for example, about 5 cm (centimeter) to 33 cm is measured.

Thus, the direct far-field method shown in FIG. 11(a) has characteristics 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. There is a way to arrange the mirror 7A. According to this method, not only can the distance between the antenna AT and the radio terminal 100A be shortened, but also the effect of reducing the propagation loss can be expected because the area of the plane wave expands from the distance immediately after being reflected by the mirror surface of the reflector 7A. be able to. The degree of plane waves can be represented by the phase difference between waves in phase. An acceptable phase difference for plane waves is, for example, λ/16. The phase difference can be evaluated with a vector network analyzer (VNA), for example.

For example, a parabola (see FIG. 12) or an offset parabola (see FIG. 13) can be used as the reflecting mirror 7A shown in FIG. 11(b). As shown in FIG. 12, the parabola has a mirror surface (paraboloid of revolution) that is symmetrical with respect to the axis passing through the antenna center O. By installing a primary radiator having directivity, it has a function of reflecting radio waves radiated from the primary radiator in a direction parallel to the axial direction. Conversely, by arranging, for example, the test antenna 5 in this embodiment at the focal position F, the parabola can detect radio waves incident on the paraboloid of revolution in a direction parallel to the axial direction (for example, radio signal) can be reflected and guided to the test antenna 5 . However, the parabola has a perfect circular planar shape when viewed from the front (z-direction) and is large in structure, making it unsuitable for placement as the reflector 7 of the OTA chamber 50 .

On the other hand, as shown in FIG. 13, the offset parabola has a shape obtained by cutting out a part of the paraboloid of revolution of a mirror surface (perfectly circular parabola (see FIG. 12)) that is asymmetric with respect to the axis of the paraboloid of revolution. ), and by installing the primary radiator with its beam axis inclined at an angle α, for example, with respect to the axis of the paraboloid of revolution, the radio waves radiated from the primary radiator has a function of reflecting in a direction parallel to the axial direction of By arranging, for example, the test antenna 5 in this embodiment at the focal position F, this offset parabola emits radio waves (for example, test signal radio waves for the DUT 100) radiated from the paraboloid of revolution. A radio wave that is reflected in a direction parallel to the axial direction of the paraboloid of revolution and is incident on the paraboloid of revolution in a direction parallel to the axial direction of the paraboloid of revolution (for example, a signal to be measured transmitted from the DUT 100 ) can be reflected by the paraboloid of revolution and guided to the test antenna 5 . An offset parabola can be positioned so that the mirror surface is nearly vertical, and requires a much smaller structure than a parabola (see FIG. 12).

Based on the findings described above, in the OTA chamber 50 of the present embodiment, as shown in FIG. It is placed on the radio wave propagation path between The reflector 7 is attached to the side surface 52b of the housing body 52 so that the center of the aperture of the test antenna 5 is the focal point.

The traveling direction of the radio wave of the radio signal transmitted from the antenna under test 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 inclined at a predetermined angle α. ing. 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 inclined 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. FIG.

As shown in FIG. 15, the antenna holding portion 61 includes an aperture plane 5a of the test antenna 5 and an aperture plane 6- of the plurality of receiving antennas 6 (6-1, 6-2, 6-3, 6-4). 1a, 6-2a, 6-3a, and 6-4a are arranged on the same plane 61a perpendicular to the beam axis BS1. It has become. Here, "perpendicular" means that the plane 61a forms an angle of about 90±10 degrees with respect to the beam axis BS1. This plane 61 a is formed of, for example, one surface of a rectangular parallelepiped electromagnetic wave absorber having openings corresponding to the opening surfaces of the test antenna 5 and the plurality of receiving antennas 6 . Note that numbers 1, 2, 3 and 4 in FIG. 14 correspond to the receiving antennas 6-1, 6-2, 6-3 and 6-4, respectively.

That is, the antenna holding unit 61 holds the in-band test antenna 5 at the focal position of the reflector 7 and holds the four out-band receiving antennas 6 outside the focal position F of the reflector 7 . Here, the placement of the four receiving antennas 6 is measured by the method described in "Annex D: Quality of the quiet zone validation" in Non-Patent Document 1 for each QoQZ (Quality of quiet zone: QoQZ). It is acceptable if the result of evaluating the receiving antenna 6 satisfies, for example, QoQZ≦1 dB. The size of the reflector 7 and the lower limit of the size of the internal space 51 are determined according to the desired size of the quiet zone QZ. For example, when the diameter Φ of the quiet zone QZ is 33 cm, the centers of the aperture planes 6-1a, 6-2a, 6-3a, and 6-4a of the four receiving antennas 6 are positioned at the focal position F in the plane 61a. is preferably positioned within 60 mm from the

In addition, the inclination angle α described above can be set to, for example, 30 degrees. In this case, the test antenna 5 and the plurality of reception antennas 6 face the reflector 7 at an elevation angle of 30 degrees, so that the aperture planes of the test antenna 5 and the plurality of reception antennas 6 are perpendicular to the beam axis BS1. It is held by the antenna holding portion 61 at an angle. By adopting the offset parabolic reflector 7, the size of the reflector 7 itself can be reduced, and the mirror surface can be arranged in an almost vertical position. .

Note that the receiving antennas 6-1, 6-2, 6-3, and 6-4 may be the antenna 200 of the first embodiment. In this case, the opening surfaces 6-1a, 6-2a, 6-3a, and 6-4a correspond to the opening surface 201a.

Here, with reference to FIGS. 8 to 10, the functional configuration of the measuring device 1 according to this embodiment will be described in more detail. In the measuring device 1 (see FIG. 8) according to the present embodiment, the integrated control device 10 has, for example, a functional configuration as shown in FIG. It has a functional configuration as shown in . The NR system simulator 20 constitutes a transmission/reception characteristic measuring device in the present invention.

As shown in FIG. 9 , the integrated control device 10 has 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. 9, this computer device is a CPU that performs predetermined information processing for realizing the functions of the measuring device 1 and overall control of the NR system simulator 20 and the signal analysis device 30. (Central Processing Unit) 11a, ROM (Read Only Memory) 11b for storing an OS (Operating System) for starting up the CPU 11a, other programs and parameters for control, etc., and the OS and applications used for the operation of the CPU 11a. A RAM (random access memory) 11c for storing execution codes, data, etc., an external interface (I/F) section 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 section 11 d is communicably connected to the NR system simulator 20 and the signal analysis device 30 via the network 19 . The external I/F section 11 d is also connected to the attitude varying 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 an input screen for the various information and measurement results.

The computer device described above functions as the control unit 11 by executing the program stored in the ROM 11b by the CPU 11a using the RAM 11c as a work area. The control unit 11 has a call connection control unit 14, a signal transmission/reception control unit 15, and a DUT attitude control unit 17, as shown in FIG. The call connection control unit 14, the signal transmission/reception control unit 15, and the DUT attitude control unit 17 are also implemented 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 (radio signal) to/from the DUT 100. 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 call connection control, and the NR system simulator 20 to send a signal transmission command. Further, the signal transmission/reception control unit 15 controls transmission of test signals via the test antenna 5 , transmits signal reception commands, and controls reception of spurious signals via a plurality of reception antennas 6 .

In addition, the signal transmission/reception control unit 15 monitors the user's operation in the operation unit 12, and when the user performs a predetermined transmission/reception characteristics measurement start operation related to the measurement of the transmission characteristics and reception characteristics of the DUT 100, call connection is performed. A signal transmission command is transmitted to the NR system simulator 20 through call connection control in the control unit 14 . Further, the signal transmission/reception control unit 15 controls transmission of the test signal via the test antenna 5 , transmits a signal reception command, and controls reception of the signal under measurement via the test antenna 5 .

The DUT attitude control section 17 controls the attitude of the DUT 100 held by the attitude varying mechanism 56 during measurement. To implement this control, for example, the ROM 11b stores in advance a DUT attitude control table 17a. The DUT attitude control table 17a stores, as control data, the number of drive pulses (the number of operation pulses) for determining the rotational drive of the stepping motors when, for example, stepping motors are employed as the drive units 56a and 56b. there is

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, as described above, the antenna under test 110 is directed sequentially in all three-dimensional directions. The attitude variable mechanism 56 is driven and controlled so that the DUT 100 changes its attitude.

Further, in the measuring device 1 according to the present embodiment, the NR system simulator 20 has, for example, a functional configuration as shown in FIG. 10(a), and the signal analysis device 30 has, for example, the It has such a functional configuration.

As shown in FIG. 10( a ), 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 . The transmission characteristics or reception characteristics of the DUT 100 are measured each time. 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 unit composed of an analog/digital converter (ADC) 21g and an analysis processing unit 21h.

In the signal generation function unit of the signal measurement unit 21, the signal generation unit 21a generates waveform data having a reference waveform, specifically, for example, an I component baseband signal and a Q component baseband signal which 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 generator 21a from a digital signal to an analog signal and outputs the analog signal to the modulator 21c. The modulation unit 21c mixes the I component baseband signal and the Q component baseband signal with a local signal, and further combines the signals to perform a modulation process of outputting 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 transmits the generated test signal to the DUT 100 via the test antenna 5 by the transmission section 21e. Output.

Further, in the signal analysis function section of the signal measuring section 21, the RF section 21d receives the signal under test in a prescribed frequency band output from the DUT 100 to which the test signal is input via the antenna under test 110, and converts the signal under test into the antenna under test. 5 and the signal processing unit 40b, the signal under measurement is received by the receiving unit 21f and then mixed with the local signal to convert it into an intermediate frequency band signal (IF signal). The ADC 21g converts the signal under measurement, which has been converted into an IF signal by the receiving section 21f of the RF section 21d, from an analog signal into a digital signal, and outputs the digital signal to the analysis processing section 21h. The signal processing unit 40b is composed of a down converter, an amplifier, a frequency filter, and the like, and performs frequency conversion (down conversion), amplification, and frequency selection on the signal under measurement input from the test antenna 5. It is designed to be processed.

The analysis processing unit 21h digitally processes the signal under measurement, which is a digital signal output from the ADC 21g, to generate waveform data corresponding to the I component baseband signal and the Q component baseband signal, respectively, and converts the waveform data to A process for analyzing the I-component baseband signal and the Q-component baseband signal is performed based on . In measuring the transmission characteristics of the DUT 100, the analysis processing unit 21h, for example, equivalent isotropically radiated power (EIRP), total radiated power (TRP), modulation accuracy (EVM), transmission power, constellation, spectrum etc. can be measured. In addition, the analysis processing unit 21h can measure, for example, reception sensitivity, bit error rate (BER), packet error rate (PER), etc. in measuring the reception characteristics of the DUT 100 . where EIRP is the radio signal strength in the main beam direction of the antenna under test. TRP is the total power radiated into space from the antenna under test.

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, a RAM, a ROM, and various input/output interfaces. The CPU performs predetermined information processing and control for realizing each function of the signal generation function section, the signal analysis function section, the operation section 23 and the display section 24 .

The operation unit 23 and the display unit 24 are connected to 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 an input screen for the various information and measurement results.

As shown in FIG. 10B, 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 changing mechanism 56. A spurious measurement of the DUT 100 is performed every time. The signal analysis unit 31 has an RF unit 31a, an ADC 31b, and an analysis processing unit 31c, and analyzes the spurious signal input from the spurious signal processing unit 41 and performs analysis processing related to spurious measurement and the signal analysis function of the NR system simulator 20. Analytical processing equivalent to the part is applied. The spurious signal processing unit 41 receives radio signals (spurious signals) in a plurality of divided frequency bands and output together with the signal under measurement from the DUT 100 to which the test signal is input, via the receiving antennas 6 corresponding to the respective divided frequency bands. 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 signals received by the respective receiving antennas 6, and then passes the spurious signals to the signal analysis unit 31. It is designed to transmit to the RF section 31a. The RF unit 31a mixes the received spurious signal with a local signal to convert it into an IF signal. The ADC 31b converts the spurious signal converted into the IF signal by the RF unit 31a from an analog signal into a digital signal, and outputs the digital signal to the analysis processing unit 31c. The analysis processing unit 31c analyzes the frequency distribution and power of the received spurious signal in each divided frequency band. The signal analysis device 30 may have a configuration in which the spurious signal processing section 41 is incorporated.

Next, spurious measurement processing of the DUT 100 using the measurement apparatus 1 according to this embodiment will be described with reference to the flowchart of FIG. In FIG. 16, of the spurious frequency bands (see FIG. 14), four receiving antennas 6 that can use each of the divided frequency bands indicated by numbers 1, 2, 3, and 4 are outside the focal position F. The spurious measurements shall be made with the 16, a case where a spurious measurement start operation for instructing the start of spurious measurement processing for the DUT 100 is performed by the operation unit 12 of the integrated control device 10 will be described. Note that the spurious measurement start operation may be performed by the operation unit 33 of the signal analysis device 30 .

In order to perform spurious measurements on the DUT 100 in the measurement apparatus 1 , first, the DUT 100 must be set inside the internal space 51 of the OTA chamber 50 . As a result, in the measurement apparatus 1, as the first process of spurious measurement, the user performs the work of holding the DUT 100 to be tested on the DUT mounting portion 56e of the attitude varying mechanism 56 of the OTA chamber 50 (holding step S1). ).

After the DUT 100 has been set, the integrated control device 10, for example, monitors whether or not the control unit 11 has operated the operation unit 12 to start spurious measurement (step S2).

Here, if it is determined that the spurious measurement start operation has not been performed (NO in step S2), the control unit 11 continues monitoring in step S2. On the other hand, if it is determined that the spurious measurement start operation has been performed (YES in step S2), the control unit 11 replaces n, which indicates the order of the segmented frequency bands for spurious measurement, with the first segmented frequency band. is set to n=1 (step S3). Note that the maximum value of n is 4 in this example.

Next, the call connection control unit 14 of the control unit 11 uses the test antenna 5 placed at the focal position F to perform call connection control by transmitting/receiving a control signal (radio signal) to/from the DUT 100. (step S4). Here, the NR system simulator 20 causes the DUT 100 to wirelessly transmit a control signal (call connection request signal) via the test antenna 5, while the DUT 100 receiving the call connection request signal transmits the connection-requested frequency. It performs call connection control to receive a control signal (call connection response signal) sent after setting. This call connection control establishes a state in which wireless signals can be transmitted and received between the NR system simulator 20 and the DUT 100 via the reflector 7 and the test antenna 5 arranged at the focal position F of the reflector 7. .

Note that processing for the DUT 100 to receive a radio signal sent from the NR system simulator 20 via the test antenna 5 and the reflector 7 is defined as downlink (DL) processing. Conversely, processing in which the DUT 100 transmits radio signals to the NR system simulator 20 via the reflector 7 and the test antenna 5 is defined as uplink (UL) processing. The test antenna 5 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 the call connection is established in step S4, the DUT attitude control unit 17 of the integrated control device 10 controls the attitude of the DUT 100 placed in the quiet zone QZ to a predetermined attitude by the attitude varying mechanism 56 (attitude varying step S5). ).

After the attitude varying mechanism 56 controls the DUT 100 to a predetermined attitude in step S<b>5 , 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 the test signal via the test antenna 5 arranged at the focal position F of the reflector 7 (test signal output step S6). .

Test signal transmission control by the NR system simulator 20 is performed as follows. In the NR system simulator 20 (see FIG. 10(a)), the control section 22 that has received the signal transmission command controls the signal generation function section and causes the signal generation section 21a to generate a signal for generating the test signal. . Thereafter, this signal is subjected to digital/analog conversion processing by the DAC 21b, and further subjected to modulation processing by the modulation section 21c. A signal (DL data) is output toward the DUT 100 via the test antenna 5 by the transmitter 21e.

A signal processing section 40a is provided between the transmitting section 21e and the test antenna 5, and the signal processing section 40a is composed of an upconverter, an amplifier, a frequency filter, and the like. The signal processing unit 40 a performs frequency conversion (up-conversion), amplification, and frequency selection on the test signal to be output to the test antenna 5 . Note that the signal transmission/reception control unit 15 controls the transmission of the test signal 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 with timing.

On the other hand, the DUT 100 transmits the test signal (DL data) sent via the test antenna 5 and the reflector 7 to the antenna under test 110 in different attitude states that are sequentially changed based on the attitude control in step S5. and transmits a signal under test which is a response signal to the test signal.

After the transmission of the test signal is started in step S6, the signal analysis device 30 continuously performs reception processing of the spurious signal received by the n-th reception 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 frequency conversion (down-conversion), amplification, and frequency selection processing. After being processed, it is input to the signal analysis unit 31 of the signal analysis device 30 .

Subsequently, the signal analysis device 30 analyzes the signal (spurious signal received by the receiving antenna 6-n) received and processed in step S7, and performs control 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, takes in the spurious signal input from the spurious signal processing unit 41 via the RF unit 31a and the ADC 31b, and For spurious signals, for example, control is performed to analyze frequency distribution and power. Further, the control unit 32 performs control 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 section 17 determines whether or not spurious measurement of the DUT 100 has been completed for all desired attitudes for the n-th divided frequency band (step S9). Here, if it is determined that the spurious measurement for the n-th divided frequency band has not ended (NO in step S9), the processing from step S5 onwards is continued.

On the other hand, if it is determined that the spurious measurement for the n-th segmented frequency band has been completed (YES in step S9), the control unit 11 determines that n is the last segmented frequency band. 4 is determined (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, if it is determined that n=4 has been reached (YES in step S10), the integrated control device 10 terminates the series of spurious measurement processes shown in FIG.

In the measuring apparatus 1 according to the present embodiment, after the test signal is transmitted from the NR system simulator 20 in step S6, the control unit 22 in the NR system simulator 20 subsequently causes the DUT 100 that has received the test signal to Control may be performed to measure the signal under test transmitted from the antenna under test 110 . Alternatively, the measurement processing of the test signal by the NR system simulator 20 may be performed at arbitrary timing independently of the spurious measurement processing shown in FIG.

In the above embodiment, for example, an example in which the four receiving antennas 6 cover the spurious frequency band of 6 GHz to 87 GHz (see FIG. 14) is given, but the present invention is not limited to this, and any spurious frequency The configuration may be such that the band is covered by any number of receiving antennas 6 . The present invention can be applied not only to an anechoic chamber but also to an anechoic chamber.

As described above, in the measuring device 1 according to this embodiment, the plurality of receiving antennas 6 for spurious measurement are arranged outside the focal position F determined from the paraboloid of revolution 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, thereby increasing the durability of the measuring apparatus 1. FIG. Furthermore, the measuring apparatus 1 according to the present embodiment can continuously measure spurious emissions in each divided frequency band for the DUT 100 that transmits and receives wireless signals in the millimeter wave band. measurements can be made.

In addition, the measuring apparatus 1 according to the present embodiment uses the antenna 200 according to the first embodiment as the test antenna 5 or the receiving antennas 6-1, 6-2, 6-3, and 6-4, so that the radiation High-quality measurements can be made by transmitting and receiving radio signals with symmetrical patterns.

Further, the measurement apparatus 1 according to the present embodiment includes the signal analysis apparatus 30, so that the DUT 100 having the antenna under test 110 that transmits or receives a radio signal in a specified frequency band is different from the specified frequency band. Spurious signals in multiple discrete frequency bands can be easily measured.

In addition, in the measuring device 1 according to the present embodiment, the centers of the aperture planes 6-1a, 6-2a, 6-3a, and 6-4a of the plurality of receiving antennas 6 are aligned 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 radio waves of radio signals are radiated from each receiving antenna 6 is less than 0.6 dB. It is desirable that the centers of the opening surfaces 6-1a, 6-2a, 6-3a, and 6-4a are arranged within (for example, within 60 mm). As a result, the measuring apparatus 1 according to the present embodiment can obtain spurious measurement results with substantially the same quality as when the plurality of receiving antennas 6 are arranged at the focal position F. FIG.

In addition, 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, and 6-4a of the plurality of receiving antennas 6 are The radio signals transmitted from the test antenna 110 and reflected by the reflector 7 are arranged on the same plane 61a perpendicular to the traveling direction of radio waves. Thereby, the measuring apparatus 1 according to the present embodiment can easily arrange the plurality of receiving antennas 6 at positions outside the focal position F where good-quality spurious measurement results can be obtained.

While embodiments of the present invention have been disclosed above, it will be appreciated that changes may be made thereto without departing from the scope of the present invention. For example, even when the upper and lower limits of the frequency band are changed due to the update of the communication standard, the embodiment of the present invention provides equivalents to which such changes are added. It is disclosed on the premise that it is included in the invention.

1 Measuring device 5 Test antenna 5a Aperture 6, 6-1, 6-2, 6-3, 6-4 Receiving antenna 6-1a, 6-2a, 6-3a, 6-4a Aperture 7 Reflector 20 NR SYSTEM SIMULATOR 30 SIGNAL ANALYSIS DEVICE 50 OTA CHAMBER 51 INTERNAL SPACE 61 ANTENNA HOLDING PORTION 61a PLANE 100 DUT
Reference Signs List 110 Antenna under test 200 Antenna 201 Horn 201a Opening surface 202 Cavity 202a Rear wall 203 First input terminal 204 Second input terminal 205, 206, 207, 208 Ridge 209 Metal member 210 First central conductor 215 First feeding region 220 Second 2 central conductor 230 central axis F focus position QZ quiet zone

Claims (6)

a horn (201) tapered with respect to a central axis (230);
a first ridge pair consisting of a pair of ridges (205, 206) arranged on the inner wall surface of the horn so as to face each other across the central axis and forming a tapered shape with respect to the central axis;
a first input terminal (203) having a first center conductor (210) for powering said first pair of ridges from outside said horn;
a hollow portion (202) that is continuous with the end of the horn opposite to the opening surface (201a) and that is located farther from the opening surface than the first central conductor;
The first center conductor passes through one ridge (205) of the pair of ridges forming the first ridge pair, and the other ridge of the pair of ridges forming the first ridge pair. (206) is arranged so that the tip protrudes inside,
The antenna according to claim 1, wherein the hollow portion narrows along a direction from a side far from the tip of the first central conductor toward the tip of the first central conductor. 2. Antenna according to claim 1, characterized in that the cavity has a rear wall (202a) comprising an inclined surface with respect to the central axis. a second ridge pair consisting of a pair of ridges (207, 208) arranged on the inner wall surface of the horn so as to face each other across the central axis and forming a tapered shape with respect to the central axis;
a second input terminal (204) having a second center conductor (220) for powering the second pair of ridges from outside the horn;
the second ridge pair is orthogonal to the first ridge pair;
The second central conductor passes through one ridge (207) of the pair of ridges forming the second ridge pair, and the other ridge of the pair of ridges forming the second ridge pair. (208) is arranged so that the tip protrudes inside,
The hollow portion is located farther from the opening surface than the second center conductor, and narrows along the direction from the side far from the tip of the second center conductor toward the tip of the second center conductor. 3. An antenna according to claim 1 or 2, characterized in that: an anechoic box (50) having an internal space (51) unaffected by the surrounding radio wave environment;
a plurality of receiving antennas (6) accommodated in the internal space and each receiving a radio signal of a plurality of preset divided frequency bands;
a reflector (7) housed in the internal space and having a predetermined paraboloid of revolution;
A test antenna (5) arranged in the internal space at a focal position (F) determined from the paraboloid of revolution and transmitting or receiving a radio signal in a prescribed frequency band;
A test signal is output to a device under test (100) via the test antenna, and a signal under test output from the device under test to which the test signal is input is received by the test antenna and received. a transmitting/receiving characteristic measuring device (20) for measuring a radio signal in the prescribed frequency band based on the signal under measurement;
receiving the radio signals of the plurality of divided frequency bands output together with the signal under test from the device under test to which the test signal is input, via the respective receiving antennas corresponding to the respective divided frequency bands; An antenna device (1) 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 reflector transmits or receives the specified frequency band through the paraboloid of revolution by an antenna under test (110) of the test object arranged within a quiet zone (QZ) in the internal space. reflects the radio wave of the radio signal of
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,
wherein the plurality of receiving antennas are positioned outside the focal position;
4. An antenna apparatus, wherein either the test antenna or the plurality of receiving antennas is the antenna according to any one of claims 1 to 3. so that the centers of the aperture planes (6-1a, 6-2a, 6-3a, 6-4a) of the plurality of receiving antennas are arranged within a distance from the focal position according to the size of the quiet zone, 5. The antenna device according to claim 4, further comprising an antenna holder (61) that holds the plurality of receiving antennas. In the antenna holding part, the aperture plane (5a) of the test antenna and the aperture planes of the plurality of receiving antennas are aligned in the traveling direction of radio waves of radio signals transmitted from the antenna under test and reflected by the reflector. 6. Antenna arrangement according to claim 5, characterized in that it holds the test antenna and the plurality of receiving antennas so that they are arranged in the same plane (61a) perpendicular to the.

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