Antenna element, antenna array, and antenna module

Abstract

An antenna element according to one embodiment of the present technology comprises: a dielectric block; a power supply terminal provided to the dielectric block; a pair of conductor layers facing each other, the dielectric block being interposed between the pair of conductor layers; and an antenna opening portion in which a first antenna opening, which opens in a first axis direction when viewed from the power supply terminal, and a second antenna opening, which opens in a second axis direction orthogonal to the first axis, are formed in a planar direction along the pair of conductor layers.

Description

Technical Field

[0001] This technology relates to, for example, antenna elements, antenna arrays, and antenna modules capable of transmitting or receiving millimeter-wave electromagnetic waves. Background Technology

[0002] In recent years, millimeter-wave modules (such as radar) for detecting people and obstacles have become increasingly popular for automotive applications. The mainstream antenna device of this type is a phased-array antenna formed on a substrate. However, because radio waves radiate in a direction perpendicular to the substrate surface, this type of antenna is difficult to make thin.

[0003] Meanwhile, a horn antenna using a technique called a cylindrical waveguide is known (for example, see Patent Document 1). A cylindrical waveguide is a waveguide comprising cylindrical walls formed by arranging multiple metal pillars (conductor pillars) electrically connected to upper and lower conductors (copper foil) of a wiring substrate. Because the cylindrical waveguide includes antenna openings on the side surface of the wiring substrate, a thinner antenna design can be achieved.

[0004] Reference List

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2022 / 097490 Summary of the Invention

[0007] Technical issues

[0008] However, in antennas that radiate radio waves from a cylindrical waveguide, the waveguide from the feed terminal to the antenna opening is divided by a conductor pillar, so the directivity is narrowed to the forward direction, making it difficult to apply the antenna to applications that require the detection of objects over a wide field of view.

[0009] In view of the above, this technology aims to provide antenna elements, antenna arrays, and antenna modules that can detect objects with a wide field of view while achieving antenna thinning.

[0010] Solution to the problem

[0011] An antenna element according to an embodiment of the present technology includes: a dielectric block; a feed terminal disposed in the dielectric block; a pair of conductor layers opposite to each other, with the dielectric block located between the pair of conductor layers; and an antenna opening, forming a first antenna opening and a second antenna opening along the planar direction of the pair of conductor layers, the first antenna opening opening in a first axial direction when viewed from the feed terminal, and the second antenna opening opening in a second axial direction orthogonal to the first axis.

[0012] An antenna array according to an embodiment of the present technology includes: a dielectric block; a plurality of feed terminals disposed in the dielectric block; a pair of conductor layers opposite to each other, with the dielectric block located between the pair of conductor layers; and an antenna opening, forming a first antenna opening and a second antenna opening along the planar direction of the pair of conductor layers, the first antenna opening opening in a first axial direction when viewed from the feed terminals, and the second antenna opening opening in a second axial direction orthogonal to the first axis.

[0013] An antenna module according to an embodiment of the present technology includes: a transmitting antenna composed of antenna elements; and a receiving antenna composed of an antenna array. Attached Figure Description

[0014] Figure 1 This is a partial transmission perspective view showing an antenna element according to an embodiment of the present technology.

[0015] Figure 2 This is a plan view of the antenna element.

[0016] Figure 3 This is a schematic side cross-sectional view showing the layered structure of the antenna element.

[0017] Figure 4 This is an illustration of the layer structure of the dielectric multilayer substrate that constitutes the antenna element.

[0018] Figure 5 This is a schematic diagram used to illustrate the gaps between conductive pillars in an antenna element.

[0019] Figure 6 This is a partially exploded perspective view showing an example of the configuration of the feed section in an antenna element.

[0020] Figure 7 This is a side cross-sectional view of the main part of the power supply section.

[0021] Figure 8 This is a partial side cross-sectional view showing another configuration example of the power supply section.

[0022] Figure 9 The simulation results show an example of the voltage standing wave ratio (VSWR) of an antenna element.

[0023] Figure 10 This shows the simulation results of the antenna element's radiation characteristics in the azimuth plane.

[0024] Figure 11 This is a simulation result showing the radiation characteristics of the antenna element in the elevation plane.

[0025] Figure 12 This is another simulation result showing the VSWR characteristics of the antenna element.

[0026] Figure 13 It is shown that has Figure 12 Simulation results of the radiation characteristics of the antenna element with the shown characteristics in the azimuth plane.

[0027] Figure 14 It is shown that has Figure 12 Simulation results of the radiation characteristics of the antenna element with the shown characteristics in the elevation (XZ) plane.

[0028] Figure 15 This is a partial transmission perspective view showing the configuration of an antenna module according to an embodiment of the present technology.

[0029] Figure 16 This is a plan view of the antenna module.

[0030] Figure 17 This is a block diagram showing the circuit configuration of the antenna module.

[0031] Figure 18 This is a conceptual diagram illustrating MIMO radar.

[0032] Figure 19 This shows the simulation results of the VSWR characteristics of each antenna in the antenna module.

[0033] Figure 20 This is a simulation result showing the radiation characteristics of each receiving antenna in the antenna module in the azimuth plane.

[0034] Figure 21 This is a simulation result showing the radiation characteristics of each receiving antenna in the antenna module in the elevation plane.

[0035] Figure 22 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to the first transmitting antenna.

[0036] Figure 23 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to the second transmitting antenna.

[0037] Figure 24 The simulation results show an example of the phase difference characteristics of received radio waves.

[0038] Figure 25 This is a plan view of the main parts of an antenna module according to another embodiment of the present technology.

[0039] Figure 26 This is a simulation result showing the radiation characteristics of each receiving antenna in the antenna module in the azimuth plane.

[0040] Figure 27 This is a simulation result showing the radiation characteristics of each receiving antenna in the antenna module in the elevation plane.

[0041] Figure 28 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to the first transmitting antenna.

[0042] Figure 29 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to the second transmitting antenna.

[0043] Figure 30 The simulation results show an example of the phase difference characteristics of the received radio waves by the antenna module.

[0044] Figure 31 This is a plan view of the main part of another configuration example of the shielding of the antenna module.

[0045] Figure 32 This is a plan view of the main part of another configuration example of the waveguide plate portion of the antenna element.

[0046] Figure 33 This is a plan view of the antenna module viewed from above according to the fourth embodiment of the present technology.

[0047] Figure 34 This is a plan view showing the internal structure of the antenna module as seen from above.

[0048] Figure 35 This is a plan view of the antenna module as seen from below.

[0049] Figure 36 This shows the simulation results of the VSWR characteristics of each antenna in the antenna module.

[0050] Figure 37 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the azimuth plane.

[0051] Figure 38 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the elevation plane.

[0052] Figure 39 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to a transmitting antenna.

[0053] Figure 40 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to another transmitting antenna.

[0054] Figure 41 The simulation results show an example of the phase difference characteristics of the received radio waves by the antenna module.

[0055] Figure 42This is a plan view of the antenna module viewed from above according to the fifth embodiment of the present technology.

[0056] Figure 43 This is a plan view showing the internal structure of the antenna module as seen from above.

[0057] Figure 44 This is a plan view of the antenna module as seen from below.

[0058] Figure 45 This is a partial transmission perspective view showing the main parts of the antenna module.

[0059] Figure 46 This shows the simulation results of the VSWR characteristics of each antenna in the antenna module.

[0060] Figure 47 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the azimuth plane.

[0061] Figure 48 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the elevation plane.

[0062] Figure 49 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to a transmitting antenna.

[0063] Figure 50 This is a simulation result showing the isolation characteristics of each receiving antenna in the antenna module relative to another transmitting antenna.

[0064] Figure 51 The simulation results show an example of the phase difference characteristics of the received radio waves by the antenna module.

[0065] Figure 52 This is a partial transmission perspective view showing an antenna element according to a sixth embodiment of the present technology.

[0066] Figure 53 This is a plan view of the antenna elements as seen from above.

[0067] Figure 54 This is a plan view showing the internal structure of the antenna element.

[0068] Figure 55 This is a cross-sectional view showing the layered structure of the antenna element.

[0069] Figure 56 This is a diagram showing how the electric field intensity distribution in the antenna element changes over time.

[0070] Figure 57 The simulation results show the VSWR characteristics of the antenna element.

[0071] Figure 58 The simulation results show the radiation characteristics of the antenna element in the azimuth and elevation planes.

[0072] Figure 59 The simulation results show the relationship between the depth of the second post waveguide and the beamwidth in the antenna element.

[0073] Figure 60 This is a partial transmission perspective view of an antenna module according to the seventh embodiment of the present technology.

[0074] Figure 61 This is a plan view of the antenna module as seen from above.

[0075] Figure 62 This is a diagram showing the electric field intensity distribution in this antenna module and an antenna module given as a comparative example.

[0076] Figure 63 This shows the simulation results of the VSWR characteristics of each antenna in the antenna module.

[0077] Figure 64 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the azimuth plane.

[0078] Figure 65 This is a simulation result showing the radiation characteristics of each antenna in the antenna module in the elevation plane.

[0079] Figure 66 This is a simulation result showing the isolation characteristics of each receiving antenna relative to each transmitting antenna in the antenna module.

[0080] Figure 67 The simulation results show an example of the phase difference characteristics of the antenna module.

[0081] Figure 68 This is a cross-sectional view showing a modified example of the power supply configuration. Detailed Implementation

[0082] In the following description, embodiments according to the present technology will be described with reference to the accompanying drawings.

[0083] <First Implementation Method>

[0084] Figure 1 This is a partial transmission perspective view showing an antenna element 100 according to a first embodiment of the present technology. Figure 2 This is a plan view of antenna element 100. Figure 3 This is a schematic side cross-sectional view showing the layered structure of antenna element 100, and Figure 4 This is an explanatory diagram of the layer structure of the dielectric multilayer substrate 1 that constitutes the antenna element 100.

[0085] Note that in each figure, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) represent three mutually orthogonal axial directions, and correspond to the length direction (front-back direction), width direction (left-right direction), and thickness direction (height direction) of the antenna element 100, respectively.

[0086] [Antenna Components]

[0087] The antenna element 100 is composed of a dielectric multilayer substrate 1 having a thickness direction in the Z-axis direction. First, the dielectric multilayer substrate 1 will be described.

[0088] (Dielectric multilayer substrate)

[0089] like Figure 4 As shown, the dielectric multilayer substrate 1 includes, from top to bottom, a plurality of dielectric layers 1A to 1E (five in this example) and a plurality of wiring layers L1 to L6 (six in this example) disposed in these dielectric layers 1A to 1E respectively. The thickness of the dielectric multilayer substrate 1 is, for example, about 1.6 mm.

[0090] Dielectric layers 1A to 1E are formed of insulating organic materials such as epoxy resins and fluorinated resins (such as polytetrafluoroethylene) or insulating inorganic materials such as ceramics. Dielectric layers 1A to 1E can be formed of the same type of dielectric material, or these layers can be formed of different dielectric materials. The dielectric constant of dielectric layers 1A to 1E can be arbitrarily set according to the frequency of the radio waves transmitted or received by antenna element 100. For example, in the case of transmitting and receiving radio waves (millimeter waves) in the 60 GHz band (60 GHz to 64 GHz in this embodiment), a material having a dielectric constant of, for example, 3.6 is used for dielectric layers 1A to 1E.

[0091] The thickness of each of dielectric layers 1A to 1E can be arbitrarily set, and in this embodiment, a core material having a greater thickness than the other dielectric layers 1A, 1B, 1D, and 1E is used for dielectric layer 1C. Compared to the case where dielectric layer 1C is composed of a laminate of dielectric layers, this makes it easier to ensure the rigidity of the dielectric multilayer substrate 1 and enables a reduction in the manufacturing cost of the dielectric multilayer substrate 1. The thickness of dielectric layer 1C is set to, for example, 1.1 mm. Dielectric layer 1C corresponds to the dielectric block according to the present technology.

[0092] Simultaneously, prepreg material can be applied to dielectric layers 1A, 1B, 1D, and 1E. In this case, dielectric layers 1A, 1B, 1D, and 1E are laminated on both sides of dielectric layer 1C using a stacking method. When the dielectric constants of dielectric layers 1A, 1B, 1D, and 1E are set to 3.6, the wavelength of electromagnetic waves propagating through dielectric layers 1A, 1B, 1D, and 1E at a frequency of 60 GHz is shortened from approximately 5 mm to 2.64 mm. In this case, the thickness of each dielectric layer in dielectric layers 1A, 1B, 1D, and 1E can be set to approximately 60 μm.

[0093] Wiring layers L1 to L6 are typically formed of a metallic material, and in this embodiment, copper foil of a predetermined thickness is used. Each of the wiring layers L1 to L6 is patterned into a predetermined shape. Therefore, in non-circuit formation areas where no wiring exists, the upper and lower dielectric layers are directly laminated without intermediate wiring layers.

[0094] Routing layers L1 to L6 are electrically connected to each other at any location. As an interlayer connection connecting routing layers L1 to L6, it can be applied in the form of connecting two adjacent routing layers. Figure 4 Through-hole (also known as LVH) V1) or in the form of connecting three or more wiring layers ( Figure 4 Through holes (also known as IVH) V2). Through holes V1 and V2 are not limited to hollow holes, and can be made of metal pillars filled with conductors such as metal plugs or metal plating.

[0095] Next, refer to Figures 1 to 3 Describe in detail the various parts of antenna element 100.

[0096] The antenna element 100 according to this embodiment includes a dielectric block 10, a conductor layer 20, a rear pillar wall 30, and a feed portion 40. The antenna element 100 can be configured as a transmitting antenna, a receiving antenna, or a transmitting / receiving antenna. Here, the case where the antenna element 100 is configured as a transmitting antenna will be described as an example, but the antenna element 100 can alternatively be configured as a receiving antenna or a transmitting / receiving antenna.

[0097] (Dielectric block)

[0098] The dielectric block 10 corresponds to the dielectric layer 1C in the aforementioned dielectric multilayer substrate 1. The dielectric block 10 is composed of a core material in a single layer, which has a thickness direction in the Z-axis direction and is parallel to the XY plane.

[0099] like Figure 2 As shown, dielectric block 10 includes a front surface 10F, a rear surface 10B, and two side surfaces 10S. Figure 1As shown, the front surface 10F is opposite to the first antenna opening 51 of the antenna element 100 in the X-axis direction, and the two side surfaces 10S are opposite to the second antenna opening 52 of the antenna element 100 in the Y-axis direction, respectively.

[0100] In addition, such as Figure 2 As conceptually illustrated, the dielectric block 10 is mainly divided into a first region R1, a second region R2, and a third region R3. The first region R1 is the region where the rear pillar wall 30 is provided, the second region R2 is the region where the feed section 40 is provided, and the third region is the region where radio waves emitted from the first antenna opening 51 and the second antenna opening 52 propagate. The first region R1 to the third region R3 are three-dimensional regions formed across the entire thickness direction of the dielectric block 10. Note that the first region R1 to the third region R3 are virtual regions used to illustrate the arrangement area of ​​the conductor layer 20, etc.

[0101] (Conductor layer)

[0102] Conductor layer 20 includes a pair of conductor layers 20A and 20B disposed on the two main surfaces of dielectric block 10. Here, the conductor layers 20A and 20B are disposed on the front surface of dielectric block 10. Figure 1 The conductor layer 20 on the upper surface of the dielectric block 10 will also be referred to as the first conductor layer 20A, while the conductor layer 20 disposed on the rear surface of the dielectric block 10 will also be referred to as the first conductor layer 20A. Figure 1 The conductor layer 20 on the lower surface of the substrate is also referred to as the second conductor layer 20B. The first conductor layer 20A corresponds to the wiring layers L1 to L3 in the dielectric multilayer substrate 1, while the second conductor layer 20B corresponds to the wiring layers L4 to L6 in the dielectric multilayer substrate 1.

[0103] The first conductor layer 20A and the second conductor layer 20B each include a base 21 and a waveguide plate portion 22. The base 21 and the waveguide plate portion 22 are integrally formed and are typically connected to ground potential.

[0104] Each base 21 is arranged in a first region R1 of the dielectric block 10 and is opposite to each other in the thickness direction (Z-axis direction) of the dielectric block 10, with the dielectric block 10 interposed therebetween. In this embodiment, the bases 21 are all formed as strips extending along the Y-axis direction, but of course, this shape is not limited to this. Figure 3 As shown, the base 21 in the first conductor layer 20A is formed by connecting wiring layers L1 to L3 via a plurality of vias VA, while the base 21 in the second conductor layer 20B is formed by connecting wiring layers L4 to L6 via a plurality of vias VB.

[0105] Waveguide plates 22 are each arranged in the second region R2 of dielectric block 10 and are opposite to each other in the thickness direction (Z-axis direction) of dielectric block 10, with dielectric block 10 interposed therebetween to form a radio wave propagation region (waveguide). Each waveguide plate 22 is formed to protrude a predetermined length forward (in the +X direction) from the base 21. Figure 3 As shown, the waveguide plate portion 22 in the first conductor layer 20A is formed by connecting the wiring layers L1 and L2 through a plurality of through holes VC, while the base portion 21 in the second conductor layer 20B is formed by the wiring layer L6.

[0106] Each waveguide portion 22 is formed in a generally rectangular shape extending along the X-axis. Each waveguide portion 22 forms a reflective surface that reflects electromagnetic waves at the interface with the dielectric block 10, and radio waves propagate through the second region R2 while being repeatedly reflected by each waveguide portion 22. Furthermore, as... Figure 1 As shown, the waveguide plate portion 22 forms a first antenna opening 51, which radiates radio waves forward (in the +X direction) through a surface orthogonal to its top end (front end) (a surface parallel to the YZ plane). Furthermore, the waveguide plate portion 22 forms a second antenna opening 52, which radiates radio waves to both sides (in the +Y and -Y directions) through surfaces orthogonal to its two side ends (surfaces parallel to the XZ plane). In this embodiment, the waveguide plate portion 22 corresponds to the antenna opening portion.

[0107] The shape of the waveguide plate portion 22 can be arbitrarily designed according to the desired antenna characteristics. In this embodiment, such as Figure 2 As shown, the waveguide plate portion 22 includes a first waveguide plate region 22a and a second waveguide plate region 22b. The first waveguide plate region protrudes from the base 21 along the X-axis direction by a first width (e.g., 2 mm), and the second waveguide plate region protrudes from the first waveguide plate region 22a along the X-axis direction by a second width (e.g., 3 mm) that is greater than the first width.

[0108] In this embodiment, the first antenna opening 51 and the second antenna opening 52 are covered by the third region R3 of the dielectric block 10. The front surface 10F of the dielectric block 10 faces the first antenna opening 51 and serves as an antenna opening for radiating radio waves forward. Furthermore, the two side surfaces 10S of the dielectric block face the second antenna opening 52 and also serve as antenna openings for radiating radio waves forward. By providing the third region R3, the directivity and gain of the antenna element 100 radiating from the antenna openings 51 and 52 can be improved.

[0109] Note that multiple vias may be formed in the third region R3 according to the desired antenna characteristics, or the corner portion between the front surface 10F and the two side surfaces 10S may be tapered or curved. Alternatively, the third region R3 may be omitted.

[0110] (Rear column wall)

[0111] The rear pillar wall 30 includes a plurality of conductive pillars P1 (conductive pillars) penetrating the dielectric block 10. Each conductive pillar P1 is a cylinder formed of metal and is connected to the base 21 of a first conductor layer 20A and a second conductor layer 20B that are opposite each other in the thickness direction (Z-axis direction), with the dielectric block 10 interposed therebetween. Each conductive pillar P1 may be a cylinder formed of metal filled with an insulator or the like.

[0112] The conductive pillar P1 is arranged along the Y-axis direction, which is the width direction of the waveguide plate portion 22. Therefore, a rear pillar wall 30 is formed to block radio waves from propagating from the second region R2 toward the rear surface 10B side of the dielectric block 10. To block the propagation of radio waves by means of the rear pillar wall 30, as... Figure 5 As shown, the conductive columnar bodies P1 are arranged with a gap D1 of less than a predetermined size. The gap D1 is preferably less than 1 / 4 (0.25λ (0.66 mm) of the wavelength λ of the electromagnetic wave propagating through the dielectric block 10.

[0113] (Power Supply Department)

[0114] Next, the power supply unit 40 will be described. Figure 6 This is a partially exploded perspective view showing an example configuration of the power supply unit 40. Figure 7 This is a side cross-sectional view of the main part of the power supply section 40.

[0115] The power supply section 40 is composed of a microstrip line connected to the second region R2 of the dielectric block 10. The power supply section 40 serves as a conversion section for the propagation of millimeter-wave signals introduced from the signal processing circuit (not shown) via the signal line 43 within the dielectric block 10.

[0116] The power supply unit 40 includes a power supply pin 41 (power supply terminal) that supplies millimeter wave signals to the second region R2 of the dielectric block 10 and a shielding portion 42 formed around the power supply pin 41.

[0117] The feed needle 41 is a conductor extending from the first waveguide plate region 22a to the second region R2 of the dielectric block 10 in the Z-axis direction from the first conductor layer 20A toward the second conductor layer 20B, and includes a base end 41a, a middle portion 41b and a tip portion 41c.

[0118] The base end 41a of the feed pin 41 penetrates the dielectric layer 1A in the dielectric multilayer substrate 1. Figure 4The corresponding through-hole of the insulating layer 44. The base end 41a is connected to the signal processing circuit (not shown) via the signal line 43 on the insulating layer 44. The base end 41a and the signal line 43 are formed as a part of the wiring layer L1 constituting the first conductor layer 20A, and are electrically insulated from the base 21 and the waveguide plate portion 22.

[0119] Note that signal line 43 forms a microstrip line opposite wiring layer L2, with dielectric layer 1A interposed therebetween. Wiring layer L2 is connected to ground potential. The linewidth of signal line 43 is arbitrarily set according to the frequency of the millimeter-wave signal to which feed pin 41 is to be introduced and the dielectric constant of the dielectric layer. For example, when the frequency of the millimeter-wave signal is 60 GHz and the dielectric constant of the dielectric layer is 3.6, the linewidth of signal line 43 is, for example, about 0.11 mm. By forming signal line 43 on the uppermost wiring layer of multilayer wiring substrate 1, signal line 43 with such a small linewidth can be stably formed.

[0120] The middle portion 41b of the feed pin 41 is formed as a part of the wiring layer L3 constituting the first conductor layer 20A. The middle portion 41b is disposed within a partially insulating layer 13d formed by filling an opening partially disposed at a predetermined position in the wiring layer L3 with insulating material, and is therefore electrically insulated from the base portion 21 and the waveguide plate portion 22. The middle portion 41b is connected to the base end portion 41a.

[0121] The tip 41c of the feed pin 41 is disposed within the second region R2 of the dielectric block 10. The feed pin 41 is formed to have a length smaller than the thickness of the dielectric block 10. In this embodiment, as... Figure 7 As shown, when the thickness of the dielectric multilayer substrate 1 is represented by D, the length of the feed pin 41 is set to 0.5D (0.8 mm).

[0122] At the same time, such as Figure 6 As shown, the shielding portion 42 includes a plurality of columnar portions 42a arranged around the feed pin 41, and an arc-shaped support layer 42b that supports each columnar portion 42a. The support layer 42b is formed of a portion of a conductor layer (wiring layer L1) formed on the front surface of the insulating layer 44, and is electrically insulated from the feed pin 41 and the signal line 43. Each columnar portion 42a is a through-hole electrically connected to the support layer 42b, penetrating the insulating layer 44, and electrically connected to the wiring layer L3 (the wiring layer L3 surrounding a portion of the insulating layer 13d).

[0123] Figure 8 This is a partial side cross-sectional view showing another configuration example of the feed section 40. The antenna element 100 according to this embodiment adopts the configuration example shown in the figure as the feed section 40.

[0124] Figure 8The feed pin 41 shown is formed by a through-hole (IVH)V extending from the first conductor layer 20A into the dielectric block 10 as an interlayer connection. As described above, the length of the feed pin 41 in the Z-axis direction is set to half the total thickness of the dielectric multilayer substrate 1.

[0125] In addition, such as Figure 1 and Figure 8 As shown, the feed section 40 includes a hole 45 having a depth reaching the feed pin 41. The length of the feed pin 41 can be adjusted according to the depth of the hole 45. In this case, after forming a through hole V for forming the feed pin 41 with a length penetrating the dielectric block 10, for example, drilling is performed on the second conductor layer 20B from the rear surface side of the dielectric multilayer substrate 1. In this case, by setting the depth of the hole 45 to half the thickness of the dielectric multilayer substrate 1, a feed pin 41 with the desired length can be easily formed. The interior of the hole 45 can be hollow or filled with an insulator, etc., and can be arbitrarily designed according to the desired antenna characteristics.

[0126] [Antenna Characteristics]

[0127] In the antenna element 100 configured as described above according to this embodiment, the millimeter-wave signal supplied to the second region R2 of the dielectric block 10 via the feed section 40 propagates towards the first antenna opening surface 51 and the second antenna opening surface 52 while being repeatedly reflected between the waveguide plate sections 22. The width and length of the waveguide plate sections 22 are not particularly limited and can be arbitrarily set according to the desired frequency band characteristics.

[0128] According to this embodiment, the antenna element 100, due to the formation of a first antenna opening 51 and a second antenna opening 52 for transmitting radio waves from the front surface 10F and the two side surfaces 10S of the dielectric block 10, can be thinner than conventional phased-array antennas. For example, when the antenna element 100 is used for automotive applications, the antenna element 100 can be installed in a small space at the front of the vehicle.

[0129] Furthermore, according to this embodiment, since the waveguide region of the radio wave sandwiched between a pair of waveguide plate portions 22 does not have a columnar waveguide structure and is open in the front and left-right directions, radio waves can be radiated from the first antenna opening 51 and the second antenna opening 52 with a wide viewing angle. This makes it feasible to detect objects with a wide viewing angle.

[0130] Figure 9 The simulation results show an example of the voltage standing wave ratio (VSWR) of the antenna element 100. As shown, the antenna element 100 according to this embodiment achieves good VSWR or matching characteristics in the frequency band in use (60 GHz to 64 GHz).

[0131] Figure 10 The simulation results show the radiation characteristics of antenna element 100 in the azimuth plane (XY plane), and Figure 11 These are simulation results showing the radiation characteristics of antenna element 100 in the elevation plane (XZ plane). In each figure, the 90° direction corresponds to the forward direction (+X direction). Additionally, each figure shows the radiation characteristics of radio waves at different frequencies: F1 is 60 GHz, F2 is 62 GHz, and F3 is 64 GHz.

[0132] According to this embodiment, such as Figure 10 As shown, the directivity of radio waves can be widened across a wide viewing angle range of ±60° (30° to 150°), while remaining centered in front. Furthermore, because it does not use a cylindrical waveguide structure as in conventional technologies, the impedance variation with frequency is smaller, thus contributing to a wider bandwidth. Additionally, as... Figure 11 As shown, the widening of the directionality in the elevation plane direction can be suppressed by a pair of waveguide plates 22.

[0133] The radiation characteristics of antenna element 100 can also be adjusted by the length Lx between the feed section 40 and the front surface 10F of dielectric block 10 along the X-axis (see...). Figure 2 ). Figure 12 The simulation results compare the VSWR characteristics of antenna element 100 when Lx values ​​are set to 5mm, 6mm, and 7mm. Furthermore, Figure 13 The simulation results show the radiation characteristics of each antenna element 100 in the azimuth plane (XY plane), and Figure 14 This is a simulation result showing the radiation characteristics of each antenna element 100 in the elevation plane (XZ plane). The radio wave frequency is 62 GHz.

[0134] like Figure 12 As shown, good VSWR characteristics can be obtained even when the length Lx changes from 5mm to 7mm. On the other hand, as Figure 13 and Figure 14 As shown, the larger the length Lx, the narrower the directionality tends to be. This is because electromagnetic waves are concentrated inside the dielectric block 10, which has a higher dielectric constant (lower impedance) than air.

[0135] <Second Implementation Method>

[0136] Next, a second embodiment of this technology will be described. Figure 15 This is a partial transmission perspective view showing the configuration of the antenna module 300 according to this embodiment. Figure 16 This is a plan view of antenna module 300, and Figure 17This is a block diagram illustrating the circuit configuration of the antenna module 300. In the following text, the corresponding parts to those in the first embodiment are indicated by the same symbols, and their detailed descriptions will be omitted.

[0137] Note that in each figure, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) represent three mutually orthogonal axial directions, and correspond to the length direction (front-back direction), width direction (left-right direction), and thickness direction (height direction) of the antenna module 300, respectively.

[0138] [Antenna Module]

[0139] The antenna module 300 is configured to include a plurality of (two in this embodiment) transmitting antenna elements 100A and 100B, and a receiving antenna array 200, which includes a plurality of (four in this embodiment) receiving antennas.

[0140] The antenna module 300 is composed of a dielectric multilayer substrate 1 having a thickness direction in the Z-axis direction. The dielectric multilayer substrate 1 is a rectangular plate material extending along the Y-axis direction, and the transmitting antenna elements 100A and 100B and the receiving antenna array 200 are arranged in the Y-axis direction with the antenna opening facing the front surface 10F side of the dielectric substrate 1 (dielectric block 10).

[0141] The basic structure of the transmitting antenna elements 100A and 100B and the receiving antenna array 200 is similar to that of the antenna element 100 described in the first embodiment. The dielectric block 10, the base 21 in the pair of conductor layers 20A and 20B, and the rear pillar wall 30 are shared by the transmitting antenna elements 100A and 100B and the receiving antenna array 200, and the rear pillar wall 30 is disposed at any position between the bases 21. A plurality of input / output terminals 460 (461 to 466) for transmitting and receiving millimeter-wave signals are disposed in the forming region of the base 21.

[0142] Meanwhile, waveguide sections 22 in a pair of conductor layers 20A and 20B are provided with waveguide sections 221 and 222 for transmitting antenna elements 100A and 100B, and a common waveguide section 223 is provided for the receiving antenna array 200. Similar to the feed section 40, feed sections 401 to 406 are individually provided for transmitting antenna elements 100A and 100B and the four receiving antennas constituting the receiving antenna array 200.

[0143] Transmitting antenna element 100A (hereinafter also referred to as transmitting antenna Tx1) includes a pair of waveguide plates 221 and a feed section 401. The feed section 401 is connected to the output terminal 461 for transmitting millimeter-wave signals via a signal line 43. Transmitting antenna element 100B (hereinafter also referred to as transmitting antenna Tx3) includes a pair of waveguide plates 222 and a feed section 402. The feed section 402 is connected to the output terminal 462 for transmitting millimeter-wave signals via a signal line 43.

[0144] The waveguide plate portion 221 and waveguide plate portion 222 in transmitting antenna Tx1 and transmitting antenna Tx3 are formed to have the same shape and size, and in this embodiment, the distance Lyl between the feed portion 401 and the feed portion 402 along the Y-axis direction is 9.2 mm.

[0145] The receiving antenna array 200 includes four receiving antennas (first receiving antenna Rx1 to fourth receiving antenna Rx4).

[0146] The feed section 403 of the first receiving antenna Rx1 is connected to the input terminal 463 for receiving millimeter-wave signals via signal line 43. The feed section 404 of the second receiving antenna Rx2 is connected to the input terminal 464 for receiving millimeter-wave signals via signal line 43. The feed section 405 of the third receiving antenna Rx3 is connected to the input terminal 465 for receiving millimeter-wave signals via signal line 43. Furthermore, the feed section 406 of the fourth receiving antenna Rx4 is connected to the input terminal 466 for receiving millimeter-wave signals via signal line 43.

[0147] The distance Ly2 between the feed sections 403 and 406 along the Y-axis is the same, and in this embodiment, it is 2.3 mm. Furthermore, the feed sections 401 to 406 for transmitting and receiving are arranged on the same straight line along the Y-axis. The distance between the feed sections 401 to 406 and the tips of the waveguide plate sections 22 (221 to 223) along the X-axis is also the same, and in this embodiment, it is 2 mm. Here, the length (width) of the waveguide plate section 223 along the Y-axis is, for example, 12 mm.

[0148] The input / output terminal group 460 has a multilayer wiring structure, for example, formed using wiring layers L1 to L3 of the dielectric multilayer substrate 1, and is electrically insulated from the base 21 of the conductor layer 20A. The input / output terminal group 460 is connected to a millimeter-wave radar IC 301 mounted on the multilayer wiring substrate 1. Figure 17 Each input / output terminal of the terminal.

[0149] The millimeter-wave radar IC 301 is a circuit component that generates millimeter-wave signals to be transmitted to transmitting antennas Tx1 and Tx2 and processes the millimeter-wave signals received by receiving antennas Rx1 to Rx4 to calculate the angle of arrival. For example... Figure 17As shown, the dielectric multilayer substrate 1 is also equipped with: a regulator 302 for regulating the voltage to be supplied to the millimeter-wave radar IC; a memory 303 for storing the driving parameters of the millimeter-wave radar IC, etc.; and a connector 304 for electrically connecting these millimeter-wave radar ICs 301, regulators 302 and memory 303 to external devices (not shown), etc.

[0150] The antenna module 300 according to this embodiment is configured as a MIMO (Multiple-Input Multiple-Output) radar antenna. According to this embodiment, since each antenna for transmission and reception is mounted on the same substrate, miniaturization and thinning of the antenna device are possible. Furthermore, since the common waveguide plate portion 223 serves as the waveguide plate portion for receiving antennas Rx1 to Rx4, the receiving antennas can be arranged at intervals of less than half the wavelength of the radio waves required for MIMO radar.

[0151] Here, we will refer to Figure 18 Briefly describe MIMO radar. Figure 18 This is a conceptual diagram of a MIMO radar. For simplicity, a MIMO radar consisting of one transmit antenna TX and two receive antennas RX1 and RX2 will be used as an example for description.

[0152] In MIMO radar, the signal transmitted from the transmit antenna Tx is reflected by the object to be received by the two receive antennas RX. To reach the second receive antenna RX2, which is farther from the transmit antenna Tx, the signal from the object needs to travel an additional distance corresponding to dsinθ (θ represents the angle of incidence (angle of arrival) of the radio wave relative to the baseline B) compared to the first receive antenna RX1, which is closer to the transmit antenna Tx. This corresponds to the phase difference between the signals received by the two receive antennas RX1 and RX2, with an angular frequency ω = (2π / λ)dsinθ. Based on this phase difference, the angle of arrival becomes:

[0153] θ=sin -1 (ωλ / 2πd).

[0154] Since the value of ω is uniquely determined only within the range of (-π to π), the maximum phase estimate angle (FOV) becomes as follows when ω = π:

[0155] θ FOV =±sin -1 (λ / 2d).

[0156] Therefore, when d = λ / 2, the maximum phase estimation angle becomes θ. FOV = ±90°. In fact, due to the influence of dielectric constant and other factors of the dielectric multilayer substrate 1, the wavelength is shortened. Therefore, the maximum phase estimation angle is achieved by setting the distance between the receiving antennas RX to d = λ / 2 or less.

[0157] Although at least two receiving antennas are required to estimate the angle, increasing the number of antennas improves the accuracy of the angle estimation and enhances the angular resolution. Regarding the transmitting antennas, the optimal distance is obtained by multiplying the distance between the receiving antennas by the number of receiving antennas. Therefore, in this embodiment, the distance Ly2 between receiving antennas Rx1 to Rx4 is 2.3 mm, and the distance Ly1 between transmitting antennas Tx1 and Tx3 is 9.2 mm.

[0158] Figure 19 The simulation results show the VSWR characteristics of each antenna of the antenna module 300 according to this embodiment as described above. Figure 20 Simulation results are shown illustrating the radiation characteristics of each of the receiving antennas Rx1 to Rx4 of the antenna module 300 in the azimuth plane (XY plane). Figure 21 Simulation results are shown illustrating the radiation characteristics of each of the receiving antennas Rx1 to Rx4 in the elevation plane (XZ plane). Figure 20 and Figure 21 In the series, F1 is 60GHz, F2 is 62GHz, and F3 is 64GHz.

[0159] According to this embodiment, since the waveguide plate portion 223 of the receiving antenna array 200 is common to the receiving antennas Rx1 to Rx4, such as Figures 19 to 21 As shown, interference between receiving antennas Rx1 to Rx4 can be reduced, and an antenna without large nulls in directivity can be formed.

[0160] <Third Implementation Method>

[0161] [Regarding the effects of direct waves and the phase difference characteristics between receiving antennas]

[0162] In antenna modules where the transmitting antenna and multiple receiving antennas are mounted on the same substrate, the following problems may occur: the influence of direct waves and the phase difference characteristics between receiving antennas.

[0163] Millimeter-wave radar estimates the angle of arrival θ of the millimeter waves emitted from the transmitting antenna and reflected by the target object. However, when the transmitting and receiving antennas are positioned close to each other, there is the influence of a direct wave from the radio waves emitted from the transmitting antenna directly input to the receiving antenna. In this case, the received level of the radio waves at the receiving antenna becomes higher than the received level of the radio waves reflected only by the target object. Therefore, the signal level of the initially detected reflected wave becomes relatively small, and a sufficient signal-to-noise ratio cannot be obtained, resulting in reduced detection accuracy.

[0164] Furthermore, regarding the phase difference characteristics between receiving antennas, while there is no specific problem if the radio waves reflected from the object being detected travel only in a straight line to reach the receiving antenna, fading may occur if radio waves reflected from the boundary surface are also received due to the structure of the receiving antenna array, dielectric constant, etc. This leads to errors in the phase difference information, thereby reducing the accuracy of angle estimation.

[0165] As an indicator of the impact of direct waves, isolation characteristics exist between the transmitting and receiving antennas. Figure 22 The simulation results show the isolation characteristics of the receiving antennas Rx1 to Rx4 relative to the first transmitting antenna Tx1. Figure 23 This shows the simulation results of the isolation characteristics of the receiving antennas Rx1 to Rx4 relative to the second transmitting antenna Tx3. When the target isolation characteristic is below -30dB in the 60GHz to 64GHz band, the values ​​in some paths (receiving antennas close to the transmitting antenna) will exceed this range.

[0166] Figure 24 This is a simulation result illustrating an example of the phase difference characteristics of received radio waves. The frequency of the radio waves used is set to 60 GHz. In the figure, the horizontal axis represents the actual angle, and the vertical axis represents the angle estimated based on the phase difference. Ideally, a straight line with a sharp rise is obtained between the receiving antennas, but fluctuations can occur as shown in the figure when fading is present. Furthermore, when 90 degrees is set as the zenith direction, and the detection range is ±60 degrees from 30 degrees to 150 degrees, the results in the figure show that the phase exceeds π around 130 degrees and reflects back. This narrows the estimable angle, and the detection accuracy decreases due to the fluctuations.

[0167] [Antenna module according to this embodiment]

[0168] Figure 25 This is a plan view of the main parts of the antenna module 400 according to the third embodiment of the present technology. In the figure, the parts corresponding to those of the antenna module 300 in the second embodiment described above are represented by the same symbols, and their detailed descriptions will be omitted.

[0169] The antenna module 400 according to this embodiment differs from that of the second embodiment in the configuration of the receiving antenna array 200. Specifically, the antenna module 400 according to this embodiment includes a shielding portion 60, which is used to suppress radio wave interference between adjacent feed terminals 403 to 406 in the first receiving antenna Rx1 to the fourth receiving antenna Rx4.

[0170] The shielding portion 60 is composed of an array of multiple pillars P2 arranged at predetermined intervals in the X-axis direction. Each pillar P2 penetrates the dielectric block 10 in the thickness direction. The pillars P2 are typically made of conductive metal pillars or through-holes (IVHs). The predetermined interval is not particularly limited, as long as it is the size at which the shielding portion 60 can suppress radio waves entering from the Y-axis direction, and can be set to, for example, less than 1 / 4 of the wavelength of the radio waves propagating through the dielectric block 10.

[0171] Furthermore, each column P2 can be formed by a hollow through-hole. In this case, the impedance characteristics of radio waves propagating through the dielectric block 10 change in the region where the column P2 is formed, thus suppressing radio wave interference between adjacent receiving antennas. Moreover, the cross-sectional shape of each column P2 is not limited to the circular shape shown in the figure, and can also be rectangular, elliptical, etc.

[0172] In this embodiment, the columnar body P2 forming the shielding portion 60 is arranged on both sides of the feed terminals 403 to 406 of the receiving antennas Rx1 to Rx4 (both sides of the width direction (Y-axis direction) of the antenna module 400) from a position opposite to the feed terminals 403 to 406 in the Y-axis direction and parallel to the X-axis direction. This allows radio waves entering from other adjacent feed terminal sides to be suppressed, thereby suppressing interference between received signals between adjacent receiving antennas. Furthermore, since the shielding portion 60 is arranged closer to the base 21 than the positions forming the feed terminals 403 to 406, radio waves entering obliquely from the first antenna opening 51 (front surface 10F of dielectric block 10) side can be received from each feed terminal 403 to 406, thereby maintaining a wide viewing angle.

[0173] As described above, according to this embodiment, since a shielding portion 60 is provided to shield the receiving antennas Rx1 to Rx4 in the width direction, the isolation between the transmitting antennas Tx1 and Tx2 and the receiving antennas Rx1 to Rx4 can be increased to reduce the influence of direct waves, and by suppressing the reception of radio waves from directions other than the direction to be detected, the influence of fading can be reduced and fluctuations can be suppressed.

[0174] Note that in this embodiment, the distance along the X-axis from the feed section 40 to the tip of the waveguide plate section 22 (221 to 223) is set to 1.5 mm. This is mainly used for impedance matching and fine-tuning of directivity.

[0175] Figure 26 Simulation results are shown for the radiation characteristics of each of the receiving antennas Rx1 to Rx4 of the antenna module 400 in the azimuth plane (XY plane). Figure 27Simulation results are shown illustrating the radiation characteristics of each of the receiving antennas Rx1 to Rx4 in the elevation plane (XZ plane). Figure 26 and Figure 27 In this context, F1 is 60GHz, F2 is 62GHz, and F3 is 64GHz. For example... Figure 26 As shown, it can be seen that compared to the case without shielding part 60 ( Figure 20 Compared to other methods, the radiation characteristics in the azimuth direction have less directional fluctuation. This means that the effects of fading are reduced.

[0176] Figure 28 The simulation results show the isolation characteristics of the receiving antennas Rx1 to Rx4 of the antenna module 400 relative to the first transmitting antenna Tx1. Figure 29 This is a simulation result showing the isolation characteristics of the receiving antennas Rx1 to Rx4 relative to the second transmitting antenna Tx3. According to this embodiment, it can be seen that, compared to the case without the shielding part 60 ( Figure 22 and Figure 23 Compared to the previous version, the isolation characteristics are significantly improved, and all receiving antennas Rx1 to Rx4 are suppressed to below -30dB.

[0177] Figure 30 The simulation results illustrate an example of the phase difference characteristics of the received radio waves by the antenna module 400. Similarly, regarding the phase difference characteristics, it has been similarly confirmed that the angle estimation width is significantly wider, and compared to the case without shielding 60 ( Figure 24 Compared to the previous method, the volatility has also improved significantly.

[0178] [Another example of an antenna element]

[0179] Furthermore, in the third embodiment described above, the shielding portion 60 is composed of an array of multiple columnar bodies P2, but the technology is not limited thereto. Figure 31 This is a plan view showing the vicinity of the receiving antenna array 200 in the wiring layer L3 that forms the first conductor layer 20A. As shown, protrusions 25 protruding along the X-axis are formed on both sides of the feed portions 403 to 406 of the wiring layer L3, and one or more columnar bodies P2 are provided at or near the tips of these protrusions 25, thereby achieving an operation and effect similar to that of the shielding portion 60 described above.

[0180] Furthermore, in the first embodiment described above, the shielding plate portion 22 of the antenna element 100 has a stepped shape including a first waveguide plate region 22a and a second waveguide plate region 22b, but the present technology is not limited thereto. For example, such as Figure 32 As shown, the shielding plate portion 22 can also be formed with the same width throughout. This configuration can be similarly applied to the transmitting antenna elements Tx1 and Tx3 described in the second and third embodiments.

[0181] Note that the configuration of the shielding portion 60 described above can be similarly applied not only to the receiving antenna array 200 but also to the transmitting antenna elements Tx1 and Tx2. In this case, for example, the wiring layer L3 on the transmitting antenna side can also be provided with... Figure 31 The protrusion 25 and column P2 are shown.

[0182] Furthermore, to improve the phase difference characteristics and directivity of antenna modules 300 and 400, cutouts or hollow through-holes can be provided at the ends or corners of the region corresponding to the third region R3 of dielectric block 10. Additionally, although the spacing between receiving antennas Rx1 to Rx4 is set to 2.3 mm, these antenna spacings can be arbitrarily adjusted according to the desired field of view (FOV), etc.

[0183] <Fourth Implementation Method>

[0184] In millimeter-wave radar systems, the phase difference characteristics of received radio waves (e.g., see...) Figure 24 (Etc., etc.) greatly affects performance in angle estimation, etc. Therefore, it is important to improve the linearity of the phase difference characteristics, that is, to reduce the fluctuations that occur in the phase difference characteristics. In this embodiment, an antenna module configured to improve such a point will be described.

[0185] Figure 33 This is a plan view of the antenna module 500 viewed from above according to the fourth embodiment of the present technology. Figure 34 This is a plan view of the internal structure of the antenna module 500 as seen from above, and Figure 35 This is a plan view of antenna module 500 as seen from below. Figure 33 and Figure 35 The structure of the upper surface (L1) and lower surface (L6) of the antenna module 500 is shown, and Figure 34 The structure of L3, which serves as the wiring layer between L1 and L6, is shown.

[0186] Antenna module 500 is configured as a transmit / receive antenna including multiple (two in this embodiment) transmit antenna elements 101A and 101B, and a receive antenna array 201, wherein the receive antenna array 201 includes multiple (four in this embodiment) receive antenna elements 101C to 101F. The basic structure of transmit antenna elements 101A and 101B is similar to that of reference [reference image]. Figure 32 The structure of the described antenna element 100, and the basic structure of the receiving antenna array 201 (receiving antenna elements 101C to 101F) are similar to the reference. Figure 31 The structure of the receiving antenna array 200 is described. Note that the structure of each of the antenna elements 101A to 101F is not limited.

[0187] like Figures 33 to 35 As shown, in the antenna module 500, the width of the waveguide plate portion 223 of the receiving antenna array 201 in the Y-axis direction is greater than that in the above embodiment ( Figure 16 The spacing between the central axis of the outermost receiving antenna element (used as a receiving antenna) in the receiving antenna array 201 and the second antenna opening 52 is set to be wider than the spacing between the feed terminals in the receiving antenna array 201.

[0188] For example, the receiving antenna element 101C, which is furthest from the transmitting antenna element 101A, and the receiving antenna element 101F, which is closest to the transmitting antenna element 101A, are the outermost receiving antenna elements arranged in the receiving antenna array 201. In this case, the distance from the central axis (an axis parallel to the X-axis and passing through the feed terminals 403 and 406 respectively) of the receiving antenna elements 101C and 101F to the end sides 223a and 223b (the second antenna opening 52) on the waveguide plate portion 223 side is set to a value larger than the distance between the feed terminals (here, 2.3 mm) (here, 3.6 mm).

[0189] In this way, by increasing the width of the copper foil (waveguide portion 223 of conductor layer 20) of the receiving antenna array 201, the component of the radio waves received by the receiving antenna array 201 that is reflected at the edge of the copper foil and causes a phase difference can be reduced. Therefore, the effect of reducing fluctuations in the phase difference characteristics can be expected.

[0190] like Figure 33 and Figure 35 As shown, the antenna module 500 has a configuration in which the leading edge 27 of a pair of conductor layers 20 (conductor layers 20A and 20B), which are different from the waveguide plate portions (221, 222, 223), is larger than that in the above embodiment ( Figure 16 (etc.) further extends forward. Here, the end edge 27 of the conductor layer 20 is, for example, a strip-shaped region provided along the front end side of the conductor layer 20 excluding the waveguide plate portion. In this embodiment, the end edge 27 is formed by the outermost wiring layers (L1, L6).

[0191] Specifically, the antenna module 500 has a structure that extends the front end of the edge portion 27 to the feed terminals 401 to 406. That is, a pair of conductor layers 20 include an edge portion 27 that extends along the X-axis between the transmitting antenna element 101A and the receiving antenna element 101F or between the transmitting antenna elements 101A and 101B constituting the transmitting antenna to the feed terminals 401 to 406. Note that here, the edge portion 27 on the outer side (lower side in the figure) of the transmitting antenna element 101B also extends in a similar manner.

[0192] In this way, by extending the end side (end edge 27) of the copper foil to the positive side of the feed terminals 401 to 406, it is possible to reduce the directivity toward the rear of the antenna and to reduce reflections of components traveling toward the rear. Therefore, it is expected to reduce fluctuations in phase difference characteristics.

[0193] Note that a portion with its end face aligned with the feed terminal may also be provided only between the transmitting antenna element 101A and the receiving antenna element 101F. This allows for significant suppression of reflection components traveling to the receiving antenna array 201. Alternatively, an end face aligned with the feed terminal may also be provided only between the transmitting antenna elements 101A and 101B.

[0194] In addition, such as Figure 34 As shown, in the antenna module 500, a plurality of conductive pillars P3 (VIA) connecting wiring layers L1 and L6 are arranged along the Y-axis relative to the copper foil (edge ​​portion 27) extending to the positive side of the feed terminals 401 to 406. Therefore, the edge portion 27 and the plurality of conductive pillars P3 form a pillar wall 28 arranged along the Y-axis.

[0195] Note that the conductive columnar body P3 constituting the column wall 28 is not covered by the copper foil of the inner wiring layers L2 to L5. For example, as Figure 34 As shown, the wiring layer L3 is configured not to contact the conductive pillars P3. In this way, the pillar wall 28 has a structure in which multiple conductive pillars P3 are arranged along the Y-axis direction, penetrating the dielectric block 10, connected to the end edge 27, and electrically isolated from other conductor layers.

[0196] By providing this column wall 28, both the L component (inductance) and C component (capacitance) can be provided, and LC resonance can be induced within the column wall 28. This allows for the absorption of radio waves traveling, for example, toward the rear, and reduces directivity in unwanted directions (unwanted reflection components). In this embodiment, the column wall 28 corresponds to a column absorbing wall.

[0197] The various characteristics of the antenna module 500 will be described below. Here, transmitting antenna elements 101A and 101B will be referred to as transmitting antenna Tx1 and transmitting antenna Tx3, respectively. In addition, receiving antenna elements 101C, 101D, 101E and 101F will be referred to as receiving antenna Rx1, receiving antenna Rx2, receiving antenna Rx3 and receiving antenna Rx4, respectively.

[0198] Figure 36 The simulation results show the VSWR characteristics of each antenna in the antenna module 500 according to this embodiment. Figure 37 Simulation results of the radiation characteristics of each antenna in antenna module 500 in the azimuth plane (XY plane) are shown, and Figure 38Simulation results of the radiation characteristics of each antenna in the elevation plane (XZ plane) are shown. Figure 37 and Figure 38 In this context, the frequency of radio waves is 62 GHz.

[0199] like Figure 36 As shown, within the frequency band in use (60GHz to 64GHz), the VSWR is below 2, and good VSWR or matching characteristics are achieved. Furthermore, from... Figure 37 The results shown demonstrate, for example, the case of a column wall 28 that does not have an absorption feature for radio waves traveling towards the rear ( Figure 20 Compared to (etc.), it reduces the directivity towards the rear of the antenna. Furthermore, it can be seen that unwanted fluctuations relative to the radiation direction are reduced. Moreover, from Figure 38 The results shown can also be described as a reduction in directivity toward the rear of the antenna.

[0200] Figure 39 The simulation results show the isolation characteristics of the receiving antennas Rx1 to Rx4 relative to the transmitting antenna Tx1. Figure 40 The simulation results show the isolation characteristics of the receiving antennas Rx1 to Rx4 relative to the transmitting antenna Tx3. In this embodiment, an improvement in isolation characteristics is observed, particularly on the Tx3 side.

[0201] Figure 41 The simulation results illustrate an example of the phase difference characteristics of the received radio waves by the antenna module 500. Similarly, regarding the phase difference characteristics, for example, confirming... Figure 24 In comparison, the angle estimation width is widened and the fluctuation is significantly improved. This is attributed to the suppression of reflected waves by the waveguide plate 223 and the absorption of direct waves by the pillar wall 28. Therefore, the angle estimation performance in millimeter-wave radar systems can be improved.

[0202] <Fifth Implementation Method>

[0203] In millimeter-wave radar systems, angle estimation accuracy is improved by enhancing the isolation characteristics between the transmitting and receiving antennas. In this embodiment, a configuration that improves isolation characteristics by reducing the direct waves reaching the receiving antenna from the transmitting antenna will be described.

[0204] Figure 42 This is a plan view of the antenna module 600 as viewed from above according to this embodiment. Figure 43 This is a plan view of the internal structure of the antenna module 600 as seen from above. Figure 44 This is a plan view of the antenna module 600 as seen from below, and Figure 45 This is a partial transmission perspective view showing the main parts of the antenna module 600. Figure 42 and Figure 44The structure of the upper surface (L1) and lower surface (L6) of the antenna module 600 is shown. Figure 43 The structure of L3, which serves as the wiring layer between L1 and L6, is shown.

[0205] Antenna module 600 is configured as a transmit / receive antenna including multiple (two in this embodiment) transmit antenna elements 102A and 102B and a receive antenna array 202, wherein the receive antenna array 202 includes multiple (three in this embodiment) receive antenna elements 102C to 102E. The basic structure of each of antenna elements 102A to 102E is similar to that of the reference antenna. Figure 32 The structure of antenna element 100 is described. Note that the structure of antenna elements 102A to 102E is not limited.

[0206] In this embodiment, the distance Ly2 between receiving antenna element 102C and receiving antenna element 102D (or receiving antenna element 102D and receiving antenna element 102E) along the Y-axis is set to be greater than the distance Ly1 between transmitting antenna element 102A and transmitting antenna element 102B along the Y-axis. Since the antenna module 600 is a MIMO radar, the optimal distance Ly2 between the receiving antennas is obtained by multiplying the distance Ly1 between the transmitting antennas by the number of transmitting antennas (see [reference]). Figure 18 (etc.). Therefore, for example, the length of Ly1 is set to 1 / 2 of the wavelength of the radio wave used (e.g., 2.3 mm), and the length of Ly2 is set to one wavelength of the radio wave used (e.g., 4.6 mm).

[0207] To improve the aforementioned isolation, antenna module 600 uses an LC resonator 35 that absorbs radio waves. Typically, it is difficult to achieve isolation between the closest transmitting antenna element 102A (Tx1) and the receiving antenna element 102E (Rx3), therefore the LC resonator 35 is positioned there. In this way, antenna module 600 includes an LC resonator 35 disposed between the transmitting antenna and the receiving antenna.

[0208] The LC resonator 35 includes a separated copper foil 36, a conductive pillar P4, and a protrusion 37. The separated copper foil 36 is a copper foil separated from one of a pair of conductor layers 20. Figure 42 and Figure 45As shown, in this embodiment, two separate copper foils 36 are formed by the uppermost wiring layer L1. The separate copper foils 36 are island-shaped patterns (here, rectangular patterns with rounded corners) that are not connected to the main body of the wiring layer L1. The separate copper foils 36 are arranged side by side in the Y-axis direction in the region between the waveguide plate portion 221 of the transmitting antenna element 102A and the waveguide plate portion 223 of the receiving antenna element 102E. In this embodiment, the separate copper foils 36 correspond to separate conductive foils.

[0209] The conductive pillar P4 penetrates the dielectric block 10 and connects the separated copper foil 36 to another conductor layer 20. In this embodiment, as... Figure 44 and Figure 45 As shown, a protrusion 37 protruding from the bottommost wiring layer L6 is formed at the position where the wiring layer L6 overlaps with the separate copper foil 36. A conductive pillar P4 electrically connects the separate copper foil 36 to the protrusion 37. Note that, as... Figure 43 As shown, the conductive pillar P4 is not connected to the intermediate wiring layer (here, wiring layer L3). Therefore, an LC resonator 35 is formed.

[0210] The LC resonator 35 has a structure in which a separate copper foil 36 is connected to another conductor layer 20 (protrusion 37) via a conductive pillar P4. This structure is similar to that of a so-called patch antenna, and the impedance can be adjusted by changing the position of the conductive pillar P4 (VIA) in the XY plane. Therefore, isolation can be significantly improved by arranging the conductive pillar P4 at a position that provides optimal isolation in the desired frequency band (the position where radio wave absorption efficiency is highest in the desired frequency band).

[0211] By placing the LC resonator 35 between the transmitting antenna element 102A and the receiving antenna element 102E in this manner, additional signals at that location can be absorbed and shielded. This reduces direct waves that do not pass through the object being measured from the transmitting antenna into the receiving antenna. Therefore, isolation can be improved and the dynamic range in the input of the millimeter-wave radar IC can be increased.

[0212] Note that a reference is provided in this embodiment. Figure 33 The column wall 28, as described above, is used to suppress reflections of radio waves traveling towards the rear. An LC resonator 35 is positioned in front of the column wall 28. By combining the column wall 28 and the LC resonator 35 in this manner, direct waves can be significantly suppressed.

[0213] The following is a description of the various characteristics of the antenna module 600. Here, transmitting antenna elements 102A and 102B will be referred to as transmitting antennas Tx1 and Tx2, respectively, and receiving antenna elements 102C, 102D and 102E will be referred to as receiving antennas Rx1, Rx2 and Rx3, respectively.

[0214] Figure 46 The simulation results show the VSWR characteristics of each antenna in the antenna module 600 according to this embodiment. Figure 47 Simulation results of the radiation characteristics of each antenna in the antenna module 600 in the azimuth plane (XY plane) are shown, and Figure 48 Simulation results of the radiation characteristics of each antenna in the elevation plane (XZ plane) are shown. Figure 47 and Figure 48 In this context, the frequency of radio waves is 62 GHz.

[0215] like Figure 46 As shown, within the frequency band in use (60GHz to 64GHz), the VSWR is below 2, and good VSWR or matching characteristics are achieved. Furthermore, from... Figure 47 and Figure 48 The results show that the directivity toward the rear of the antenna is reduced in both the azimuth and elevation planes.

[0216] Figure 49 The simulation results show the isolation characteristics of the receiving antennas Rx1 to Rx3 relative to the transmitting antenna Tx1. Figure 50 This shows the simulation results illustrating the isolation characteristics of the receiving antennas Rx1 to Rx3 relative to the transmitting antenna Tx2. Figure 49 and Figure 50 In the frequency band in use (60GHz to 64GHz), the isolation characteristic value is below -48, and it is consistent with the case where the LC resonator 35 is not set. Figure 22 and Figure 23 Compared to [previous method], this significantly improves isolation. This is attributed to the LC resonator 35's effective absorption of the direct wave's influence.

[0217] Figure 51 These are simulation results illustrating an example of the phase difference characteristics of the received radio waves by the antenna module 600. It was also found that, for example, regarding the phase difference characteristics, compared to... Figure 24 Compared to the angle estimation, the width becomes wider.

[0218] <Sixth Implementation Method>

[0219] An interface between a dielectric material and air is formed at the ends of dielectric multilayer substrates used in antenna modules and the like. It is well known that radio waves are reflected at this interface due to the difference in dielectric constant between the dielectric material and air. For example, when radio waves radiated from a transmitting antenna are reflected at the interface at the end of the substrate, the radio waves remain within the substrate and are not radiated to the outside. Radio waves retained within the substrate in this way can propagate through the dielectric layer to reach the receiving antenna. In this case, the radio waves propagating through the dielectric layer become direct waves, which, in MIMO radar antennas composed of multiple antennas, lead to reduced isolation between the transmitting and receiving sides.

[0220] In this embodiment, an antenna element that can improve the isolation as described above while achieving a wide field of view will be described.

[0221] Figure 52 This is a partial transmission perspective view showing the antenna element 110 according to the sixth embodiment of the present technology. Figure 53 This is a plan view of antenna element 110 as seen from above. Figure 54 This is a plan view showing the internal structure of antenna element 110, and Figure 55 This is a cross-sectional view showing the layer structure of antenna element 110.

[0222] In each figure, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) represent three mutually orthogonal axial directions, and correspond to the length direction (front-back direction), width direction (left-right direction), and thickness direction (height direction) of the antenna element 110, respectively.

[0223] (Dielectric multilayer substrate)

[0224] Figure 55 The upper and lower figures are respectively along Figure 53 The cross-sectional view in the XZ plane intercepted by lines AA and BB. (See diagram below.) Figure 55 As shown, the antenna element 110 is constructed from a dielectric multilayer substrate 1, which includes multiple dielectric layers and multiple wiring layers disposed between the dielectric layers. In this example, five dielectric layers 1A to 1E are laminated sequentially from top to bottom. Also in the dielectric multilayer substrate 1, six wiring layers L1 to L6 are disposed, with dielectric layers 1A to 1E respectively interposed therebetween. The thickness of the dielectric multilayer substrate 1 is, for example, approximately 1.6 mm. This structure is similar to a reference design. Figure 4 The structure described.

[0225] Dielectric layers 1A to 1E are all made of a dielectric material having a dielectric constant corresponding to the frequency of the radio waves to be transmitted or received by the antenna element 110. Dielectric layer 1C is a core material that is thicker than the other dielectric layers, and its thickness is set to, for example, 1.1 mm. Furthermore, the other dielectric layers 1A, 1B, 1D, and 1E are formed of prepreg material, etc., and the thickness of each layer is set to, for example, 60 μm.

[0226] Wiring layers L1 to L6 are formed of, for example, copper foil of a predetermined thickness and patterned into a predetermined shape. Furthermore, wiring layers L1 to L6 are electrically connected to each other at any location through vias V (LVH) connecting two adjacent wiring layers or through vias V (IVH) connecting three or more wiring layers.

[0227] Next, refer to Figures 52 to 55 The antenna element 110 is described in detail.

[0228] The antenna element 110 according to this embodiment includes a dielectric block 70, a conductor layer 80, a plurality of conductive pillars 85, a feed portion 40, a convex dielectric waveguide 75, and a pillar waveguide portion 90. The antenna element 110 can be configured as a transmitting antenna, a receiving antenna, or a transmitting / receiving antenna. Here, the case where the antenna element 110 is configured as a transmitting antenna will be described as an example.

[0229] (Dielectric block)

[0230] The dielectric block 70 corresponds to the dielectric layer 1C, which serves as the core of the dielectric multilayer substrate 1. The dielectric block 70 includes a front surface 70F, a rear surface 70B, and two side surfaces 70S. The front surface 70F is an end surface formed in front of the antenna element 110 and orthogonal to the X-axis direction. The rear surface 70B is a rear end surface located on the opposite side of the front surface 70F. The two side surfaces 70S are end surfaces orthogonal to the Y-axis direction. Furthermore, in the dielectric block 70, a convex dielectric waveguide 75, described later, is formed to protrude from the front surface 70F.

[0231] (Conductor layer)

[0232] Conductor layer 80 includes a pair of conductor layers 80A and 80B. Here, they are disposed on the surface of dielectric block 70. Figure 1 The conductor layer 80 on the upper surface of the dielectric block 70 will also be referred to as the first conductor layer 80A, and is disposed on the rear surface of the dielectric block 70. Figure 1 The conductor layer 80 on the lower surface of the substrate is also referred to as the second conductor layer 80B. The first conductor layer 80A corresponds to the wiring layers L1 to L3 in the dielectric multilayer substrate 1, while the second conductor layer 80B corresponds to the wiring layers L4 to L6 in the dielectric multilayer substrate 1.

[0233] The first conductor layer 80A and the second conductor layer 80B each include a substrate portion 81 and a waveguide portion 82. The substrate portion 81 and the waveguide portion 82 are integrally formed and are generally connected to ground potential. The substrate portion 81 is the portion that forms various wirings, including microstrip lines connected to the feed portion 40. The waveguide portion 82 is the portion that constitutes the pillar waveguide portion 90, which will be described later.

[0234] Figure 53 This is a plan view of the first conductor layer 80A as seen from above, and it also shows the topmost wiring layer L1. Furthermore, Figure 54 This is a plan view of the second conductor layer 80B arranged below the dielectric block 70, viewed from above, and shows the wiring layer L4 arranged directly below the dielectric block 70 and the wiring layer L6 arranged as the bottom layer.

[0235] like Figure 53 As shown, the pattern of wiring layer L1 includes a strip-shaped region disposed along the Y-axis on the rear side of the feed section 40 and a rectangular protruding region extending a predetermined distance forward (in the +X direction) from the strip-shaped region beyond the feed section 40. Furthermore, as... Figure 54 As shown, wiring layer L4 includes a strip-shaped area with a pattern similar to wiring layer L1 and a protruding area extending forward from the strip-shaped area so as not to overlap with the power supply section 40. Note that the patterns of the other wiring layers L2, L3, and L5, which are provided as inner layers, are the same as the pattern of wiring layer L4, and the pattern of wiring layer L6 is the same as the pattern of wiring layer L1.

[0236] In this embodiment, in each of the wiring layers L1 to L6, a strip-shaped region disposed on the rear side of the feed section 40 serves as a substrate section 81. Furthermore, a rectangular protruding region protruding from the substrate section 81 toward the front side serves as a waveguide section 82. Here, in wiring layers L1 and L6, the distance from the front end of the waveguide section 82 to the front surface 70F of the dielectric block 70 is set to 1.00 mm.

[0237] (Conductive columnar body)

[0238] Multiple conductive pillars 85 penetrate the dielectric block 10 (core material) and connect to a pair of conductor layers 80. The conductive pillars 85 are, for example, through-holes, also known as IVHs, and electrically connect the first conductor layer 80A and the second conductor layer 80B. Therefore, the conductive pillars 85 are essentially at ground potential.

[0239] like Figure 52 As shown, the antenna element 110 has a large number of conductive pillars 85 disposed in the entire conductor layer 80, including the substrate portion 81 and the waveguide plate portion 82. Among them, the conductive pillars 85 connected to the waveguide plate portion 82 together with the waveguide plate portion 82 form a pillar waveguide portion 90.

[0240] (Power Supply Department)

[0241] The power supply unit 40 converts the millimeter-wave signal introduced from the signal processing circuit (not shown) via the signal line 43 into radio waves that propagate inside the dielectric block 10. The power supply unit 40 includes a power supply pin 41 (power supply terminal) connected to the signal line 43. Furthermore, the signal line 43 is arranged on the dielectric layer 1A and forms a microstrip line opposite to the wiring layer L2, with the dielectric layer 1A interposed therebetween.

[0242] In this embodiment, a reference similar to the one used is employed. Figure 8 The structure of the feed section 40 is described. Specifically, the feed pin 41 is first formed as a VIA penetrating the dielectric multilayer substrate 1. Then, as... Figure 55 As shown in the lower figure, a VIA is drilled from the back surface using a drilling process to form a hole 45. The length of the feed pin 41 is adjusted by the depth of the hole 45. This allows the feed pin 41 to be easily formed with a desired length. The length of the feed pin 41 is adjusted to, for example, about half the thickness of the dielectric multilayer substrate 1. Note that the configuration of the feed portion 40 is not limited, and feed portions 40 with other structures can be used (e.g., Figure 6 and Figure 7 (e.g., power supply unit 40 shown in the image).

[0243] (Convex dielectric waveguide)

[0244] The convex dielectric waveguide 75 is a waveguide formed on the front surface 70F of the dielectric block 70, and is formed to protrude from the first post waveguide 91a, which will be described later. Figure 53 and Figure 54 As shown, the convex dielectric waveguide 75 is a waveguide with a generally rectangular planar shape and a rectangular parallelepiped shape. In addition, the central axis of the convex dielectric waveguide 75 along the X-axis direction is aligned with the central axis of the first pillar waveguide 91a (the axis passing through the feed pin 41).

[0245] A convex dielectric waveguide 75 forms a first antenna opening 71 in the X-axis direction and a second antenna opening 72 in the Y-axis direction. The first antenna opening 71 is a surface parallel to the YZ plane and is an end surface opposite to the opening end of the first pillar waveguide 91a in the X-axis direction. The second antenna opening 72 is a surface parallel to the XZ plane and is an end surface on both sides opposite to each other in the Y-axis direction, separated by the convex dielectric waveguide 75. In this embodiment, the convex dielectric waveguide 75 corresponds to the antenna opening.

[0246] The thickness (width in the Z-axis direction) of the convex dielectric waveguide 75 is determined by the thickness of the dielectric multilayer substrate 1 constituting the antenna element 110. Therefore, the thickness of the convex dielectric waveguide 75 is, for example, equal to the thickness of the laminated dielectric layers 1A to 1E.

[0247] Incidentally, in a waveguide, radio waves propagate by inducing resonance. Therefore, the width of the convex dielectric waveguide 75 must also be at least half the wavelength of the frequency used. To this end, the width of the convex dielectric waveguide 75 in the Y-axis direction is set to a length approximately half the wavelength λ of the radio wave used. Here, the width is set to 2.4 mm, which is close to half the wavelength of the frequency 59 GHz. Therefore, radio waves entering the convex dielectric waveguide 75 propagate in the HE11 mode, which is the basic mode of the dielectric waveguide, and effectively radiate towards the front of the convex dielectric waveguide 75 as a point-symmetric or line-symmetric beam.

[0248] Furthermore, the degree of reflection caused by the difference in dielectric constant between the tip of the dielectric waveguide and air varies depending on the length of the waveguide relative to the wavelength. Therefore, the length of the convex dielectric waveguide 75 (the length protruding from the front surface 70F of the dielectric block 70 in the X-axis direction) is set to optimize reflection at the tip (first antenna opening 71) of the convex dielectric waveguide 75. In other words, the length of the convex dielectric waveguide 75 is set to suppress the amount of radio wave reflection at the tip. Here, the length of the convex dielectric waveguide 75 is set to 2.35 mm.

[0249] In this way, a beam with a certain degree of diffusion can be efficiently radiated toward the front side of the antenna element 110 through the convex dielectric waveguide 75, which includes a first antenna opening 71 and a second antenna opening 72 in a rectangular parallelepiped shape. In other words, radio waves propagating toward the rear side can be reduced. This allows for improved isolation, for example, compared to the case where the convex dielectric waveguide 75 is not provided.

[0250] (Cylindrical waveguide section)

[0251] The pillar waveguide section 90 includes a plurality of pillar waveguides 91 (here, three pillar waveguides 91). Here, the pillar waveguide 91 is a waveguide surrounded by a pair of conductor layers 80 and a plurality of conductive pillars 85. In the following text, the plurality of conductive pillars 85 constituting the pillar waveguides 91 in the pillar waveguide section 90 will be referred to as conductive pillars P5.

[0252] The pillar waveguide 91 includes pillar walls 92 in which a plurality of conductive pillars P5 are arranged along the X-axis. The spacing of the conductive pillars P5 constituting the pillar walls 92 is set such that radio waves do not pass through the pillar walls 92, and this spacing is set, for example, to be less than 1 / 4 of the wavelength of the radio waves used in the dielectric block 70. Therefore, the pillar walls 92 serve as the wall surface of a waveguide that confines radio waves, similar to the conductor layer 80.

[0253] As described above, a pillar waveguide 91 is formed in the waveguide plate portion 82 of the conductor layer 80. That is, the pillar waveguide 91 is formed by dividing the space between the waveguide plate portion 82 of the first conductor layer 80A and the waveguide plate portion 82 of the second conductor layer 80B by a pair of pillar walls 92 arranged along the X-axis direction.

[0254] In this embodiment, the pillar waveguide section 90 is provided with a first pillar waveguide 91a and two second pillar waveguides 91b and 91c.

[0255] The first column waveguide 91a is connected to the feed pin 41 and forms a column waveguide along the X-axis direction from the feed pin 41. For example... Figure 53 and Figure 54 As shown, the first column waveguide 91a is a waveguide divided by two column walls 92 (first column walls) arranged opposite to each other in the Y-axis direction and separated by a feed pin 41, and extends from the feed pin 41 to the front end of the waveguide plate portion 82.

[0256] Furthermore, the first post waveguide 91a generates radio waves by supplying millimeter-wave signals to the feed pin 41, and radiates the generated radio waves from the front opening. The radio waves radiated from the first post waveguide 91a enter the convex dielectric waveguide 75 disposed in front of the first post waveguide 91a.

[0257] Typically, the fundamental mode for radio waves propagating through a cylindrical waveguide is the TE10 mode. Additionally, as mentioned above, the fundamental mode for radio waves propagating through a dielectric waveguide is the HE11 mode. Both the TE10 and HE11 modes are vertically polarized wave modes. Therefore, a cylindrical waveguide can effectively excite electromagnetic waves within a dielectric waveguide. Thus, in antenna element 110, by providing a first cylindrical waveguide 91a in front of the convex dielectric waveguide 75, radio waves within the convex dielectric waveguide 75 can be excited more efficiently, for example, compared to the case where no cylindrical waveguide is used.

[0258] The second post waveguides 91b and 91c are waveguides formed adjacent to the first post waveguide 91a along the X-axis direction, and are open at one end and closed at the other end in the same direction as the first post waveguide 91a. Figure 53 and Figure 54 As shown, when viewed from the front through the feed pin 41, the second post waveguides 91b and 91c are formed to the left (upper side in the figure) and right (lower side in the figure) of the first waveguide 91a, respectively.

[0259] Second pillar waveguides 91b and 91c have openings at the front. Simultaneously, conductive pillars P5 (hereinafter referred to as bottom pillars 93) are positioned within the waveguides at a distance from the front openings. Here, two conductive pillars P5 are positioned as bottom pillars 93 in each waveguide, but the number of conductive pillars P5 can be one. For example, the distance from the front opening to the bottom pillar 93 becomes the depth of the pillar waveguide 91.

[0260] In this manner, second post waveguides 91b and 91c, without feed sections 40, are arranged on both sides of the first post waveguide 91a. With this configuration, radio waves radiated from the opening of the first post waveguide 91a at the center are diffracted and scattered by the adjacent second post waveguides 91b and 91c. Therefore, the phase of the radiated electromagnetic waves can be shifted to control the beamwidth.

[0261] In this embodiment, the first post waveguide 91a and the second post waveguide 91b (or 91c) are arranged in the Y-axis direction at a spacing of 1 / 2 of the wavelength λ of the radio wave used. Specifically, the spacing between the central axes of each post waveguide 91 is set to λ / 2. Therefore, diffraction and reflection of the radio wave emitted from the first post waveguide 91a are efficiently generated in the second post waveguides 91b and 91c. Furthermore, by setting the spacing between the central axes to λ / 2, it is easy to configure MIMO radar, etc. (see [link to documentation]). Figure 61 (etc.). Here, the spacing between the central axes of each pillar waveguide 91 is set to 2.3 mm, which is close to the length of half a wavelength at a frequency of 59 GHz.

[0262] Furthermore, the second pillar waveguides 91b and 91c are constructed with pillar walls 92 (second pillar walls) that are different from the pillar walls 92 (first pillar walls) constituting the first pillar waveguide 91a. In other words, the first pillar waveguide 91a and the second pillar waveguides 91b and 91c do not share pillar walls 92. This allows the width of each pillar waveguide 91 in the Y-axis direction and the spacing (distance between the central axes) of each pillar waveguide 91 to be set independently. Here, the width of each pillar waveguide 91 in the Y-axis direction is set to 1.6 mm.

[0263] Furthermore, the first pillar waveguide 91a and the second pillar waveguides 91b and 91c have open ends at the same positions in the X-axis direction. That is, the pillar waveguides 91 are configured such that the open ends are aligned along the Y-axis direction. This allows for efficient diffraction and reflection of radio waves emitted from the first pillar waveguide 91a.

[0264] Furthermore, the depths of the second waveguides 91b and 91c (the distance from the opening end to the bottom post 93 on the front side) do not need to be the same as the depth of the first waveguide 91a (the distance from the opening end to the feed pin 41). Here, the depths of the second waveguides 91b and 91c are set to be 1.85 mm less than the depth of the first waveguide 91a. Note that by adjusting the depths of the second waveguides 91b and 91c, the diffraction and reflection of radio waves can be easily controlled (see...). Figure 59 wait).

[0265] Furthermore, the dimensions of the aforementioned convex dielectric waveguide 75 can be set according to the dimensions of each pillar waveguide 91. For example, the width of the convex dielectric waveguide 75 in the Y-axis direction can be set to be equal to or greater than the width of the first pillar waveguide 91a in the Y-axis direction and equal to or less than the center distance between the second pillar waveguides 91b and 91c disposed on both sides of the first pillar waveguide 91a. This allows, for example, the desired level of isolation to be achieved while widening the beamwidth.

[0266] Figure 56 A graph showing the electric field intensity distribution in antenna element 110 as a function of time is shown. Figure 56 In this diagram, time flows at regular intervals from time t1 to time t5. For example, in the diagram at time t1, it can be seen that the electric field strength increases near the feed section 40 in the first column waveguide 91a, and radio waves are generated in the basic mode (TE10 mode). Furthermore, although four regions with high electric field strength are generated to the right of the feed section 40, these regions are distributed due to the propagation of radio waves generated in the basic mode before time t1.

[0267] For example, as shown in the figures t1 to t5, radio waves generated near the feed section 40 enter the convex dielectric waveguide 75 from the first pillar waveguide 91a. At this time, radio waves are excited in the convex dielectric waveguide 75 in the basic mode of the dielectric waveguide (HE11 mode). This allows radio waves to be transmitted to the convex dielectric waveguide 75 efficiently.

[0268] Furthermore, since the radio waves propagating through the convex dielectric waveguide 75 are excited in their fundamental mode, when radiated forward, the radio waves become a beam that expands in a point-symmetric or line-symmetric manner. In this way, in the antenna element 110, radio waves can propagate through the convex dielectric waveguide 75 and radiate smoothly forward. Therefore, reflections at the interface between the dielectric and air are suppressed, and the gain is improved. In addition, isolation is improved due to the reduction of reflection components at the interface.

[0269] Furthermore, in antenna element 110, radio waves are diffracted onto second post waveguides 91b and 91c adjacent to the first post waveguide 91a. For example, figures t2 to t3 show the state where radio waves are diffracted and reach the second post waveguides 91b and 91c from the opening of the first post waveguide 91a. Figures t4 to t5 show the state where the components diffracted and reflected by the second post waveguides 91b and 91c form a beam with a wider extension. In this way, by arranging the second post waveguides 91b and 91c and diffracting and reflecting the radio waves, the beamwidth can be further widened in a plane (XY plane) parallel to the substrate.

[0270] In this manner, the antenna element 110 according to this embodiment has a configuration in which three pillar waveguides 91a to 91c are arranged using a dielectric multilayer substrate 1, and a convex dielectric waveguide 75 is provided on the same straight line as the center of the pillar waveguide 91a. This allows for improved isolation while maintaining a wide beamwidth. Furthermore, the antenna element 110 radiates a beam along the planar direction (in-plane direction of the XY plane) of the dielectric multilayer substrate 1. This allows for a thinner element compared to, for example, a phased-array antenna.

[0271] Figure 57 The simulation results show an example of the voltage standing wave ratio (VSWR) of antenna element 110. As shown in the figure, the antenna element 110 according to this embodiment has a VSWR value of 2 or less in the frequency band used (59 GHz to 63 GHz), and obtains good VSWR characteristics or matching characteristics.

[0272] Figure 58 A shows the simulation results of the radiation characteristics of antenna element 110 in the azimuth plane (XY plane). Figure 58 Figure B shows the simulation results of the radiation characteristics of antenna element 110 in the elevation plane (XZ plane). In each figure, the 90° direction corresponds to the forward direction (+X direction). In addition, each figure shows the radiation characteristics of radio waves at different frequencies: F1 is 57 GHz, F2 is 59 GHz, and F3 is 61 GHz.

[0273] According to this embodiment, such as Figure 58 As shown in Figure A, the directionality of radio waves can extend across a wide viewing angle range of ±60° (30° to 150°) centered in front. Furthermore, as... Figure 58 As shown in Figure B, the extension of directivity in the elevation plane is suppressed by using a convex dielectric waveguide 75. Therefore, an elliptical beam that is wide in the horizontal direction (azimuth) and narrow in the vertical direction (elevation) can be radiated.

[0274] Figure 59 The simulation results show the relationship between the depth of the second pillar waveguide and the beamwidth. Figure 59 Curve F1 and Figure 58 The same applies to F1 (57 GHz) in A. Conversely, curve F1' shows the radiation characteristics of radio waves at 57 GHz in a configuration where the second pillar waveguides 91b and 91c are adjusted to a shallow depth.

[0275] Specifically, the position of the base post 93 in the X-axis direction is changed to match the composition. Figure 53 and Figure 54The foremost pillar (conductive pillar P5) of the pillar wall 92 in the second pillar waveguides 91b and 91c shown is at the same position. In this case, as shown by curve F1', the beamwidth can be narrowed. In this way, the beamwidth in the horizontal direction can be changed by varying the depth of the second pillar waveguides 91b and 91c.

[0276] <Seventh Implementation Method>

[0277] In this embodiment, an antenna module in which a plurality of antenna elements 110 described in the sixth embodiment are arranged will be described as a MIMO radar antenna. Figure 60 This is a partial transmission perspective view of the antenna module 700 according to the seventh embodiment of the present technology, and Figure 61 This is a plan view of the antenna module 700 as seen from above. In the following text, the corresponding parts to those in the sixth embodiment are indicated by the same symbols, and their detailed descriptions will be omitted.

[0278] In each figure, the X-axis (first axis), Y-axis (second axis), and Z-axis (third axis) represent three mutually orthogonal axial directions, and correspond to the length direction (front-back direction), width direction (left-right direction), and thickness direction (height direction) of the antenna module 700, respectively.

[0279] [Antenna Module]

[0280] The antenna module 700 is configured as a transmit / receive antenna including a transmit antenna array 710 and a receive antenna array 720. The transmit antenna array 710 includes a plurality of (two in this embodiment) transmit antenna elements 110A and 110B, and the receive antenna array 720 includes a plurality of (three in this embodiment) receive antenna elements 110C to 110E.

[0281] The antenna module 700 is composed of a dielectric multilayer substrate 1 having a thickness direction in the Z-axis direction. The dielectric multilayer substrate 1 is a rectangular material extending along the Y-axis direction, and the antenna elements 110A to 110E constituting the transmitting antenna array 710 and the receiving antenna array 720 are arranged in the Y-axis direction such that a convex dielectric waveguide 75 (dielectric block 70) protrudes from the front surface 70F of the dielectric multilayer substrate 1.

[0282] The basic structure of each of antenna elements 110A to 110E is similar to that of antenna element 110 described above in the sixth embodiment. The substrate portion 81 in the dielectric block 70 and the pair of conductor layers 80A and 80B is shared by antenna elements 110A to 110E and is disposed at any location. Furthermore, multiple input / output terminal groups 460 (461 to 465) for transmitting and receiving millimeter-wave signals are disposed in the formation area of ​​the substrate portion 81.

[0283] As waveguide plate portions 82 in each of a pair of conductor layers 80A and 80B, a waveguide plate portion 82T shared with the transmitting antenna array 710 (transmitting antenna elements 110A and 110B) is provided, and a waveguide plate portion 82R shared with the receiving antenna array 720 (receiving antenna elements 110C to 110E) is provided. Feed portions 40 (feed terminals 401 to 405) are provided for each antenna element 110A to 110E.

[0284] Furthermore, a pillar waveguide portion 90 is formed in each of the waveguide plate portion 82T of the transmitting antenna array 710 and the waveguide plate portion 82R of the receiving antenna array 720. The pillar waveguide portion 90 includes a plurality of pillar waveguides 91 formed along the X-axis direction. The plurality of pillar waveguides 91 includes a first pillar waveguide 91a provided for each feed portion 40. Additionally, the plurality of pillar waveguides 91 also includes a second pillar waveguide 91b that does not have a feed portion.

[0285] For example, as referenced Figure 53 , Figure 54 As described above, in antenna element 110, the pillar waveguides 91 (first pillar waveguide 91a and second pillar waveguide 91b) disposed in pillar waveguide section 90 can be arranged at intervals of 1 / 2 of the wavelength of the radio wave used. Therefore, this arrangement can be applied even when configuring an antenna array. That is, in transmitting antenna array 710 and receiving antenna array 720, the center-to-center distance of adjacent pillar waveguides 91 among the plurality of pillar waveguides 91 is set to 1 / 2 (λ / 2) of the wavelength of the radio wave used. This allows for reference... Figure 18 In the MIMO radar described above, the arrangement of antenna elements using λ / 2 as the unit can be easily realized.

[0286] In addition, such as Figure 53 As shown, in antenna element 110, the distance from the open end (front end of waveguide plate portion 82) of each of the pillar waveguides 91a to 91c to the front surface 70F of dielectric block 70 is set to 1.00 mm, but this distance can be shorter. Therefore, in dielectric block 70, the path of radio waves propagating in the Y-axis direction is narrowed, and thus direct waves can be suppressed.

[0287] First, the configuration of the transmitting antenna array 710 will be described. Transmitting antenna element 110A (hereinafter also referred to as transmitting antenna Tx1) includes a feed terminal 401 connected to output terminal 461. Transmitting antenna element 110B (hereinafter also referred to as transmitting antenna Tx2) includes a feed terminal 402 connected to output terminal 462.

[0288] In the transmitting antenna array 710, the distance Lyl between the feed terminals 401 and 402 along the Y-axis is set to λ / 2 (here, 2.3 mm). That is, the center distance between the first pillar waveguides 91a constituting the transmitting antennas Tx1 and Tx2 (the center distance between the convex dielectric waveguides 75) is set to λ / 2.

[0289] In this case, for example, the first post waveguide 91a of transmitting antenna Tx2 is used as the second post waveguide 91b of transmitting antenna Tx1. Conversely, the first post waveguide 91a of transmitting antenna Tx1 is used as the second post waveguide 91b of transmitting antenna Tx2. Note that a second post waveguide 91b without a feed section is formed on the outer side of the two adjacent first post waveguides 91a.

[0290] The configuration of the receiving antenna array 720 will now be described. Receiving antenna element 110C (hereinafter also referred to as receiving antenna Rx1) includes a feed terminal 403 connected to input terminal 463. Receiving antenna element 110D (hereinafter also referred to as receiving antenna Rx2) includes a feed terminal 404 connected to input terminal 464. Receiving antenna element 110E (hereinafter also referred to as receiving antenna Rx3) includes a feed terminal 405 connected to input terminal 465.

[0291] As described above, the transmitting antenna array 710 is provided with two transmitting antennas Tx1 and Tx2 spaced apart by λ / 2. Therefore, in the receiving antenna array 720, the distance Ly2 along the Y-axis between the feed terminals 403 and 405 is set to 2×λ / 2=λ (here, 4.6mm). That is, the spacing between the first pillar waveguides 91a constituting the receiving antennas Rx1 to Rx3 (the spacing between the convex dielectric waveguides 75) is set to λ.

[0292] In this configuration, among the receiving antennas Rx1 to Rx3, a second post waveguide 91b without a feed section 40 is provided between the three adjacent first post waveguides 91a. These second post waveguides 91b are shared by the antenna elements on both sides. Note that a second post waveguide 91b without a feed section is also formed on the outer side of the three adjacent first post waveguides 91a.

[0293] Furthermore, the spacing between the transmitting antenna array 710 and the receiving antenna array 720 is set to be as large as possible to improve isolation. Here, the spacing between the receiving antenna Rx3 and the transmitting antenna Tx1 is set to 10 mm.

[0294] Figure 62A diagram showing the electric field intensity distribution in antenna module 700 and antenna module 701 given as a comparative example is shown. In antenna module 701 given as a comparative example, a cylindrical waveguide 91 similar to that in antenna module 700 is provided, but the convex dielectric waveguide 75 is not provided. Note that in antenna module 701, the position of the front surface 70F of dielectric block 70 in the X-axis direction is the same as the position of the front end (first antenna opening 71) of the convex dielectric waveguide 75 in antenna module 700.

[0295] exist Figure 62 In the figures shown, radio waves are transmitted from the transmitting antenna Tx2 at the bottom of the figure. For example, in antenna module 701, it can be seen that the radio waves propagate upward along the front surface 70F of dielectric block 70 in the figure, and the direct wave reaches the receiving antenna array 720 side.

[0296] On the other hand, in the antenna module 700 provided with the convex dielectric waveguide 75 according to this embodiment, the beam radiates forward from the transmitting antenna Tx2 in a broadened manner, but almost no radio waves propagate along the front surface 70F of the dielectric block 70. Therefore, it can be seen that direct waves reaching the receiving antenna array 720 side are suppressed. In this way, by providing the convex dielectric waveguide 75, isolation can be significantly improved.

[0297] Figure 63 The simulation results show the VSWR characteristics of each antenna in the antenna module 700 according to this embodiment. Figure 64 The simulation results show the radiation characteristics of each antenna in the antenna module 700 in the azimuth plane (XY plane), and Figure 65 Simulation results of the radiation characteristics of each antenna in the elevation plane (XZ plane) are shown. Figure 64 and Figure 65 In the series, F1 is 57GHz, F2 is 59GHz, and F3 is 61GHz.

[0298] according to Figures 63 to 65 The results shown demonstrate the variation in characteristics observed in antennas configured as an antenna array when compared to the characteristics of individual antennas, and also reveal differences in characteristics between antennas. This is because arranging multiple antennas adjacent to each other increases the influence of the conductors and dielectrics surrounding the antennas on their characteristics.

[0299] For example, in Figure 63 In the frequency band in use (59GHz to 63GHz), the VSWR is slightly higher than that of a standalone antenna. On the other hand, in the current frequency band, the VSWR value is below 3, and therefore it can be said that good VSWR characteristics or matching characteristics are also achieved in antenna module 700.

[0300] like Figure 64 As shown, a wide beamwidth is achieved in all transmitting antennas Tx1 and Tx2, and receiving antennas Rx1 to Rx3. Furthermore, as... Figure 65 As shown, it can be seen that the beam spread of each antenna in the elevation plane is suppressed compared to the azimuth plane.

[0301] Figure 66 This is a simulation result showing the isolation characteristics of the receiving antennas Rx1 to Rx3 in antenna module 700 relative to the transmitting antennas Tx1 and Tx2. From... Figure 66 The results shown can be seen, for example, with Figure 22 Compared to the configuration without the convex dielectric waveguide 75, the overall isolation characteristics are improved. For example, in Figure 22 In the worst case, the isolation property value is approximately -28. Conversely, in... Figure 66 In the worst case, the isolation characteristic value is approximately -37. Because isolation from direct waves can be ensured in this way, for example, the dynamic range of the receiver can be guaranteed and the detection accuracy of the radar can be improved.

[0302] Next, the phase difference characteristics of the antenna module 700 will be described. For example, large differences in the phase characteristics of the individual antennas included in the antenna module 700 affect the phase difference characteristics between the antennas, ultimately leading to a deterioration in object detection accuracy. To address this, in this antenna, the depth of the second post waveguide 91b adjacent to the first post waveguide 91a used for feeding is adjusted to reduce the differences in the phase characteristics of the individual antennas.

[0303] exist Figure 61 In the example shown, for instance, to improve the difference in phase characteristics of each antenna, the position of the through-hole (bottom post 93) is offset to adjust the depth of the second post waveguide 91b. Here, the position of the bottom post 93 is adjusted at the location surrounded by the fine dotted coil.

[0304] Figure 67 This is a simulation result illustrating an example of the phase difference characteristics of antenna module 700. The result shows the phase characteristics when viewed at an angle 30 cm away from the origin where antenna module 700 is located. Note that in each of the Rx1-Rx2 and Rx2-Rx3 plots, the phase characteristics between the transmitting antennas (Tx1 to Tx2) have been subtracted. It can be seen that by shifting the position of the base post 93 and adjusting the waveguide depth as described above, the results are comparable to those without the base post waveguide. Figure 24 Compared to the phase difference characteristics shown in the figure, the fluctuations in each curve become smaller and the characteristics are closer to the ideal value. This makes it possible to improve the detection accuracy of radar.

[0305] In MIMO radar antennas composed of multiple antennas, achieving adequate isolation between the transmitting and receiving sides is crucial. However, reflections of radio waves emitted from the transmitting antenna at the interface between the dielectric substrate and air degrade the isolation. If the isolation deteriorates, the signal-to-noise ratio (SN ratio) of the reflected wave from the target becomes smaller, and the target may become more easily missed.

[0306] For example, there are methods that involve setting up pillars between antennas as a way to improve isolation using pillars. There are also methods that involve drilling holes in the antennas to adjust impedance and improve directivity, thereby improving isolation. In these methods, the processing of the antennas, etc., may be costly.

[0307] According to this embodiment, the antenna module 700 is provided with antenna elements 110, each including a convex dielectric waveguide 75. Therefore, radio waves converted by the feed section 40 propagate through the convex dielectric waveguide and are effectively radiated in front, and radio waves reflected at the interface between the dielectric and air are unlikely to propagate to adjacent antennas.

[0308] Furthermore, the multiple cylindrical waveguides 91 are arranged at intervals of 1 / 2 of the wavelength in the antenna element 110. Therefore, radio waves radiated from each antenna element 110 are diffracted and reflected by adjacent cylindrical waveguides, thereby achieving a wide beamwidth in the horizontal direction.

[0309] Furthermore, in the antenna element 110 according to this embodiment, for example, the convex dielectric waveguide 75 can be formed simply by changing the shape of the dielectric multilayer substrate 1, thus suppressing manufacturing costs. Moreover, by forming the convex dielectric waveguide 75, a wide beamwidth in the horizontal direction can be achieved while significantly improving isolation.

[0310] <Variation Example>

[0311] In the above embodiments, the entire power supply section 40 (power supply pin 41) is composed of, as follows: Figure 8 The vias (IVHs) shown are formed, but the technology is not limited to this, and the wiring layers L1 to L3 of the first conductor layer 20A corresponding to the upper part of the feed section 40 can be connected by separate vias (LVHs), for example, as shown. Figure 68 As shown. In this case, the portion of the power supply section 40 disposed inside the dielectric block 10 can be composed of... Figure 8 The through-hole (IVH) shown is similar to the through-hole (IVH) formation.

[0312] Furthermore, although the hole 45 is formed in the dielectric block 10 through a back-drilled hole for adjusting the length of the feed pin 41, the hole 45 can be filled with resin for long-term reliability. Alternatively, instead of forming the hole 45, the feed pin 41 can be shorted to the wiring layer L6 in the second conductor layer 20B.

[0313] Note that, although not described in the above embodiments, protective layers (solder resist) for protecting wiring can be provided on both surfaces of the dielectric multilayer substrate 1. The effect of dielectric loss (tanδ) varies depending on the presence or absence of the protective layer, differences in materials, etc., but in this technology, the presence or absence of the protective layer and differences in materials are not particularly important.

[0314] When solder resist is applied, the loss in the transmission line (signal line) of millimeter-wave signals may increase due to the large dielectric loss tangent of the solder resist material. On the other hand, when solder resist is not applied, gold plating or similar methods are required to prevent corrosion in that area. Therefore, from the perspective of long-term reliability and cost, it is advantageous to minimize the area without solder resist coating as much as possible.

[0315] To address this, when applying solder resist, it can be avoided only around the periphery of the millimeter-wave signal transmission line. This reduces losses in the transmission line and decreases the area required for processes like gold plating. Note that for the antenna section, losses are further reduced when no solder resist is applied. Simultaneously, by also applying solder resist to the antenna section, radiation in unwanted directions is suppressed. Whether or not to apply solder resist to the antenna section can be determined by considering these characteristics.

[0316] In the aforementioned features according to the present invention, at least two features can be combined. In other words, the various features described in the various embodiments can be arbitrarily combined without distinguishing between embodiments. Furthermore, the various effects described above are merely examples and are not limiting, and other effects may also occur.

[0317] Note that this technology can also be configured as follows.

[0318] (1) An antenna element, comprising:

[0319] Dielectric block;

[0320] The power supply terminal is located within the dielectric block;

[0321] A pair of conductor layers, facing each other, with a dielectric block between the pair of conductor layers; and

[0322] The antenna openings form a first antenna opening and a second antenna opening along the planar direction of a pair of conductor layers. The first antenna opening is open in the direction of the first axis when viewed from the feed terminal, and the second antenna opening is open in the direction of the second axis orthogonal to the first axis.

[0323] (2) The antenna element according to (1) also includes:

[0324] Multiple conductive pillars are arranged in a first region of the dielectric block and penetrate the dielectric block in the thickness direction, wherein...

[0325] The power supply terminals are arranged in the second region of the dielectric block.

[0326] Each of the pair of conductor layers includes: a base disposed in a first region and connected to a plurality of conductive pillars; and a waveguide portion disposed in a second region and protruding from the base along a first axis.

[0327] The waveguide plate forms a first antenna opening and a second antenna opening as antenna openings. The first antenna opening is open in the first axial direction, and the second antenna opening is open in the second axial direction.

[0328] (3) Based on the antenna elements in (2), where,

[0329] Multiple conductive pillars form a pillar wall, and within the pillar wall, the multiple conductive pillars are arranged along a second axis at intervals less than 1 / 4 of the wavelength of the electromagnetic wave propagating through the dielectric block.

[0330] (4) Based on the antenna element of (2) or (3), wherein,

[0331] The power supply terminal extends from one conductor layer in a pair of conductor layers to the other conductor layer in the pair of conductor layers, and

[0332] The length of the power supply terminal along the thickness direction of the dielectric block is less than the thickness of the dielectric block.

[0333] (5) Based on the antenna element in (4), where,

[0334] The dielectric block includes a hole drilled from one side of the other conductor layer in a pair of conductor layers, and the hole has a depth that reaches the feed terminal.

[0335] (6) Based on the antenna element in (5), where,

[0336] The length of the power supply terminal is half the thickness of the dielectric block.

[0337] (7) An antenna element based on any one of (2) to (6), wherein,

[0338] The waveguide plate portion includes a first waveguide plate region and a second waveguide plate region. The first waveguide plate region protrudes from the base by a first width in a first axial direction, and the second waveguide plate region protrudes from the first waveguide plate region by a second width in the first axial direction. The second width is greater than the first width.

[0339] (8) An antenna element based on any one of (2) to (7), wherein,

[0340] The dielectric block also includes a third region that covers each of the first antenna opening and the second antenna opening.

[0341] (9) The antenna element according to (1) also includes:

[0342] Multiple conductive pillars penetrate the dielectric block and connect to a pair of conductor layers; and

[0343] A pillar waveguide section includes at least one pillar waveguide surrounded by a pair of conductor layers and a plurality of conductive pillars, wherein,

[0344] The pillar waveguide section includes a first pillar waveguide, which is connected to a feed terminal and formed from the feed terminal along a first axial direction.

[0345] The dielectric block includes a convex dielectric waveguide, which is formed to protrude in front of the first pillar waveguide and forms a first antenna opening and a second antenna opening as antenna openings. The first antenna opening is open in the first axial direction, and the second antenna opening is open in the second axial direction.

[0346] (10) According to the antenna element in (9), where,

[0347] The pillar waveguide section includes a second pillar waveguide, which is formed adjacent to the first pillar waveguide along a first axis direction. The second pillar waveguide has one open end and the other closed end in the same direction as the first pillar waveguide.

[0348] (11) According to the antenna element of (10), where,

[0349] The first and second post waveguides are arranged at a distance of 1 / 2 of the wavelength of the radio wave used in the second axial direction.

[0350] (12) The antenna element according to (10) or (11), wherein,

[0351] The width of the convex dielectric waveguide in the second axial direction is equal to or greater than the width of the first pillar waveguide in the second axial direction, and equal to or less than the center distance of the second pillar waveguides disposed on both sides of the first pillar waveguide.

[0352] (13) An antenna element based on any one of (10) to (12), wherein,

[0353] The pillar waveguide includes a pillar wall, within which multiple conductive pillars are arranged along a first axis.

[0354] The second pillar waveguide is composed of a second pillar wall that is different from the first pillar wall that constitutes the first pillar waveguide.

[0355] (14) An antenna element based on any one of (10) to (13), wherein,

[0356] The opening ends of the first and second pillar waveguides are located at the same position in the first axis direction.

[0357] (15) An antenna element according to any one of (10) to (14), wherein,

[0358] The first and second waveguides differ in depth at their opening ends.

[0359] (16) An antenna array comprising:

[0360] Dielectric block;

[0361] Multiple power supply terminals are disposed within the dielectric block;

[0362] A pair of conductor layers, facing each other, with a dielectric block between the pair of conductor layers; and

[0363] The antenna openings form a first antenna opening and a second antenna opening along the planar direction of a pair of conductor layers. The first antenna opening is open in the direction of the first axis when viewed from the feed terminal, and the second antenna opening is open in the direction of the second axis orthogonal to the first axis.

[0364] (17) The antenna array according to (16) also includes:

[0365] Multiple conductive pillars are arranged in a first region of the dielectric block and penetrate the dielectric block in the thickness direction, wherein...

[0366] Multiple power supply terminals are arranged in the second region of the dielectric block.

[0367] Each of the pair of conductor layers includes: a base disposed in a first region and connected to a plurality of conductive pillars; and a waveguide portion disposed in a second region and protruding from the base along a first axis.

[0368] The waveguide plate forms a first antenna opening and a second antenna opening as antenna openings. The first antenna opening is open in the direction of the first axis, and the second antenna opening is open in the direction of the second axis orthogonal to the first axis.

[0369] (18) Based on the antenna array of (17), where,

[0370] Multiple power supply terminals are arranged at intervals of less than 1 / 2 of the wavelength of the radio waves used in the second axial direction.

[0371] (19) The antenna array according to (17) or (18) further includes:

[0372] A shielding section is installed between multiple feed terminals to suppress radio wave interference between adjacent feed terminals.

[0373] (20) Based on the antenna array of (19), where,

[0374] The shielding portion includes multiple columnar bodies that penetrate the second region, and

[0375] Multiple columnar bodies are arranged on both sides of each of the multiple power supply terminals, in the second axial direction from the position opposite to the multiple power supply terminals toward the base, parallel to the first axial direction.

[0376] (21) The antenna array according to (16) also includes:

[0377] Multiple conductive pillars penetrate the dielectric block and connect to a pair of conductor layers; and

[0378] A pillar waveguide section includes at least one pillar waveguide surrounded by a pair of conductor layers and a plurality of conductive pillars, wherein,

[0379] The pillar waveguide section includes a first pillar waveguide, which is connected to a feed terminal and formed from the feed terminal along a first axial direction.

[0380] The dielectric block includes a convex dielectric waveguide, which is formed to protrude in front of the first pillar waveguide and forms a first antenna opening and a second antenna opening as antenna openings. The first antenna opening is open in the first axial direction, and the second antenna opening is open in the second axial direction.

[0381] (22) Based on the antenna array of (21), where,

[0382] The pillar waveguide section includes multiple pillar waveguides, each pillar waveguide including a first pillar waveguide for each of a plurality of feed terminals, and the plurality of pillar waveguides are formed along a first axis direction.

[0383] The center-to-center distance between adjacent pillar waveguides in a multi-pillar waveguide system is half the wavelength of the radio wave used.

[0384] (23) An antenna module, comprising:

[0385] The transmitting antenna is composed of antenna elements according to (1); and

[0386] The receiving antenna is composed of an antenna array according to (16).

[0387] (24) An antenna module, comprising:

[0388] The transmitting antenna is composed of antenna elements according to (2); and

[0389] The receiving antenna is composed of an antenna array according to (17).

[0390] (25) Based on the antenna module of (24), where,

[0391] The distance between the central axis of the outermost antenna element of the antenna array that will become the receiving antenna and the second antenna opening is greater than the distance between the central axis of the antenna element that constitutes the transmitting antenna and the second antenna opening.

[0392] (26) The antenna module according to (24) or (25), wherein,

[0393] A pair of conductor layers includes end edges that extend at least between the transmitting antenna and the receiving antenna or between the antenna elements constituting the transmitting antenna to a feed terminal in a first axial direction.

[0394] (27) The antenna module according to (26) also includes:

[0395] The column absorber wall has multiple conductive columnar bodies arranged along the second axis. These conductive columnar bodies penetrate the dielectric block, connect to the end edge, and are electrically isolated from other conductor layers.

[0396] (28) The antenna module according to any one of (24) to (27) further includes:

[0397] An LC resonator includes a separate conductive foil separated from one of a pair of conductive layers, and a conductive pillar connecting the separate conductive foil to the other of the pair of conductive layers, and the LC resonator is arranged between a transmitting antenna and a receiving antenna.

[0398] (29) An antenna module, comprising:

[0399] The transmitting antenna is composed of antenna elements according to (9); and

[0400] The receiving antenna is composed of an antenna array according to (21).

[0401] (30) An antenna element, comprising:

[0402] The dielectric block includes a first region and a second region;

[0403] Multiple conductive pillars are arranged in the first region and penetrate the dielectric block in the thickness direction of the dielectric block;

[0404] The power supply terminals are arranged in the second area; and

[0405] A pair of conductor layers, facing each other, with a dielectric block between the pair of conductor layers, wherein...

[0406] Each of the pair of conductor layers includes: a base disposed in a first region and connected to a plurality of conductive pillars; and a waveguide portion disposed in a second region and protruding from the base along a first axis.

[0407] The waveguide plate forms a first antenna opening and a second antenna opening. The first antenna opening is open in the direction of the first axis, and the second antenna opening is open in the direction of the second axis orthogonal to the first axis.

[0408] (31) An antenna array, comprising:

[0409] The dielectric block includes a first region and a second region;

[0410] Multiple conductive pillars are arranged in the first region and penetrate the dielectric block;

[0411] Multiple power supply terminals are arranged in the second area; and

[0412] A pair of conductor layers, facing each other, with a dielectric block between the pair of conductor layers, wherein...

[0413] Each of the pair of conductor layers includes: a base disposed in a first region and connected to a plurality of conductive pillars; and a waveguide portion disposed in a second region and protruding from the base along a first axis.

[0414] The waveguide plate forms a first antenna opening and a second antenna opening. The first antenna opening is open in the direction of the first axis, and the second antenna opening is open in the direction of the second axis orthogonal to the first axis.

[0415] (32) An antenna element, comprising:

[0416] Dielectric block;

[0417] The power supply terminal is located within the dielectric block;

[0418] A pair of conductor layers are opposite to each other, and a dielectric block is located between the pair of conductor layers;

[0419] Multiple conductive pillars penetrate the dielectric block and connect to a pair of conductor layers; and

[0420] A pillar waveguide section includes at least one pillar waveguide surrounded by a pair of conductor layers and a plurality of conductive pillars, wherein,

[0421] The pillar waveguide section includes a central pillar waveguide, which is connected to the feed terminal and formed from the feed terminal along a first axial direction.

[0422] The dielectric block includes a dielectric protrusion that is formed to protrude in front of the central pillar waveguide and forms a first antenna opening and a second antenna opening. The first antenna opening is open in a first axial direction, and the second antenna opening is open in a second axial direction orthogonal to the first axis.

[0423] (33) An antenna array, comprising:

[0424] Dielectric block;

[0425] Multiple power supply terminals are disposed within the dielectric block;

[0426] A pair of conductor layers are opposite to each other, and a dielectric block is located between the pair of conductor layers;

[0427] Multiple conductive pillars penetrate the dielectric block and connect to a pair of conductor layers; and

[0428] A pillar waveguide section includes at least one pillar waveguide surrounded by a pair of conductor layers and a plurality of conductive pillars, wherein,

[0429] The pillar waveguide section includes a central pillar waveguide, which is connected to the feed terminal and formed from the feed terminal along a first axial direction.

[0430] The dielectric block includes a dielectric protrusion that is formed to protrude in front of the central pillar waveguide and forms a first antenna opening and a second antenna opening. The first antenna opening is open in a first axial direction, and the second antenna opening is open in a second axial direction orthogonal to the first axis.

[0431] Reference number list

[0432] 1…Dielectric multilayer substrate

[0433] 10, 70… Dielectric blocks

[0434] 20, 80… conductor layers

[0435] 20A, 80A… First conductor layer

[0436] 20B, 80B… Second conductor layer

[0437] 21…base

[0438] 22… Waveguide plate section

[0439] 30…Rear column wall

[0440] 40, 401, 402, 403, 404, 405, 406… Power Supply Section

[0441] 41…feed needle

[0442] 43…signal line

[0443] 51, 71… First antenna opening

[0444] 52, 72… The second day's chart opening

[0445] 60… Shielding section

[0446] 75…convex dielectric waveguide

[0447] 90… Pillar waveguide section

[0448] 91a…First Pillar Waveguide

[0449] 91b, 91c… Second column waveguide

[0450] 100, 100A, 100B, 110… Antenna elements

[0451] 200, 201, 202, 720… Receiver antenna arrays

[0452] 300, 400, 500, 600, 700… antenna modules

[0453] P1, P3, P4, P5… conductive pillars

[0454] P2…Columnar body

[0455] Rx1, Rx2, Rx3, Rx4… Receiving antennas

[0456] Tx1, Tx3... Transmitting antennas.

Claims

1. An antenna element, comprising: Dielectric block; A power supply terminal is disposed in the dielectric block; A pair of conductor layers opposite to each other, with the dielectric block located between the pair of conductor layers; as well as The antenna opening has a first antenna opening and a second antenna opening in a planar direction along the pair of conductor layers. The first antenna opening is open in a first axial direction when viewed from the feed terminal, and the second antenna opening is open in a second axial direction orthogonal to the first axis.

2. The antenna element according to claim 1, further comprising: Multiple conductive pillars are arranged in a first region of the dielectric block and penetrate the dielectric block in the thickness direction, wherein... The power supply terminal is arranged in the second region of the dielectric block. Each of the pair of conductor layers includes: a base disposed in the first region and connected to the plurality of conductive pillars; and a waveguide plate portion disposed in the second region and protruding from the base along the first axis direction. The waveguide plate portion forms the first antenna opening and the second antenna opening as the antenna opening portion, the first antenna opening is open in the first axial direction, and the second antenna opening is open in the second axial direction.

3. The antenna element according to claim 2, wherein, The plurality of conductive pillars form a pillar wall, wherein the plurality of conductive pillars are arranged along the second axial direction at intervals less than 1 / 4 of the wavelength of the electromagnetic wave propagating through the dielectric block.

4. The antenna element according to claim 2, wherein, The power supply terminal extends from one of the pair of conductor layers to the other conductor layer of the pair of conductor layers, and The length of the feed terminal along the thickness direction of the dielectric block is less than the thickness of the dielectric block.

5. The antenna element according to claim 4, wherein, The dielectric block includes a hole drilled from one side of the other conductor layer of the pair of conductor layers, and the hole has a depth reaching the feed terminal.

6. The antenna element according to claim 5, wherein, The length of the power supply terminal is half the thickness of the dielectric block.

7. The antenna element according to claim 2, wherein, The waveguide plate portion includes a first waveguide plate region and a second waveguide plate region. The first waveguide plate region protrudes from the base by a first width in the first axial direction, and the second waveguide plate region protrudes from the first waveguide plate region by a second width in the first axial direction. The second width is greater than the first width.

8. The antenna element according to claim 2, wherein, The dielectric block further includes a third region that covers each of the first antenna opening and the second antenna opening.

9. The antenna element according to claim 1, further comprising: Multiple conductive pillars penetrate the dielectric block and connect to the pair of conductor layers; as well as The pillar waveguide section includes at least one pillar waveguide surrounded by the pair of conductor layers and the plurality of conductive pillars, wherein, The pillar waveguide portion includes a first pillar waveguide, which is connected to the feed terminal and formed from the feed terminal along the first axial direction. The dielectric block includes a convex dielectric waveguide that is formed to protrude in front of the first pillar waveguide and forms a first antenna opening and a second antenna opening as the antenna opening portion. The first antenna opening is open in the first axial direction and the second antenna opening is open in the second axial direction.

10. The antenna element according to claim 9, wherein, The pillar waveguide portion includes a second pillar waveguide, which is formed adjacent to the first pillar waveguide along the first axis direction. The second pillar waveguide has one open end and the other closed end in the same direction as the first pillar waveguide.

11. The antenna element according to claim 10, wherein, The first pillar waveguide and the second pillar waveguide are arranged at a distance of 1 / 2 of the wavelength of the radio wave used in the second axial direction.

12. The antenna element according to claim 10, wherein, The width of the convex dielectric waveguide in the second axial direction is equal to or greater than the width of the first cylindrical waveguide in the second axial direction, and equal to or less than the center distance of the second cylindrical waveguides disposed on both sides of the first cylindrical waveguide.

13. An antenna array, comprising: Dielectric block; Multiple power supply terminals are disposed in the dielectric block; A pair of conductor layers opposite to each other, with the dielectric block located between the pair of conductor layers; as well as The antenna opening has a first antenna opening and a second antenna opening in a planar direction along the pair of conductor layers. The first antenna opening is open in a first axial direction when viewed from the feed terminal, and the second antenna opening is open in a second axial direction orthogonal to the first axis.

14. The antenna array according to claim 13, further comprising: Multiple conductive pillars are arranged in a first region of the dielectric block and penetrate the dielectric block in the thickness direction, wherein... The plurality of power supply terminals are arranged in the second region of the dielectric block. Each of the pair of conductor layers includes: a base disposed in the first region and connected to the plurality of conductive pillars; and a waveguide plate portion disposed in the second region and protruding from the base along the first axis direction. The waveguide plate portion forms the first antenna opening and the second antenna opening as the antenna opening portion. The first antenna opening is open in the first axial direction, and the second antenna opening is open in the second axial direction orthogonal to the first axis.

15. The antenna array according to claim 14, wherein, The plurality of feed terminals are arranged at intervals of less than 1 / 2 of the wavelength of the radio waves used in the second axial direction.

16. The antenna array according to claim 14, further comprising: A shielding section is disposed between the plurality of power supply terminals to suppress radio wave interference between adjacent power supply terminals.

17. The antenna array according to claim 16, wherein, The shielding portion includes multiple columnar bodies that penetrate the second region, and The plurality of columnar bodies are arranged parallel to the first axis direction on both sides of each of the plurality of power supply terminals, from a position opposite to the plurality of power supply terminals toward the base in the second axial direction.

18. The antenna array according to claim 13, further comprising: Multiple conductive pillars penetrate the dielectric block and connect to the pair of conductor layers; as well as The pillar waveguide section includes at least one pillar waveguide surrounded by the pair of conductor layers and the plurality of conductive pillars, wherein, The pillar waveguide portion includes a first pillar waveguide, which is connected to the feed terminal and formed from the feed terminal along the first axial direction. The dielectric block includes a convex dielectric waveguide that is formed to protrude in front of the first pillar waveguide and forms a first antenna opening and a second antenna opening as the antenna opening portion. The first antenna opening is open in the first axial direction and the second antenna opening is open in the second axial direction.

19. The antenna array according to claim 18, wherein, The pillar waveguide portion includes a plurality of pillar waveguides, each pillar waveguide including a first pillar waveguide disposed for each of the plurality of feed terminals, and the plurality of pillar waveguides are formed along the first axis direction. The center-to-center distance between adjacent pillar waveguides in the plurality of pillar waveguides is 1 / 2 of the wavelength of the radio wave used.

20. An antenna module, comprising: The transmitting antenna is composed of the antenna element according to claim 1; as well as The receiving antenna is composed of the antenna array according to claim 13.

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