Antenna equipment and radar system

Abstract

To provide an antenna device and a radar system that can improve the performance.SOLUTION: According to an embodiment, an antenna device includes a transmission antenna that includes multiple transmission elements, and a reception antenna that includes multiple reception elements. The maximum value of the mutual coupling between the multiple reception elements is less than the maximum value of the mutual coupling between the multiple transmission elements.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to an antenna device and a radar system.

Background Art

[0002] For example, performance improvement is desired in an antenna device.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Embodiments of the present invention provide an antenna device and a radar system capable of improving performance.

Means for Solving the Problems

[0005] According to an embodiment of the present invention, an antenna device includes a transmitting antenna including a plurality of transmitting elements and a receiving antenna including a plurality of receiving elements. The maximum value of mutual coupling between the plurality of receiving elements is smaller than the maximum value of mutual coupling between the plurality of transmitting elements.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a schematic perspective view illustrating an antenna device according to the first embodiment. [Figure 2] FIG. 2 is a schematic plan view illustrating a part of the antenna device according to the first embodiment. [Figure 3] FIG. 3 is a schematic plan view illustrating a part of the antenna device according to the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view illustrating a part of the antenna device according to the first embodiment. [Figure 5] Figure 5 is a schematic plan view illustrating a part of the antenna device according to the first embodiment. [Figure 6] Figure 6 is a schematic plan view illustrating a part of the antenna device according to the first embodiment. [Figure 7] Figure 7 is a schematic cross-sectional view illustrating a part of the antenna device according to the first embodiment. [Figure 8] Figure 8 is a schematic diagram illustrating an antenna device according to the first embodiment. [Figure 9] Figure 9 is a schematic diagram illustrating an antenna device according to the first embodiment. [Figure 10] Figure 10 is a schematic perspective view illustrating an antenna device according to the second embodiment. [Figure 11] Figure 11 is a schematic plan view illustrating a part of the antenna device according to the second embodiment. [Figure 12] Figure 12 is a schematic plan view illustrating a part of the antenna device according to the second embodiment. [Figure 13] Figure 13 is a schematic plan view illustrating a part of the antenna device according to the embodiment. [Figure 14] Figure 14 is a schematic cross-sectional view illustrating a part of the antenna device according to the embodiment. [Figure 15] Figure 15 is a block diagram illustrating a radar device according to an embodiment. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described below with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may be depicted differently in different drawings. In this specification and in each figure, elements similar to those described above are denoted by the same reference numerals with respect to previously shown figures, and detailed explanations are omitted as appropriate.

[0008] (First Embodiment) FIG. 1 is a schematic perspective view illustrating an antenna device according to the first embodiment. FIGS. 2 and 3 are schematic plan views illustrating a part of the antenna device according to the first embodiment. FIG. 4 is a schematic cross-sectional view illustrating a part of the antenna device according to the first embodiment. FIGS. 5 and 6 are schematic plan views illustrating a part of the antenna device according to the first embodiment. FIG. 7 is a schematic cross-sectional view illustrating a part of the antenna device according to the first embodiment.

[0009] As shown in FIG. 1, an antenna device 110 according to the embodiment includes a transmitting antenna 10 and a receiving antenna 20. The transmitting antenna 10 includes a plurality of transmitting elements 15. The receiving antenna 20 includes a plurality of receiving elements 25. In the embodiment, the maximum value of the mutual coupling between the plurality of receiving elements 25 is smaller than the maximum value of the mutual coupling between the plurality of transmitting elements 15. Thereby, for example, high receiving performance can be obtained.

[0010] The transmitting antenna 10 is, for example, a transmitting array antenna. The plurality of transmitting elements 15 are, for example, a plurality of feeding elements for transmission. The receiving antenna 20 is, for example, a receiving array antenna. The plurality of receiving elements 25 are, for example, a plurality of feeding elements for reception.

[0011] The mutual coupling between the plurality of transmitting elements 15 is the inter-element mutual coupling between one of the plurality of transmitting elements 15 and another one of the plurality of transmitting elements 15. The mutual coupling between the plurality of receiving elements 25 is the inter-element mutual coupling between one of the plurality of receiving elements 25 and another one of the plurality of receiving elements 25.

[0012] For example, in a first reference example where the mutual coupling in the receiving antenna 20 is large, an electromagnetic field from the coupled elements is easily received and becomes noise. Thereby, for example, when the antenna device is applied to a radar or the like, the detection characteristics are likely to deteriorate.

[0013] In an embodiment, the maximum value of the mutual coupling between elements of the receiving array antenna is smaller than the maximum value of the mutual coupling between elements of the transmitting array antenna. Since the mutual coupling between elements of the receiving array antenna is small, the influence of the electromagnetic field from the coupled elements can be reduced. Noise is suppressed. According to the embodiment, an antenna device capable of improving performance can be provided.

[0014] As shown in FIG. 1, in this example, the transmitting antenna 10 includes a first substrate 18. The first substrate 18 includes a first surface 18f. The receiving antenna 20 includes a second substrate 28. The second substrate 28 includes a second surface 28f. The plane including the second surface 28f intersects the plane including the first surface 18f. A plurality of transmitting elements 15 are provided along the first surface 18f. A plurality of receiving elements 25 are provided along the second surface 28f.

[0015] For example, the first surface 18f extends along a first direction D1 and a second direction D2. The second direction D2 intersects the first direction D1. The second surface 28f extends along the first direction D1 and a third direction D3. The third direction D3 intersects the plane including the first direction D1 and the second direction D2.

[0016] The first direction D1 is, for example, the Z-axis direction. One direction perpendicular to the Z-axis direction is defined as the Y-axis direction. A direction perpendicular to the Z-axis direction and the Y-axis Towards direction is defined as the X-axis direction.

[0017] The second direction D2 may be, for example, the Y-axis direction. The third direction D3 may be, for example, the X-axis direction. The second direction D2 may be, for example, orthogonal to the first direction D1. The third direction D3 may be orthogonal to the first direction D1 and the second direction D2.

[0018] As shown in FIG. 1, the transmission direction 10D of the transmitting antenna 10 is along the first direction D1. The reception direction 20D of the receiving antenna 20 is along the first direction D1.

[0019] For example, the first substrate 18 includes a first side surface 18s. The first side surface 18s intersects with the first surface 18f. The transmission direction 10D of the transmitting antenna 10 intersects with the first side surface 18s. The transmission direction 10D may be substantially perpendicular to the first side surface 18s, for example.

[0020] For example, the second substrate 28 includes a second side surface 28s. The second side surface 28s intersects with the second surface 28f. The receiving direction 20D of the receiving antenna 20 intersects with the second side surface 28s. The receiving direction 20D may be substantially perpendicular to the second side surface 28s, for example.

[0021] Figures 2 to 4 correspond to the transmitting antenna 10. Figure 4 is a cross-sectional view taken along line A1-A2 in Figures 2 and 3. As shown in Figure 4, the first substrate 18 includes a first surface 18fa. The first surface 18fa is aligned with the first surface 18f. The first surface 18fa may be the same as the first surface 18f. Multiple transmitting elements 15 are provided, for example, on the first surface 18fa. Alternatively, at least some of the multiple transmitting elements 15 may be provided inside the first substrate 18. The first substrate 18 includes a dielectric. The first substrate 18 is an insulating substrate.

[0022] Figures 5 to 7 correspond to the receiving antenna 20. Figure 7 is a cross-sectional view taken along line B1-B2 in Figures 5 and 6. As shown in Figure 7, the second substrate 28 includes a second surface 28fa. The second surface 28fa is aligned with the second surface 28f. The second surface 28fa may be the same as the second surface 28f. Multiple receiving elements 25 are provided, for example, on the second surface 28fa. Alternatively, at least some of the multiple receiving elements 25 may be provided inside the second substrate 28. The second substrate 28 includes a dielectric. The second substrate 28 is an insulating substrate.

[0023] As shown in Figures 1 and 2, the multiple transmitting elements 15 are arranged along the second direction D2. For example, the mutual coupling between the multiple transmitting elements 15 depends on the distance (e.g., pitch) between the multiple transmitting elements 15 along the second direction D2. The longer the distance, the smaller the mutual coupling.

[0024] As shown in Figures 1 and 5, the multiple receiving elements 25 are arranged along the third direction D3. For example, the mutual coupling between the multiple receiving elements 25 depends on the distance (e.g., pitch) between the multiple receiving elements 25 along the third direction D3. A longer distance results in weaker mutual coupling. By changing the distance (pitch), the mutual coupling can be changed.

[0025] As shown in Figures 2 and 5, in this embodiment, the shape of one of the multiple receiving elements 25 may differ from the shape of one of the multiple transmitting elements 15. This allows the maximum interconnection between the multiple receiving elements 25 to be smaller than the maximum interconnection between the multiple transmitting elements 15.

[0026] For example, at least some of the multiple transmitting elements 15 include an SIW 15B (Substrate Integrated Waveguide) (see Figures 2 to 4). At least some of the multiple transmitting elements 15 may further include a director 15A (see Figures 2 to 4). The SIW 15B is, for example, a post-wall waveguide. On the other hand, for example, at least some of the multiple receiving elements 25 include a pseudo-Yagi antenna 25A (see Figures 5 to 7).

[0027] In the example of the antenna device 110, the multiple transmitting elements 15 include an SIW 15B and a director 15A. The multiple receiving elements 25 are a pseudo-Yagi antenna 25A. In the SIW 15B, a TE mode electric field parallel to the third direction D3 propagates, and an electric field parallel to the third direction D3 is transmitted via the director 15A. In the pseudo-Yagi antenna 25A, an electric field parallel to the third direction D3 is received.

[0028] The following describes examples of the shapes of multiple transmitting elements 15. As shown in Figure 4, the first substrate 18 of the transmitting antenna 10 includes a first surface 18f and a first other surface 18g. The direction from the first other surface 18g to the first surface 18f is along the third direction D3. A first conductive member 16f is provided on the first surface 18f. A first other conductive member 16g is provided on the first other surface 18g. The first substrate 18 is provided between these conductive members.

[0029] As shown in Figures 2 to 4, the first conductive layer 15c is formed by the first conductive member 16f. The first non-conductive layer 15d is formed by the first non-conductive member 16g. The first conductive layer 15c and the first non-conductive layer 15d are electrically connected by the first electrode member 15a and the second electrode member 15b. The direction from the second electrode member 15b to the first electrode member 15a is along the second direction D2. The first conductive layer 15c, the first non-conductive layer 15d, the first electrode member 15a, and the second electrode member 15b form a waveguide 15A.

[0030] As shown in Figures 2 to 4, the first conductive member 16f forms the first waveguide conductive layer 17a. The first non-conductive member 16g forms the first non-conductive waveguide conductive layer 17b. The first waveguide conductive layer 17a and the first non-conductive waveguide conductive layer 17b are electrically connected by a plurality of first waveguide electrode members 16a and a plurality of second waveguide electrode members 16b. The plurality of first waveguide electrode members 16a and the plurality of second waveguide electrode members 16b extend along the third direction D3. The plurality of first waveguide electrode members 16a are aligned along the first direction D1. The plurality of second waveguide electrode members 16b are aligned along the first direction D1. The direction from the plurality of first waveguide electrode members 16a to the plurality of second waveguide electrode members 16b is along the second direction D2. The SIW15B is formed by a first waveguide conductive layer 17a, a first other waveguide conductive layer 17b, a plurality of first waveguide electrode members 16a, and a plurality of second waveguide electrode members 16b.

[0031] In this example, a third waveguide electrode member 16c and a fourth waveguide electrode member 16d are provided. The third waveguide electrode member 16c and the fourth waveguide electrode member 16d are electrically connected to the first waveguide conductive layer 17a and the first other waveguide conductive layer 17b. The distance between the third waveguide electrode member 16c and the fourth waveguide electrode member 16d along the second direction D2 is shorter than the distance between the plurality of first waveguide electrode members 16a and the plurality of second waveguide electrode members 16b along the second direction D2. The position of the third waveguide electrode member 16c in the first direction D1 is between the position of the first conductive layer 15c in the first direction D1 and the positions of the plurality of first waveguide electrode members 16a in the first direction D1. The position of the fourth waveguide electrode member 16d in the first direction D1 is between the position of the first conductive layer 15c in the first direction D1 and the positions of the plurality of second waveguide electrode members 16b in the first direction D1.

[0032] For example, an opening 15Ba is provided at the first direction D1 end of SIW15B. The opening 15Ba functions as an aperture antenna. SIW15B includes the portion excluding the opening 15Ba. The portion excluding the opening 15Ba corresponds to the feed line SIW15Bb. The opening 15Ba is located, for example, between the third waveguide electrode member 16c and the director 15A, and between the fourth waveguide electrode member 16d and the director 15A.

[0033] One SIW15B is coupled with another waveguide (another SIW15B) and another director 15A. Multiple structures are provided, each including the director 15A, SIW15B, another waveguide (SIW15B), and the other director 15A. Multiple such structures are arranged along the second direction D2.

[0034] The potential of the first other conductive member 16g is fixed, for example. The potential of the first other conductive member 16g may be, for example, the ground potential.

[0035] The following describes examples of the shapes of multiple receiving elements 25. As shown in Figure 7, the second substrate 28 of the receiving antenna 20 includes a second surface 28f and a second other surface 28g. The direction from the second other surface 28g to the second surface 28f is along the second direction D2. A second conductive member 26f is provided on the second surface 28f. A second other conductive member 26g is provided on the second other surface 28g. The second substrate 28 is provided between these conductive members.

[0036] As shown in Figures 5 and 7, the second conductive member 26f forms a pseudo-Yagi antenna 25A. The pseudo-Yagi antenna 25A includes, for example, a second waveguide conductive layer 25c, a first radiating conductive layer 25a, and a first other radiating conductive layer 25b. The direction from the first other radiating conductive layer 25b to the first radiating conductive layer 25a is along the third direction D3. The first radiating conductive layer 25a extends along the third direction D3. The first other radiating conductive layer 25b extends along the third direction D3. The second waveguide conductive layer 25c is separated from the first radiating conductive layer 25a and the first other radiating conductive layer 25b along the first direction D1. In the first direction D1, the second waveguide conductive layer 25c faces the first radiating conductive layer 25a and the first other radiating conductive layer 25b.

[0037] As shown in Figure 5, the first radiating conductive layer 25a and the first other radiating conductive layer 25b are electrically connected to the power supply line 24a. In this example, a balun 26B is provided between the first radiating conductive layer 25a and the power supply line 24a, and between the first other radiating conductive layer 25b and the power supply line 24a. The balun 26B is capable of mutual conversion between balanced and unbalanced lines. The balun 26B is formed by the second conductive member 26f. In this example, the first radiating conductive layer 25a is connected to the balun 26B by the conductive layer 27a. The first other radiating conductive layer 25b is connected to the balun 26B by the conductive layer 27b.

[0038] The second other conductive member 26g forms the second other conductive waveguide layer 24b. The potential of the second other conductive member 26g (second other conductive waveguide layer 24b) is fixed, for example. The potential of the second other conductive member 26g may be, for example, the ground potential.

[0039] Multiple receiving elements 25 (pseudo-Yagi antenna 25A) as described above are arranged along the third direction D3.

[0040] The maximum value of the mutual coupling between the multiple receiving elements 25 (pseudo-Yagi antenna 25A) described above is smaller than the maximum value of the mutual coupling between the multiple transmitting elements 15 (aperture 15Ba of SIW15B) described above.

[0041] In a typical array antenna, multiple elements in both the transmitting and receiving antennas operate simultaneously. However, in systems like multistatic radar, multiple elements in the transmitting and receiving array antennas operate independently. For example, in a multistatic radar, one element in the transmitting array antenna transmits sequentially, while multiple elements in the receiving array antenna receive simultaneously. In an array antenna, multiple elements are interconnected. This interconnection affects the antenna's operational characteristics. In this case, the transmitting array antenna can properly terminate any non-operating transmitting elements. Therefore, the radar's detection characteristics are not affected by interconnection between elements.

[0042] On the other hand, if the mutual coupling in the receiving antenna is large, the electromagnetic field from the coupled elements is received as noise. This noise degrades the detection characteristics. High detection characteristics can be maintained by reducing the mutual coupling in the receiving antenna. For example, different shapes can be applied to the transmitting array antenna and the receiving array antenna. This makes it easy to make the maximum mutual coupling between elements of the receiving array antenna smaller than the maximum mutual coupling between elements of the transmitting array antenna.

[0043] For example, there are reference examples where metamaterials (including metal walls, etc.) are placed between multiple elements. This can suppress inter-element coupling. For instance, in a patch antenna that radiates electromagnetic waves perpendicular to the substrate, it is easy to form metamaterials by creating metal patterns on or inside the substrate surface. However, when applying the metamaterial method to an antenna that radiates in the direction of the side of the substrate, processing is performed on the side of the substrate. Furthermore, when installing metal walls between multiple elements in high-frequency bands such as the millimeter wave band, processing with high precision is required.

[0044] With the above configuration, which allows for the omission of metamaterials and other components, high performance can be more easily obtained in millimeter-wave band substrate-side-radiating antennas.

[0045] As shown in Figure 5, distance d25 is defined as the distance along the third direction D3 between the position of one of the multiple receiving elements 25 in the third direction D3 and the position of another of the multiple receiving elements 25 in the third direction D3. Distance d25 is less than or equal to the wavelength of the signal received by the multiple receiving elements 25. The other one of the multiple receiving elements 25 is adjacent to the other one. Distance d25 corresponds to the pitch of the multiple receiving elements 25. By shortening distance d25, the device can be miniaturized.

[0046] As shown in Figure 1, the antenna device 110 may include another transmitting antenna 10A and another receiving antenna 20A. In this example, the direction from transmitting antenna 10 to another transmitting antenna 10A is along the third direction D3. In this example, the direction from receiving antenna 20 to another receiving antenna 20A is along the second direction D2. The configuration of the other transmitting antenna 10A may be the same as that of transmitting antenna 10. The configuration of the other receiving antenna 20A may be the same as that of receiving antenna 20.

[0047] Figures 8 and 9 are schematic diagrams illustrating an antenna device according to the first embodiment. Figure 8 illustrates a transmitting antenna 10. In the transmitting antenna 10, multiple transmitting elements 15 may be coupled to a first electronic circuit 15D. For example, radio waves are transmitted from the multiple transmitting elements 15 by the operation of the first electronic circuit 15D. The transmitting antenna 10 may include the first electronic circuit 15D. The first electronic circuit 15D may be provided separately from the transmitting antenna 10.

[0048] Figure 9 illustrates a receiving antenna 20. In the receiving antenna 20, multiple receiving elements 25 may be coupled to a second electronic circuit 25D. For example, the operation of the second electronic circuit 25D processes the radio waves received by the multiple receiving elements 25. The receiving antenna 20 may include the second electronic circuit 25D. The second electronic circuit 25D may be provided separately from the receiving antenna 20.

[0049] The first electronic circuit 15D and the second electronic circuit 25D may include a control circuit 70. For example, the radar device 210 includes an antenna device 110 and a control circuit 70.

[0050] Information regarding mutual coupling can be obtained by various methods. For example, methods for estimating the amount of mutual coupling from measured antenna radiation patterns include using the Fourier transform and the least squares method. In the least squares method, let "F" be the radiation pattern when there is no mutual coupling between antennas (the far-field radiation field of a single antenna), and "F'" be the radiation pattern when mutual coupling between antennas exists. If "C" is the amount of mutual coupling between antennas, then "F" is equal to the product of "F'" and "C". By utilizing this relationship, the amount of mutual coupling "C" can be determined. For example, radiation pattern "F" corresponds to the radiation pattern measured for the antenna being measured alone, with all other antennas removed. Radiation pattern "F'", which is altered by the array, corresponds to the radiation pattern measured with terminators connected to the antennas other than the one being measured.

[0051] The mutual coupling value between the multiple transmitting elements 15 may be, for example, the mutual coupling value between the aperture 15Ba of the SIW15B included in one of the multiple transmitting elements 15 and the aperture 15Ba of the SIW15B included in another of the multiple transmitting elements 15.

[0052] (Second Embodiment) Figure 10 is a schematic perspective view illustrating an antenna device according to the second embodiment. Figure 11 is a schematic plan view illustrating a part of the antenna device according to the second embodiment. As shown in Figure 10, in the antenna device 111 according to this embodiment, the configuration of the receiving antenna 20 is different from the configuration of the receiving antenna 20 in antenna device 110. The rest of the configuration of antenna device 111 may be the same as that of antenna device 110. For example, the configuration of the transmitting antenna 10 in antenna device 111 is the same as the configuration of the transmitting antenna 10 in antenna device 110.

[0053] Figure 11 illustrates a receiving antenna 20 in an antenna device 111. As shown in Figure 11, the receiving antenna 20 includes a plurality of receiving elements 25. The plurality of receiving elements 25 include a plurality of first elements 21 and a plurality of second elements 22. In the antenna device 111, the following first maximum values ​​are smaller than the maximum mutual coupling between the plurality of transmitting elements 15. The first maximum values ​​are the maximum mutual coupling between the plurality of first elements 21, the maximum mutual coupling between the plurality of second elements 22, and the maximum mutual coupling between the plurality of first elements 21 and the plurality of second elements 22. This allows for noise suppression and provides an antenna device with improved performance.

[0054] The shape of one of the multiple first elements 21 may differ from the shape of one of the multiple second elements 22. Different types of elements are provided as the multiple first elements 21 and the multiple second elements 22.

[0055] In this example, one of the multiple first elements 21 is placed between one of the multiple second elements 22 and another of the multiple second elements 22. One of the multiple second elements 22 is placed between one of the multiple first elements 21 and another of the multiple first elements 21.

[0056] In this example, one of the multiple first elements 21 includes a pseudo-Yagi antenna 25A. One of the multiple second elements 22 includes an SIW25S. The configuration of the SIW25S may be similar to that of, for example, the SIW15B. The SIW25S includes an aperture, similar to the SIW15B. One of the multiple second elements 22 may further include a director similar to the director 15A, in addition to the SIW25S.

[0057] Thus, in the antenna device 111, each of the multiple transmitting elements 15 includes an SIW 15B with an aperture 15Ba. One of the multiple receiving elements 25 includes a pseudo-Yagi antenna 25A. Another of the multiple receiving elements 25 includes an SIW 25S.

[0058] Figure 12 is a schematic plan view illustrating a part of the antenna device according to the second embodiment. As shown in Figure 12, in the antenna device 112 according to this embodiment, the configuration of the transmitting antenna 10 differs from the configuration of the transmitting antenna 10 in the antenna device 110. The rest of the configuration of the antenna device 112 may be the same as that of the antenna device 110. For example, the configuration of the receiving antenna 20 in the antenna device 112 is the same as the configuration of the receiving antenna 20 in the antenna device 110.

[0059] As shown in Figure 12, the transmitting antenna 10 includes a plurality of transmitting elements 15. The plurality of transmitting elements 15 includes a plurality of third elements 13 and a plurality of fourth elements 14. The following second maximum value is greater than the maximum mutual coupling between the plurality of receiving elements 25. The second maximum value is the maximum mutual coupling between the plurality of third elements 13, the maximum mutual coupling between the plurality of fourth elements 14, and the maximum mutual coupling between the plurality of third elements 13 and the plurality of fourth elements 14.

[0060] In this case as well, the mutual coupling among the multiple receiving elements 25 is small. Noise can be suppressed. An antenna device with improved performance can be provided.

[0061] The shape of one of the multiple third elements 13 differs from the shape of one of the multiple fourth elements 14. Different types of elements are provided as the multiple third elements 13 and the multiple fourth elements 14.

[0062] One of the multiple third elements 13 is provided between one of the multiple fourth elements 14 and another of the multiple fourth elements 14. One of the multiple fourth elements 14 is provided between one of the multiple third elements 13 and another of the multiple third elements 13.

[0063] In this example, one of the multiple third elements 13 includes an SIW 15B with an aperture 15Ba. One of the multiple fourth elements 14 includes a pseudo-Yagi antenna 14Y. The configuration of the pseudo-Yagi antenna 14Y may be the same as, for example, that of the pseudo-Yagi antenna 25A.

[0064] As described below, at least some of the multiple transmitting elements 15 may include an SIW 15B with an aperture 15Ba. In this case, at least some of the multiple receiving elements 25 may include a tapered slot antenna.

[0065] For example, each of the multiple transmitting elements 15 includes an SIW 15B with an aperture 15Ba. In this case, one of the multiple receiving elements 25 may include a pseudo-Yagi antenna 25A, and another of the multiple receiving elements 25 may include a tapered slot antenna.

[0066] The following describes an example of a tapered slot antenna. Figure 13 is a schematic plan view illustrating a part of the antenna device according to the embodiment. Figure 14 is a schematic cross-sectional view illustrating a part of the antenna device according to the embodiment. As shown in Figures 13 and 14, the tapered slot antenna 35A includes, for example, a third substrate 38, a feed line 38b, and a conductive layer 38a. When at least some of the multiple receiving elements 25 include the tapered slot antenna 35A, the third substrate 38 may be continuous with the second substrate 28 (see Figure 1, etc.). The third substrate 38 includes a third surface 38f and a third other surface 38g. In this example, the direction from the third other surface 38g to the third surface 38f is along the second direction D2.

[0067] As shown in Figure 14, the power supply line 38b is provided on, for example, the third other surface 38g. The conductive layer 38a is provided on the third surface 38f. The conductive layer 38a is, for example, a ground conductor. In the second direction D2, the power supply line 38b overlaps with a portion of the conductive layer 38a. The power supply line 38b is, for example, a microstrip line.

[0068] As shown in Figure 13, in the third surface 38f, the width 38w along the third direction D3 of the region where the conductive layer 38a is not provided changes in the first direction D1. This region is tapered.

[0069] The tapered slot antenna 35A can transmit and receive electric fields in the +Z direction (away from the feed line 38b in the Z-axis direction). The electric field is parallel to the X-axis direction.

[0070] Multiple tapered slot antennas 35A may be provided, for example, along a third direction D3. Such tapered slot antennas 35A may be at least some of the multiple receiving elements 25.

[0071] The antenna device described above can be used in a radar device. The embodiment may include a radar device. The radar device is installed in a facility. The facility includes, for example, an airport, a train station, a shopping mall, a concert hall, or an exhibition hall. The radar device is used, for example, to perform security checks to determine whether a person being inspected (a user of the facility) is carrying dangerous goods.

[0072] For example, a radar device sequentially emits radio waves to each point on the target and sequentially receives the radio waves reflected by each point on the target. This scans the target. Based on the received signals obtained through scanning, an image including the target is generated.

[0073] By reviewing this image, facility managers can determine whether the person in question is possessing hazardous materials. For example, managers can determine whether hazardous materials are hidden among the person's belongings. Radar equipment or external devices may analyze the amplitude of the received signal. Radar equipment or external devices may also warn about the level of likelihood that the person is possessing hazardous materials.

[0074] For example, in security checks, multiple hazardous materials may be detected in clothing pockets. Radar devices used in security checks require high angular resolution. Angular resolution is determined by the aperture length of the array antenna. For example, MIMO (Multi-input and Multi-output) radar expands the aperture length and improves angular resolution. MIMO radar uses a large number of antennas. This makes the design complex and expensive. In this embodiment, the array antenna includes a small number of antennas. In this embodiment, a design that simplifies wiring is employed.

[0075] Figure 15 is a block diagram illustrating a radar device according to an embodiment. The radar device 100 includes, for example, a transmitting / receiving unit 200, a reference signal generation unit 300, a signal processing unit 400, and a controller 500. The antenna device described above is provided on the transmitting / receiving unit 200. The radar device 100 may be, for example, a radar system. The radar system may be, for example, an inspection radar system. The radar system may be, for example, a safety inspection radar system.

[0076] The reference signal generation unit 300 includes a reference signal generation unit 310, a DAC (Digital to Analog Converter) 320, and a reference clock generation unit 330.

[0077] Various radar systems can be employed. For example, the FMCW (Frequency Modulated Continuous Wave) system can be used. In an FMCW radar system, radio waves are emitted from the target, and the reflected radio waves from the target are received. In an FMCW radar system, the distance to the target can be measured from the difference between the frequency of the transmitted signal and the frequency of the received signal.

[0078] The reference signal generation unit 310 generates, for example, a digital signal. This digital signal represents an FMCW signal (hereinafter referred to as a chirp signal). The frequency of the FMCW signal increases linearly over time.

[0079] The DAC320 converts the digital signal generated by the reference signal generation unit 310 into an analog signal. The DAC320 generates a chirp signal for the analog signal.

[0080] The reference clock generation unit 330 generates a reference clock.

[0081] The chirp signal and reference clock generated by the reference signal generation unit 300 are output to the transmit / receive unit 200. The connection between the reference signal generation unit 300 and the transmit / receive unit 200 is made, for example, by wire or wireless.

[0082] The transmitting / receiving unit 200 includes at least one (in this case, four) radar panels 210a, 210b, 210c, and 210d. The number of radar panels included in the transmitting / receiving unit 200 may be two or more, or it may be just one.

[0083] Each of the radar panels 210a to 210d is supplied with a chirp signal and a reference clock. Each of the radar panels 210a to 210d emits radio waves corresponding to the chirp signal to the target and receives reflected radio waves from the target.

[0084] In this embodiment, the wavelength of the radio wave is, for example, 1 mm to 30 mm. Radio waves with a wavelength of 1 mm to 30 mm are, for example, millimeter waves. Radio waves with a wavelength of 10 mm to 100 mm are, for example, microwaves. Radio waves with a wavelength of 100 μm to 1 mm are, for example, terahertz waves. In this embodiment, millimeter waves, microwaves, or terahertz waves may be used.

[0085] Each of the radar panels 210a to 210d converts the received reflected radio wave signal into an intermediate frequency signal (IF signal). The IF signals obtained by each of the radar panels 210a to 210d are output to the signal processing unit 400. The connection between each of the radar panels 210a to 210d and the signal processing unit 400 may be made by wire or wireless connection.

[0086] The signal processing unit 400 includes, for example, a calibration unit 410, a distance estimation unit 420, a virtual array expansion unit 430, and an approach direction estimation unit 440. The signal processing unit 400 performs signal processing on each of the IF signals of radar panels 210a to 210d.

[0087] The signal processing unit 400 can obtain an image of the subject 600 (subject) within the plane 700. The plane 700 is a plane within the inspection space 800. The plane 700 is parallel to the radar panels 210a to 210d. The inspection space 800 is a three-dimensional space located in the direction of radiation of the radio waves emitted from each of the radar panels 210a to 210d. The image is displayed, for example, by a display device. For example, by observing this image, the inspector can detect that the subject 600 is carrying a dangerous object 610 (e.g., a gun).

[0088] The radar device 100 may continuously emit radio waves into the inspection space 800 to perform inspections at all times. The radar device 100 may include a camera that takes pictures of the inspection space 800. The radar device 100 may recognize the target 600 from the image of the inspection space 800 taken by the camera. If the radar device 100 recognizes the target 600, it may perform inspections by emitting radio waves only towards the target 600. The controller 500 controls the operation of the radar device 100, including the transmitting and receiving unit 200.

[0089] The transmitting / receiving unit 200 is connected to the controller 500 by wire or wireless connection. The controller 500 controls the transmission frequency and bandwidth of the transmitting antenna, as well as the transmission timing of each of the multiple transmitting antennas. The controller 500 also controls the reception timing (time from transmission to reception) of each of the multiple receiving antennas.

[0090] The embodiment may include the following configuration (e.g., proposed technical details). (Composition 1) A transmitting antenna including multiple transmitting elements, A receiving antenna comprising a plurality of receiving elements, wherein the maximum value of the mutual coupling between the plurality of receiving elements is less than the maximum value of the mutual coupling between the plurality of transmitting elements, An antenna device equipped with this device.

[0091] (Configuration 2) The transmitting antenna includes a first substrate including a first surface, The receiving antenna includes a second substrate which includes a second surface, The plane containing the second surface intersects the plane containing the first surface, The plurality of transmitting elements are provided along the first surface, The plurality of receiving elements are provided along the second surface, as described in Configuration 1 of the antenna device.

[0092] (Composition 3) The first surface is aligned along the first and second directions, The second direction intersects the first direction, The second surface is aligned along the first and third directions, The antenna device according to configuration 2, wherein the third direction intersects with a plane including the first and second directions.

[0093] (Composition 4) The second direction is perpendicular to the first direction, The antenna device according to configuration 3, wherein the third direction is orthogonal to the first and second directions.

[0094] (Composition 5) The transmission direction of the transmitting antenna is along the first direction, The receiving direction of the receiving antenna is along the first direction, as described in configuration 3 or 4 of the antenna device.

[0095] (Composition 6) The plurality of transmitting elements are provided on the first surface of the first substrate, or at least a portion of the plurality of transmitting elements are provided inside the first substrate. The first surface is along the first surface, The plurality of receiving elements are provided on the second surface of the second substrate, or at least a portion of the plurality of receiving elements are provided inside the second substrate. The antenna device according to any one of configurations 3 to 5, wherein the second surface is aligned with the second surface.

[0096] (Composition 7) An antenna device according to any one of configurations 1 to 6, wherein the shape of one of the plurality of receiving elements is different from the shape of one of the plurality of receiving elements.

[0097] (Composition 8) The plurality of receiving elements include a plurality of first elements and a plurality of second elements, The first maximum value is smaller than the maximum value of the mutual coupling between the plurality of transmitting elements. The antenna device according to any one of configurations 1 to 6, wherein the first maximum value is the maximum value of the mutual coupling between the plurality of first elements, the maximum value of the mutual coupling between the plurality of second elements, and the maximum value of the mutual coupling between the plurality of first elements and the plurality of second elements.

[0098] (Composition 9) One of the plurality of first elements is provided between one of the plurality of second elements and another of the plurality of second elements. The antenna device according to configuration 8, wherein one of the plurality of second elements is provided between one of the plurality of first elements and another of the plurality of first elements.

[0099] (Composition 10) The antenna device according to configuration 8, wherein the shape of one of the plurality of first elements is different from the shape of one of the plurality of second elements.

[0100] (Composition 11) The aforementioned plurality of transmitting elements include a plurality of third elements and a plurality of fourth elements, The second maximum value is greater than the maximum value of the mutual coupling between the plurality of receiving elements. The antenna device according to any one of configurations 1 to 6, wherein the second maximum value is the maximum value of the mutual coupling between the plurality of third elements, the maximum value of the mutual coupling between the plurality of fourth elements, and the maximum value of the mutual coupling between the plurality of third elements and the plurality of fourth elements.

[0101] (Composition 12) One of the plurality of third elements is provided between one of the plurality of fourth elements and another of the plurality of fourth elements. The antenna device according to configuration 11, wherein one of the plurality of fourth elements is provided between one of the plurality of third elements and another of the plurality of third elements.

[0102] (Composition 13) The antenna device according to configuration 11, wherein the shape of one of the plurality of third elements is different from the shape of one of the plurality of fourth elements.

[0103] (Composition 14) At least a portion of the plurality of transmitting elements includes an SIW (Substrate Integrated Waveguide) with an aperture, An antenna device according to any one of configurations 1 to 6, wherein at least some of the plurality of receiving elements include a pseudo-Yagi antenna.

[0104] (Composition 15) Each of the aforementioned plurality of transmitting elements includes an SIW (Substrate Integrated Waveguide) including an aperture, One of the aforementioned receiving elements includes a pseudo-Yagi antenna, The antenna device according to any one of configurations 1 to 6, wherein another of the plurality of receiving elements includes an SIW with an aperture.

[0105] (Composition 16) At least a portion of the plurality of transmitting elements includes an SIW (Substrate Integrated Waveguide) with an aperture, An antenna device according to any one of configurations 1 to 6, wherein at least some of the plurality of receiving elements include a tapered slot antenna.

[0106] (Composition 17) Each of the aforementioned plurality of transmitting elements includes an SIW (Substrate Integrated Waveguide) including an aperture, One of the aforementioned receiving elements includes a pseudo-Yagi antenna, The antenna device according to any one of configurations 1 to 6, wherein another of the plurality of receiving elements includes a tapered slot antenna.

[0107] (Composition 18) The plurality of receiving elements are arranged along the third direction, The distance along the third direction between the position of one of the plurality of receiving elements in the third direction and the position of another of the plurality of receiving elements in the third direction is less than or equal to the wavelength of the signal received by the plurality of receiving elements. The antenna device according to any one of configurations 3 to 6, wherein one of the plurality of receiving elements is adjacent to one of the plurality of receiving elements.

[0108] (Composition 19) The antenna device described in Configuration 1, A controller capable of controlling the transmission of the transmitting antenna and the reception of the receiving antenna, A radar system equipped with [a specific feature / feature].

[0109] According to the embodiment, it is possible to provide an antenna device and radar system that can improve performance.

[0110] Embodiments of the present invention have been described above with reference to examples. However, the present invention is not limited to these examples. For example, the specific configuration of each element included in an antenna device, such as a transmitting antenna, transmitting element, receiving antenna, receiving element, and substrate, is included within the scope of the present invention as long as those skilled in the art can appropriately select from the known scope to implement the present invention in the same way and obtain similar effects.

[0111] Combinations of two or more elements from each example, to the extent technically feasible, are also included within the scope of the present invention, insofar as they encompass the gist of the invention.

[0112] All antenna devices that a person skilled in the art can implement by appropriately modifying the design based on the antenna device described above as an embodiment of the present invention also fall within the scope of the present invention, insofar as they encompass the gist of the present invention.

[0113] Within the scope of the concept of this invention, a person skilled in the art would be able to conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of this invention.

[0114] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0115] 10, 10A: Transmitting antenna, 10D: Transmitting direction, 13, 14: Third and fourth elements, 14Y: Pseudo-Yagi antenna, 15: Transmitting element, 15A: Director, 15B: SIW, 15Ba: Aperture, 15Bb: Feed line SIW, 15D: First electronic circuit, 15a, 15b: First and second electrode members, 15c: First conductive layer, 15d: First other conductive layer, 16a~16d: First to fourth waveguide electrode members, 16f: First conductive member, 16g: First other conductive member, 17a: First waveguide conductive layer, 17b: First other waveguide conductive layer, 18: First substrate, 18f: First surface, 18fa: First surface, 18g: First other surface, 18s: First side 20, 20A: Receiving antenna, 20D: Receiving direction, 21, 22: First and second elements, 24a: Feed line, 24b: Second other waveguide conductive layer, 25: Receiving element, 25A: Pseudo-Yagi antenna, 25D: Second electronic circuit, 25S: SIW, 25a: First radiating conductive layer, 25b: First other radiating conductive layer, 25c: Second waveguide conductive layer, 26B: Balun, 26f: Second conductive member, 26g: Second other conductive member, 27a, 27b: Conductive layer, 28: Second substrate, 28f: Second surface, 28fa: Second surface, 28g: Second other surface, 28s: Second side, 35A: Tapered slot antenna, 38: Third substrate, 38a: Conductive layer, 38b: Power supply line, 38f: Third surface, 38g: Third other surface, 70: Control circuit, 100: Radar device, 110~112: Antenna device, 200: Transceiver unit, 210: Radar device, 210a~210d: Radar panel, 300: Reference signal generation unit, 310: Reference signal generation unit, 330: Reference clock generation unit, 400: Signal processing unit, 410: Calibration unit, 420: Distance estimation unit, 430: Virtual array expansion unit, 440: Direction of arrival estimation unit, 500: Controller, 600: Target, 610: Hazardous material, 700: Plane, 800: Inspection space, D1~D3: First to third directions, d25: Distance

Claims

1. A transmitting antenna including multiple transmitting elements, A receiving antenna including multiple receiving elements, Equipped with, The transmitting antenna and the receiving antenna satisfy any of the first, second, third, and fourth conditions. In the first condition described above, at least a portion of the plurality of transmitting elements includes a Substrate Integrated Waveguide (SIW) including an aperture, and at least a portion of the plurality of receiving elements includes a pseudo-Yagi antenna. In the second condition described above, each of the plurality of transmitting elements includes a Substrate Integrated Waveguide (SIW) including an aperture, one of the plurality of receiving elements includes a pseudo-Yagi antenna, and another of the plurality of receiving elements includes an SIW including an aperture. In the third condition described above, at least a portion of the plurality of transmitting elements includes a Substrate Integrated Waveguide (SIW) including an aperture, and at least a portion of the plurality of receiving elements includes a tapered slot antenna. An antenna device in the fourth condition described above, wherein each of the plurality of transmitting elements includes a Substrate Integrated Waveguide (SIW) including an aperture, one of the plurality of receiving elements includes a pseudo-Yagi antenna, and another of the plurality of receiving elements includes a tapered slot antenna.

2. The transmitting antenna includes a first substrate including a first surface, The receiving antenna includes a second substrate which includes a second surface, The plane containing the second surface intersects the plane containing the first surface, The plurality of transmitting elements are provided along the first surface, The antenna device according to claim 1, wherein the plurality of receiving elements are provided along the second surface.

3. The first surface is aligned along the first and second directions, The second direction intersects the first direction, The second surface is aligned with the first and third directions, The antenna device according to claim 2, wherein the third direction intersects a plane including the first and second directions.

4. The second direction is perpendicular to the first direction, The antenna device according to claim 3, wherein the third direction is orthogonal to the first and second directions.

5. The transmission direction of the transmitting antenna is along the first direction, The antenna device according to claim 3, wherein the receiving direction of the receiving antenna is along the first direction.

6. The plurality of transmitting elements are provided on the first surface of the first substrate, or at least a portion of the plurality of transmitting elements are provided inside the first substrate. The first surface is along the first surface, The plurality of receiving elements are provided on the second surface of the second substrate, or at least a portion of the plurality of receiving elements are provided inside the second substrate. The antenna device according to claim 3, wherein the second surface is aligned with the second surface.

7. The antenna device according to claim 1, wherein the shape of one of the plurality of receiving elements is different from the shape of one of the plurality of receiving elements.

8. The plurality of receiving elements include a plurality of first elements and a plurality of second elements, One of the plurality of first elements is provided between one of the plurality of second elements and another of the plurality of second elements. The antenna device according to claim 1, wherein one of the plurality of second elements is provided between one of the plurality of first elements and another of the plurality of first elements.

9. The antenna device according to claim 1, A controller capable of controlling the transmission of the transmitting antenna and the reception of the receiving antenna, A radar system equipped with [a specific feature / feature].

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