Radar system, method, and program

Abstract

To provide a radar system with space saving, a method, and a program.SOLUTION: According to an embodiment, a radar system includes a plurality of first radar modules, a plurality of second radar modules, and a processing unit. The processing unit causes one of the plurality of first radar modules to transmit a first radar signal and at least one of the plurality of second radar modules to transmit a second radar signal. A distance between the one first radar module and the at least one second radar module is more than twice a distance between the one first radar module and a furthest point from the one first radar module in a sensing area of the one first radar module.SELECTED DRAWING: Figure 21

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a radar system, method and program. [Background technology]

[0002] Integrated circuits with radar functions have been commercialized, making radar devices available at low cost. It is expected that radar devices will be applied in a wide variety of fields, such as automobiles, non-destructive testing, medicine, and security.

[0003] Commercially available radar integrated circuits can only accommodate a small number of antennas, which limits the aperture length of the antenna array and makes it difficult to improve spatial resolution.

[0004] In order to increase the number of applications of radar equipment, it is desirable to be able to easily adjust and expand the aperture length of the antenna array. One example of this is the installation of multiple modules equipped with multiple integrated circuits and antenna arrays.

[0005] As the aperture length of the antenna array increases, the number of antennas increases, requiring more installation space, making it difficult to install multiple modules. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2023-000084 A Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a space-saving radar system, method and program. [Means for solving the problem]

[0008] A radar system according to an embodiment includes a plurality of first radar modules, a plurality of second radar modules, and a processing unit. The first radar modules are capable of transmitting a plurality of first radar signals to a first area and receiving a plurality of first reflected signals obtained when the plurality of first radar signals are reflected by a first inspection object in the first area. The second radar module is capable of transmitting a plurality of second radar signals to a second area and receiving a plurality of second reflected signals obtained when the plurality of second radar signals are reflected by a second inspection object in the second area. The processing unit controls the transmission timing of the first radar module and the transmission timing of the second radar module. The processing unit causes one first radar module of the plurality of first radar modules to transmit the first radar signal, and causes at least one second radar module of the plurality of second radar modules to transmit the second radar signal. The distance between the one first radar module and at least one second radar module is more than twice the distance between the one first radar module and the point in the sensing range of the one first radar module that is farthest from the one first radar module. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating an example of a radar device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram for explaining an example of an IC according to the embodiment. [Diagram 3] FIG. 11 is a block diagram illustrating another example of a radar device according to an embodiment. [Figure 4] 1A and 1B are diagrams for explaining the principle of a walk-through type inspection device that is an application example of the radar device according to the embodiment. [Diagram 5] 4A and 4B are diagrams for explaining the direction in which radio waves are transmitted from a transmission module according to the embodiment and the direction in which radio waves are received from a reception module according to the embodiment. [Figure 6] FIG. 1 is a perspective view for explaining an example of a walk-through type inspection device, which is an application example of the radar device according to the embodiment. [Figure 7]1 is a schematic perspective view for explaining an example of a transmitting antenna or a receiving antenna according to an embodiment, which is configured as a SIW aperture antenna. [Figure 8] FIG. 2 is a schematic plan view for explaining an example of a transmitting antenna or a receiving antenna according to the embodiment. [Figure 9] 1 is a schematic cross-sectional view for explaining an example of a transmitting antenna or a receiving antenna according to an embodiment. [Figure 10] 1 is a schematic cross-sectional view for explaining an example of a transmitting antenna or a receiving antenna according to an embodiment. [Figure 11] FIG. 2 is a schematic perspective view for explaining an example of a receiving antenna or a transmitting antenna according to an embodiment, which is configured as a dipole antenna with a reflector. [Figure 12] FIG. 2 is a schematic plan view for explaining an example of a receiving antenna or a transmitting antenna according to the embodiment. [Figure 13] 7 is a block diagram for explaining an example of an electrical configuration of the radar device shown in FIG. 6. [Figure 14] FIG. 13 is a perspective view for explaining another example of a walk-through type inspection device that is an application example of the radar device according to the embodiment. [Figure 15] FIG. 11 is a block diagram for explaining an example of an electrical configuration of another example of an inspection apparatus according to an embodiment. [Figure 16] FIG. 4 is a diagram for explaining an example of a transmission and reception sequence of the inspection apparatus according to the embodiment. [Figure 17] 11 is a diagram for explaining another example of the transmission and reception sequence of the inspection apparatus according to the embodiment. FIG. [Figure 18] FIG. 13 is a perspective view for explaining still another example of the walk-through type inspection apparatus according to the embodiment. [Figure 19] FIG. 11 is a diagram for explaining one possibility of interference occurring in yet another example of the inspection apparatus according to the embodiment. [Figure 20] 13A and 13B are diagrams for explaining another possibility that interference may occur in yet another example of the inspection apparatus according to the embodiment. [Figure 21] FIG. 11 is a diagram for explaining an example of interference in yet another example of the inspection apparatus according to the embodiment. [Figure 22] FIG. 11 is a diagram for explaining an example of a condition in which no interference occurs in yet another example of the inspection apparatus according to the embodiment. [Figure 23] 13 is a diagram for explaining another example of the condition in which no interference occurs in still another example of the inspection apparatus according to the embodiment. FIG. [Figure 24] FIG. 11 is a block diagram for explaining an example of an electronic circuit of still another example of the inspection device according to the embodiment. [Diagram 25] FIG. 11 is a block diagram for explaining a detailed example of an electronic circuit of still another example of the inspection device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments will be described with reference to the drawings. The following description is an example of an apparatus and method for embodying the technical idea of ​​the embodiment, and the technical idea of ​​the embodiment is not limited to the structure, shape, arrangement, material, etc. of the components described below. Modifications that a person skilled in the art can easily conceive are naturally included in the scope of the disclosure. In order to make the description clearer, the size, thickness, planar dimensions, or shape of each element may be changed from the actual embodiment and shown diagrammatically. Elements having different dimensional relationships or ratios may be included in multiple drawings. In multiple drawings, corresponding elements may be given the same reference numerals and duplicated descriptions may be omitted. Some elements may be given multiple names, but these examples of names are merely examples and do not deny the use of other names for these elements. In addition, it is not denied that elements not given multiple names may be given other names. In the following description, "connection" may include not only direct connection but also connection via other elements.

[0011] FIG. 1 is a block diagram for explaining an example of a radar device 110 according to an embodiment. The radar device 110 is configured by a module equipped with an integrated circuit having a radar function. The module includes a transmitting radar module 10 that performs a transmitting function, a receiving module 20 that performs a receiving function, and a signal generating module 30 that generates a reference signal and a clock signal. FIG. 1 shows an example in which there is only one transmitting module 10 and one receiving module 20. The embodiment also includes an example in which there are multiple transmitting modules 10 and multiple receiving modules 20. By connecting multiple transmitting modules 10 and multiple receiving modules 20 together and connecting them to a single signal generating module 30, it is possible to easily realize synchronous control of multiple integrated circuits and adjustment and expansion of the aperture length of the antenna array.

[0012] The radar device 110 also includes a processor 90. The processor 90 is connected to the transmitting module 10, the receiving module 20, and the signal generating module 30. The processor 90 includes a CPU 92, a ROM 96, and a RAM 98. The ROM 96 stores a program for controlling the radar device 110. The RAM 98 temporarily stores various data during operation. The CPU 92 executes the program to provide the functions of a scheduler 94 and an image generating module 95. The scheduler 94 generates a trigger signal for controlling the transmission timing. The image generating module 95 generates an image of the inspection object based on the received signal from the receiving module 20.

[0013] The signal generating module 30 generates a signal for controlling transmission and reception of a radar signal according to a radar method. One example of the radar method is a Linear Frequency Modulated Continuous Wave (L-FMCW) method in which the frequency increases linearly with time. The signal generating module 30 includes an integrated circuit (hereinafter referred to as IC) 32 having a radar function of the L-FMCW method, and a distributor 34. Other examples of the radar method include an unmodulated CW method and a pulse method. The embodiment is not limited to the radar method, and can be applied to other radar methods.

[0014] The IC 32 generates a clock signal and an L-FMCW signal (hereinafter referred to as a chirp signal) as a reference signal. When there is no need to distinguish between the chirp signal and the clock signal, these signals are simply referred to as "signals".

[0015] The transmitting module 10 and the receiving module 20 operate according to a clock signal output by the signal generating module 30. Therefore, the transmitting module 10 and the receiving module 20 operate in synchronization with each other.

[0016] The output signal of IC 32 is input to a distributor 34. The distributor 34 distributes the input signal to two output terminals. A first output signal of the distributor 34 is supplied to the transmitting module 10. A second output signal of the distributor 34 is supplied to the receiving module 20. A clock signal from the single signal generating module 30 is supplied to the transmitting module 10 and the receiving module 20, so that the transmitting operation and the receiving operation are synchronized.

[0017] The transmitting module 10 includes a plurality of ICs 12 having an L-FMCW radar transmission function, a plurality of transmitting antennas 16, and a plurality of distributors 18. The transmitting module 10 may include a substrate (not shown), on which the plurality of ICs 12, the plurality of transmitting antennas 16, and the plurality of distributors 18 are formed. The number of ICs 12 is, for example, four. The number of transmitting antennas 16 is, for example, sixteen. The number of distributors 18 is, for example, three. The distributor 18 distributes an input signal to two output terminals.

[0018] The signal from the distributor 34 is input to the distributor 18c. The distributor 18c distributes the input signal to two output terminals. The first output signal of the distributor 18c is input to the distributor 18a. The second output signal of the distributor 18c is input to the distributor 18b.

[0019] The distributor 18a distributes an input signal to two output terminals. A first output signal of the distributor 18a is input to IC12a. A second output signal of the distributor 18a is input to IC12b. IC12a is connected to four transmitting antennas 16a, 16b, 16c, and 16d. IC12b is connected to four transmitting antennas 16e, 16f, 16g, and 16h.

[0020] The distributor 18b distributes the input signal to two output terminals. A first output signal of the distributor 18b is input to IC12c. A second output signal of the distributor 18b is input to IC12c. IC12c is connected to four transmitting antennas 16i, 16j, 16k, and 16l. IC12d is connected to four transmitting antennas 16m, 16n, 16o, and 16p.

[0021] A clock signal from the signal generating module 30 is supplied to IC12a-IC12d. The transmission operations of IC12a-IC12d are synchronized based on the clock signal. IC12a transmits radio waves (hereinafter referred to as radar signals) corresponding to the chirp signal from transmitting antennas 16a-16d to the target. IC12b transmits radar signals corresponding to the chirp signal from transmitting antennas 16e-16h to the target. IC12c transmits radar signals corresponding to the chirp signal from transmitting antennas 16i-16l to the target. IC12d transmits radar signals corresponding to the chirp signal from transmitting antennas 16m-16p to the target.

[0022] The number of transmitting antennas connected to each of the ICs 12a-12 is not limited to four, but may be two, six or more, or an odd number. The number of transmitting antennas connected to each of the ICs 12a-12d is not limited to the same number, but may be different for each IC. The intervals between all adjacent antennas (e.g., 16a and 16b) among the transmitting antennas 16a-16p may be set to a constant interval or may be set to multiple intervals that are mutually prime. An example of the constant interval is one wavelength or a half wavelength.

[0023] The receiving module 20 includes a plurality of ICs 22 having an L-FMCW radar receiving function, a plurality of receiving antennas 26, and a plurality of distributors 28. The receiving module 20 may include a substrate (not shown), on which the ICs 22, the plurality of receiving antennas 26, and the plurality of distributors 28 are formed. The number of ICs 22 is, for example, four. The number of receiving antennas 26 is, for example, sixteen. The number of distributors 28 is, for example, three. The distributor 28 distributes an input signal to two output terminals.

[0024] The signal from the distributor 34 is input to the distributor 28c. The distributor 28c distributes the input signal to two output terminals. The first output signal of the distributor 28c is input to the distributor 28a. The second output signal of the distributor 28c is input to the distributor 28b.

[0025] The distributor 28a distributes an input signal to two output terminals. A first output signal of the distributor 28a is input to IC22a. A second output signal of the distributor 28a is input to IC22b. IC22a is connected to four receiving antennas 26a, 26b, 26c, and 26d. IC22b is connected to four receiving antennas 26e, 26f, 26g, and 26h.

[0026] The distributor 28b distributes the input signal to two output terminals. A first output signal of the distributor 28b is input to IC22c. A second output signal of the distributor 28b is input to IC22c. IC22c is connected to four receiving antennas 26i, 26j, 26k, and 26l. IC22d is connected to four receiving antennas 26m, 26n, 26o, and 26p.

[0027] A clock signal from the signal generating module 30 is provided to ICs 22a-22d. ICs 22a-22d perform synchronized receiving operations based on the clock signal. IC 22a processes signals received by receiving antennas 26a-26d in response to the chirp signal. IC 22b processes signals received by receiving antennas 26e-26h in response to the chirp signal. IC 22c processes signals received by receiving antennas 26i-26l in response to the chirp signal. IC 22d processes signals received by receiving antennas 26m-26p in response to the chirp signal.

[0028] The number of receiving antennas connected to each of the ICs 22a-22d is not limited to four, but may be two, six or more, or an odd number. The number of receiving antennas connected to each of the ICs 22a-22d is not limited to the same number, but may be different for each IC. The intervals between all adjacent antennas (e.g., 26a and 26b) among the receiving antennas 26a-26p may be set to a constant interval, or may be set to multiple intervals that are mutually prime. An example of the constant interval is one wavelength or a half wavelength.

[0029] The transmitting module 10, the receiving module 20, and the signal generating module 30 are connected to a processor 90. The processor 90 is a device at a higher level than the radar device 110. The processor 90 may perform beamforming processing of the transmitting beam and the receiving beam. The processor 90 performs initial setting and timing control of the transmitting module 10. The processor 90 may perform array signal processing of the received signal to detect the presence or absence of belongings, the direction of the belongings, the distance to the belongings, and the type of the belongings, and may display an image of the belongings. In this case, the CPU 92 has the function of an image generating module in addition to the function of the scheduler 94.

[0030] The spatial resolution required for direction estimation and image display of the radar device 110 using an antenna array consisting of multiple antennas is determined by the number of antennas. Only a limited number of antennas can be connected to one IC 12, 22 having a radar function, and the spatial resolution cannot be increased. In the embodiment, a plurality of ICs, for example, four ICs 12a-12d, are cascaded to realize a transmitting antenna array consisting of 16 antennas 16a-16p. A plurality of ICs, for example, four ICs 22a-22d, are cascaded to realize a receiving antenna array consisting of 16 antennas 26a-26p. Each of the transmitting antenna array and the receiving antenna array is a multiple-input multiple-output (MIMO) antenna. This allows the spatial resolution of the radar device 110 to be four times that of a case in which one IC 12 is used in the transmitting module 10 and one IC 22 is used in the receiving module 20.

[0031] Each of IC12a-12d, IC22a-22d, and IC32 may be a dedicated IC, but the same IC may also be used in common.

[0032] 2 is a block diagram for explaining an example of a single IC 38 used in common as each of the ICs 12a-12d, ICs 22a-22d, and IC 32 according to the embodiment. The IC 38 includes a transmitting circuit 40, a receiving circuit 50, and a signal generating circuit 60.

[0033] The signal generating circuit 60 includes an oscillator 62 and a clock generator 64. The oscillator 62 generates a chirp signal. The output signal of the signal generating circuit 60 is outputted to the outside of the IC 38 via an output terminal 60a.

[0034] The transmitting circuit 40 includes transmitting amplifiers 42a, 42b, 42c, 42d, distributors 44a, 44b, 44c, and a control unit 46. A chirp signal and a clock signal are input to the input terminal 40a from outside the IC 38. A trigger signal is input to the control unit 46 from the processor 90. The processor 90 sequentially supplies the trigger signal to the control unit 45 of the transmitting circuit 40 that starts transmission.

[0035] The clock signal is input to the control unit 46. The control unit 46 controls the operation timing of each transmitting amplifier 42 based on the clock signal and the trigger signal. The chirp signal is input to the distributor 44c. The distributor 44c supplies the chirp signal to distributors 44a and 44b. The distributor 44a supplies the chirp signal from the distributor 44c to the transmitting amplifiers 42a and 42b. The distributor 44b supplies the chirp signal from the distributor 44c to the transmitting amplifiers 42c and 42d.

[0036] The transmitting amplifiers 42a-42d are respectively connected to the four transmitting antennas 16. This causes the four transmitting antennas 16 to radiate radar signals corresponding to the chirp signals.

[0037] An example of the radio wave as a radar signal used in the embodiment is a radio wave with a wavelength of 1 to 30 millimeters. Radio waves with a wavelength of 1 to 10 millimeters are also called millimeter waves, and radio waves with a wavelength of 10 to 100 millimeters are also called microwaves. Another example of the radio wave is a radio wave with a wavelength of 100 micrometers to 1 millimeter, called a terahertz wave.

[0038] The distributor 44a is installed at a position approximately equidistant from the transmitting amplifier 42a and the transmitting amplifier 42b. Therefore, the length of the signal line S11 between the distributor 44a and the transmitting amplifier 42a can be easily made equal to the length of the signal line S12 between the distributor 44a and the transmitting amplifier 42b. The distributor 44b is installed at a position approximately equidistant from the transmitting amplifier 42c and the transmitting amplifier 42d. Therefore, the length of the signal line S13 between the distributor 44b and the transmitting amplifier 42c can be easily made equal to the length of the signal line S14 between the distributor 44b and the transmitting amplifier 42d. The distributor 44c is installed at a position approximately equidistant from the distributor 44a and the distributor 44b. Therefore, the length of the signal line S15 between the distributor 44c and the distributor 44a can be easily made equal to the length of the signal line S16 between the distributor 44c and the distributor 44b.

[0039] In this way, by splitting the signal from the input terminal 40a into two signals by the splitter 44c and then splitting each of the two split signals into two signals, the signal lines between the input terminal 40a and the four transmitting amplifiers 42a-42d can be easily made equal in length. This makes it possible to suppress the variation in the transmission delay of the four chirp signals input to the four transmitting amplifiers 42a-42d, and to accurately control the directivity of the transmitting antenna array. If the signal from the input terminal 40a is split into four by one splitter, the signal lines must be routed in a detour in order to make the four signal lines equal in length, which makes it difficult to increase the integration density of the IC.

[0040] The receiving circuit 50 includes receiving amplifiers 52a, 52b, 52c, and 52d, mixers 54a, 54b, 54c, and 54d, A / D converters (ADCs) 56a, 56b, 56c, and 56d, distributors 58a, 58b, and 58c, and a control unit 59. A chirp signal and a clock signal from outside the IC 38 are input to the input terminal 50a.

[0041] The clock signal is input to the control unit 59. The control unit 59 controls the operation timing of the receiving circuit 50 based on the clock signal. This synchronizes the operations of the transmitting circuit 40 and the receiving circuit 50. The control unit 59 simultaneously operates the receiving amplifiers connected to all of the receiving antennas 26a-26p.

[0042] The chirp signal is input to a distributor 58c. The four receiving antennas 26 are connected to receiving amplifiers 52a-52d, respectively.

[0043] The outputs of the receiving amplifiers 52a-52d are supplied to the ADCs 56a-56d via the mixers 54a-54d, respectively.

[0044] The distributor 58c supplies the chirp signal and the clock signal from the input terminal 50a to distributors 58a and 58b. The distributor 58a supplies the chirp signal from the distributor 58c to the mixers 54a and 54b, and supplies the clock signal from the distributor 58c to the ADCs 56a and 56b. The distributor 58b supplies the chirp signal from the distributor 58c to the mixers 54c and 54d, and supplies the clock signal from the distributor 58c to the ADCs 56c and 56d.

[0045] The mixers 54a-54d use the chirp signal to convert the RF signals from the receiving amplifiers 52a-52d into IF band receiving signals, and the ADCs 56a-56d convert the IF band receiving signals into digital signals in synchronization with a clock signal.

[0046] The digital signals from the ADCs 56a-56d are supplied to a processor 90 via output terminals (not shown).

[0047] The distributor 58a is installed at a position approximately equidistant from the mixers 54a and 54b and from the ADCs 56a and 56b. Therefore, the length of the signal line S21 between the distributor 58a and the mixer 54a can be easily made equal to the length of the signal line S22 between the distributor 58a and the mixer 54b, and the length of the signal line S23 between the distributor 58a and the ADC 56a can be easily made equal to the length of the signal line S24 between the distributor 58a and the ADC 56b.

[0048] The distributor 58b is installed at a position approximately equidistant from the mixers 54c and 54d and from the ADCs 56c and 56d. Therefore, the length of the signal line S25 between the distributor 58b and the mixer 54c can be easily made equal to the length of the signal line S26 between the distributor 58b and the mixer 54d, and the length of the signal line S27 between the distributor 58b and the ADC 56c can be easily made equal to the length of the signal line S28 between the distributor 58b and the ADC 56d.

[0049] The distributor 58c is installed at a position approximately equidistant from the distributors 58a and 58b, so that the length of the signal line S29 between the distributors 58c and 58a can easily be made equal to the length of the signal line S30 between the distributors 58c and 58b.

[0050] In this way, by dividing the signal from the input terminal 50a into two signals by the distributor 58c and further dividing each of the two divided signals into two signals, the signal lines between the input terminal 50a and the four mixers 54a-54d can be easily made equal in length, and the signal lines between the input terminal 50a and the four ADCs 56a-56d can be easily made equal in length. This makes it possible to suppress the variation in the transmission delay of the four chirp signals input to each of the four mixers 54a-54d, and to convert the RF signal into an IF signal without causing a phase shift. Furthermore, it is possible to suppress the variation in the timing shift of the four clock signals input to each of the four ADCs 56a-56d, and to convert the IF signal into a digital signal with the correct timing. If the signal from the input terminal 50a is divided into four, in order to make the four signal lines equal in length, the signal lines must be routed in a detour, and the integration density of the integrated circuit cannot be increased.

[0051] Fig. 3 is a block diagram for explaining another example of the radar device 120 according to the embodiment. Fig. 1 shows an example in which the number of antennas in the transmit / receive antenna array is 16. Fig. 3 shows an example in which the number of antennas in the transmit / receive antenna array is 64. The radar device 120 includes a transmitting unit 122, a receiving unit 124, a signal generating module 30, and a processor 90.

[0052] A signal generating module 30 is connected to the transmitting unit 122 and the receiving unit 124. A clock signal from the single signal generating module 30 is provided to the transmitting unit 122 and the receiving unit 124 so that the transmitting and receiving operations can be synchronized.

[0053] The transmitting unit 122 includes transmitting modules 10a, 10b, 10c, and 10d and distributors 130a, 130b, and 130c. Each of the transmitting modules 10a, 10b, 10c, and 10d is equivalent to the transmitting module 10 shown in FIG. 1. Each of the transmitting modules 10a, 10b, 10c, and 10d includes 16 transmitting antennas 16. The transmitting unit 122 includes 64 transmitting antennas 16. The number of transmitting modules 10 included in the transmitting unit 122 is not limited to four, and may be any number as long as it is plural.

[0054] The distributor 130c supplies the signals (chirp signal and clock signal) from the signal generating module 30 to the distributors 130a and 130b. The distributor 130a supplies the signal from the distributor 130c to the transmitting modules 10a and 10b. The distributor 130b supplies the signal from the distributor 130c to the transmitting modules 10c and 10d.

[0055] The distributor 130c is installed at a position approximately equidistant from the distributors 130a and 130b. The distributor 130a is installed at a position approximately equidistant from the transmitting modules 10a and 10b. The distributor 130b is installed at a position approximately equidistant from the transmitting modules 10c and 10d. For this reason, the chirp signal from the signal generating module 30 is supplied to each of the transmitting modules 10a-10d via signal lines of approximately equal length. The operations of the transmitting modules 10a-10d are synchronized based on the clock signal from the signal generating module 30.

[0056] The receiving unit 124 includes receiving modules 20a, 20b, 20c, and 20d and distributors 132a, 132b, and 132c. Each of the receiving modules 20a, 20b, 20c, and 20d is equivalent to the receiving module 20 shown in FIG. 1. Each of the receiving modules 20a, 20b, 20c, and 20d includes 16 receiving antennas. The receiving unit 124 includes 64 receiving antennas 26. The number of receiving modules 20 included in the receiving unit 124 is not limited to four, and may be any number as long as it is plural. The distributor 132c supplies signals (chirp signals and clock signals) from the signal generating module 30 to the distributor 132a and the distributor 132b. The distributor 132a supplies signals from the distributor 132c to the receiving module 20a and the receiving module 20b. The distributor 132b supplies the signal from the distributor 132c to the receiving module 20c and the receiving module 20d.

[0057] The distributor 132c is installed at a position approximately equidistant from the distributors 132a and 132b. The distributor 132a is installed at a position approximately equidistant from the receiving modules 20a and 20b. The distributor 132b is installed at a position approximately equidistant from the receiving modules 20c and 20d. For this reason, the chirp signal and the clock signal from the signal generating module 30 are supplied to each of the receiving modules 20a-20d via signal lines of approximately equal length. The operations of the receiving modules 20a-20d are synchronized based on the clock signal from the signal generating module 30.

[0058] The transmitting modules 10 a , 10 b , 10 c , and 10 d , the receiving modules 20 a , 20 b , 20 c , and 20 d , and the signal generating module 30 are connected to a processor 90 .

[0059] 3 operates 64 transmitting antennas 16 using 16 ICs 12, and operates 64 receiving antennas 26 using 16 ICs 22. Therefore, the radar device 120 can achieve four times the spatial resolution as compared with the radar device 110, which operates 16 transmitting antennas 16 using four ICs 12, and operates 16 receiving antennas 26 using four ICs 22.

[0060] One application example of the radar devices 110 and 120 according to the embodiment is a security system that inspects the belongings of an inspection target. Examples of places where this system is installed include near the entrance gate of an area where security is desired to be maintained, such as a station, an amusement park, a concert hall, or a building. This system inspects the inspection target when the inspection target passes through the entrance gate, and prevents the inspection target carrying a specific item from entering the area. It is not preferable to make the inspection target stop for the inspection. Therefore, a walk-through type inspection device that irradiates radio waves to the inspection target passing through the gate is preferable.

[0061] Fig. 4 is a diagram for explaining the principle of a walk-through type inspection device, which is an application example of the radar device according to the embodiment. Fig. 4 shows an example of a walk-through type inspection device to which the radar device 120 shown in Fig. 3 is applied. The radar device 110 shown in Fig. 1 can also be applied to the walk-through type inspection device.

[0062] The inspection device inspects belongings of inspection subject 140 walking along passage 142. Passage 142 is also referred to as an inspection lane. A left housing 144 is installed on the left side of passage 142. A right housing 146 is installed on the right side of passage 142. In this specification, right and left are the right and left as seen from inspection subject 140 walking along passage 142. Left housing 144 and right housing 146 are formed of a material that does not absorb or reflect radio waves, such as resin.

[0063] The transmitting unit 122 shown in FIG. 3 is divided into two parts. Here, the transmitting modules 10a, 10b constitute the first part, and the transmitting modules 10c, 10d constitute the second part. The number of transmitting modules 10 does not have to be divided evenly. For example, the transmitting unit 122 may be divided into three transmitting modules and one transmitting module. The transmitting modules 10a, 10b of the first part are installed in the left housing 144. The transmitting modules 10c, 10d of the second part are installed in the right housing 146.

[0064] The receiving unit 124 shown in FIG. 3 is divided into two parts. Here, the receiving modules 20a and 20b constitute a first part, and the receiving modules 20c and 20d constitute a second part. The number of receiving modules 20 does not have to be divided evenly. For example, the receiving unit 124 may be divided into three receiving modules and one receiving module. The receiving modules 20a and 20b of the first part are installed in the left housing 144. The receiving modules 20c and 20d of the second part are installed in the right housing 146.

[0065] 4 does not specifically show the installation locations / orientations of the transmitting module 10 and the receiving module 20 in the left housing 144 and the right housing 146. The installation locations / orientations of the transmitting module 10 and the receiving module 20 in the left housing 144 and the right housing 146 may be arbitrary, and can be determined according to specifications such as the spatial resolution and performance to be achieved.

[0066] 5 is a diagram for explaining the direction of radio waves transmitted by the transmitting module 10 (transmitting antenna 16) according to the embodiment and the direction of radio waves received by the receiving module 20 (receiving antenna 26) according to the embodiment. The direction of radio waves is represented by the direction of the main lobe in the radiation pattern of the antenna.

[0067] The direction of radio waves transmitted from the transmitting module 10 (transmitting antenna 16) in the left housing 144 is to the right, so that the target inspection area is the passage 142. The direction of radio waves received from the receiving module 20 (receiving antenna 26) in the left housing 144 is to the right, so that the target inspection area is the passage 142.

[0068] The direction of radio waves transmitted from the transmitting module 10 (transmitting antenna 16) in the right housing 146 is directed leftward so that the passage 142 is the target inspection area. The direction of radio waves received from the receiving module 20 (receiving antenna 26) in the right housing 146 is directed leftward so that the passage 142 is the target inspection area.

[0069] The rightward and leftward directions are not limited to a single angle, but are determined by an angle range. For example, if the circumference is 360 degrees and 0 degrees is the direction of travel of the object, then the rightward direction is +90 degrees and the leftward direction is +270 (-90) degrees. The rightward direction is within the angle range of +90 degrees ±90 degrees, and the leftward direction is within the angle range of +270 degrees ±90 degrees.

[0070] FIG. 6 is a perspective view for explaining an example of a walk-through type inspection device, which is an application example of the radar device 120 according to the embodiment.

[0071] In the left housing 144, the boards of the transmitting modules 10a and 10b are installed parallel to the surface of the passage 142, i.e., horizontally. The boards of the receiving modules 20a and 20b are installed perpendicular to the surface of the passage 142, i.e., vertically. The transmitting modules 10a, 10b and the receiving modules 20a, 20b are installed so as to form a radar module 262 in the shape of a rectangular prism.

[0072] In the transmitting modules 10a and 10b, 16 transmitting antennas 16 are arranged in a row at one end of the transmitting modules 10a and 10b (substrates). In the receiving modules 20a and 20b, 16 receiving antennas 26 are arranged in a row at one end of the receiving modules 20a and 20b (substrates).

[0073] The transmitting modules 10a, 10b in the left housing 144 are installed in an orientation such that the transmitting antenna 16 faces the passageway 142. The receiving modules 20a, 20b in the left housing 144 are installed in an orientation such that the receiving antenna 26 faces the passageway 142.

[0074] The above-mentioned arrangement of the transmitting modules 10a, 10b and the receiving modules 20a, 20b is one example, and they may be arranged in other arrangements, for example, in one or two linear rows, or simply in four rows. The transmitting antennas 16 and the receiving antennas 26 in the radar module 262 may also be arranged in other arrangements, for example, in one or two linear rows, or simply in four rows. Furthermore, multiple radar modules 262 may be installed in the housing 144 along the length direction (the direction in which the inspection object 140 travels) or height direction of the passage 142.

[0075] Also located within the left housing 144 are distributors 130, 132.

[0076] In the right housing 146, the boards of the transmitting modules 10c and 10d are installed parallel to the surface of the passage 142, i.e., horizontally. The boards of the receiving modules 20c and 20d are installed perpendicular to the surface of the passage 142, i.e., vertically. The transmitting modules 10c and 10d and the receiving modules 20c and 20d are installed so as to form a radar module 264 in the shape of a rectangular prism.

[0077] In the transmitting modules 10c and 10d, 16 transmitting antennas 16 are arranged in a row at one end of the transmitting modules 10c and 10d (substrates). In the receiving modules 20c and 20d, 16 receiving antennas 26 are arranged in a row at one end of the receiving modules 20c and 20d (substrates).

[0078] The transmitting modules 10c and 10d in the right housing 146 are installed in an orientation such that the transmitting antenna 16 faces the passageway 142. The receiving modules 20c and 20d in the right housing 146 are installed in an orientation such that the receiving antenna 26 faces the passageway 142.

[0079] The above-mentioned arrangement of the transmitting modules 10c, 10d and the receiving modules 20c, 20d is merely an example, and they may be arranged in other arrangements, for example, in one or two linear rows, or simply in four rows. The transmitting antennas 16 and the receiving antennas 26 in the radar module 264 may also be arranged in other arrangements, for example, in one or two linear rows, or simply in four rows. Furthermore, multiple radar modules 264 may be installed in the housing 146 along the length or height of the passage 142.

[0080] Also located within the right housing 146 are distributors 130, 132.

[0081] The signal generating module 30 is connected to the distributors 130c and 132c. A clock signal output from the signal generating module 30 is supplied to the transmitting unit 122 and the receiving unit 124. Therefore, the ICs 12 and 22 operate in synchronization with each other.

[0082] A radar signal transmitted from one of the transmitting antennas 16 in the transmitting modules 10a, 10b in the left housing 144 propagates toward the passage 142 and is reflected by a left area of ​​the inspection target 140 on the passage 142. A reflected wave of the radar signal (hereinafter referred to as a reflected signal) propagates toward the left housing 144. The reflected signal is received by all of the receiving antennas 26 of the receiving modules 20a, 20b in the left housing 144. The receiving modules 20a, 20b process the received signal and supply the processed received signal to the processor 90. The processor 90 inspects belongings in the left area of ​​the inspection target 140 based on the received signal. The processor 90 may generate an image of the inspection target 140 based on the received signal and inspect the belongings based on the image.

[0083] A radar signal transmitted from one of the transmitting antennas 16 in the transmitting modules 10c, 10d in the right housing 146 propagates toward the passage 142 and is reflected by a right area of ​​the inspection target 140 on the passage 142. The reflected signal propagates toward the right housing 146. The reflected signal is received by all of the receiving antennas 26 in the receiving modules 20c, 20d in the right housing 146. The receiving modules 20c, 20d process the received signal and provide the processed received signal to the processor 90. The processor 90 inspects belongings in the right area of ​​the inspection target 140 based on the received signal. The processor 90 may generate an image of the inspection target 140 based on the received signal and inspect the belongings based on the image.

[0084] 6 shows an example in which the antennas 16, 26 and the ICs 12, 22 (including the distributors 130, 132) are integrally formed on a module substrate. The antennas 16, 26 and the ICs 12, 22 (including the distributors 130, 132) may be formed on separate substrates.

[0085] Examples of the transmitting antenna 16 and the receiving antenna 26 according to the embodiment are a patch antenna, a dipole antenna with a reflector, or a SIW (Substrate Integrated Waveguide) aperture antenna. A dipole antenna with a reflector transmits and receives polarized waves parallel to the substrate. A SIW aperture antenna transmits and receives polarized waves perpendicular to the substrate. As shown in FIG. 6, when one of the transmitting antenna array and the receiving antenna array is installed horizontally and the other of the transmitting antenna array and the receiving antenna array is installed vertically, one antenna array is either a dipole antenna with a reflector or a SIW aperture antenna, and the other antenna array is either a SIW aperture antenna or a dipole antenna with a reflector.

[0086] FIG. 7 is a schematic perspective view for explaining an example of the transmitting antenna 16 or the receiving antenna 26 according to the embodiment, which is configured by a SIW aperture antenna. FIG. 8 is a schematic plan view for explaining an example of the transmitting antenna 16 or the receiving antenna 26 according to the embodiment. FIG. 9 is a schematic cross-sectional view for explaining an example of the transmitting antenna 16 or the receiving antenna 26 according to the embodiment. FIG. 9 is a cross-sectional view taken along the line A1-A2 in FIG. 8. FIG. 10 is a schematic cross-sectional view for explaining an example of the transmitting antenna 16 or the receiving antenna 26 according to the embodiment. FIG. 10 is a cross-sectional view taken along the line A3-A4 in FIG. 8.

[0087] The substrate 318 includes a plurality of antennas 315. The antennas 315 include a first structure 310W. The first structure 310W is a SIW. The antennas 315 are SIW aperture antennas.

[0088] The first structure 310W includes a first waveguide conductive layer 316f, a first other waveguide conductive layer 316g, a plurality of first waveguide electrode members 316a, and a plurality of second waveguide electrode members 316b. The direction from the first other waveguide conductive layer 316g to the first waveguide conductive layer 316f is along a third direction D3. As shown in FIG. 8, the direction from the plurality of first waveguide electrode members 316a to the plurality of second waveguide electrode members 316b is along a second direction D2.

[0089] The first waveguide conductive layer 316f and the first other waveguide conductive layer 316g are electrically connected by a plurality of first waveguide electrode members 316a and a plurality of second waveguide electrode members 316b. The first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other. The third direction D3 may be referred to as the X-axis direction. In that case, the second direction D2 is referred to as the Y-axis direction, and the first direction D1 is referred to as the Z-axis direction.

[0090] The first structure 310W may further include a third waveguide electrode member 316c and a fourth waveguide electrode member 316d. The third waveguide electrode member 316c is electrically connected to the first waveguide conductive layer 316f and the first other waveguide conductive layer 316g. The fourth waveguide electrode member 316d is electrically connected to the first waveguide conductive layer 316f and the first other waveguide conductive layer 316g. The distance between the third waveguide electrode member 316c and the fourth waveguide electrode member 316d along the second direction D2 is shorter than the distance between the plurality of first waveguide electrode members 316a and the plurality of second waveguide electrode members 316b along the second direction D2. The first structure 310W may not include the third waveguide electrode member 316c and the fourth waveguide electrode member 316d.

[0091] A portion of the substrate 318 lies between the first waveguide conductive layer 316f and the first other waveguide conductive layer 316g, and between the first plurality of waveguide electrode members 316a and the second plurality of waveguide electrode members 316b.

[0092] The first structure 310W includes an opening 310o. The opening 310o is provided at an end of the first structure 310W in the first direction D1. The opening 310o functions as an opening antenna. Radio waves are emitted from the opening 310o.

[0093] The antenna 315 may include a director 315W. The director 315W includes a first conductive layer 315c, a first other conductive layer 315d, a first electrode member 315a, and a first other electrode member 315b. The direction from the first other conductive layer 315d to the first conductive layer 315c is along the third direction D3. The direction from the first other electrode member 315b to the first electrode member 315a is along the second direction D2. The first conductive layer 315c and the first other conductive layer 315d are electrically connected to each other by the first electrode member 315a and the first other electrode member 315b.

[0094] At least a portion of the substrate 318 is between the first conductive layer 315c and the first other conductive layer 315d, and between the first electrode member 315a and the first other electrode member 315b.

[0095] The position of the third waveguide electrode member 316c in the first direction D1 is between the position of the first conductive layer 315c in the first direction D1 and the position of the first waveguide electrode members 316a in the first direction D1. The position of the fourth waveguide electrode member 316d in the first direction D1 is between the position of the first conductive layer 315c in the first direction D1 and the position of the second waveguide electrode members 316b in the first direction D1. The first waveguide electrode members 316a and the second waveguide electrode members 316b forming the opening 310o may face one of the directors 315W. The third waveguide electrode member 316c and the fourth waveguide electrode members 316d forming the opening 310o may face one of the directors 315W.

[0096] The direction from the first waveguide conductive layer 316f to the first conductive layer 315c is along the first direction D1. The direction from the first other waveguide conductive layer 316g to the first other conductive layer 315d is along the first direction D1. The first other waveguide conductive layer 316g may be at a fixed potential (e.g., ground potential), for example.

[0097] The substrate 318 includes a first surface 318f and a first other surface 318g. The direction from the first other surface 318g to the first surface 318f is along the third direction D3. The first conductive layer 315c is provided on the first surface 318f. The first other conductive layer 315d is provided on the first other surface 318g. One of the multiple directors 315W extending in the substrate 318 along the third direction D3 can be coupled to one of the multiple first structures 310W.

[0098] Fig. 11 is a schematic perspective view for explaining an example of the receiving antenna 26 or the transmitting antenna 16 according to the embodiment, which is configured as a dipole antenna with a reflector. Fig. 12 is a schematic plan view for explaining an example of the receiving antenna 26 or the transmitting antenna 16 according to the embodiment.

[0099] The substrate 328 includes a plurality of antennas 325. The antenna 325 includes a second conductive layer 325a. At least a portion of the second conductive layer 325a extends along the third direction D3. The antenna 325 may include a second other conductive layer 325b. At least a portion of the second other conductive layer 325b extends along the third direction D3. The direction from the second other conductive layer 325b to the second conductive layer 325a is along the third direction D3. The second conductive layer 325a and the second other conductive layer 325b configure a dipole antenna. The antenna 325 is a dipole antenna with a reflector.

[0100] The second conductive layer 325a and the second other conductive layer 325b are provided on a second surface 328f of the substrate 328.

[0101] The substrate 328 may include a second waveguide conductive layer 327a and a second other waveguide conductive layer 327b. The direction from the second other waveguide conductive layer 327b to the second waveguide conductive layer 327a is along the second direction D2. A part of the substrate 328 is between the second other waveguide conductive layer 327b and the second waveguide conductive layer 327a. The second waveguide conductive layer 327a can be coupled to the second conductive layer 325a (and the second other conductive layer 325b). The second other waveguide conductive layer 327b can be at a fixed potential (e.g., ground potential), for example. A plurality of second waveguide conductive layers 327a may be provided. One of the plurality of second waveguide conductive layers 327a can be coupled to the second conductive layer 325a (and the second other conductive layer 325b).

[0102] The substrate 328 may include a second other surface 328g. The direction from the second other surface 328g to the second surface 328f is along the second direction D2. The second waveguide conductive layer 327a may be provided on the second surface 328f. The second other waveguide conductive layer 327b may be provided on the second other surface 328g.

[0103] Fig. 13 is a block diagram for explaining an example of the electrical configuration of the radar device 120 shown in Fig. 6. The radar device 120 includes a transmitting unit 122, a receiving unit 124, a signal generating module 30, and a processor 90. The transmitting unit 122 is divided into two transmitting sub-units 122a and 122b. The receiving unit 124 is divided into two receiving sub-units 124a and 124b.

[0104] The transmitting subunit 122a is installed in the left housing 144. The transmitting subunit 122a includes transmitting modules 10a and 10b and a distributor 130a. The transmitting subunit 122b is installed in the right housing 146. The transmitting subunit 122b includes transmitting modules 10c and 10d and a distributor 130b. The distributor 130c is not included in either the left housing 144 or the right housing 146, and is installed near the signal generating module 30. A first output terminal of the distributor 130c is connected to the transmitting subunit 122a (distributor 130a), and a second output terminal of the distributor 130c is connected to the transmitting subunit 122b (distributor 130b).

[0105] The receiving subunit 124a is installed in the left housing 144. The receiving subunit 124a includes the receiving modules 20a and 20b and a distributor 132a. The receiving subunit 124b is installed in the right housing 146. The receiving subunit 124b includes the receiving modules 20c and 20d and a distributor 132b. The distributor 132c is not included in either the left housing 144 or the right housing 146, and is installed near the signal generating module 30. A first output terminal of the distributor 132c is connected to the receiving subunit 124a (distributor 132a), and a second output terminal of the distributor 132c is connected to the receiving subunit 124b (distributor 132b).

[0106] The radar module 262 installed in the left housing 144 includes a transmitting subunit 122a and a receiving subunit 124a. The radar module 264 installed in the right housing 146 includes a transmitting subunit 122b and a receiving subunit 124b.

[0107] The radar devices 110 and 120 according to the embodiment can inspect belongings of an inspection target 140 walking along a passage 142. Since the inspection target 140 does not need to stop for inspection, the inspection throughput of the radar devices 110 and 120 is improved.

[0108] In order to further improve the inspection throughput, it is possible to prepare multiple radar devices and simultaneously inspect multiple inspection targets in multiple inspection lanes. In this case, the number of radar devices to be introduced increases according to the number of inspection lanes, which increases costs. In addition, the overall inspection lanes are expanded due to the size of the radar device housing and the margin area between radar devices (between inspection lanes) for the purpose of installation and maintenance. Furthermore, since adjacent radar devices operate asynchronously, there is a possibility that interference between the signals of multiple radar devices will occur at unexpected times, affecting the inspection results. Interference can be avoided by introducing materials that absorb radio waves or control radio wave reflection between the radar devices, but the introduction of such materials leads to increased costs and increased margin space.

[0109] FIG. 14 is a perspective view for explaining an example of a walk-through type inspection device 210 which is an application example of the radar device according to the embodiment. The inspection device 210 includes a plurality of radar devices 120 (FIG. 6) arranged along a plurality of paths. The inspection device 210 may include a plurality of radar devices 100 (FIG. 1) arranged along a plurality of paths instead of the radar devices 120. For convenience of explanation, FIG. 14 shows a two-lane inspection device 210, but an inspection device 210 with three or more lanes is similarly configured. A first path 1421 and a second path 1422 are defined. The second path 1422 is located to the right of the first path 1421.

[0110] A first left housing 1441 is installed on the left side of the first passage 1421. A first right housing 1461 is installed on the right side of the first passage 1421. A second left housing 1442 is installed on the left side of the second passage 1422. A second right housing 1462 is installed on the right side of the second passage 1422. There is no need to leave a gap between the first right housing 1461 and the second left housing 1442, and they may be close to each other. In other words, the first right housing 1461 and the second left housing 1442 may be a single housing.

[0111] The configurations of the first left housing 1441 and the second left housing 1442 are the same as the left housing 144 shown in Fig. 6. The configurations of the first right housing 1461 and the second right housing 1462 are the same as the right housing 146 shown in Fig. 6.

[0112] The signal generating module 30 is connected to a first left housing 1441 , a first right housing 1461 , a second left housing 1442 and a second right housing 1462 .

[0113] 15 is a block diagram for explaining an example of an electrical configuration of an inspection device 210 according to an embodiment. The inspection device 210 includes a transmitting unit 122, a receiving unit 124, a signal generating module 30, and a processor 90.

[0114] The transmitting unit 122 includes four transmitting subunits 122a1, 122b1, 122a2, and 122b2. The configurations of the transmitting subunits 122a1 and 122a2 are the same as the transmitting subunit 122a in the left housing 144 shown in Fig. 13. The configurations of the transmitting subunits 122b1 and 122b2 are the same as the transmitting subunit 122b in the right housing 146 shown in Fig. 13. The transmitting unit 122 also includes distributors 130c1 and 130c2.

[0115] The receiving unit 124 includes four receiving subunits 124a1, 124b1, 124a2, and 124b2. The configurations of the receiving subunits 124a1 and 124a2 are the same as the receiving subunit 124a in the left housing 144 shown in Fig. 13. The configurations of the receiving subunits 124b1 and 124b2 are the same as the receiving subunit 124b in the right housing 146 shown in Fig. 13. The receiving unit 124 also includes distributors 132c1 and 132c2.

[0116] A first output signal of the signal generating module 30 is supplied to the distributor 212. A second output signal of the signal generating module 30 is supplied to the distributor 214. The two output signals of the distributor 212 are supplied to the distributors 130c1 and 130c2, respectively. The two output signals of the distributor 214 are supplied to the distributors 132c1 and 132c2, respectively. The distributors 130C1 and 130C2 are not installed inside any of the first left housing 1441, the first right housing 1461, the second left housing 1442, or the second right housing 1462, but are installed near the distributor 212. The distributors 132C1 and 132C2 are not installed inside any of the first left housing 1441, the first right housing 1461, the second left housing 1442, or the second right housing 1462, but are installed near the distributor 214.

[0117] The transmitting subunit 122a1 and the receiving subunit 124a1 are installed in a left housing 1441 of the first passage 1421. The transmitting subunit 122b1t and the receiving subunit 124b1 are installed in a right housing 1461 of the first passage 1421. The transmitting subunit 122a2 and the receiving subunit 124a2 are installed in a left housing 1442 of the second passage 1422. The transmitting subunit 122b2 and the receiving subunit 124b2 are installed in a right housing 1462 of the second passage 1422.

[0118] The radar module 2621 installed in the first left housing 1441 includes a transmitting subunit 122a1 and a receiving subunit 124a1. The radar module 2641 installed in the first right housing 1461 includes a transmitting subunit 122b1 and a receiving subunit 124b1. The radar module 2622 installed in the second left housing 1442 includes a transmitting subunit 122a2 and a receiving subunit 124a2. The radar module 2642 installed in the second right housing 1462 includes a transmitting subunit 122b2 and a receiving subunit 124b2.

[0119] In the radar modules 2641, 2642, 2643, and 2644, all of the transmitting modules 10 and receiving modules 20 are controlled by a chirp signal and a clock signal supplied from the signal generating module 30 and a trigger signal supplied from the processor 90. Therefore, the signal generating module 30 is shared by multiple inspection lanes, which reduces costs, and synchronization between the inspection lanes can be achieved, which reduces the effects of unexpected interference.

[0120] The processor 90 selectively supplies trigger signals to the transmission module 10 to drive the transmission antennas 16 in separate domains in order to avoid mutual interference caused by the transmission of radar signals at the same time from multiple transmission antennas 16. Examples of domains are time, frequency, and code.

[0121] Fig. 16 is a diagram for explaining an example of a transmission and reception sequence of the inspection device 210 according to the embodiment. Fig. 16 shows an example of time-division transmission of a radar signal. The processor 90 sequentially drives the radar module 2621 installed in the first left housing 1441 and the radar module 2641 installed in the first right housing 1461 to inspect the first passage 1421, and then supplies a trigger signal to the transmission module to sequentially drive the radar module 2622 installed in the second left housing 1442 and the radar module 2642 installed in the second right housing 1462 to inspect the second passage 1422.

[0122] Specifically, in order to inspect the first passage 1421, the processor 90 supplies a trigger signal to the transmitting module 10a in the radar module 2621 installed in the first left housing 1441. The transmitting module 10a causes the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the first passage 1421. Next, the processor 90 supplies a trigger signal to the transmitting module 10b in the radar module 2621. The transmitting module 10b causes the transmitting antennas 16a, ... to transmit radar signals sequentially toward the first passage 1421. Next, the processor 90 supplies a trigger signal to the transmitting module 10c in the radar module 2641 installed in the first right housing 1461. The transmitting module 10c causes the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the first passage 1421. Next, the processor 90 supplies a trigger signal to the transmitting module 10d in the radar module 2641. The transmitting module 10d causes the transmitting antennas 16a, . . . to transmit radar signals sequentially toward the first passage 1421.

[0123] When the transmitting antenna 16 in the radar module 2621 for the first path 1421 transmits a radar signal, the processor 90 causes all the receiving antennas 26a to 26p of all the receiving modules 20a, 20b, 20c, and 20d in the radar modules 2621 and 2641 for the first path 1421 to receive the reflected signal from the first path 1421. This completes the inspection of the first path 1421.

[0124] After that, in order to inspect the second passage 1422, the processor 90 supplies a trigger signal to the transmitting module 10a in the radar module 2622 installed in the second left housing 1442. The transmitting module 10a causes the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the second passage 1422. Next, the processor 90 supplies a trigger signal to the transmitting module 10b in the radar module 2622. The transmitting module 10b causes the transmitting antennas 16a, ... to transmit radar signals sequentially toward the second passage 1422. Next, the processor 90 supplies a trigger signal to the transmitting module 10c in the radar module 2642 installed in the second right housing 1462. The transmitting module 10c causes the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the second passage 1422. Next, the processor 90 supplies a trigger signal to the transmitting module 10d in the radar module 2642. The transmitting module 10d causes the transmitting antennas 16a, . . . to transmit radar signals sequentially toward the second path 1422.

[0125] When the transmitting antenna 16 in the radar module 2622 for the second path 1422 transmits a radar signal, the processor 90 causes all the receiving antennas 26a to 26p of all the receiving modules 20a, 20b, 20c, and 20d in the radar modules 2622 and 2642 for the second path 1422 to receive the reflected signal from the second path 1422. This completes the inspection of the second path 1422.

[0126] In this type of time division driving, increasing the number of inspection lanes (passages) imposes restrictions on the time available for inspection for each lane, resulting in poor inspection efficiency. The same is true for frequency division driving and code division driving.

[0127] In order to avoid this, it is possible to carry out inspections in multiple lanes simultaneously. Fig. 17 is a diagram for explaining another example of a transmission and reception sequence of the inspection device 210 according to the embodiment. Fig. 17 shows an example of simultaneous transmission of radar signals in multiple lanes. The processor 90 simultaneously drives the radar module 2621 installed in the first left housing 1441 and the radar module 2622 installed in the second left housing 1442, and then simultaneously drives the radar module 2641 installed in the first right housing 1461 and the radar module 2642 installed in the second right housing 1462.

[0128] In this specification, "simultaneous" does not necessarily mean exactly the same time, but also includes a difference of a few seconds between the transmission start timings of the radar module 2641 in the first right housing 1461 and the radar module 2642 in the second right housing 1462. An example of a few seconds is 2 to 3 seconds.

[0129] Specifically, the processor 90 supplies a trigger signal to transmitting modules 10a, 10b in the radar module 2621 installed in the first left housing 1441 and transmitting modules 10c, 10d in the radar module 2641 installed in the first right housing 1461 for inspecting the first passage 1421, and at the same time supplies a trigger signal to transmitting modules 10a, 10b in the radar module 2622 installed in the second left housing 1442 and transmitting modules 10c, 10d in the radar module 2642 installed in the second right housing 1462 for inspecting the second passage 1422. As a result, the transmitting modules 10a, 10b in the radar module 2621 cause the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the first passage 1421, the transmitting modules 10c, 10d in the radar module 2641 cause the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the first passage 1421, while the transmitting modules 10a, 10b in the radar module 2622 cause the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the second passage 1422, and the transmitting modules 10c, 10d in the radar module 2642 cause the transmitting antennas 16a, 16b, ... to transmit radar signals sequentially toward the second passage 1422.

[0130] When the transmitting antennas 16 in the radar modules 2621, 2622, 2641, and 2642 transmit radar signals, the processor 90 causes all of the receiving antennas 26 in the radar modules 2621, 2622, 2641, and 2642 to receive the reflected signals.

[0131] By simultaneously transmitting radar signals to multiple lanes in this manner, even if a common signal generating module 30 is used to inspect multiple lanes, a decrease in inspection efficiency can be avoided.

[0132] FIG. 18 is a perspective view for explaining another example of a walk-through type inspection device 210 which is an application example of the radar device according to the embodiment.

[0133] The first left housing 1441 includes two radar modules 262. 11 , 262 12 The radar module 262 11 , 262 12 Each of the radar modules 262 includes transmitting modules 10a and 10b and receiving modules 20a and 20b arranged in a rectangular prism shape. The arrangement of the transmitting modules 10a and 10b and the receiving modules 20a and 20b is the same as that in the example of FIG. 14. 11 , 262 12 are disposed along the length of the passage 1421.

[0134] The first right housing 1461 includes two radar modules 264. 11 , 264 12 The radar module 264 11 , 264 12 Each of the radar modules 264 includes transmitting modules 10c and 10d and receiving modules 20c and 20d arranged in a rectangular prism shape. The orientations of the transmitting modules 10c and 10d and the receiving modules 20c and 20d are the same as those in the example of FIG. 14. 11 , 264 12 are disposed along the length of the passage 1421.

[0135] The second left housing 1442 includes two radar modules 262. 21 , 262 22 The radar module 262 21 , 262 22 Each of the radar modules 262 includes transmitting modules 10a and 10b and receiving modules 20a and 20b arranged in a rectangular prism shape. The arrangement of the transmitting modules 10a and 10b and the receiving modules 20a and 20b is the same as that in the example of FIG. 14. 21 , 262 22 are disposed along the length of the passageway 1422.

[0136] The second right housing 1462 includes two radar modules 264. 21 , 264 22 The radar module 264 21 , 264 22 Each of the radar modules 264 includes transmitting modules 10c and 10d and receiving modules 20c and 20d arranged in a rectangular prism shape. The orientations of the transmitting modules 10c and 10d and the receiving modules 20c and 20d are the same as those in the example of FIG. 14. 21 , 264 22 are disposed along the length of the passageway 1422.

[0137] In the inspection device 210 shown in FIG. 18, first, the radar module 262 on the front side in the traveling direction of the inspection object 140 of each of the cases 1441, 1461, 1442, and 1462 is 11 , 264 11 , 262 21 , 264 21 16 or 17, and then the radar module 262 on the far side in the traveling direction of the inspection object 140 of each of the housings 1441, 1461, 1442, and 1462 12 , 264 12 , 262 22 , 264 22 The transmission and reception are performed in the sequence shown in FIG.

[0138] When the radar module for the first passage and the radar module for the second passage simultaneously transmit radar signals according to the transmission and reception sequence shown in FIG. 17, depending on the position of the inspection object, the radar module for the first passage may receive a reflected signal of the radar signal transmitted by the radar module for the first passage and a radar signal transmitted by the radar module for the second passage or its reflected signal, which may cause interference.

[0139] FIG. 19 is a diagram for explaining one possibility of interference occurring in the inspection device 210. In the first passage 1421, the radar module 262 11 The multiple transmitting antennas 16 of the transmitting module 10 sequentially transmit radar signals, and the radar module 262 11 During the transmission of the inspection radar signal in the first path 1421, the radar module 264 in the second path 1422 receives the reflected radar signal from the radar module 264. 22 Assume that one of the transmitting antennas 16 of the transmitting module 10 transmits a radar signal. The inspection radar signal or its reflected signal of the second path 1422 may be propagated to the first path 1421. 11 When any of the receiving antennas 26 of the receiving modules 20 receives a radar signal or its reflected signal propagated from the second path 1422, the inspection radar signal or its reflected signal of the second path 1422 interferes with the inspection reflected signal of the first path 1421.

[0140] 20 is a diagram for explaining another possibility that interference may occur in the inspection device 210. FIG. 20 illustrates a case where the radar module 264 is in a second path 1422 while the inspection radar signal is being transmitted in the first path 1421. 21 In this example, one transmitting antenna 16 of the transmitting module 10 transmits a radar signal, and the reflected signal is propagated to the first path 1421. In this case, the radar module 262 for inspection of the first path 1421 is also 11When any of the receiving antennas 26 of the receiving modules 20 receives a reflected signal propagated from the second path 1422 , the reflected signal for inspection on the second path 1422 interferes with the reflected signal for inspection on the first path 1421 .

[0141] Figure 21 is a diagram showing an example of the operation of a radar device when interference occurs. A radar device irradiates an inspection object with a radar signal and observes the reflected signal (echo) to measure the direction of the inspection object and the distance to the inspection object. The strength of the reflected signal depends on the distance to the inspection object. A radar device receives reflected signals of a certain strength or more. A radar device cannot receive reflected signals below a certain strength. A radar device has a predetermined detection range B, which indicates how far away the reflected signal reflected from an inspection object it can receive.

[0142] Detection range B is the range in which the reflected signal of the radar signal transmitted by the radar device can be observed and the direction and distance of the inspection target can be measured. Detection range B is defined by a component in the width direction X of the passage and a component in the length direction Z of the passage. Note that since radio waves are irradiated in a three-dimensional space, detection range B also includes a component in the height direction Y of the passage, but for convenience of explanation, detection range B in Figure 21 will be explained as a two-dimensional detection range at a certain coordinate y in the Y direction.

[0143] When the radar device receives a reflected signal (called clutter) other than the reflected signal from the inspection target 140, the detection performance is degraded. In this specification, the degradation of the detection performance due to the reception of clutter is called interference. As shown in Figures 19 and 20, a radar signal from a radar module in an adjacent lane or its reflected signal can also be clutter.

[0144] The radar device (image generation module 95) receives the reflected signal and processes the received signal to generate an image of a certain area within detection range B. The image generation range is called sensing range A. Detection range B is determined by the physical positional relationship between the transmitting module 10 and the receiving module 20. Sensing range A is determined by the image generation algorithm of the image generation module 95. An example of detection range B is a square area of ​​6 m by 6 m, and an example of sensing range A is a square area of ​​2 m by 2 m.

[0145] Assume that clutter occurs within detection range B. If the source of the clutter (the position where the clutter is reflected) is within sensing range A, image generation module 95 generates image 204 based on the clutter. Processor 90, which inspects personal belongings based on the image, cannot determine whether image 204 is based on the reflected signal of the inspection target or based on clutter. Therefore, if the source of the clutter is within sensing range A, inspection of personal belongings is hindered. If the source of clutter 206 is outside sensing range A, image generation module 95 does not generate an image based on the clutter. If the source of clutter is outside sensing range A, there is no hinderance in the inspection of personal belongings.

[0146] Among combinations of a radar module that transmits a radar signal for inspection of a certain lane and a radar module that transmits a radar signal for inspection of an adjacent lane, there exists a combination that does not generate clutter that interferes with inspection of belongings even if simultaneous transmission is performed. The combination includes one radar module in a certain lane and at least one radar module in the adjacent lane. When designing the inspection device 210, a combination of radar modules capable of simultaneous transmission among the radar modules in two adjacent lanes is obtained. The combination of radar modules capable of simultaneous transmission that has been obtained in advance is stored in the RAM 98 or ROM 96 in the processor 90. Based on the information stored in the RAM 98 or ROM 96, the scheduler 95 causes a radar signal to be transmitted from at least one radar module capable of simultaneous transmission when a radar signal is transmitted from a certain radar module in the first lane.

[0147] FIG. 22 is a diagram for explaining an example of two radar modules in which no clutter source is located within the sensing range A of the two-lane radar modules. The sensing range A1 of the first lane radar device is (0, z0), (x I ,z0),(x I ,z I ),(0,z I The origin of the XZ coordinates is the radar module 262 of the first lane. 11 The sensing range A2 of the radar device in the second lane is the same size as the sensing range A1. The Z coordinate values ​​of the upper sides of the sensing range A1 and the sensing range A2 are equal to each other. The Z coordinate values ​​of the lower sides of the sensing range A1 and the sensing range A2 are equal to each other.

[0148] Radar module 262 in the first lane 11 One transmitting antenna in the radar module 262 transmits a radar signal. 11 The radar signal transmitted from the radar module 262 is reflected by the test object 1401. 11 All receiving antennas in the radar module 262 receive the reflected signal. 11 The distance between the test object 1401 in the first lane and the test object 1401 in the first lane is r1.

[0149] Radar Module 262 11 transmits a radar signal, the radar module 264 of the second lane 22 and radar module 264 21 Suppose that radar module 264 transmits a radar signal. 22 The radar signal transmitted by the radar module 264 is propagated to the first lane. 21 The radar signal transmitted from the radar module 262 is reflected by the test object 1402. The reflected signal is propagated to the first lane. 11 is radar module 264 22 and a radar signal transmitted from the radar module 264. 21 Receives a reflected signal of a radar signal transmitted from the

[0150] A radar module 264 for transmitting a radar signal. 22 and a radar module 262 for receiving radar signals. 11 The distance between and is r CT The radar module 262 transmits a radar signal. 21 The distance between the reflection point of the inspection object 1402 and aT The reflection points of the inspection object 1402 and the radar module 262 that receives the radar signal are shown in FIG. 11 The distance between and is r aR Radar module 264 22 is radar module 262 11 From the perspective of the sensor, it is farther away than the sensing range A1.

[0151] Radar module 262 in the first lane 11 Position of the radar module 264 in the second lane 22 When the position of the radar module 264 is in the relationship of Equation 1, 22 The direct wave from the radar module 264 does not enter the sensing range A1 of the first lane, and the image of the first lane is not captured by the radar module 264. 22 The components based on the direct waves of the radar module 262 are not included. Examples of the position of the radar module include the center of the substrate and the center of the MIMO antenna. The center of the MIMO antenna may be defined by the center of the transmitting antenna array and the receiving antenna array. Therefore, the radar module 262 11 Transmitting antenna and radar module 264 22 Even if two radar signals are transmitted simultaneously from the transmitting antenna, clutter will not interfere with the inspection of personal belongings.

number

[0152] Radar module 262 in the first lane 11 The position of the transmitting antenna transmitting the radar signal of the second lane and the radar module 264 of the second lane 21When the position of the transmitting antenna that transmits the radar signal is in the relationship of Equation 2, the radar module 264 21 The reflected wave of the radar signal from the transmitting antenna of the first lane does not enter the sensing range A1 of the first lane, and the radar module 264 21 Therefore, the radar module 262 does not include a component based on a reflected wave of the radar signal from 11 Transmitting antenna and radar module 264 21 Even if two radar signals are transmitted simultaneously from the transmitting antenna, clutter will not interfere with the inspection of personal belongings.

number

[0153] The combination of transmitting antennas that satisfies Equations 1 and 2 is determined according to the positions of the radar modules 262 and 264 when the inspection device 210 is designed.

[0154] The distance included in formula 2 changes depending on the position of inspection object 1402. The distance included in formula 2 is smallest when inspection object 1402 is located at the entrance of the passage (the position where the Z coordinate of sensing range A2 is z0). If the condition of formula 2 is satisfied when the distance is smallest, the condition of formula 2 will also be satisfied when the distance is greater than that. Therefore, the right side of formula 2 is set to the value when inspection object 1402 is located at the entrance of the passage.

[0155] An example of two radar modules that satisfy both formulas 1 and 2 is two radar modules whose transmission and reception directions are not opposed to each other. For example, the radar module 264 in the right housing 1461 of the first passage 1421 11 , 264 12 The transmission and reception direction of the radar module 262 in the left housing 1442 of the second passage 1422 is to the left. 21 , 262 22 The transmission and reception directions of the radar module 264 are to the right, and the transmission and reception directions of the two modules are not opposite to each other. 11 , 26412 and radar module 262 21 , 262 22 Even if radar signals are transmitted from both the receiver and the receiver simultaneously, no interference occurs in the sensing range.

[0156] FIG. 23 is a diagram for explaining another example of two radar modules in which the clutter source is not located within the sensing range A of the two-lane radar modules. Assume that the inspection target 1401 in the first lane is located on the near side of the passage (smaller Z coordinate). The radar module 262 in the first lane 11 The radar module 264 in the second lane inspects the back of the inspection target 1401. The inspection target 1402 in the second lane is located at the back of the passage (large Z coordinate). 22 inspects the front surface of the inspection object 1402.

[0157] Radar Module 264 22 and radar module 262 11 The inspection object 1402 is located between the radar module 264 and the 22 The radar signal from the radar module 262 is blocked by the test object 1402. 11 , and the radar module 262 11 Therefore, the radar module 262 11 and radar module 264 22 Even if the radar modules 264 and 265 transmit radar signals simultaneously, clutter does not interfere with the inspection of the belongings. 22 and radar module 262 11 There is also a timing when the inspection target 1401 is located between the radar module 262 and the target 1401. 11 and radar module 264 22 Even if multiple radar signals are transmitted at the same time, clutter will not interfere with the inspection of personal belongings.

[0158] 23 is obtained according to the position of the inspection object 140 while the inspection device is in operation. The position of the inspection object 140 is obtained by a camera, a sensor, etc. that are separately provided in the inspection device. The scheduler 94 determines a combination of radar modules that can transmit simultaneously according to the position of the inspection object 140 obtained by the camera, the sensor, etc., and causes multiple radar signals to be transmitted simultaneously from the multiple radar modules.

[0159] 24 is a diagram for explaining an example of an electronic circuit of the inspection device 120 of an embodiment that enables simultaneous transmission. A signal generating module 30 and a CPU 92 (scheduler 94, image generating module 95) are connected to each radar module 262 in the left housing 144 of each lane and each radar module 264 in the right housing 146 of each lane.

[0160] Fig. 25 is a diagram for explaining details inside the radar module 262 of Fig. 24. Each of the radar modules 262, 264 includes a plurality of transmitting circuits 40 (Fig. 2) and a plurality of receiving circuits 40 (Fig. 2). Each transmitting circuit 40 is connected to four transmitting antennas 16. Each receiving circuit 50 is connected to four receiving antennas 26.

[0161] The clock signal and the chirp signal generated by the signal generating module 30 are supplied to the transmitting circuit 40 and the receiving circuit 50 of the radar module of a certain lane. The clock signal generated by the signal generating module 30 is supplied to the receiving circuit 50.

[0162] The scheduler 94 sequentially supplies trigger signals to the transmission circuits 40. When the scheduler 94 supplies a trigger signal to the transmission circuit 40 of a certain lane, the scheduler 94 also supplies trigger signals to the transmitting antennas of the radar modules of other lanes that satisfy the conditions of Equation 1 and Equation 2 stored in the ROM 96 or RAM 98.

[0163] The receiving circuit 50 amplifies the reflected signals received by all of the receiving antennas 26 , mixes them with the chirp signal, converts them into IF signals, and supplies the digital signals of the IF signals to the image generation module 95 .

[0164] According to the embodiment, in order to improve the throughput of the inspection, a radar system is realized in which multiple radar devices are arranged in multiple lanes and the multiple radar devices operate synchronously with a common clock signal. As a result, the timing of radar transmission between the radar devices, which was unknown, becomes known. When transmission between the radar devices is started, multiple radar modules that do not cause interference within the sensing range transmit radar signals simultaneously. As a result, the multiple radar devices can be controlled by a common clock signal generating module, and a signal generating module for each radar device is not required. In addition, since simultaneous inspection is possible while minimizing the influence of interference between the radar devices, the throughput of the inspection is improved.

[0165] In order to inspect a wide range of inspection objects, a large number of antennas are required. In the embodiment, a MIMO antenna, which is an antenna array, is used as the transmitting antenna 16 and the receiving antenna 26. Each transmitting antenna transmits a radar signal in a time-division manner. Reflected signals of the radar signal are received simultaneously by all receiving antennas. This makes it possible to receive a large number of reflected signals with a small number of antennas, and thus reduce the number of antennas. Note that the embodiment can also be applied to a radar device that does not use a MIMO antenna.

[0166] The processor 90 is connected to the transmitting module 10, the receiving module 20, and the signal generating module 30, and is responsible for transmission control and image generation, but the configuration of the processor 90 can be changed in various ways. For example, the processor 90 may be connected to an external server, the image generating module 95 may be omitted from the processor 90, and the image generating module 95 may be provided in the server.

[0167] The present invention is not limited to the above-described embodiment as it is, and in the implementation stage, the components can be modified and embodied without departing from the gist of the invention. In addition, various inventions can be formed by appropriate combinations of the multiple components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0168] 10: transmitting module, 12: IC, 16: transmitting antenna, 20: receiving module, 22: IC, 26: receiving antenna, 30: signal generating module, 94: scheduler, 95: image generating module

Claims

1. a plurality of first radar modules each capable of transmitting a plurality of first radar signals to a first area and receiving a plurality of first reflected signals obtained when the plurality of first radar signals are reflected by a first inspection object in the first area; a plurality of second radar modules each capable of transmitting a plurality of second radar signals to a second region and receiving a plurality of second reflected signals obtained when the plurality of second radar signals are reflected by a second inspection object in the second region; a processing unit that controls transmission timings of the first radar modules and transmission timings of the second radar modules, the processing unit causes one first radar module among the plurality of first radar modules to transmit the first radar signal, and causes at least one second radar module among the plurality of second radar modules to transmit the second radar signal; A radar system, wherein the distance between the one first radar module and the at least one second radar module is more than twice the distance between the one first radar module and a point in the sensing range of the one first radar module that is farthest from the one first radar module.

2. the first radar modules and the second radar modules face each other, 2. The radar system of claim 1, wherein the first region and the second region are located between the first plurality of radar modules and the second plurality of radar modules.

3. A pair of first housings installed in the first area; A pair of second housings disposed in the second area, the plurality of first radar modules are installed in at least one of the pair of first housings, The radar system according to claim 1 , wherein the plurality of second radar modules are installed in at least one of the pair of second housings.

4. Each of the first radar modules and the second radar modules comprises a plurality of multiple-input multiple-output (MIMO) radars; The radar system of claim 1 , wherein each of the plurality of MIMO radars comprises a plurality of transmit antennas and a plurality of receive antennas.

5. the one first radar module is also capable of receiving the second radar signals and the second reflected signals, and generating an image of a rectangular area including the first inspection object based on the first reflected signals, the second radar signals, and the second reflected signals; 2. The radar system of claim 1, wherein the image does not include a component based on at least one second radar signal transmitted by the at least one second radar module and a component based on a second reflected signal of the at least one second radar signal.

6. The radar system of claim 5 , wherein the at least one second radar module is located farther away from the rectangular area than the one first radar module.

7. 6. The radar system of claim 5, wherein half the distance between the one first radar module and the at least one second radar module is greater than a diagonal length of the rectangular area generated by the one first radar module.

8. 6. The radar system of claim 5, wherein half the sum of the distance between the one first radar module and the second inspection object and the distance between the at least one second radar module and the second inspection object is greater than the length of a diagonal of the rectangular area generated by the one first radar module.

9. The radar system of claim 1 , wherein at least one of the first test object or the second test object is located between the one first radar module and the at least one second radar module.

10. 2. The radar system of claim 1, further comprising: determining means for determining the location of the one first radar module and the at least one second radar module based on the locations of the plurality of first radar modules and the locations of the plurality of second radar modules.

11. a sensor for measuring a position of the first inspection object and a position of the second inspection object; 11. The radar system of claim 10, wherein the determining means determines the one first radar module and the at least one second radar module based on positions of the plurality of first radar modules and outputs of the plurality of second radar modules and the sensor.

12. a plurality of first radar modules each capable of transmitting a plurality of first radar signals to a first area and receiving a plurality of first reflected signals obtained when the plurality of first radar signals are reflected by a first inspection object in the first area; a plurality of second radar modules each capable of transmitting a plurality of second radar signals into a second region and receiving a plurality of second reflected signals obtained when the plurality of second radar signals are reflected by a second test object in the second region, the method comprising: transmitting the first radar signal from one first radar module of the plurality of first radar modules and transmitting the second radar signal from at least one second radar module of the plurality of second radar modules; A method according to claim 1, wherein the distance between the one first radar module and the at least one second radar module is greater than or equal to twice the distance between the one first radar module and a point of the sensing range of the one first radar module that is farthest from the one first radar module.

13. a plurality of first radar modules each capable of transmitting a plurality of first radar signals to a first area and receiving a plurality of first reflected signals obtained when the plurality of first radar signals are reflected by a first inspection object in the first area; a plurality of second radar modules each capable of transmitting a plurality of second radar signals to a second area and receiving a plurality of second reflected signals obtained when the plurality of second radar signals are reflected by a second inspection object in the second area, causing a computer to transmit the first radar signal from one first radar module of the plurality of first radar modules and transmit the second radar signal from at least one second radar module of the plurality of second radar modules; A program, wherein the distance between the one first radar module and the at least one second radar module is more than twice the distance between the one first radar module and a point in the sensing range of the one first radar module that is farthest from the one first radar module.

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