Antenna directivity estimation device, antenna directivity estimation system, control method for antenna directivity estimation device, and program for causing execution of control method for antenna directivity estimation device

Abstract

To provide an antenna directivity estimation device capable of reducing the measurement time of the horizontal directivity with respect to the longitudinal direction of an antenna to be measured by calculating the horizontal directivity on the same circumference of the antenna to be measured by correcting the received radio wave without stopping the antenna to be measured.SOLUTION: An antenna directivity estimation device includes: an output unit that outputs transmission radio wave signal information generating transmission radio wave signals to be transmitted to a plurality of probe antennas arranged circumferentially or an antenna arranged movably along the center axis of a circumference formed by a plurality of probe antennas; an input unit that accepts input of received radio wave signal information from the received radio wave signal; and an estimation unit that, if the received radio wave signal information includes information from a measurement point where the antenna has moved along the center axis direction, estimates the directivity of the antenna in the circumferential direction of a concentric circle with respect to the center axis of the antenna from the received radio wave signal information generated from the received radio wave signal generated in the antenna or the received radio wave signal information generated from the received radio wave signal generated in the probe antenna.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an antenna directivity estimation apparatus, an antenna directivity estimation system, a control method for an antenna directivity estimation apparatus, and a program for causing a computer to execute the control method for an antenna directivity estimation apparatus.

Background Art

[0002] Measurement of the directivity of an antenna is usually performed by a far-field measurement method. Since the far-field measurement method directly measures the directivity, it has the advantage that complicated analysis is not required. However, when the antenna is large, it has to be performed outdoors, so errors due to the ground, surrounding reflections, etc. become a problem. In addition, it is necessary to measure at a sufficient distance from the antenna, and in many cases, the actual required measurement distance cannot be secured. Furthermore, it is restricted by weather such as rain, snow, and wind, and there are disadvantages such as interference with other wireless lines.

[0003] Therefore, instead of the far-field measurement, a near-field measurement (NFM) method may be used in which the distribution of the electric field (or electromagnetic field) near the antenna is measured, and the far-field directivity and gain of the antenna are calculated based on strict electromagnetic field theory.

[0004] The near-field measurement method requires a scanning system, an anechoic chamber, and a computer for calculation. However, the near-field measurement method has great advantages that are not available in far-field measurements, such as the ability to measure a large-aperture antenna in a relatively small anechoic chamber, the ability to perform stable and highly accurate measurements, and the ability to obtain all information within the measured angular range by calculation after measurement.

[0005] For example, according to an antenna near-field measurement system using a cylindrical surface scanning method in Non-Patent Document 1 below, a probe antenna is arranged on a circumference orthogonal to the extending direction of the antenna to be measured, and the antenna to be measured is stepped to enable measurement of the horizontal plane directivity. Note that since the data analysis theory based on the cylindrical surface scanning method is already a known technique, details thereof are omitted.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] As described above, in the antenna near-field measurement system using the cylindrical surface scanning method, the horizontal plane directivity of the antenna under measurement is analyzed by the probe antenna arranged on the same circumference with the center of the antenna under measurement as the center of the circle receiving radio waves. However, since the reception of radio waves by the probe antenna is performed with the antenna under measurement and the probe antenna in a stationary state, the movement and stop of the antenna under measurement are repeated for the measurement in the length direction of the antenna under measurement, so it takes time for the measurement of the horizontal plane directivity.

[0008] Therefore, an object of the present invention is to enable shortening of the measurement time of the horizontal plane directivity with respect to the length direction of the antenna under measurement.

Means for Solving the Problems

[0009] Among the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

[0010] An antenna directivity estimation apparatus according to a representative embodiment of the present invention includes an output unit that outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to a plurality of probe antennas arranged in a circumferential shape or an antenna that is movably arranged along a central axis of a circle formed by the plurality of probe antennas, an input unit that inputs reception radio wave signal information generated from a reception radio wave signal generated in the antenna that receives the transmission radio wave radiated from the probe antenna to which the transmission radio wave signal is transmitted, or a reception radio wave signal generated in the probe antenna that receives the transmission radio wave radiated from the antenna to which the transmission radio wave signal is transmitted, and an estimation unit that estimates the directivity of the antenna in the circumferential direction of a concentric circle with respect to the central axis of the antenna from the reception radio wave signal information generated from the reception radio wave signal generated in the antenna or the reception radio wave signal information generated from the reception radio wave signal generated in the probe antenna when the reception radio wave signal information input from the input unit includes information corresponding to a reception radio wave or a transmission radio wave from a measurement point where the antenna has moved along the central axis direction.

Advantages of the Invention

[0011] Among the inventions disclosed in the present application, the effects obtained by representative ones are briefly described as follows. According to a representative embodiment of the present invention, it is possible to shorten the measurement time of the horizontal plane directivity with respect to the length direction of the antenna to be measured.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Note that the disclosure is merely an example, and for those that can be easily conceived by those skilled in the art with appropriate modifications while maintaining the gist of the invention, they are naturally included in the scope of the present invention. Also, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present invention.

[0014] Also, in this specification and each figure, elements that are the same as those described above with respect to the previously shown figures may be given the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0015] <Antenna Arrangement Example> FIG. 1 is a perspective view showing an example of the arrangement of the antenna under measurement and the probe antenna used in the antenna directivity estimation system.

[0016] The antenna 100 for measuring directivity is mounted on a positioner 23 that can move in the laying direction of the rails 24a and 24b arranged substantially in parallel. The longitudinal direction (axial direction) of the antenna 100 is mounted so as to be substantially parallel to the rails 24a and 24b. Further, since the rails 24a and 24b are laid through the housing 22, the antenna 100 can also pass through the housing 22. In FIG. 1, the rails 24a and 24b arranged substantially in parallel are not shown in the figure but are laid behind the housing 22, and the antenna 100 has a length sufficient to penetrate the housing 22. Note that the rails 24a and 24b may be collectively referred to as the rail 24.

[0017] The housing 22 is preferably composed of a radio wave absorber that absorbs radio waves. Alternatively, it is preferable that the inside of the housing 22 is covered with a radio wave absorber, and the radio waves transmitted and received by the antenna 100 or the probe antenna 11 and the reflected radio waves are absorbed. For example, a configuration in which a conductive material such as a carbon material or a metal is made fibrous and kneaded into a resin, a configuration using a dielectric absorption material in which carbon particles or the like are mixed with urethane or rubber, and a configuration using a magnetic material such as ferrite can be cited as an example of the radio wave absorber. In the example shown in FIG. 1, as will be described later, the pyramid-shaped radio wave absorber 21 covers the inside of the housing 22.

[0018] The pyramid-shaped radio wave absorber 21 is preferably composed of a radio wave absorber that absorbs radio waves. The pyramid-shaped radio wave absorber 21 has broadband absorption characteristics due to its shape when the pyramid height is selected according to the lowest frequency to be absorbed. Therefore, there is no particular limitation as the frequency increases, and it is possible to obtain good absorption performance up to the millimeter wave band. The pyramid-shaped radio wave absorber 21 can be configured by impregnating beads such as expanded polystyrene with graphite or the like to form a pyramid shape and attaching a ferrite tile to the bottom surface. However, the structure of the pyramid-shaped radio wave absorber 21 is not limited to this, and any radio wave absorber material and manufacturing method can be adopted. The pyramid-shaped radio wave absorber 21 can be arranged to cover the inside of the housing 22.

[0019] The pyramid-shaped radio wave absorbers 25a, 25b, 25c, 25d, 25e, 25f preferably have a structure in which radio waves transmitted and received and reflected by the antenna 100 or the probe antenna are absorbed. Note that the pyramid-shaped radio wave absorbers 25a, 25b, 25c, 25d, 25e, 25f may be collectively referred to as the pyramid-shaped radio wave absorber 25. The pyramid-shaped radio wave absorber 25 is preferably arranged around a radio wave reflection pair that may affect the directivity estimation result in the antenna directivity estimation system.

[0020] The probe antennas 11a, 11b, 11c, 11d, 11e ··· 11o are preferably arranged on the same circumference. Also, except between 11a and 11o, the intervals between the probe antennas are arranged at an isocenter angle of approximately 22.5 degrees. Also, the probe antennas 11a, 11b, 11c, 11d, 11e ··· 11o may be collectively referred to as the probe antenna 11. The antenna 100 is configured to be able to move back and forth along the rail 24 along the central axis of the concentric circles formed by the probe antenna 11. Note that the position of the probe antenna 11 is preferably fixed. The detailed configuration of the probe antenna 11 will be described in FIG. 2.

[0021] <Configuration Example of Probe Antenna> FIG. 2 illustrates an example of the configuration of a probe antenna. FIG. 2 shows the configuration of a probe antenna 11a as a representative of the probe antennas 11. Each probe antenna 11 includes a horizontally polarized antenna and a vertically polarized antenna so that it can transmit and receive horizontally polarized and vertically polarized radio waves individually. The horizontally polarized antenna and the vertically polarized antenna are attached so as to intersect. The probe antenna 11a in FIG. 2 has a horizontally polarized antenna 11ah and a vertically polarized antenna 11av attached so as to be orthogonal to each other. The horizontally polarized antenna 11ah and the vertically polarized antenna 11av are constituted by horn antennas using the copper foil portions of a printed circuit board.

[0022] The size of the printed circuit board is approximately 200 mm in length × approximately 220 mm in width, and the frequency band is approximately 0.7 GHz to approximately 2.2 GHz. The horizontally polarized antenna 11ah is formed on a horizontally polarized substrate 11ahb, and the vertically polarized antenna 11av is formed on a vertically polarized substrate 11avb. A coaxial connector (not shown) is attached to the horizontally polarized antenna 11ah, and a horizontally polarized signal is input to a network analyzer (described later) via a coaxial cable 11ahc. Similarly, a coaxial connector is also attached to the vertically polarized antenna 11av, and a vertically polarized signal is input to the network analyzer (described later) via a coaxial cable 11avc. The other probe antennas 11b, 11c, 11d, 11e ··· 11o also have the same configuration as the probe antenna 11a shown in FIG. 2.

[0023] <Configuration Example of Antenna for Measurement> FIG. 3 shows an example of the configuration of an antenna for measuring directivity. An example of the antenna 100 shown in FIG. 1 includes a shared antenna. FIG. 3 shows an example in the case where the antenna 100 is a shared antenna by means of a block diagram.

[0024] Antenna 100 includes a radio wave radiation unit 110. The antenna input / output unit 130 of the antenna 100 to be measured may be realized by a connector or by wiring. When the antenna input / output unit 130 to be measured is realized by a connector, the antenna input / output unit 130 to be measured is included in the configuration of the antenna 100.

[0025] The radio wave radiation unit 110 includes a low-band radiation element unit 111 and a high-band radiation element unit 112. The low-band radiation element unit 111 and the high-band radiation element unit have different frequency bands of radio waves to be transmitted and received, and the frequency band of the high-band radiation element unit is higher in frequency than the frequency band of the low-band radiation element unit 111. Each frequency band can be set by the system to any value and frequency range as long as the frequency band of the high-band radiation element unit is higher in frequency than the frequency band of the low-band radiation element unit 111. Also, it is possible for a part of the frequency bands to overlap. As an example of each frequency band in this embodiment, the frequency band of the high-band radiation element unit is 1 GHz or higher, and the frequency band of the low-band radiation element unit 111 is 1 GHz or lower. However, as described above, it is not intended to be limited to these frequency bands. It is only for the ease of explanation of this embodiment that the above frequency bands are described as an example. Also, both the low-band radiation element unit 111 and the high-band radiation element unit 112 can have a function of receiving radio waves. That is, the frequency band of the radio waves transmitted and received from the high-band radiation element unit 112 is higher than the frequency band of the radio waves transmitted and received from the low-band radiation element unit 111, and the frequency band of the high-band radiation element unit 112 includes the gigahertz band.

[0026] In addition, the antenna 100 may include the antenna-under-test input / output unit 130. The antenna-under-test input / output unit 130 includes a low-band input / output unit 131 and a high-band input / output unit 132. A low-band vertically polarized signal Slv is input to the low-band input / output unit 131, enabling the low-band radiating element unit 111 to radiate vertically polarized radio waves in the low band. Also, a low-band horizontally polarized signal Slh is input to the low-band input / output unit 131, enabling the low-band radiating element unit 111 to radiate horizontally polarized radio waves in the low band. Note that the low-band vertically polarized signal Slv and the low-band horizontally polarized signal Slh may be received signals of vertically polarized radio waves and horizontally polarized radio waves input to the low-band radiating element unit 111.

[0027] Similarly, a high-band vertically polarized signal Shv is input to the high-band input / output unit 132, enabling the high-band radiating element unit 112 to radiate vertically polarized radio waves in the high band. Also, a high-band horizontally polarized signal Shh is input to the high-band input / output unit 132, enabling the high-band radiating element unit 112 to radiate horizontally polarized radio waves in the high band. Note that the high-band vertically polarized signal Shv and the high-band horizontally polarized signal Shh may be received signals of vertically polarized radio waves and horizontally polarized radio waves input to the high-band radiating element unit 112. Note that the antenna-under-test input / output unit 130 may be a connector for a coaxial cable. Also, the wiring between each of the antenna-under-test input / output unit 130 and the radio wave radiating unit 110 can be connected by a coaxial cable or a substrate pattern circuit while achieving impedance matching.

[0028] <Configuration Example of Antenna Directivity Estimation System> FIG. 4 is a diagram showing an example of the configuration of the antenna directivity estimation system according to the present embodiment.

[0029] The antenna directivity estimation system 1000 includes an antenna 100, an antenna directivity estimation device 200, a switch timing control unit 310, a network analyzer 320, a positioner control unit 330, and a positioner 23. In addition, the antenna directivity estimation system 1000 further includes a housing 22 including a switch SW1, a switch SW2, rails 24a and 24b, and a probe antenna 11.

[0030] Note that the antenna directivity estimation device 200 and the switch timing control unit 310 are connected by a control line Sc1, and the antenna directivity estimation device 200 and the positioner control unit 330 are connected by a control line Sc2. The control line Sc1 and the control line Sc2 can be mainly used to determine the transmission and reception timing of radio waves.

[0031] Also, the switch timing control unit 310 and the switch SW1 are connected by a control line Sc4, and the switch timing control unit 310 and the switch SW2 are connected by a control line Sc5. The control line Sc4 can be used to turn on the switch SW1 during radio wave radiation, and the control line Sc5 can be used to turn on the switch SW2 during radio wave reception.

[0032] Furthermore, the antenna directivity estimation device 200 and the network analyzer 320 are connected by a data line Sd8. The received radio waves input to the network analyzer 320 are input to the antenna directivity estimation device 200 via the data line Sd8 as received radio wave signal information. Also, the radio waves radiated from the probe antenna 11 are received by the antenna 100. The received radio waves are input to the network analyzer 320 as received radio wave signals via a data line Sd4 connecting the antenna 100 and the switch SW2 and a data line Sd5 connecting the switch SW2 and the network analyzer 320. As described above, the data information is input and output between the antenna directivity estimation device 200 and the network analyzer 320 via the data line Sd8.

[0033] Regarding the control signals and data transmitted by the control lines Sc1 to Sc2, Sc4 to Sc5, and the data lines Sd1 to Sd5 described above, a detailed explanation will be given based on the operation flow of the antenna directivity estimation system 1000.

[0034] Note that since the directivity of the antenna is reversible and equal during transmission and reception, in the configuration example of the antenna directivity estimation system 1000, the following explanation will be made with the probe antenna 11 as the transmitting antenna and the antenna 100 as the receiving antenna. Also, in the following explanation, the focus will be on the operation and operation procedure of the antenna directivity estimation system 1000, and the description of each functional block will be carried out as appropriate according to the need.

[0035] First, in the antenna directivity estimation system 1000, the antenna directivity estimation device 200 generates a trigger signal. The antenna directivity estimation device 200 transmits the trigger signal to the positioner control unit 330 via the control line Sc2. The positioner control unit 330 that receives the trigger signal reads the position information of the positioner 23 via the data line Sd1 and moves the antenna 100 mounted on the positioner 23 inside the housing 22. The positioner control unit 330 moves the antenna 100 to a position where it can receive radio waves from the probe antenna 11. The positioner 23 that has moved the antenna 100 to a position where it can receive radio waves from the probe antenna 11 transmits a reception preparation completion signal to the antenna directivity estimation device 200 via the positioner control unit 330.

[0036] The antenna directivity estimation device 200 that has received the reception preparation completion signal transmits a measurement start signal to the switch timing control unit 310 via the control line Sc1 and to the positioner control unit 330 via the control line Sc2. The switch timing control unit 310 that has received the measurement start signal turns on the switch circuits of the switches SW1 and SW2. Also, the antenna directivity estimation device 200 outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the antenna 100 or the probe antenna 11 to the network analyzer 320. Note that, as described above, the antenna 100 is disposed so as to be movable along the central axis Z of the circle formed by the probe antennas 11 arranged in a circumferential shape. The network analyzer 320 functions as a transmission radio wave signal generation device that generates a transmission radio wave signal from the transmission radio wave signal information. Then, the network analyzer 320 transmits the transmission radio wave signal to the probe antenna 11 via the switch SW1, and when the transmission radio wave signal is input to the probe antenna 11, the transmission radio wave is radiated.

[0037] The transmission radio wave radiated from the probe antenna 11 is received by the antenna 100. The antenna 100 converts the received radio wave into a received radio wave signal as an analog electrical signal. The received radio wave signal is input to the switch SW2 via the data line Sd4 and input to the network analyzer 320 via the data line Sd5. In the network analyzer 320, the received radio wave signal is A / D (Analog-to-digital) converted and input to the antenna directivity estimation device 200 via the data line Sd8 as received radio wave signal information that is digital information. Note that, in this case, the network analyzer 320 functions as a received radio wave signal information generation device.

[0038] For example, the antenna directivity estimation device 200 receives the received radio wave signal information of the radio wave radiated from the probe antenna 11a at the antenna 100 via the network analyzer 320. Then, the antenna directivity estimation device 200 transmits a radio wave acquisition signal to the switch timing control unit 310. In this case, the radio wave acquisition signal is transmitted to the switch timing control unit 310 via the control line Sc1. When the switch timing control unit 310 receives the radio wave acquisition signal, it turns off the switch SW1 via the control line Sc4 and turns off the switch SW2 via the control line Sc5. The positioner control unit 330 moves the antenna 100 in the Z direction inside the housing 22.

[0039] When the antenna 100 travels a predetermined distance, the switch timing control unit 310 turns on the switch SW1 via the control line Sc4 and turns on the switch SW2 via the control line Sc5. Then, transmission radio waves are radiated from the probe antenna 11b arranged concentrically adjacent to the probe antenna 11a. The antenna directivity estimation device 200 receives the received radio wave signal information of the radio wave radiated from the probe antenna 11b at the antenna 100 via the network analyzer 320. Then, the antenna directivity estimation device 200 transmits a radio wave acquisition signal to the switch timing control unit 310. In this case, the radio wave acquisition signal is transmitted to the switch timing control unit 310 via the control line Sc1. When the switch timing control unit 310 receives the radio wave acquisition signal, it turns off the switch SW1 via the control line Sc4 and turns off the switch SW2 via the control line Sc5. The positioner control unit 330 moves the antenna 100 in the Z direction inside the housing 22. The above operations are repeated from the probe antenna 11a to the probe antenna 11o. The positional relationship between the measurement points of the probe antenna 11 and the antenna 100 will be described in detail in FIG. 6.

[0040] Incidentally, the above-mentioned predetermined distance can be set to any value by the antenna directivity estimation device 200. However, during the measurement from the probe antenna 11a to the probe antenna 11o, it is preferable that the above-mentioned predetermined distance is the same value. Incidentally, during the measurement from the probe antenna 11a to the probe antenna 11o, it is preferable that the antenna 100 moves in the Z direction inside the housing 22 at a constant speed.

[0041] <Configuration Example of Antenna Directivity Estimation Device> FIG. 5 is a block diagram showing an example of the configuration of the antenna directivity estimation device according to the present embodiment.

[0042] Incidentally, the antenna directivity estimation device 200 may be configured as a device implemented by hardware such as a semiconductor circuit or a microcomputer (not shown) that executes processing related to the functions of each block diagram described later. Alternatively, the antenna directivity estimation device 200 may be configured by a general-purpose server device or a virtual server constructed on a cloud computing service. Further, the antenna directivity estimation device 200 may be configured by a CPU (Central Processing Unit) (not shown). Then, the antenna directivity estimation device 200 may be executed by executing middleware such as an OS (Operating System) developed on a memory from a recording device such as an HDD (Hard Disk Drive), and software operating thereon. The processing related to each function described later may be executed by the middleware or software described above.

[0043] Further, the antenna directivity estimation device 200 may be configured by appropriately combining the implementation by these hardware and the implementation by software. Further, the antenna directivity estimation device 200 is not limited to a configuration in which the whole is implemented in one housing, and a part of the functions may be implemented in another housing, and these housings may be interconnected by a communication cable or the like. That is, the implementation form of the antenna directivity estimation device 200 is not particularly limited, and can be appropriately and flexibly configured according to the environment of the system or the like.

[0044] Furthermore, the antenna directivity estimation device 200 may be implemented in combination with other devices in the system. For example, the antenna directivity estimation device 200 may be implemented by being added to other hardware in the system or by being added to other software in the system.

[0045] The antenna directivity estimation device 200 can include an input unit 210, an estimation unit 220, an output unit 230, and a storage unit 240.

[0046] The input unit 210 has a function of converting the received radio wave into a received radio wave signal which is an analog electrical signal from the received radio wave received by the antenna 100 or the probe antenna 11, and further inputting the received radio wave signal information which is the digital signal information obtained by A / D converting the received radio wave signal. The input unit 210 also has a function of inputting information such as various timing signals or the position information of the antenna 100 as digital signals. Furthermore, the input unit 210 may also have a function as a man-machine interface. For example, the input unit 210 preferably inputs the received radio wave signal information generated from the received radio wave signal generated by the antenna 100 that receives the transmitted radio wave radiated from the probe antenna 11 through which the transmitted radio wave signal is transmitted. Also, the input unit 210 preferably inputs the received radio wave signal information generated from the received radio wave signal generated by the probe antenna 11 that receives the transmitted radio wave radiated from the antenna 100 through which the transmitted radio wave signal is transmitted.

[0047] As described above, the estimation unit 220 can be realized, for example, using a microcomputer including a CPU. A computer program (antenna directivity estimation program) for causing the microcomputer to function as the estimation unit 220 is installed and executed on the microcomputer. Thereby, the microcomputer functions as a plurality of information processing units included in the estimation unit 220. Here, an example of realizing the estimation unit 220 by software is shown. Of course, it is also possible to prepare dedicated hardware for executing each information process and configure the estimation unit 220. The dedicated hardware includes devices such as application-specific integrated circuits (ASICs) and conventional circuit components arranged to execute the functions described in the embodiments. Further, the plurality of information processing units included in the estimation unit 220 may be configured by individual hardware.

[0048] The estimation unit 220 can include a trigger signal generation unit 221, a radiated radio wave information generation unit 222, a received radio wave signal information analysis unit 223, an inverse Fourier transform unit 224, a measurement point correction unit 225, a probe correction unit 226, and a coordinate conversion unit 227. Also, the estimation unit 220 is not intended to exclude other components.

[0049] When the trigger signal generation unit 221 receives a measurement start information signal for starting the measurement input from the input unit 210, it generates a trigger signal. For example, the measurement start information signal may be input from the input unit 210 that functions as an input interface such as a keyboard or a touch panel (not shown). Also, when the trigger signal generation unit 221 receives a reception preparation completion signal from the positioner control unit 330, it generates a trigger signal to be transmitted to the switch timing control unit 310 and the positioner control unit 330 in order to start the measurement. Further, when starting the measurement, the trigger signal generation unit 221 continuously transmits a signal for inquiring about the position of the antenna 100 to the positioner control unit 330. When the trigger signal generation unit 221 receives a signal from the positioner control unit 330 indicating that the position of the antenna 100 has reached a predetermined position, it transmits a trigger signal to the switch timing control unit 310 and the network analyzer 320. Next, the antenna directivity estimation device 200 receives, via the network analyzer 320, received radio wave signal information of the radio waves radiated from the probe antenna 11 at the antenna 100. The antenna directivity estimation device 200 repeats the above operation for each predetermined position. Also, when the trigger signal generation unit 221 receives a signal from the positioner control unit 330 indicating that the position of the antenna 100 has exceeded the last position to be measured, it transmits a signal for stopping the movement of the antenna 100 to the positioner control unit 330.

[0050] The radiated radio wave information generation unit 222 has a function of generating information such as frequency information, modulation information, and amplification information for radiating horizontally polarized radio waves and vertically polarized radio waves from the probe antenna 11. This information needs to be determined in consideration of the characteristic information of the transmitting antenna that radiates radio waves and the characteristic information of the interface relationship with the transmitting antenna. Since a specific information generation method is a known technique, details are omitted in this embodiment. The radiated radio wave information generation unit 222 also has a function of generating information such as frequency information, modulation information, and amplification information when horizontally polarized radio waves and vertically polarized radio waves are radiated from the antenna 100. Also, this information may be included in the transmitted radio wave signal information.

[0051] The received radio wave signal information analysis unit 223 has a function of analyzing the received horizontal polarization radio wave signal and the received vertical polarization radio wave signal that are received by the antenna 100 and A / D converted by the network analyzer 320. For example, it has a function of converting the received radio wave signal information having the amplitude information and the phase information of the received horizontal polarization radio wave signal and the received vertical polarization radio wave signal into discrete data with respect to the central angle in the circumferential direction (the arrangement angle of the probe antenna 11) and the distance in the Z-axis direction. Note that the received radio wave signal information analysis unit 223 also has a function of analyzing the received horizontal polarization radio wave signal and the received vertical polarization radio wave signal that are received by the probe antenna 11 and A / D converted by the network analyzer 320. For example, it has a function of converting the received radio wave signal information having the amplitude information and the phase information of the received horizontal polarization radio wave signal and the received vertical polarization radio wave signal into discrete data with respect to the central angle such as the central angle in the circumferential direction and the distance in the Z-axis direction.

[0052] The inverse Fourier transform unit 224 performs an inverse Fourier transform on the discrete data collected by the received radio wave signal information analysis unit 223 with respect to the distance in the Z-axis direction. Thereafter, the inverse Fourier transform unit 224 performs an inverse Fourier transform with respect to the central angle in the circumferential direction, and I n (r) (n is the wave number component in the circumferential direction, r is the wave number component in the Z-axis direction) can be obtained. Using the inverse fast Fourier transform for the inverse Fourier transform does not prevent the acceleration of the calculation.

[0053] The measurement point correction unit 225 has a function of performing a correction calculation on the difference between the distance x from the probe antenna 11 to the measurement point of the antenna 100 where the radio wave originally to be measured is radiated and the distance a to the actually measured measurement point. The measurement point correction unit 225 expresses the difference Δ in terms of the phase Pa, and corrects the measurement data as phase Pa = k (wave number) × Δ. The actual calculation formula will be described in detail in FIGS. 7 and 8.

[0054] The probe correction unit 226 removes the reception characteristics of the receiving antenna from the inversely Fourier-transformed I n (r) and calculates the transmission characteristics of the transmitting antenna. I n(r) is indicated by the transmission characteristics of the antenna 100 and the reception characteristics of the probe antenna 11. On the other hand, since it is a known technique that reversibility holds for the radio wave transmission and reception characteristics, the far-field of the probe antenna 11 is also represented by a known value or formula through prior measurement or theoretical analysis. Regarding only the central angle of the far-field E1(φ, θ), the inverse Fourier transform formula and the sum regarding n of the product with the Hankel function H n (2) (κρ0) are calculated by a predetermined formula to obtain the reception characteristics R n (r) of the probe antenna 11. Next, I n (r) is removed from R n (r) to calculate the source scattering matrix T n (r) indicating the transmission characteristics of the antenna 100, which is the antenna under measurement. Note that for the calculation of the source scattering matrix T n (r), the interaction of the reception characteristics of the horizontal and vertical radio waves of the probe antenna 11 is also considered, but since it is a known technique, detailed explanations of the detailed calculation formula are omitted.

[0055] The coordinate conversion unit 227 Fourier-transforms the source scattering matrix T n (r) with respect to n to calculate the far-field E(φ, θ) regarding the antenna 100, which is the antenna under measurement. Note that the elevation angle θ is cos -1 (r / k), where r is the wave number in the central axis direction of the antenna 100 and k is the wave number in the radial direction of the antenna 100. Also, for the calculation of the far-field E(φ, θ), the second-kind Hankel function is used, but since it is a known technique, detailed explanations of the detailed calculation formula are omitted.

[0056] The output unit 230 preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the antenna 100. Further, the output unit 230 preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the probe antenna 11. The antenna 100 preferably moves along the central axis of the circle formed by the probe antennas 11 arranged in a circumferential shape. The network analyzer 320 functions as a transmission radio wave generation device that generates a transmission radio wave signal from the transmission radio wave signal information.

[0057] When the received radio wave signal information input from the input unit 210 corresponds to a received radio wave or a transmission radio wave from a measurement point that has moved in a spiral direction on the outer peripheral circle of the antenna, the estimation unit 220 can execute the following processing. That is, the estimation unit 220 can estimate the directivity of the antenna 100 in the circumferential direction of the concentric circle with respect to the central axis of the antenna 100 from the received radio signal wave information input from the input unit 210. The received radio signal wave information is preferably generated from the received radio wave signal generated in the antenna 100. Alternatively, the received radio wave signal information is preferably generated from the received radio wave signal generated in the probe antenna 11.

[0058] The storage unit 240 can be a computer-readable recording medium. For example, the storage unit 240 may be composed of at least one of ROM (Read Only Memory), RAM (Random Access Memory), etc. Further, the storage unit 240 may be composed of at least one of EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), etc. in addition to ROM and RAM. The storage unit 240 may be referred to as a register, a cache, a main memory (main storage device), etc. The storage unit 240 can also store a program (program code), a software module, etc. that can be executed to implement the processing according to an embodiment of the present disclosure.

[0059] Further, the memory unit 240 can store the information input from the input unit 210, input and output information to and from the estimation unit 220, and store the information to be input and output. Further, the memory unit 240 can also store the information between each functional block in the estimation unit 220. Further, the memory unit 240 can also store the information to be output from the output unit 230.

[0060] <Principle Explanation of Measurement Position Correction Method> FIGS. 6 and 7 are principle diagrams for explaining a method of estimating the concentric direction directivity of the antenna 100 from the received radio waves measured when the antenna 100 is moved forward or backward along the central axis. That is, it is a diagram for explaining the principle of the conversion correction method from the radio wave measurement value at the actual radio wave measurement position to the virtual radio wave measurement value at the virtual radio wave measurement position where the radio wave should have been measured. When the antenna 100 moves a distance b along the central axis, the probe antennas 11 arranged concentrically transmit radio waves in order in the circumferential direction of the concentric circles. The antenna 100 generates a received radio wave signal of the radio waves transmitted from each probe antenna 11. Note that the distance from the central axis C1 of the antenna 100 to each probe antenna 11 is a cylindrical shape with a radius a.

[0061] In FIG. 6, the antenna 100 moves in the Z direction parallel to the central axis C1 of the antenna 100. Also, the probe antennas 11 arranged concentrically transmit radio waves in order in the circumferential direction of the concentric circles. Therefore, the measurement points of the radio waves of the antenna 100 draw a so-called spiral curve on the central axis C1. However, in FIG. 6, the measurement points are drawn to move linearly on the central axis C1. Strictly speaking, since the antenna 100 also has a radius, the measurement points move in a spiral direction on the outer peripheral circle of the antenna. The antenna 100 receives the radio waves radiated from the probe antenna 11a at the measurement point P1, and the antenna directivity estimation device 200 acquires the received radio wave signal information. In order to obtain the directivity in the concentric circle direction orthogonal to the central axis of the antenna 100 including the measurement point P1, the next probe antenna 11b needs to radiate radio waves at a position where the central angle is deviated from the measurement point P1, and the antenna 100 needs to receive the radio waves. However, since the antenna 100 moves along the central axis C1, the next probe antenna 11b after the probe antenna 11a radiates radio waves above the measurement point P2.

[0062] In this embodiment, the positioner control unit 330 controls the linear movement of the antenna 100 via the positioner 23. Therefore, when the antenna 100 moves a distance b along the central axis C1 from the position corresponding to the measurement point P1, the positioner control unit 330 transmits a reception preparation completion signal to the antenna directivity estimation device 200. The measurement point P2 and the measurement point P1 are in a parallel or substantially parallel positional relationship with respect to the central axis of the antenna 100. The substantially parallel positional relationship means a range of parallelism such that the value of the estimated result of the antenna directivity in the antenna directivity estimation of the antenna directivity estimation device 200 falls within the error range. As an example, the substantially parallel may mean allowing a deviation in parallelism in the range of about ±5 degrees from the true parallel relationship in some cases.

[0063] Similarly, when the antenna 100 moves a distance b along the central axis C1 from the position corresponding to the measurement point P2, the position control unit 330 transmits a reception preparation completion signal to the antenna directivity estimation device 200. The measurement point P3 and the measurement point P2 are in a parallel or substantially parallel positional relationship with respect to the central axis of the antenna 100. The substantially parallel positional relationship means a range of parallelism such that the value of the estimated result of the antenna directivity in the antenna directivity estimation of the antenna directivity estimation device 200 falls within the error range. As an example, the substantially parallel may mean allowing a deviation in parallelism within a range of about ±5 degrees from the true parallel relationship in some cases.

[0064] Also, as an example for realizing the operation of the antenna directivity estimation system 1000 described above, the position control unit 330 can move the antenna 100 at a constant speed in the Z-axis direction via the positioner 23. According to such a configuration, as long as there is no disturbance, the position control unit 330 transmits a reception preparation completion signal to the antenna directivity estimation device 200 at a predetermined timing, enabling the transmission and reception of radio waves at each predetermined measurement point. It is preferable that at least one of the antenna directivity estimation device 200 and the position control unit 330 sets the moving speed of the antenna 100 in advance.

[0065] Also, as an example for realizing the operation of the antenna directivity estimation system 1000 described above, the position control unit 330 can be configured to acquire the position information of the antenna 100 via the positioner 23. In this case, the position control unit 330 operates to cause the antenna directivity estimation system 1000 to execute the transmission and reception of the radio waves described above each time the antenna 100 reaches a predetermined position.

[0066] Therefore, the correspondence relationship between the radio wave transmission center positions of each probe antenna 11 that transmits radio waves and arranged circumferentially, and the radio wave reception center position of the antenna 100 that receives the radio waves preferably is as follows. That is, it is preferable that the central angle between the transmission center positions of adjacent probe antennas 11 coincides with the central angle between the adjacent reception center positions of the antenna 100, and the distance in the Z-axis direction of the antenna 100 between the adjacent reception center positions of the antenna 100 is the same. However, it does not exclude the case where the distances in the Z-axis direction are different. Also, in principle, the correspondence relationship between the radio wave reception center positions of each probe antenna 11 that receives radio waves and arranged circumferentially, and the radio wave transmission center position of the antenna 100 that transmits the radio waves preferably is as follows. That is, it is preferable that the central angle between the reception center positions of adjacent probe antennas 11 coincides with the central angle between the adjacent transmission center positions of the antenna 100, and the distance in the Z-axis direction of the antenna 100 between the adjacent transmission center positions of the antenna 100 is the same. However, it does not exclude the case where the distances in the Z-axis direction are different. A specific correction method regarding the above-described positional relationship will be further described below.

[0067] FIG. 7 is a diagram showing that radio waves are radiated from the position of the probe antenna 11b (point O) facing the measurement point P2. Further, FIG. 7 is a diagram showing the positional relationship among the probe antenna 11b (point O), the measurement point P2 of the antenna 100, and the measurement point P2' when the antenna 100 receives the radio waves at the measurement point P2. As described above, the measurement point P2' coincides with the measurement point P1 and is the point that should have been measured by the probe antenna 11b in the conventional measurement method. Therefore, the antenna 100 has moved a distance b from the measurement point P2' to the measurement point P2. Let the distance from the probe antenna 11b (point O) to the measurement point P2' be x, and the distance from the probe antenna 11b (point O) to the measurement point P2 be a. Then, the triangle having sides O·P2', O·P2, and P2'·P2 is a right triangle with the angle ∠P2'·P2·O being a right angle. Let the angle formed by the angle ∠P2'·O·P2 be θ. Then, the angle formed by the perpendicular dropped from the measurement point P2 to the side OP2' and the side P2'·P2 is also θ. Note that the measurement points P2 and P2' are measurement points on the central axis C1 of the antenna 100.

[0068] In FIG. 7, if the difference between the distance x from the probe antenna 11b to the measurement point P2' where the radio waves radiated from the probe antenna 11b are originally to be measured and the distance a to the actually measured measurement point P2 is Δ, then Δ = x - a cos θ = b sin θ.

[0069] That is, when the difference Δ is expanded using two right triangles having the angle θ as an interior angle, Δ = b×(b / x) = b 2 / x = b 2 / (a 2 +b 2 ) 1 / 2 is obtained. Here, if the speed of light is c, the frequency of the radio wave is f, and the wavelength of the radio wave is λ, then when the wavelength λ of the radio wave is expressed in terms of the speed of light and the frequency, λ = (c / f). Therefore, when the difference Δ is expressed in terms of the phase Pa, the phase Pa = (Δ×2π) / λ = k×Δ (k (wave number) = (2π) / λ). That is, the phase Pa to be corrected is the phase Pa = k×Δ = k×b 2 / (a 2 +b 2 ) 1 / 2 is obtained.

[0070] <Flowchart of the directivity estimation operation example in the far field from the reception measurement in the near field of the antenna directivity estimation device> FIG. 8 is a flowchart showing an example of a processing operation in which the antenna directivity estimation device estimates received radio waves on the same circumference and estimates the directivity of transmitted radio waves on the same circumference using the antenna directivity estimation system shown in FIGS. 1 and 4.

[0071] In step S801, the received radio wave signal information analysis unit 223 of the antenna directivity estimation device 200 acquires received radio wave signal information obtained by receiving radio waves radiated from the probe antennas 11a, 11b, 11c,... at the measurement points P1, P2, P3,... of the antenna 100. The received radio waves include both horizontally polarized received radio waves and vertically polarized received radio waves. In the following description, the horizontally polarized received radio waves and the vertically polarized received radio waves are collectively described as received radio waves without distinction. Φ0 is an angle corresponding to the central angle formed by adjacent probe antennas 11. However, in this embodiment, it is assumed that the central angle between the probe antenna 11o and the probe antenna 11a is 2Φ0. In the embodiment of FIG. 1, since 15 probe antennas 11 are arranged on the same circumference and the central angle is at intervals of 22.5 degrees, n max +1 = 16, and (n max +1)×Φ0 = 16×22.5 (degrees) = 360 (degrees) = 2π.

[0072] Also, Z0 represents the distance in the Z-axis direction of each measurement point, which is the distance b shown in FIG. 7. The b shown in step S801 n shows an example of a method for determining the initial measurement position in the Z-axis direction of the measurement point P shown in FIG. 6. b n =(n×Z0) / (n max +1)=(n×b) / 16=n×(b / 16). So, if b1 = b / 16, it is understood that the moving speed of the antenna 100 in the Z-axis direction is set to about 1 / 16 of the explanation shown in FIG. 7. Note that if b n =(n×Z0) is set, it is understood that it will be about the same as the moving speed in the Z-axis direction in the explanation shown in FIG. 7. That is, b nThe conditions are not limited to the conditional expression defined in step S801. In the antenna directivity estimation device 200 or the position control unit 330, b is set so that at least about 360 degrees of the measurement result of the directivity of the antenna 100 can be obtained while moving in at least one direction on the rail 24. n Preferably, such a condition is set. Next, the antenna directivity estimation device 200 proceeds to step S802.

[0073] In step S802, the inverse Fourier transform unit 224 of the antenna directivity estimation device 200 performs an inverse Fourier transform on the received radio wave signal information acquired in step S801 with respect to Z, and designates it as I’(φ, r). Since this numerical value is shown in the polar coordinate form of the length from the central axis of the antenna 100 to the probe antenna 11 direction and the angle in the circumferential direction, it becomes possible to use the phase Pa of the difference Δ of the length to be corrected shown in FIG. 7 as a correction term. The inverse Fourier transform unit 224 of the antenna directivity estimation device 200 then proceeds to step S803.

[0074] In step S803, the inverse Fourier transform unit 224 of the antenna directivity estimation device 200 passes the process to the measurement point correction unit 225, and the measurement point correction unit 225 executes the following process. Specifically, the measurement point correction unit 225 uses the phase Pa = k×Δ = k×b 2 / (a 2 +b 2 ) 1 / 2 as the imaginary unit of the exponential function for I’(φ, r). That is, the measurement point correction unit 225 executes the correction of the measurement point as I(φ, r) = I’(φ, r)exp(i×k×b n 2 / (a 2 +b n 2 ) 1 / 2 ). Here, a is the distance from the measurement point P2 on the central axis C1 of the antenna 100 to the probe antenna 11 (point O), i is the imaginary unit, k is the wave number of the radio wave frequency, and exp represents the exponential function. Next, the measurement point correction unit 225 of the antenna directivity estimation device 200 proceeds to step S804.

[0075] As described above, the estimation unit 220 performs an inverse Fourier transform in the central axis direction of the antenna 100 on the received radio wave signal information received by the antenna 100 from the probe antenna 11, and then performs correction processing in the central axis direction of the antenna 100 at the measurement point. Alternatively, in principle, the estimation unit 220 can perform correction processing in the central axis direction of the antenna 100 at the measurement point after performing an inverse Fourier transform in the central axis direction of the antenna 100 on the received radio wave signal information received by the probe antenna 11 from the antenna 100. As described above, the inverse Fourier transform is actually performed by the inverse Fourier transform unit 224 included in the estimation unit 220.

[0076] In step S804, the measurement point correction unit 225 of the antenna directivity estimation device 200 passes the process to the inverse Fourier transform unit 224. The inverse Fourier transform unit 224 performs an inverse Fourier transform on I(φ, r) whose measurement point has been corrected by the measurement point correction unit 225 with respect to the central angle, and n obtains I(r). Next, the antenna directivity estimation device 200 proceeds to step S805.

[0077] In step S805, the inverse Fourier transform unit 224 of the antenna directivity estimation device 200 passes the process to the probe correction unit 226, and the probe correction unit 226 performs probe correction processing. That is, the probe correction unit 226 removes the reception characteristics of the receiving antenna from the inverse Fourier-transformed I(r) and calculates the transmission characteristics of the transmitting antenna. I(r) is represented by the transmission characteristics of the antenna 100 and the reception characteristics of the probe antenna 11. On the other hand, since it is a known technique that reversibility holds for the radio wave transmission and reception characteristics, the far-field of the probe antenna 11 is also assumed to be represented by a known value or formula through prior measurement or theoretical analysis. The sum of the formula obtained by performing an inverse Fourier transform on the far-field E1(φ, θ) only with respect to the central angle and the product of the Hankel function H n (κρ0) with respect to n is calculated by a predetermined formula to obtain the reception characteristics R of the probe correction n (r). n (2) (κρ0) and the sum regarding n is calculated by a predetermined formula to obtain the reception characteristics R of the probe correction nLet it be (r). For probe correction, the interaction between vertically polarized radio waves and horizontally polarized radio waves is also calculated, but since it is a known technique, the details are omitted. That is, from the above description and calculation, T n (r), that is, the wave source scattering matrix can be calculated. Next, the probe correction unit 226 of the antenna directivity estimation device 200 proceeds to step S806.

[0078] In step S805, the probe correction unit 226 of the antenna directivity estimation device 200 passes the process to the coordinate conversion unit 227, and the coordinate conversion unit 227 performs a Fourier transform of the wave source scattering matrix T n (r) with respect to n to calculate the far - field E(φ, θ) of the antenna under measurement. Note that the far - field in the elevation angle θ direction corresponds to the wave source scattering matrix T for r determined by r = kcosθ. That is, θ = cos -1 (r / k) has a relationship.

[0079] According to the operation of the antenna directivity estimation device 200 described above, while the antenna 100 is moving, each radio wave transmitted from the probe antennas 11a to 11n is received at each measurement point P1 to Pn of the antenna 100. And it becomes possible to correct each received radio wave as a radio wave received on the same circumference of the antenna 100. Also, due to the reversibility of radio wave transmission and reception, it becomes possible to show the characteristics of the received radio wave of the antenna 100 as the characteristics of the transmitted radio wave. Therefore, rather than measuring the radio wave characteristics in the concentric - circle direction of the antenna 100 by repeating the stop and movement of the antenna 100, it becomes possible to continuously move the antenna 100 and estimate and measure the radio wave characteristics in the concentric - circle direction of the antenna 100. As a result, it becomes possible to acquire the necessary characteristics of the antenna 100 in a short time.

[0080] <Experimental Result 1> FIG. 9 is a graph showing an example of the measurement result of the horizontal plane directivity of an antenna using the antenna directivity estimation system according to the present embodiment.

[0081] Since the frequency of the radio wave used for measurement is 2.0 GHz, the antenna 100 also receives the 2.0 GHz radio wave radiated from the probe antenna 11 in the high-band radiation element unit 112. The vertical axis in FIG. 9 is based on the radiation level when the radiation direction (front surface) of the antenna 100 is 0 degrees. Also, the horizontal axis in FIG. 9 sets the radiation direction (front surface) of the antenna 100 to 0 degrees and the angle in the direction opposite to the radiation direction (back surface) to ±180 degrees.

[0082] The dashed line is a comparative example and is an example of the measurement result of the horizontal plane directivity of the antenna by the conventional measurement method. That is, the antenna 100 stops at a point on the Z-axis which is the central axis direction of the antenna 100, and the probe antennas 11a to 11o sequentially transmit 2.0 GHz horizontally polarized radio waves and vertically polarized radio waves. The antenna 100 receives the radio wave and converts it from a near-field radio wave to a far-field radio wave.

[0083] The solid line is the experimental result of this embodiment and almost coincides with the measurement result of the horizontal plane directivity of the antenna by the conventional measurement method. There is almost no region where the radiation levels of the horizontal plane directivity of the experimental result of this embodiment and the experimental result by the conventional measurement method differ by an integer unit of decibels. Note that in the vicinity of the minimum or maximum value where the horizontal plane directivity fluctuates steeply, a difference in radiation level of about several decibels may occur over an angular range of several degrees. However, in an actual application, due to the influence of external disturbances in the surrounding environment, the difference between the experimental result of this embodiment and the experimental result by the conventional measurement method is likely to be within the error range.

[0084] <Experimental Result 2> FIG. 10 is a graph showing another example of the measurement result of the horizontal plane directivity of the antenna using the antenna directivity estimation system according to this embodiment.

[0085] The frequency of the radio wave used for measurement is 1.8 GHz. The antenna 100 is a dipole antenna. The dipole antenna is receiving the 1.8 GHz radio wave radiated from the probe antenna 11. The vertical axis in FIG. 10 also shows the radiation level of the radio wave in decibels, and is based on the radiation level when the angle in the vertically upward direction of the dipole antenna is 0°. Also, the horizontal axis in FIG. 10 shows the circumferential angle around the central axis of the dipole antenna in degrees, with the angle in the vertically upward direction of the dipole antenna being 0°, and the angle in the vertically downward direction of the dipole antenna being ±180°.

[0086] The dashed line is a comparative example and is an example of the measurement result of the horizontal plane directivity of a dipole antenna by a conventional measurement method. That is, the dipole antenna stops at a point on the Z-axis which is the central axis direction of the dipole antenna. The probe antennas 11a to 11o sequentially transmit horizontally polarized radio waves and vertically polarized radio waves of 1.8 GHz, the dipole antenna receives the radio waves, and converts the received radio waves in the near field to the transmitted radio waves in the far field.

[0087] The solid line is the experimental result of this embodiment and almost coincides with the measurement result of the horizontal plane directivity of the antenna by the conventional measurement method. There is almost no region where the radiation levels of the horizontal plane directivities of the experimental result of this embodiment and the experimental result by the conventional measurement method differ in integer units of decibels. Note that in the vicinity of the minimum value or the maximum value where the horizontal plane directivity fluctuates steeply, a difference in radiation level of about several decibels may occur over a circumferential angle of several degrees. However, also in the case of this experimental result, in an actual application, due to the influence of disturbances in the surrounding environment, the difference between the experimental result of this embodiment and the experimental result by the conventional measurement method is likely to be within the error range.

[0088] It can be understood from the experimental results of the above-described antenna directivity estimation apparatus 200 that the following corrections are possible. That is, the antenna directivity estimation apparatus 200 can measure the radio wave transmitted from the probe antenna 11 while moving the antenna 100 such as a dipole antenna along the central axis, and correct the received radio wave as the radio wave received on the circumference of the antenna 100. Also, due to the reversibility of radio wave transmission and reception, it becomes possible to show the characteristics of the received radio wave of the antenna 100 as the characteristics of the transmitted radio wave. Therefore, it becomes possible to estimate and measure the radio wave characteristics in the concentric circle direction of the antenna 100 by continuously moving the antenna 100, rather than repeatedly stopping and moving the antenna 100 to measure the radio wave characteristics in the concentric circle direction of the antenna 100. As a result, it becomes possible to acquire the necessary characteristics of the antenna 100 in a short time.

[0089] (Modification example) The above embodiment has described the form in which the antenna 100 linearly moves along the central axis C1 of the antenna 100. However, in the present disclosure, it is also possible to estimate the directivity of the antenna 100 when the antenna 100 linearly moves along the central axis C1 and rotates about the central axis C1. In this case, the probe antenna 11 only needs to be fixed at a location where transmission and reception are possible and spatially separated from the antenna 100. That is, one probe antenna 11 is sufficient. For example, it is sufficient that one probe antenna 11 is fixed so as to face the direction of the antenna 100 at any location in the housing 22.

[0090] As an example, the position control unit 330 moves the antenna 100 in the Z direction while rotating it inside the housing 22. Therefore, the positioner 23 continuously and simultaneously executes the operation of rotating the antenna 100 around the central axis of the antenna 100 and the operation of moving the antenna 100 in the central axis direction of the antenna 100. In this way, the positioner 23 rotates and moves the antenna 100 so that the points on the outer peripheral surface of the antenna 100 trace a helix. The antenna directivity estimation device 200 rotates the antenna 100 through the positioner 23 via the position control unit 330 until the central angle of rotation of the antenna 100 reaches a predetermined angle while moving the antenna 100 in the Z direction. Then, the antenna directivity estimation device 200 turns on the switch SW1 and the switch SW2 via the switch timing control unit 310. Then, the network analyzer 320 radiates radio waves from the probe antenna 11 via the switch SW1. The antenna 100 receives the radio waves radiated from the probe antenna 11. The received radio wave signal is A / D converted in the network analyzer 320 via the switch SW2 and input to the antenna directivity estimation device 200 as received radio wave signal information. Then, the antenna directivity estimation device 200 turns off the switch SW1 and the switch SW2 via the switch timing control unit 310. The above operations are repeated until the antenna 100 rotates a predetermined number of times. Note that the above-mentioned predetermined angle can be set to any angle by the antenna directivity estimation device 200. Also, the above-mentioned predetermined number of rotations can be set to any number by the antenna directivity estimation device 200.

[0091] According to the above configuration, it is possible to calculate the horizontal plane directivity characteristics on the same circumference of the antenna under measurement by correcting the received radio waves without stopping the antenna under measurement, and to shorten the measurement time of the horizontal plane directivity with respect to the length direction of the antenna under measurement.

[0092] The features of the antenna directivity estimation device 200, the antenna directivity estimation system 1000, the control method of the antenna directivity estimation device 200, and the program for controlling the antenna directivity estimation device 200 according to the present embodiment will be described below.

[0093] The antenna directivity estimation device 200 according to the first aspect of the present disclosure preferably includes an output unit 230 having the following configuration. The output unit 230 preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the antenna 100. Further, the output unit 230 preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the probe antenna 11. The antenna 100 preferably moves along the central axis of the circle formed by the probe antennas 11 arranged in a circular shape. The antenna directivity estimation device 200 preferably includes an input unit 210 having the following configuration. The input unit 210 preferably inputs received radio wave signal information generated from a received radio wave signal generated in the antenna 100 that receives the transmission radio wave radiated from the probe antenna 11 to which the transmission radio wave signal is transmitted. Further, the input unit 210 preferably inputs received radio wave signal information generated from a received radio wave signal generated in the probe antenna 11 that receives the transmission radio wave radiated from the antenna 100 to which the transmission radio wave signal is transmitted. Further, the antenna directivity estimation device 200 preferably includes an estimation unit 220 having the following configuration. When the received radio wave signal information input from the input unit 210 is information corresponding to a received radio wave or a transmission radio wave from a measurement point that has moved in a spiral direction on the outer peripheral circle of the antenna, the estimation unit 220 can execute the following processing. That is, the estimation unit 220 can estimate the directivity of the antenna 100 in the circumferential direction of the concentric circle with respect to the central axis of the antenna 100 from the received radio signal wave information input from the input unit 210. The received radio signal wave information is preferably generated from a received radio wave signal generated in the antenna 100. Alternatively, the received radio wave signal information is preferably generated from a received radio wave signal generated in the probe antenna 11.

[0094] According to the above configuration, without stopping the antenna under measurement, by correcting the received radio wave, it is possible to calculate the horizontal plane directivity characteristics on the same circumference of the antenna under measurement, and shorten the measurement time of the horizontal plane directivity with respect to the length direction of the antenna under measurement.

[0095] In the antenna directivity estimation apparatus 200 according to the second aspect of the present disclosure, it is preferable that the estimation unit 220 executes the following correction process. That is, the estimation unit 220 preferably executes an inverse Fourier transform in the central axis direction of the antenna 100 from the received radio wave signal information of the received radio wave received by the antenna 100 from the probe antenna 11, and then executes a correction process in the central axis direction of the antenna 100 at the measurement point. Alternatively, the estimation unit 220 preferably executes an inverse Fourier transform in the central axis direction of the antenna 100 from the received radio wave signal information of the received radio wave received by the probe antenna 11 from the antenna 100, and then executes a correction process in the central axis direction of the antenna 100 at the measurement point.

[0096] According to the above configuration, since the correction process of the measurement point position in the central axis direction of the antenna 100 is executed as phase correction using trigonometric functions, it becomes possible to execute the correction process of the measurement point position quickly and easily.

[0097] The antenna directivity estimation system 1000 according to the third aspect of the present disclosure preferably includes a probe antenna 11 arranged in a circular shape. Further, the antenna directivity estimation system 1000 preferably includes an antenna that moves along the central axis of the circle formed by the probe antennas 11 arranged in a circular shape. That is, it is preferable that the positioner 23 of the antenna directivity estimation system 1000 is capable of executing an operation of moving the antenna 100 in the central axis direction of the antenna 100 so as to pass inside the probe antennas 11 arranged concentrically. Further, the antenna directivity estimation system 1000 preferably includes the antenna directivity estimation apparatus according to the first aspect or the second aspect.

[0098] According to the above configuration, the antenna directivity estimation system 1000 can use the near-field measurement method. Therefore, the antenna directivity estimation system 1000 can measure a large-aperture antenna in a relatively small anechoic chamber, perform stable and highly accurate measurements, and calculate all information within the measured angular range after the measurement.

[0099] In the antenna directivity estimation system 1000 according to the fourth aspect of the present disclosure, it is preferable to have the following positional relationship. For example, the correspondence between the radio wave transmission / reception center positions of each probe antenna 11 arranged in a circular shape for transmitting or receiving radio waves and the radio wave transmission / reception center position of the antenna 100 for receiving or transmitting the radio waves is preferably the following relationship. Specifically, the central angle between the transmission / reception center positions of adjacent probe antennas 11 is preferably the same as the central angle between the adjacent transmission / reception center positions of the antenna 100, and the distance in the Z-axis direction of the antenna 100 between the adjacent transmission / reception center positions of the antenna 100 is preferably the same or different.

[0100] According to the above configuration, even when the antenna 100 moves in the direction of the central axis, the transmission / reception center position can maintain a positional relationship parallel to the central axis. Therefore, the antenna directivity estimation system 1000 can easily perform correction calculations on the horizontal plane directivity characteristics of the antenna under measurement on the same circumference without requiring a complicated configuration. Also, since the rotation speed and movement speed of the antenna 100 do not need to be at that speed, the configuration of the positioner 23 can also be made a simple configuration.

[0101] The probe antenna 11 of the antenna directivity estimation system 1000 according to the fifth aspect of the present disclosure is preferably configured to be able to transmit and receive horizontally polarized radio waves and vertically polarized radio waves. That is, for example, the probe antenna 11a is preferably configured such that the horizontally polarized antenna 11ah and the vertically polarized antenna 11av are attached so as to intersect. The antenna 100 is also preferably configured to be able to transmit and receive horizontally polarized radio waves and vertically polarized radio waves.

[0102] According to the above configuration, when performing probe correction or the like in the antenna directivity estimation system 1000, it becomes possible to consider the interaction between horizontally polarized radio waves and vertically polarized radio waves. Conventionally, the antennas used for transmission and reception were rotated according to the polarization direction to be measured. However, since the probe antenna 11 is configured to be able to transmit and receive both horizontally polarized radio waves and vertically polarized radio waves, when measuring two polarizations, it becomes possible to shorten the setup time for rotating and aligning the antenna in the polarization direction. Also, the horizontal polarization antenna 11ah and the vertical polarization antenna 11av can be used as long as they are orthogonal polarizations (such as ±45-degree polarizations).

[0103] The antenna directivity estimation system 1000 according to the sixth aspect of the present disclosure preferably includes a low-band radiation element unit 111 and a high-band radiation element unit 112. The frequency band of the radio waves transmitted and received from the high-band radiation element unit 112 is preferably higher than the frequency band of the radio waves transmitted and received from the low-band radiation element unit 111. The frequency band of the high-band radiation element unit 112 preferably includes the gigahertz band.

[0104] According to the above configuration, the antenna directivity estimation system 1000 according to the present embodiment can estimate and measure the directivity characteristics in the concentric circle direction of the antenna at once in a short time without physically changing the settings of the antenna to be measured such as a shared antenna. Also, it becomes possible to estimate and measure the directivity characteristics in the concentric circle direction of the antenna at once in a short time not only in the low-frequency band but also up to a high-frequency band such as the mobile radio frequency band.

[0105] The control method of the antenna directivity estimation device 200 according to the seventh aspect of the present disclosure preferably includes the following output steps. The output step preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the antenna 100. Further, the output step preferably outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to the probe antenna 11. The antenna 100 preferably moves along the central axis of the circle formed by the probe antennas 11 arranged in a circular shape. The antenna directivity estimation device 200 preferably includes an input step having the following configuration. The input step preferably inputs received radio wave signal information generated from a received radio wave signal generated in an antenna that receives the transmission radio wave radiated from the probe antenna 11 to which the transmission radio wave signal is transmitted. Further, the input step preferably inputs received radio wave signal information generated from a received radio wave signal generated in the probe antenna 11 that receives the transmission radio wave radiated from the antenna 100 to which the transmission radio wave signal is transmitted. Further, the control method of the antenna directivity estimation device 200 preferably includes an estimation step having the following configuration. The estimation unit 220 can execute the following processing when the received radio wave signal information input from the input unit 210 is information corresponding to a received radio wave or a transmission radio wave from a measurement point that has moved in a spiral direction on the outer peripheral circle of the antenna. That is, the estimation step can estimate the directivity of the antenna 100 in the circumferential direction of the concentric circle with respect to the central axis of the antenna 100 from the received radio signal wave information input in the input step. The received radio signal wave information is preferably generated from a received radio wave signal generated in the antenna 100 from a transmission radio wave radiated from the probe antenna 11. Alternatively, the received radio wave signal information is preferably generated from a received radio wave signal generated in the probe antenna 11 from a transmission radio wave radiated from the antenna 100.

[0106] According to the above configuration, without stopping the antenna under measurement, by correcting the received radio wave, the horizontal plane directivity characteristics on the same circumference of the antenna under measurement can be calculated, and the measurement time of the horizontal plane directivity with respect to the length direction of the antenna under measurement can be shortened.

[0107] A program for controlling an antenna directivity estimation apparatus according to an eighth aspect of the present disclosure is a program for causing a computer to execute the method for controlling the antenna directivity estimation apparatus according to the seventh aspect.

[0108] According to the above configuration, by simply adding or installing a program, it is possible to calculate the horizontal plane directivity characteristics on the same circumference of the antenna under measurement by correcting the received radio waves without stopping the antenna under measurement, and to shorten the measurement time.

[0109] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist thereof. For example, the antenna directivity estimation apparatus 200 can also be applied to antennas of different types from the antennas described above. Further, for example, the above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, it is possible to add, delete, or replace a part of the configuration of the above embodiment with other configurations.

[0110] In addition, each of the above configurations, functions, processing units, processing means, etc. may be realized in hardware by designing part or all of them, for example, by an integrated circuit. Also, each of the above configurations, functions, etc. may be realized in software by a processor interpreting and executing a program for realizing each function. Information such as programs, tables, and files for realizing each function can be stored in a recording device such as a memory, a hard disk, an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

[0111] Also, in each of the above figures, control lines and information lines show those considered necessary for explanation, and do not necessarily show all the control lines and information lines in actual implementation. In practice, it may be considered that almost all configurations are interconnected.

[0112] As described above, the invention made by the inventor has been specifically described based on the embodiments. However, it goes without saying that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof.

Explanation of Reference Numerals

[0113] 200... Antenna directivity estimation device, 210... Input unit, 220... Estimation unit, 221... Trigger signal generation unit, 222... Radiated radio wave information generation unit, 223... Received radio wave signal information analysis unit, 224... Inverse Fourier transform unit, 225... Measurement point correction unit, 226... Probe correction unit, 227... Coordinate conversion unit, 230... Output unit, 240... Storage unit, 1000... Antenna directivity estimation system

Claims

1. An output unit that outputs transmission radio wave signal information for generating a transmission radio wave signal transmitted to a plurality of probe antennas arranged circumferentially or an antenna movably arranged along the central axis of the circumference formed by the plurality of probe antennas; An input unit that inputs received radio wave signal information generated from a received radio wave signal generated in the antenna that receives the transmission radio wave radiated from the probe antenna to which the transmission radio wave signal is transmitted, or a received radio wave signal generated in the probe antenna that receives the transmission radio wave radiated from the antenna to which the transmission radio wave signal is transmitted; An estimation unit that estimates the directivity of the antenna in the circumferential direction of a concentric circle with respect to the central axis of the antenna from the received radio wave signal information generated from the received radio wave signal generated in the antenna, or the received radio wave signal information generated from the received radio wave signal generated in the probe antenna, when the received radio wave signal information input from the input unit includes information corresponding to the received radio wave or transmission radio wave from the measurement point where the antenna has moved along the central axis direction; An antenna directivity estimation device comprising the above.

2. The antenna directivity estimation device according to claim 1, wherein the estimation unit performs inverse Fourier transform in the central axis direction of the antenna after performing inverse Fourier transform in the central axis direction of the measurement point from the received radio wave signal information of the received radio wave received by the antenna from the probe antenna or the received radio wave signal information of the received radio wave received by the probe antenna from the antenna.

3. The antenna directivity estimation device according to claim 1 or 2, The probe antenna, The antenna, A positioner capable of performing an operation of moving the antenna so that the antenna passes through the inside of the probe antennas arranged concentrically in the central axis direction of the antenna; An antenna directivity estimation system comprising the above.

4. The correspondence relationship between the radio wave transmission / reception center position of each probe antenna that transmits or receives radio waves and is arranged in a circumferential shape, and the radio wave transmission / reception center position of the antenna that receives or transmits the radio wave is The antenna directivity estimation system according to claim 3, wherein the central angle between the transmission / reception center positions of adjacent probe antennas is the same as the central angle between the adjacent transmission / reception center positions of the antenna, and the distance in the Z-axis direction of the antenna between the adjacent transmission / reception center positions of the antenna is the same or different.

5. The antenna directivity estimation system according to claim 3 or 4, wherein the probe antenna is configured such that a horizontal polarization antenna and a vertical polarization antenna are attached so as to intersect so that the probe antenna can transmit and receive horizontal polarization radio waves and vertical polarization radio waves, and the antenna is also configured to be able to transmit and receive horizontal polarization radio waves and vertical polarization radio waves.

6. The antenna includes a low-band radiation element part and a high-band radiation element part, The frequency band of the radio waves transmitted and received from the high-band radiation element part is higher than the frequency band of the radio waves transmitted and received from the low-band radiation element part, and the frequency band of the high-band radiation element part includes the giga Hz band. The antenna directivity estimation system according to claim 3.

7. An output step of outputting transmission radio wave signal information for generating a transmission radio wave signal to an antenna arranged to be movable along the central axis of a circle formed by probe antennas arranged in a circumferential shape or to the probe antennas, and An input step of inputting received radio wave signal information generated from a received radio wave signal generated in the antenna that receives the transmission radio wave radiated from the probe antenna to which the transmission radio wave signal is transmitted, or from a received radio wave signal generated in the probe antenna that receives the transmission radio wave radiated from the antenna to which the transmission radio wave signal is transmitted. When the received radio wave signal information input in the input step is information corresponding to a received radio wave or a transmitted radio wave from a measurement point that has moved in a spiral direction on the outer peripheral circle of the antenna, an estimation step of estimating the directivity of the antenna in the circumferential direction of the concentric circle with respect to the central axis of the antenna from the received radio wave signal information generated from the received radio wave signal generated in the antenna or the received radio wave signal information generated from the received radio wave signal generated in the probe antenna; A control method for an antenna directivity estimation device comprising the above.

8. A program for causing a computer to execute the control method of the antenna directivity estimation device according to claim 7.

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