Horn Antenna

Abstract

The horn antenna according to one embodiment of the present invention comprises a waveguide tube part and a horn part. The waveguide tube part has a first dielectric block and a first post wall. The first post wall: includes a plurality of conductive columnar bodies that pass through the first dielectric block; and demarcates a first waveguide that extends in one axial direction. The horn part includes a first widening part that is connected to one end of the waveguide tube part in the one axial direction. The first widening part has a second dielectric block and a second post wall. The second dielectric block is thicker than the first dielectric block. The second post wall: includes a plurality of conductive columnar bodies that pass through the second dielectric block; and demarcates a second waveguide that widens with increasing distance from the first waveguide.

Description

[Technical Field]

[0001] The present technology relates to a horn antenna capable of transmitting or receiving electromagnetic waves, for example, millimeter waves. [Background technology]

[0002] In recent years, millimeter-wave modules for detecting people and obstacles, such as radar, have become popular, mainly for in-vehicle applications. The most common antenna device for this type is a phased patch antenna formed on a substrate. However, this antenna radiates radio waves perpendicular to the substrate surface, making it difficult to make it thinner.

[0003] On the other hand, antennas using a technology called post-wall waveguide are known (see, for example, Patent Document 1). A post-wall waveguide is a waveguide with post walls formed by arranging multiple metal pillars (conductor posts) that electrically connect conductors (copper foils) on the top and bottom of a wiring board. The post-wall waveguide has an antenna opening on the side of the wiring board, which makes it possible to achieve a thinner antenna. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-175624 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the post-wall waveguide antenna described in Patent Document 1, the antenna aperture is limited by the width and thickness of the post waveguide, making it difficult to improve the antenna gain.

[0006] In view of the above circumstances, an object of the present technology is to provide a post-wall waveguide type horn antenna that can improve antenna gain. [Means for solving the problem]

[0007] A horn antenna according to an embodiment of the present technology includes a waveguide portion and a horn portion. The waveguide portion has a first dielectric block and a first post wall that defines a first waveguide that includes a plurality of first conductive columns that penetrate the first dielectric block and extends in one axial direction. The horn portion includes a first widened portion connected to one end of the waveguide portion in the uniaxial direction, the first widened portion having a second dielectric block thicker than the first dielectric block, and a second post wall defining a second waveguide including a plurality of second conductive pillars penetrating the second dielectric block and having a path width that increases with increasing distance from the first waveguide.

[0008] The first dielectric block and the second dielectric block may be formed of a common dielectric multilayer substrate, in which case the first waveguide and the second waveguide are provided inside the dielectric multilayer substrate.

[0009] The first post wall may further include two first conductor layers that face each other across the first dielectric block and are connected to the plurality of first conductive columns.

[0010] The second post wall may further include two second conductor layers and an interlayer connector. The two second conductor layers face each other across the second dielectric block and are connected to the plurality of second conductive columns. The interlayer connector electrically connects the first conductor layer and the second conductor layer.

[0011] The horn antenna may further include a conductive shield layer connected to the first conductor layer and the second conductor layer and covering the waveguide portion and the horn portion.

[0012] The horn portion may further include a second widening portion having a third dielectric block and a third post wall. The third dielectric block is connected to one end of the second dielectric layer in the uniaxial direction and is thicker than the second dielectric block. The third post wall includes a plurality of third conductive pillars penetrating the third dielectric block and defines a third waveguide whose path width increases with increasing distance from the second waveguide.

[0013] The waveguide section may include a plurality of air holes provided in the first dielectric block and having an opening width smaller than the wavelength of the electromagnetic wave propagating through the first dielectric.

[0014] The horn may include a plurality of air holes provided in at least one of the second dielectric block and the third dielectric block, each having an opening width smaller than the wavelength of an electromagnetic wave propagating through the second dielectric block and the third dielectric block.

[0015] The horn may further include a dielectric lens, the dielectric lens being provided at one end in the axial direction and being formed by a part of the plurality of air holes.

[0016] The horn antenna may further include a dielectric portion connected to one end of the horn portion in the axial direction and having a length along the axial direction that is equal to or greater than the wavelength of the electromagnetic wave propagating through the second waveguide.

[0017] The dielectric portion may have a plurality of air holes having an opening width smaller than the wavelength of an electromagnetic wave propagating through the dielectric portion, and a dielectric lens portion formed by a part of the plurality of air holes.

[0018] The horn antenna may further include a feed portion having a signal line connected to the first waveguide.

[0019] A horn antenna according to another embodiment of the present technology includes a dielectric multilayer substrate, a waveguide portion, and a horn portion. The dielectric multilayer substrate has a side surface that forms an antenna opening. The waveguide portion is provided inside the dielectric multilayer substrate and includes two first conductor layers facing each other across a first gap in the thickness direction of the dielectric multilayer substrate, and a first post wall that is provided between the two first conductor layers and defines a first waveguide that extends in a uniaxial direction perpendicular to the thickness direction of the dielectric multilayer substrate. The horn portion includes a first widened portion provided between the waveguide portion and the side portion, the first widened portion having two second conductor layers facing each other at a second interval in the thickness direction of the dielectric multilayer substrate that is larger than the first interval, and a second post wall provided between the two second conductor layers and defining a second waveguide whose path width increases with increasing distance from the first waveguide. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a partially see-through perspective view showing the horn antenna according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 1 is a plan view of a horn antenna according to a first embodiment. [Figure 4] 1 is a side cross-sectional view schematically showing a dielectric multilayer substrate that constitutes a horn antenna according to a first embodiment. [Figure 5] 3A and 3B are schematic diagrams illustrating gaps between conductive columns in the horn antenna according to the first embodiment. [Figure 6] 2 is a partially exploded perspective view showing the layer structure of a power feed section in the horn antenna according to the first embodiment. FIG. [Figure 7] FIG. 2 is a front cross-sectional view of a main part of the power supply unit. [Figure 8] FIG. 2 is a schematic plan view of a main part of the power supply unit. [Figure 9] FIG. 10 is a schematic overall perspective view of a horn antenna according to a comparative example. [Figure 10] FIG. 10 is a side cross-sectional view of the widthwise center of a horn antenna according to a comparative example. [Figure 11]10 is a simulation result showing radiation characteristics of a horn antenna according to a comparative example. [Figure 12] 4 is a simulation result showing radiation characteristics of the horn antenna according to the first embodiment. [Figure 13] 3A and 3B are diagrams showing a comparison of radiation patterns of the horn antenna according to the first embodiment and a horn antenna according to a comparative example. [Figure 14] FIG. 10 is a partially see-through perspective view showing a horn antenna according to a second embodiment. [Figure 15] 10 is a simulation result showing the difference in radiation characteristics of an antenna depending on whether or not there is an air hole. [Figure 16] FIG. 10 is a schematic plan view showing a horn antenna according to a third embodiment. [Figure 17] FIG. 10 is a schematic plan view of a main part of a horn antenna according to a third embodiment. [Figure 18] FIG. 10 is a schematic perspective view showing a horn antenna according to a fourth embodiment. [Figure 19] FIG. 10 is a schematic cross-sectional side view of a horn antenna according to a fourth embodiment, taken at the center in the width direction. [Figure 20] 10A and 10B are diagrams illustrating an effect of a horn antenna without a shielding layer. [Figure 21] 10 is a simulation result showing radiation characteristics of the horn antenna according to the fourth embodiment. [Figure 22] FIG. 10 is a schematic plan view showing a horn antenna according to a fifth embodiment. [Figure 23] 10 is a simulation result showing radiation characteristics of the horn antenna according to the fifth embodiment. [Figure 24] FIG. 10 is a schematic plan view showing a horn antenna according to a sixth embodiment. [Figure 25] 13 is a simulation result showing the radiation characteristics of the horn antenna according to the sixth embodiment. [Figure 26] 13 is a simulation result showing the radiation characteristics of the horn antenna according to the sixth embodiment. [Figure 27]13 is a simulation result showing radiation characteristics when the length of the dielectric part in the horn antenna according to the sixth embodiment is set to 1.3 mm. [Figure 28] FIG. 10 is a diagram showing the radiation pattern of the horn antenna according to the sixth embodiment in comparison with other structures. [Figure 29] 13 is a simulation result showing radiation characteristics when the length of the dielectric part in the horn antenna according to the sixth embodiment is set to 4.0 mm. [Figure 30] 13 is a simulation result showing radiation characteristics when the length of the dielectric part in the horn antenna according to the sixth embodiment is set to 5.2 mm. [Figure 31] FIG. 10 is a diagram showing the radiation pattern of the horn antenna according to the sixth embodiment in comparison with other structures. [Figure 32] FIG. 13 is a schematic plan view showing an antenna device according to a seventh embodiment. [Figure 33] FIG. 2 is a partially transparent perspective view showing a horn antenna according to Reference Example 1. [Figure 34] 1 is a side cross-sectional view of the horn antenna according to Reference Example 1 at the center in the width direction. [Figure 35] FIG. 2 is a schematic plan view of a horn antenna according to a first reference example. [Figure 36] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 1. [Figure 37] FIG. 10 is a schematic plan view showing a horn antenna according to Reference Example 2. [Figure 38] FIG. 10 is a cross-sectional side view of the horn antenna according to Reference Example 2 at the center in the width direction. [Figure 39] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 2. [Figure 40] FIG. 10 is a schematic plan view showing a horn antenna according to a third reference example. [Figure 41] FIG. 11 is a cross-sectional side view of the horn antenna according to Reference Example 3 at the center in the width direction. [Figure 42] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 3. [Figure 43] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 3. [Figure 44] FIG. 10 is a schematic plan view showing a horn antenna according to a fourth reference example. [Figure 45] FIG. 11 is a cross-sectional side view of the horn antenna according to Reference Example 4 at the center in the width direction. [Figure 46] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 4. [Figure 47] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 4. [Figure 48] FIG. 10 is a schematic plan view showing a horn antenna according to Reference Example 5. [Figure 49] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 5. [Figure 50] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 5. [Figure 51] FIG. 13 is a schematic plan view showing a horn antenna according to a sixth reference example. [Figure 52] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 6. [Figure 53] 10 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 6. [Figure 54] FIG. 13 is a schematic plan view showing a horn antenna according to Reference Example 7. [Figure 55] 13 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 7. [Figure 56] 13 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 7. [Figure 57] 13 is a schematic cross-sectional side view showing a horn antenna according to Reference Example 8 and an enlarged view of a main part thereof. FIG. [Figure 58] 13 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 8. [Figure 59] 13 is a simulation result showing the radiation characteristics of the horn antenna according to Reference Example 8. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0022] First Embodiment FIG. 1 is a partially transparent perspective view showing a horn antenna 100 according to a first embodiment of the present technology, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is a plan view of horn antenna 100, and FIG. 4 is a side cross-sectional view schematically showing a dielectric multilayer substrate 1 constituting horn antenna 100.

[0023] In each figure, the X-axis, Y-axis, and Z-axis indicate three mutually orthogonal axial directions, which correspond to the width direction, length direction, and thickness direction of horn antenna 100, respectively.

[0024] [Horn antenna] Horn antenna 100 of this embodiment has waveguide section 10, horn section 20, and power supply section 40. Horn antenna 100 may be configured as a transmitting antenna, a receiving antenna, or a transmitting and receiving antenna. Here, an example in which horn antenna 100 is configured as a transmitting antenna will be described.

[0025] Horn antenna 100 is provided inside dielectric multilayer substrate 1, whose thickness direction is in the Z-axis direction. First, dielectric multilayer substrate 1 will be described.

[0026] (Dielectric multilayer substrate) As shown in FIG. 4, the dielectric multilayer substrate 1 has, from the top down, a plurality of (seven in this example) dielectric layers 1A to 1G and a plurality of (eight in this example) wiring layers L1 to L8 individually arranged between each of these dielectric layers 1A to 1G.

[0027] Each of the dielectric layers 1A-1G is made of an insulating organic material, such as an epoxy resin or a fluorine-based resin such as polytetrafluoroethylene, or an insulating inorganic material, such as ceramics. The dielectric constant of each of the dielectric layers 1A-1G can be set arbitrarily depending on the frequency of the radio waves transmitted or received by the horn antenna 10. For example, when used to transmit or receive radio waves (millimeter waves) in the 60 GHz band, a material with a dielectric constant of, for example, 3.6 is used for each of the dielectric layers 1A-1G.

[0028] The thickness of each of the dielectric layers 1A-1G can also be set arbitrarily. For example, a core material thicker than the other dielectric layers 1A, 1B, 1D, 1F, and 1G may be used for the dielectric layer 1C and the dielectric layer 1E. This ensures the rigidity of the dielectric multilayer substrate 1. In this case, a prepreg material can be used for the dielectric layer 1D disposed between the dielectric layers 1C and 1E to bond these dielectric layers 1C and 1E. Similarly, a prepreg material can be used for the dielectric layers 1A, 1B, 1F, and 1G. In this case, the dielectric layers 1A, 1B, 1F, and 1G are sequentially stacked on the core material using a build-up method.

[0029] When the dielectric constant of each of the dielectric layers 1A to 1G is 3.6, the wavelength of a radio wave with a frequency of 60 GHz is approximately 2.64 mm. In this case, the thickness of the dielectric layers 1A, 1B, 1F, and 1G can be set to approximately 80 μm, the thickness of the dielectric layer 1C can be set to approximately 750 μm, the thickness of the dielectric layer 1D can be set to approximately 110 μm, and the thickness of the dielectric layer 1E can be set to approximately 200 μm.

[0030] The wiring layers L1 to L8 are typically made of a metal material, and in this embodiment, copper foil of a predetermined thickness is used. Each wiring layer L1 to L8 is patterned into a predetermined shape. Therefore, in the non-circuit forming area where no wiring exists, the upper and lower dielectric layers are directly laminated without an intervening wiring layer.

[0031] The wiring layers L1 to L8 are electrically connected to one another at any position. As interlayer connectors connecting the wiring layers L1 to L8, a form connecting two adjacent wiring layers (through hole V1 in FIG. 4) or a form connecting three or more wiring layers in common (through hole V2 in FIG. 4) can be applied. The through holes V1 and V2 may be formed from metal pillars filled with a conductor such as a metal plug or metal plating.

[0032] Next, each part of horn antenna 100 will be described in detail with reference to FIGS.

[0033] (Waveguide section) The waveguide section 10 has a first dielectric block 11, a first post wall 12, and two conductor layers 13 and 14.

[0034] The first dielectric block 11 is formed in a roughly rectangular parallelepiped shape. The first dielectric block 11 is a laminate of inner dielectric layers 1C, 1D, and 1E in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L4, L5 present at the interfaces between these dielectric layers 1C to 1E.

[0035] The first post wall 12 includes a plurality of conductive pillars P1 (first conductive pillars) penetrating the first dielectric block 11, and defines a first waveguide G1 extending in one axial direction (Y-axis direction) within the first dielectric block 11. The first waveguide G1 is a dielectric waveguide that forms a transmission path for radio waves (millimeter waves). The conductive pillars P1 form both side walls of the first waveguide G1 and a rear wall on the side opposite to the horn 20.

[0036] Each conductive pillar P1 is a metal cylinder that connects two first conductor layers 13 and 14 that face each other in the thickness direction (Z-axis direction) with the first dielectric block 11 in between. One first conductor layer 13 corresponds to the wiring layer L3 in FIG. 4, and the other first conductor layer 14 corresponds to the wiring layer L6 in FIG. 4. The first conductor layers 13 and 14 face each other at a distance (first distance) equivalent to the total thickness of the dielectric layers 1C to 1E. Each of the first conductor layers 13 and 14 is formed in a rectangular shape with its long side in the Y-axis direction, defines the top and bottom surfaces of the first waveguide G1, and is typically connected to ground potential.

[0037] The conductive pillars P1 are arranged along the long sides of the first conductor layers 13 and 14 and the short sides opposite the horn section 20. In order to confine the radio waves to the first waveguide G1 by the first post wall 12, the conductive pillars P1 are arranged with a gap D1 of a predetermined size or less, as shown in FIG. 5. If the wavelength of the radio waves propagating through the dielectric (first waveguide G1) is λ, the gap D1 is preferably equal to or less than one-fourth of the wavelength λ (0.25λ (0.66 mm)).

[0038] (Horn section) Horn section 20 is connected to one end of waveguide section 10 in the axial direction.

[0039] The first widened portion 201 includes a second dielectric block 21, a second post wall 22, and two conductor layers 23 and 24.

[0040] The second dielectric block 21 is formed into a trapezoidal cube that is thicker than the first dielectric block 11. The second dielectric block 21 is a laminate of inner dielectric layers 1B, 1C, 1D, 1E, and 1F in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L3 to L6 present at the interfaces between these dielectric layers 1B to 1F.

[0041] The second post wall 22 includes a plurality of conductive pillars P2 (second conductive pillars) penetrating the second dielectric block 21, and defines a second waveguide G2 within the second dielectric block 21. The second waveguide G2 has a path width that increases with increasing distance from the first waveguide G1. The second waveguide G2 is a dielectric waveguide that forms a transmission path for radio waves. The conductive pillars P2 form both side walls of the second waveguide G2.

[0042] Each conductive pillar P2 is a metal cylinder that connects two second conductor layers 23, 24 that face each other in the thickness direction (Z-axis direction) with the second dielectric block 21 in between. One second conductor layer 23 corresponds to the wiring layer L2 in FIG. 4, and the other second conductor layer 24 corresponds to the wiring layer L7 in FIG. 4. The second conductor layers 23, 24 face each other at a distance (second distance) equivalent to the total thickness of the dielectric layers 1B to 1F. Each of the second conductor layers 23, 24 is formed in a trapezoidal shape with one bottom surface facing the first waveguide G1, defines the top and bottom surfaces of the second waveguide G2, and is typically connected to ground potential.

[0043] The conductive pillars P2 constituting the second post wall 22 may be pillars having the same height as the conductive pillars P1 constituting the first post wall 12, and the upper and lower ends of the conductive pillars P2 may be electrically connected to the second conductor layers 23, 24 via interlayer connectors. Alternatively, the conductive pillars P2 may be pillars having a height equivalent to the opposing distance between the second conductor layers 23, 24.

[0044] The second conductor layer 23 is electrically connected to the first conductor layer 13 via a plurality of interlayer connectors T21. Similarly, the second conductor layer 24 is electrically connected to the first conductor layer 14 via a plurality of interlayer connectors T22. The interlayer connectors T21 are through holes that penetrate the dielectric layer 1B, and the interlayer connectors T22 are through holes that penetrate the dielectric layer 1F. The interlayer connectors T21 and T22 are arranged along the bottom sides of the second conductor layers 23 and 24 on the waveguide section 10 side.

[0045] The conductive columns P2 are linearly arranged along the two oblique sides of the second conductor layers 23 and 24, but are not limited to this and may be arranged in a curved manner like a trumpet. The inclination angle of the oblique sides from the Y-axis direction is not particularly limited and is, for example, 10° to 70°. In order to confine the radio waves in the second waveguide G2 by the second post walls 22, the conductive columns P2 are arranged at intervals of 0.66 mm or less (a quarter of the wavelength of the radio waves propagating through the second waveguide G2). Similarly, the interlayer connectors T21 and T22 are arranged at intervals of 0.66 mm or less.

[0046] On the other hand, the second widened portion 202 has a third dielectric block 31, a third post wall 32, and two conductor layers 33 and .

[0047] The third dielectric block 31 is formed into a trapezoidal cube that is thicker than the second dielectric block 21. The third dielectric block 31 is a laminate of the dielectric layers 1A, 1B, 1C, 1D, 1E, 1F, and 1G in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L2 to L7 present at the interfaces between these dielectric layers 1A to 1G.

[0048] The third post wall 32 includes a plurality of conductive pillars P3 (third conductive pillars) penetrating the third dielectric block 31, and defines a third waveguide G3 within the third dielectric block 31. The third waveguide G3 has a path width that increases with increasing distance from the second waveguide G2. The third waveguide G3 is a dielectric waveguide that forms a transmission path for radio waves. The conductive pillars P3 form both side walls of the third waveguide G3.

[0049] Each conductive pillar P3 is a metal cylinder, and connects two second conductor layers 33, 34 that face each other in the thickness direction (Z-axis direction) with the third dielectric block 31 in between. One third conductor layer 33 corresponds to the wiring layer L1 in FIG. 4, and the other third conductor layer 34 corresponds to the wiring layer L8 in FIG. 4. Each of the third conductor layers 33, 34 is formed in a trapezoidal shape with one bottom surface facing the second waveguide G2, defines the top and bottom surfaces of the third waveguide G3, and is typically connected to ground potential.

[0050] The conductive pillars P3 constituting the third post wall 32 may be pillars having the same height as the conductive pillars P1 constituting the first post wall 12, and the upper and lower ends of the conductive pillars P3 may be electrically connected to the third conductor layers 33 and 34 via interlayer connectors. Alternatively, the conductive pillars P3 may be pillars having a height equivalent to the opposing distance between the third conductor layers 33 and 34.

[0051] The third conductor layer 33 is electrically connected to the second conductor layer 23 via a plurality of interlayer connection portions T31. Similarly, the third conductor layer 34 is electrically connected to the second conductor layer 24 via a plurality of interlayer connection portions T32. The interlayer connection portions T31 are through holes that penetrate the dielectric layer 1A, and the interlayer connection portions T32 are through holes that penetrate the dielectric layer 1G. The interlayer connection portions T31 and T32 are arranged along the bottom sides of the third conductor layers 33 and 34 on the first widened portion 201 side.

[0052] The conductive pillars P3 are linearly arranged along the two hypotenuses of the third conductor layers 33 and 34. In this embodiment, as shown in FIG. 3, the third post walls 32 are arranged on the same straight line as the second post walls 22. In order to confine the radio waves in the third waveguide G2 by the third post walls 32, the conductive pillars P3 are arranged with a gap of 0.66 mm or less (a quarter of the wavelength of the radio waves propagating through the third waveguide G3). The interlayer connectors T31 and T32 are also similarly arranged with a gap of 0.66 mm or less.

[0053] The tip of the horn section 20 in the Y-axis direction forms an antenna opening 20s that radiates radio waves. This antenna opening 20s may be in contact with the air surface, or may be covered with the dielectric layer of the dielectric multilayer substrate 1. This reduces the radiation loss of radio waves from the third waveguide G3 to the atmosphere, thereby improving the antenna gain. The length of the dielectric layer from the antenna opening 20s to the air surface is preferably at least one-fourth the wavelength of the radio waves propagating through the third waveguide G3.

[0054] The size of each part of the horn antenna 100 is not particularly limited, and for example, the distance from the feeding probe 41 to the horn section 20 along the Y-axis direction is 5 mm, the length of the horn section 20 along the Y-axis direction is 8 mm, and the length of the tip of the horn section 20 (antenna opening 20s) along the X-axis direction is 8 mm.

[0055] Horn section 20 is not limited to the example configured with first widened section 201 and second widened section 202, but may be configured with only first widened section 201. This also applies to the following embodiments.

[0056] (Power supply unit) Next, a description will be given of power supply unit 40. Fig. 6 is a partially exploded perspective view showing the layer structure of power supply unit 40, Fig. 7 is a front cross-sectional view of the main part of power supply unit 40, and Fig. 8 is a schematic plan view of the main part of power supply unit 40.

[0057] The power feeding unit 40 is formed of a microstrip line connected to the waveguide unit 10. The power feeding unit 40 functions as a converter that converts a millimeter wave signal introduced from a signal processing circuit (not shown) via a signal line 43 into a waveguide mode in the first waveguide G1.

[0058] The power feeding section 40 includes a power feeding probe 41 that supplies a millimeter wave signal to the first waveguide G1, and a shield section 42 formed around the power feeding probe 31.

[0059] The feed probe 41 is a conductor inserted in the Z-axis direction near the rear wall of the first waveguide G1, and has a base end 41a, an intermediate portion 41b, and a tip end 41c.

[0060] The base end 41a of the power feed probe 41 is a through-hole that penetrates an insulating layer 44 that constitutes the top surface of the waveguide section 10. The base end 41a is connected to a signal processing circuit (not shown) via a signal line 43 on the insulating layer 44 that extends in the Y-axis direction. The base end 41a and the signal line 43 are formed as part of the wiring layer L1 of the multilayer wiring board 1 shown in FIG. 4. The insulating layer 44 is a laminate of dielectric layers 1A and 1B, and is a layer made only of dielectric material with no wiring layer L present at the interface between these dielectric layers 1A and 1B.

[0061] The signal line 43 forms a microstrip line facing the wiring layer L2 across the dielectric layer 1A. The wiring layer L2 is connected to the ground potential. The line width of the signal line 43 is set arbitrarily depending on the frequency of the millimeter-wave signal introduced into the power supply 41 and the dielectric constant of the dielectric layer. For example, if the frequency of the millimeter-wave signal is 60 GHz and the dielectric constant of the dielectric layer is 3.6, the line width of the signal line 43 is, for example, approximately 0.11 mm. By forming the signal line 43 in the outermost wiring layer of the multilayer wiring board 1, it is possible to stably form the signal line 43 with such a fine line width.

[0062] The intermediate portion 41b of the power feed probe 41 is formed from a part of the first conductor layer 13. The intermediate portion 41b is provided in a partial insulating layer 13d formed by filling an insulating material into an opening locally provided at a predetermined position on the first conductor layer 13, and is thereby electrically insulated from the first conductor layer 13. The intermediate portion 41b is connected to the base end portion 41a.

[0063] A tip 41c of the power feed probe 41 is provided on the first dielectric block 11 that forms the first waveguide G1. The power feed probe 41 is formed to have a length shorter than the thickness of the first dielectric block 11. In this embodiment, as shown in Fig. 7, when the thickness of the first dielectric block 11 is 0.5λ, the power feed probe 41 is formed to have a length of, for example, 0.25λ (0.66 mm) from the first conductor layer 13 toward the second conductor layer 14.

[0064] The feed probe 41 is composed of a metal-plated columnar body, such as copper-plated. The base end 41a, middle portion 41b, and tip end 41c of the feed probe 41 are integrated with one another during the process of sequentially building up the dielectric layers 1B and 1A on the wiring layer L3 in the dielectric multilayer substrate 1 shown in Fig. 4. As shown in Fig. 8, when the center-to-center distance along the X-axis direction of the conductive columns P1 constituting both side walls of the first post wall 12 is 1λ, the feed probe 41 is positioned 0.5λ from both side walls of the first post wall 12 and 0.25λ from the rear wall of the first post wall 12.

[0065] 6, the shield section 42 has a plurality of columnar sections 42a arranged around the power supply section 41 and an arc-shaped base layer 42b that commonly supports the columnar sections 42a. The base layer 42b is configured as part of a conductor layer (wiring layer L1) formed on the surface of the insulating layer 44, and is electrically insulated from the power supply probe 41 and the signal line 43. Each columnar section 42a is electrically connected to the base layer 42b, and is a through-hole that penetrates the insulating layer 44 and is electrically connected to the first conductor layer 13 (the first conductor layer 13 around the partial insulating layer 13d).

[0066] [Antenna characteristics] In the horn antenna 10 of this embodiment configured as described above, a millimeter-wave signal supplied to the waveguide section 10 via the power feed section 40 propagates toward the horn section 20 via the first waveguide G1. The waveguide section 10 functions as a filter that determines the frequency band of the radio waves propagating through the first waveguide G1. The length of the waveguide section 10 is not particularly limited and can be set arbitrarily according to the desired band characteristics.

[0067] Horn section 20 propagates the radio waves transmitted from waveguide section 10 toward antenna opening 20s while spreading them in the width direction (X-axis direction) and height direction (Z-axis direction). The length of horn section 20 along the Y-axis direction is not particularly limited, but the greater the length, the more the directivity of the radio waves radiated from antenna opening 20s can be improved.

[0068] Furthermore, according to this embodiment, the thicknesses of second waveguide G2 and third waveguide G3 constituting horn section 20 are gradually increased by first widened section 201 and second widened section 202. Therefore, horn section 20 has an opening angle in its height direction, and therefore the area of ​​antenna aperture 20s is larger than when horn section 20 is formed with the same thickness as waveguide section 10, thereby improving the antenna gain.

[0069] 9 and 10 are a schematic overall perspective view and a side cross-sectional view of the center in the width direction (X-axis direction) of horn antenna 110 according to the comparative example. Horn antenna 110 according to the comparative example differs from horn section 20 of horn antenna 10 of the present embodiment in that horn section 20A is formed entirely with the same thickness as waveguide section 10. That is, in the comparative example, the conductor layers forming the top and bottom surfaces of horn section 20A are composed of conductor layers 13 and 14 that form the top and bottom surfaces of waveguide section 10, respectively.

[0070] The same reference numerals are used to denote parts corresponding to those of horn antenna 10 of the present embodiment. In addition, the comparative example has the same configuration as horn antenna 10 of the present embodiment described above, except for horn section 20A.

[0071] 11 shows the results of a simulation showing the radiation characteristics of a horn antenna 110 according to a comparative example, where (A) is the voltage standing wave ratio (VSWR), (B) is the three-dimensional radiation pattern, (C) on the left is the azimuth plane (XY plane) pattern, and (C) on the right is the elevation plane (YZ plane) pattern. Note that (B) and (C) are radiation patterns at 60.5 GHz.

[0072] 12 shows the results of a simulation showing the radiation characteristics of the horn antenna 100 according to this embodiment, where (A) is the voltage standing wave ratio (VSWR), (B) is the three-dimensional radiation pattern, and (C) on the left is the azimuth angle plane pattern and on the right is the elevation angle plane pattern. (B) and (C) are radiation patterns at 60.5 GHz. Furthermore, FIG. 13 is a diagram showing a comparison of the radiation patterns of horn antenna 100 according to this embodiment (first embodiment) and horn antenna 110 according to a comparative example.

[0073] As shown in Figures 11(A) and 12(A), horn antenna 100 of this embodiment has a wider peak width at the resonance point near 60.5 GHz than the comparative example, and therefore can achieve a wider frequency band characteristic than the comparative example. Also, as shown in Figure 13, this embodiment has a higher main lobe directivity (lower back lobe and side lobe) than the comparative example, and therefore can improve antenna gain.

[0074] Second Embodiment 14 is a partially see-through perspective view showing a horn antenna 200 according to a second embodiment of the present technology, in which the dielectric multilayer substrate 1 is omitted from the illustration. The following mainly describes the configurations that differ from the first embodiment, and the same configurations as those in the first embodiment are given the same reference numerals and their description will be omitted or simplified.

[0075] When a horn antenna is formed inside a dielectric multilayer substrate, an impedance mismatch occurs between the dielectric material that makes up the substrate and the space when radio waves are emitted from the horn antenna, which tends to reduce the antenna's radiation efficiency. Since a reduction in radiation efficiency leads to a reduction in antenna gain, it is necessary to minimize the reduction in radiation efficiency.

[0076] Therefore, in horn antenna 200 of this embodiment, multiple air holes 35 are provided in second widened section 202 of horn section 20. Air holes 35 are through-holes that pass through the formation area of ​​third dielectric block 31 and third conductor layers 33, 34 (see FIG. 2) that make up third waveguide G3 in the Z-axis direction, and their interiors are filled with air and communicate with the outside air. Air holes 35 are typically cylindrical, but the shape is not limited to this and may be, for example, elliptical, rectangular, or another cylindrical shape.

[0077] The opening width (diameter) of air hole 35 is smaller than the wavelength λ of the radio waves propagating through third dielectric 31, and is preferably λ / 4 (0.66 mm in this example) or less. This makes it possible to prevent radio waves from leaking from air hole 35.

[0078] The impedance mismatch between the interior of horn antenna 200 and the space is alleviated by adjusting the dielectric constant of third waveguide G3, which is the final waveguide of horn antenna 200, to a value between the dielectric constant of third dielectric 31 (e.g., 3.6) and the dielectric constant of air (1.0). Air holes 35 are preferably distributed in horn section 20 so that the number or density of air holes 35 increases with increasing proximity to antenna opening 20s. This facilitates impedance matching between third dielectric 31 and air, thereby reducing radiation loss of radio waves from antenna opening 20s. This improves antenna gain compared to a configuration without air holes 35.

[0079] As an example, Fig. 15 shows the difference in radiation characteristics depending on whether or not air hole 35 is present. (A) is a simulation result showing the radiation characteristics of a horn antenna (corresponding to the first embodiment) that does not have air hole 35, with the left showing the azimuth angle planar pattern and the right showing the elevation angle planar pattern. Meanwhile, Fig. 15(B) is a similar simulation result showing the radiation characteristics of horn antenna 200 of this embodiment that has air hole 35. As shown in FIGS. 15(A) and 15(B), according to this embodiment, the directivity of the main lobe is higher than in the case where there are no air holes 35, and therefore the gain can be improved.

[0080] <Third embodiment> 16 is a schematic plan view showing a horn antenna 300 according to a third embodiment of the present technology, in which the dielectric multilayer substrate 1 is omitted from the illustration. The following description will mainly focus on the configurations that differ from the first and second embodiments, and the same components as those in the first and second embodiments will be given the same reference numerals and their description will be omitted or simplified.

[0081] In the second embodiment described above, air hole 35 is formed in second widened portion 202 of horn portion 20, whereas in this embodiment, similar air holes 15, 25 are also formed in waveguide portion 10 and first widened portion 201 of horn portion 20, which is different from the second embodiment in that the opening width (diameter) of air hole 35 is set to the same as the opening width (diameter) of air hole 35.

[0082] The air holes 15 provided in the waveguide section 10 (first waveguide G1) are cylindrical through-holes that pass through the formation area of ​​the first dielectric block 11 and the first conductor layers 13 and 14 (see FIG. 2) in the Z-axis direction, and their interiors are filled with air and communicate with the outside air. By forming multiple air holes 15 in the waveguide section 10, the dielectric constant of the first waveguide G1 can be made smaller than the dielectric constant of the first dielectric block 11. The number and arrangement of the air holes 15 can be set as desired depending on the desired dielectric constant of the first waveguide G1. As an example, an arrangement of the air holes 15 is shown in FIG. 17.

[0083] As shown in Figure 17, the long sides of the first waveguide G1 are 5.2 mm and the short sides are 3.2 mm. Consider the case where a total of 17 air holes 15 are formed in the first waveguide G1, with the diameter of the air holes 15 being 0.4 mm and the arrangement pitch being 0.8 mm, as shown in the figure. In this case, the area of ​​each air hole 15 is 0.1256 mm 2 (π×0.2mm 2 ), the area of ​​the first waveguide P1 (5.2 mm × 3.2 mm = 16.64 mm 2 ) to the total area of ​​the air hole portion 15 (0.1256 mm 2 ×17=2.1352mm 2 ) is 12.83%. As a result, the dielectric constant of the first waveguide G1 is 12.83% less than the dielectric constant (3.6) of the first dielectric block 11, that is, approximately 3.14. The diameter of each conductive columnar body P1 constituting the first post wall 12 or the gap between them is set to, for example, one-fourth or less the wavelength of the radio wave propagating through the first waveguide G1 having the air hole portion 15. Here, the diameter of each conductive columnar body P1 is set to 0.2 mm, and the arrangement pitch is set to 0.4 mm.

[0084] Air holes 25, 35 provided in horn section 20 (second waveguide G2, third waveguide G3) can also be formed in the same manner as air hole 15 described above. This makes it possible to bring the dielectric constant of each of waveguides G1 to G3 of horn antenna 300 closer to the dielectric constant of air, thereby further mitigating impedance mismatch with air and further reducing radiation loss at antenna opening 20s.

[0085] Air hole 35 provided in second widened section 202 (third waveguide G3) of horn section 20 may have a dielectric lens section 36 formed from a part of multiple air holes 35 at one end in the Y-axis direction, i.e., at one end on the antenna opening 20s side. This dielectric lens section 36 has a curved surface that is convex from antenna opening 20s toward waveguide section 10. This allows dielectric lens section 36 to function as a converging lens that converges radio waves traveling from horn section 20 toward antenna opening 20s in the Y-axis direction, further increasing the directivity of radio waves in the forward direction. However, the present invention is not limited to this, and the air hole 35 provided in the second widened portion 202 (third waveguide G3) of the horn portion 20 may be configured in the same manner as in the second embodiment.

[0086] <Fourth embodiment> FIG. 18 is a schematic perspective view showing a horn antenna 400 according to a fourth embodiment of the present technology (dielectric multilayer substrate 1 is omitted from the illustration), and FIG. 19 is a schematic side cross-sectional view at the center in the width direction (X-axis direction) thereof. The following mainly describes the configurations that differ from the first embodiment, and the same configurations as those in the first embodiment are given the same reference numerals and their description will be omitted or simplified.

[0087] As described above, when the frequency of the millimeter-wave signal introduced into the power supply unit 40 is in the 60 GHz band, the signal line 43 has a microstrip line structure. That is, the signal line 43 transmits a high-frequency signal by creating an electric field between itself and the wiring layer L2 connected to the ground potential directly below it. This electric field component couples the transmission line of the power supply unit 40 and the horn antenna. As a result, as shown in FIG. 20, radio waves are emitted from the first to third conductor layers 13, 23, and 33 (wiring layers L1, L2, and L3), which may cause degradation of the antenna characteristics.

[0088] To solve this problem, horn antenna 400 of this embodiment includes a shield layer 433 that covers first conductor layer 13 and second conductor layer 23, as shown in Fig. 19. Shield layer 433 is formed by extending third conductor layer 33 to directly above waveguide section 10 and first widened section 201 of horn section 20. Shield layer 433 is electrically connected to first conductor layer 13 and second conductor layer 23 via a plurality of through holes 33v. Shield layer 433 is also connected to ground potential and is composed of wiring layer L1 that is electrically insulated from signal line 43.

[0089] 21 shows simulation results showing the radiation characteristics of horn antenna 400 according to this embodiment, where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, the right side of (B) is the elevation angle planar pattern, and (C) is a diagram comparing the radiation patterns of horn antenna 400 according to this embodiment (Embodiment 4) and horn antenna 100 according to the first embodiment (Embodiment 1). Note that (B) and (C) are radiation patterns at 60.5 GHz.

[0090] As shown in FIG. 21(A), horn antenna 400 of this embodiment has a resonance point near 60.5 GHz, and the width of the band is not significantly different from that of embodiment 1 (see FIG. 12(A)). On the other hand, as shown in Fig. 21(C), according to this embodiment, the directivity of the main lobe is higher and the antenna gain is improved compared to Embodiment 1. In particular, as shown on the right side of Fig. 21(C), the radiation to the upper side is reduced, confirming the effect of the shield layer 433.

[0091] Fifth Embodiment 22 is a schematic plan view showing a horn antenna 500 according to a fifth embodiment of the present technology. Configurations different from the first embodiment will be mainly described below, and configurations similar to those in the first embodiment will be assigned the same reference numerals, and descriptions thereof will be omitted or simplified.

[0092] Horn antenna 500 of this embodiment differs from the first embodiment described above in that it has a dielectric portion 51 that covers the opening of horn portion 20. Dielectric portion 51 is a laminate of dielectric layers 1A-1G in dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectric material, with no wiring layers L2-L7 present at the interfaces between these dielectric layers 1A-1G. Dielectric portion 51 is provided at one end of horn portion 20 on the antenna opening 20s side, and the tip surface of dielectric portion 51 in the Y-axis direction forms antenna opening 20s.

[0093] The dielectric portion 51 is provided with a plurality of air holes 52 that penetrate in the thickness direction (Z-axis direction). Each air hole 52 serves to reduce the difference in dielectric constant between the dielectric portion 51 and air, thereby suppressing radiation loss of radio waves emitted from the antenna opening 20s. The air holes 52 are typically cylindrical (with a diameter of approximately 0.4 mm) and are formed at predetermined positions within the surface of the dielectric portion 51. The opening width (diameter) of the air holes 52 is smaller than the wavelength λ of the radio waves propagating through the dielectric portion 51, and is preferably λ / 4 (0.66 mm in this example) or less.

[0094] In this embodiment, dielectric lens portion 53 is formed at some of the multiple air holes 52. In plan view, dielectric lens portion 53 is formed in a roughly triangular shape that convexes from the tip of horn portion 20 toward antenna opening 20s. This allows dielectric lens portion 53 to function as a converging lens that converges radio waves traveling from horn portion 20 toward antenna opening 20s in the Y-axis direction, further increasing the directivity of radio waves in the forward direction.

[0095] The length Ly of the dielectric portion 51 along the Y-axis direction is typically equal to or greater than one-quarter (λ / 4) of the wavelength of the radio wave propagating through the dielectric portion 51, and in this embodiment is approximately one wavelength (2.4 mm). The sizes of the various parts of the horn antenna 500 are not particularly limited, and in this embodiment, as shown in Fig. 22, the length of the long side of the dielectric portion 1 along the Y-axis direction is 18.75 mm, the length of the short side of the dielectric portion 1 along the X-axis direction is 7.5 mm, the length of the long side of the waveguide portion 10 is 3.55 mm, the length of the short side of the waveguide portion 10 is 2.4 mm, the distance along the Y-axis from the feed probe 41 to the horn portion 20 is 2.75 mm, and the length of the horn portion 20 along the Y-axis direction is 10.3 mm.

[0096] 23 shows simulation results showing the radiation characteristics of horn antenna 500 according to this embodiment, where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, the right side of (B) is the elevation angle planar pattern, and (C) is a diagram comparing the radiation patterns of horn antenna 500 according to this embodiment (Embodiment 5) and horn antenna 100 according to the first embodiment (Embodiment 1). Note that (B) and (C) are radiation patterns at 60.5 GHz.

[0097] As shown in FIG. 23(A), horn antenna 500 of this embodiment has a resonance point near 60.3 GHz, and the frequency band is wider than that of the first embodiment, but the VSWR is worse (see FIG. 12(A)). 23(C), according to this embodiment, the directivity of the main lobe is higher and the antenna gain is improved compared to the first embodiment. This is presumably due to the effect of the dielectric lens portion 53.

[0098] Sixth Embodiment 24 is a schematic plan view showing a horn antenna 600 according to the sixth embodiment of the present technology. Hereinafter, configurations different from the fifth embodiment will be mainly described, and configurations similar to those in the fifth embodiment will be assigned the same reference numerals, and descriptions thereof will be omitted or simplified.

[0099] Horn antenna 600 of this embodiment is similar to the fifth embodiment described above in that it has dielectric portion 51 that covers the opening of horn portion 20, but differs from the fifth embodiment in that it does not have air hole portion 51. The length Ly of dielectric portion 51 along the Y-axis direction is 2.4 mm, and the other portions are also formed to have the same sizes as those of the fifth embodiment described above.

[0100] Figures 25 and 26 show simulation results showing the radiation characteristics of horn antenna 600 according to this embodiment. Figure 25(A) shows the voltage standing wave ratio (VSWR), the left side of Figure 25(B) shows the azimuth angle planar pattern, and the right side of Figure 25(B) shows the elevation angle planar pattern. Figure 25(B) shows the radiation pattern at 60.5 GHz. FIG. 26(A) is a diagram showing a comparison of the radiation patterns of horn antenna 600 according to this embodiment (embodiment 6) and horn antenna 100 according to the first embodiment (embodiment 1) described above, and FIG. 26(B) is a diagram showing a comparison of the radiation patterns of horn antenna 600 according to this embodiment (embodiment 6) and horn antenna 500 according to the fifth embodiment (embodiment 5) described above.

[0101] As shown in FIG. 25(A), horn antenna 600 of this embodiment has a resonance point near 60 GHz, and the frequency band is the same as that of the first embodiment (see FIG. 12(A)). 26(A), the directivity of the main lobe is higher and the antenna gain is improved according to this embodiment compared to the first embodiment. This is presumably because the matching with the air layer is improved by interposing the dielectric portion 51 of a predetermined length between the horn portion 20 and the antenna opening 20s.

[0102] On the other hand, as shown in Fig. 26(B), according to this embodiment, the directivity of the main lobe was reduced compared to the fifth embodiment. This is thought to be because the dielectric portion 51 does not have air holes 52. However, from the results in Fig. 26(A), it was confirmed that a significant improvement in radiation characteristics can be expected by providing the dielectric portion 51 with length Ly at the output end of the horn portion 20. Therefore, Figs. 27 to 31 show the results of comparing the antenna characteristics when the length Ly of the dielectric portion 51 along the Y-axis direction is changed.

[0103] (Embodiment 6-1) Fig. 27 shows the simulation results of the radiation characteristics of the horn antenna when the length Ly of the dielectric portion 51 is set to 1.3 mm (corresponding to λ / 2), where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, and the right side of (B) is the elevation angle planar pattern. Note that Fig. 25(B) is the radiation pattern at 60.5 GHz. Moreover, Figure 28(A) is a diagram showing a comparison of the radiation patterns of the horn antenna according to this embodiment (embodiment 6-1) and the horn antenna 100 according to the first embodiment (embodiment 1) described above, and Figure 28(B) is a diagram showing a comparison of the radiation patterns of the horn antenna according to this embodiment (embodiment 6-1) and the horn antenna 600 according to embodiment 6.

[0104] As shown in FIG. 27(A), the horn antenna of this embodiment has a resonance point of 59.1 GHz, which is shifted to a lower frequency side than that of the first embodiment. Furthermore, as shown in FIG. 28(A), according to this embodiment, the directivity of the main lobe is higher and the antenna gain is improved compared to the first embodiment, but the improvement effect of the antenna gain is smaller than in embodiment 6.

[0105] (Embodiment 6-2) 29 shows simulation results showing the radiation characteristics of a horn antenna when the length Ly of the dielectric portion 51 is 4.0 mm (corresponding to 3λ / 2), where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, the right side of (B) is the elevation angle planar pattern, and (C) is a diagram comparing the radiation patterns of the horn antenna according to this embodiment (embodiment 6-2) and the horn antenna 600 according to embodiment 6. Note that FIG. 29(B) shows the radiation pattern at 60.5 GHz.

[0106] As shown in FIG. 29(A), the horn antenna of this embodiment has a resonance point of 60.0 GHz, which is slightly shifted to the lower frequency side than that of the first embodiment. Furthermore, as shown in FIG. 29(C), according to this embodiment, the directivity of the main lobe is higher than in the sixth embodiment, and the antenna gain is improved.

[0107] (Embodiment 6-3) Figure 30 shows the simulation results of the radiation characteristics of the horn antenna when the length Ly of the dielectric portion 51 is set to 5.2 mm (corresponding to 2λ), where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, and the right side of (B) is the elevation angle planar pattern. Note that Figure 30(B) is the radiation pattern at 60.5 GHz. Moreover, Figure 31(A) is a diagram showing a comparison of the radiation patterns of the horn antenna according to this embodiment (embodiment 6-3) and the horn antenna 600 according to embodiment 6, and Figure 31(B) is a diagram showing a comparison of the radiation patterns of the horn antenna according to this embodiment (embodiment 6-3) and the horn antenna according to embodiment 6-2.

[0108] As shown in FIG. 30(A), the horn antenna of this embodiment has a resonance point of 59.6 GHz, which is shifted to a lower frequency side than that of the first embodiment. Furthermore, as shown in Figure 31(A), according to this embodiment, the directivity of the main lobe was higher and the antenna gain was improved compared to embodiment 6, but as shown in Figure 31(B), the radiation level in the vertical direction was higher than in embodiment 6-2.

[0109] As described above, it was confirmed that a larger antenna gain than that of the first embodiment can be obtained when the length Ly of the dielectric portion 51 is λ / 2 or more, but it was also confirmed that a length of λ or more and 3λ / 2 or less is preferable.

[0110] Seventh Embodiment FIG. 32 is a schematic plan view showing an antenna device 700 according to an embodiment of the present technology.

[0111] Antenna device 700 is configured as an antenna module in which multiple antennas (TX1 to TX3, RX1 to RX4) are mounted on a single support substrate 71. Each antenna has the same configuration as horn antenna 100 according to the first embodiment described above. However, the configuration is not limited to this, and horn antennas according to other embodiments may also be used.

[0112] The multiple antennas include three transmitting antennas TX1, TX2, and TX3 and four receiving antennas RX1, RX2, RX3, and RX4. The antennas are arranged at predetermined intervals in the X-axis direction, with the tips of the horn portions 20 facing one of the long sides of the support substrate 71.

[0113] The support substrate 71 is typically a wiring substrate, and in this embodiment is configured, for example, by the dielectric multilayer substrate 1 shown in Fig. 4. That is, multiple antennas are created inside the common dielectric multilayer substrate 1. In this example, one side surface of the support substrate 71 facing the horn portion 20 of each antenna forms the antenna opening 20s.

[0114] The support substrate 71 further has mounted thereon a signal processing circuit 72. The signal processing circuit 72 includes one or more semiconductor integrated circuit (IC) components and their peripheral components (passive components). The signal processing circuit 72 is electrically connected to each antenna via signal lines 43 and is configured to be able to control each antenna individually. The signal processing circuit 72 typically includes a processor, a modulator, a mixer, an AD converter, etc.

[0115] The sensor device 700 of this embodiment configured as described above transmits radio waves (millimeter waves) to an object from multiple transmitting antennas TX1 to TX3, and receives the reflected waves from multiple receiving antennas RX1 to RX4. Since each antenna is positioned with a phase shift, it is possible to obtain data as if there were a total of 12 antennas, with three transmitting antennas and four receiving antennas. This makes it possible to detect the position, moving speed, distance, etc. of an object with high accuracy.

[0116] According to this embodiment, multiple antennas are mounted on the same substrate, and an antenna opening 20s is formed on one side of the substrate as a surface for transmitting and receiving radio waves, thereby making it possible to achieve a thinner antenna device compared to conventional phased patch antennas, etc. For example, when the antenna device 700 is used for vehicle installation, the antenna device can be mounted in a small space at the front of the vehicle.

[0117] Furthermore, antenna device 700 can be incorporated into an image display device such as a television set, and configured as a sensor that detects a user's gesture and generates control signals for executing power control, channel selection control, volume control, etc. In this case, antenna device 700 can be incorporated into a narrow space such as a picture frame or nameplate on the front of the image display device.

[0118] Furthermore, the antenna device 700 can also be configured as a sensor for detecting biological information such as pulse, breathing, etc. For example, by incorporating the antenna device 700 into a controller for a game machine, it is possible to detect the excitement level of a user playing a game.

[0119] [Reference example] <Reference example 1> Figure 33 is a partially transparent perspective view showing horn antenna 801 according to reference example 1 of the present technology, Figure 34 is a side cross-sectional view at the center of horn antenna 801 in the width direction (X-axis direction), and Figure 35 is a schematic plan view of horn antenna 801. The following mainly describes the configurations that differ from the first embodiment, and the same configurations as those in the first embodiment are given the same reference numerals and their description will be omitted or simplified.

[0120] Horn antenna 801 in this reference example is provided inside dielectric multilayer substrate 1, and includes horn portion 80 and power supply portion 40. Horn antenna 801 may be configured as a transmitting antenna, a receiving antenna, or a transmitting and receiving antenna. Here, an example will be described in which horn antenna 801 is configured as a receiving antenna.

[0121] Horn antenna 801 differs from horn antenna 100 (FIG. 1) in the first embodiment in that feeder 40 is connected to horn section 80 without via waveguide section 10, and that horn section 80 is composed of a single widened section. Details of this will be described below.

[0122] In this reference example, the horn section 80 has a first dielectric block 81 that supports the feeding section 40, and a first post wall .

[0123] The first dielectric block 81 is formed in the shape of a trapezoidal cube. The first dielectric block 81 is a laminate of inner dielectric layers 1C, 1D, and 1E in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L4, L5 present at the interfaces between these dielectric layers 1C to 1E.

[0124] The first post wall 82 includes a plurality of conductive pillars M1 (first conductive pillars) penetrating the first dielectric block 81, and defines within the first dielectric block 81 a first waveguide H1 whose path width increases with increasing distance from the power feeding section 40. The first waveguide H1 is a dielectric waveguide that forms a transmission path for radio waves. The conductive pillars M1 form both side walls of the first waveguide H1 and a rear wall located behind the power feeding probe 41.

[0125] Each conductive pillar M1 is a metal cylinder, and connects two first conductor layers 83 and 84 that face each other in the thickness direction (Z-axis direction) with the first dielectric block 81 in between. One first conductor layer 83 corresponds to the wiring layer L3 in Fig. 4, and the other first conductor layer 84 corresponds to the wiring layer L6 in Fig. 4. Each of the first conductor layers 83 and 84 is formed in a trapezoidal shape, defines the top and bottom surfaces of the first waveguide H1, and is typically connected to ground potential.

[0126] The conductive pillars M1 are linearly arranged along the two hypotenuses of the first conductor layers 83 and 84, but are not limited to this and may be arranged curvedly. In order to confine the radio waves in the first waveguide H1 by the first post wall 82, the conductive pillars M1 are arranged at intervals of equal to or less than one-fourth the wavelength (0.66 mm) of the radio waves propagating through the first waveguide H1.

[0127] The tip of the horn 80 in the Y-axis direction forms an antenna opening 80s into which radio waves enter. This antenna opening 80s may be in contact with the air surface, or may be covered with the dielectric layer of the dielectric multilayer substrate 1.

[0128] The size of each part of horn antenna 801 is not particularly limited, and for example, the distance along the Y-axis direction from feeding probe 41 to antenna opening 80s is 7.2 mm, the length along the X-axis direction of the base of the short side of horn section 80 is 2.25 mm, the length along the X-axis direction of the base of the long side of horn section 80 is 8 mm, the length along the Y-axis direction from the base of the short side of horn section 80 to feeding section 41 is 0.8 mm, and the length along the Y-axis direction of dielectric multilayer substrate 1 is 13.55 mm.

[0129] 36 shows the results of a simulation showing the radiation characteristics of horn antenna 801 according to this example, where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, the right side of (B) is the elevation angle planar pattern, and (C) is a diagram comparing the radiation patterns of horn antenna 801 according to this example (Reference Example 1) and horn antenna 110 according to the comparative example (FIG. 9). Note that (B) is the radiation pattern at 57.3 GHz.

[0130] 36(A), with horn antenna 801 of this example, the reception frequency was 57.3 GHz, which was shifted to the lower frequency side than the comparative example, and the receivable band was wider than the comparative example. Furthermore, as shown in FIG. 36(C), according to this example, the directivity of the main lobe was higher and the antenna gain was improved compared to the comparative example.

[0131] <Reference example 2> FIG. 37 is a schematic plan view showing a horn antenna 802 according to a second reference example of the present technology, and FIG. 38 is a side cross-sectional view of the horn antenna 802 at the center in the width direction (X-axis direction). The following mainly describes the configurations that differ from the first embodiment, and the same configurations as those in the first embodiment are given the same reference numerals and their description will be omitted or simplified.

[0132] In horn antenna 802 in this example, horn portion 80 differs from reference example 1 in that it has first widened portion 801 and second widened portion 802, similar to the first embodiment.

[0133] The first widened portion 201 has a first dielectric block 81 and a first post wall 82.

[0134] The first dielectric block 81 is formed in the shape of a trapezoidal cube. The first dielectric block 81 is a laminate of inner dielectric layers 1C, 1D, and 1E in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L4, L5 present at the interfaces between these dielectric layers 1C to 1E.

[0135] The first post wall 82 includes a plurality of conductive pillars M1 penetrating the first dielectric block 81, and defines within the first dielectric block 81 a first waveguide H1 whose path width increases with increasing distance from the feed probe 41. The first waveguide H1 is a dielectric waveguide that forms a transmission path for radio waves. The conductive pillars M1 form both side walls of the first waveguide G1 and a rear wall located behind the feed probe 41.

[0136] Each conductive pillar M1 is a metal cylinder, and connects two first conductor layers 83 and 84 that face each other in the thickness direction (Z-axis direction) with the first dielectric block 81 in between. One first conductor layer 83 corresponds to the wiring layer L3 in Fig. 4, and the other first conductor layer 84 corresponds to the wiring layer L6 in Fig. 4. Each of the first conductor layers 83 and 84 is formed in a trapezoidal shape, defines the top and bottom surfaces of the first waveguide H1, and is typically connected to ground potential.

[0137] The conductive pillars M1 are linearly arranged along the two hypotenuses of the first conductor layers 83 and 84, but are not limited to this and may be arranged curvedly. In order to confine the radio waves in the first waveguide H1 by the first post wall 82, the conductive pillars M1 are arranged at intervals of equal to or less than one-fourth the wavelength (0.66 mm) of the radio waves propagating through the first waveguide H1.

[0138] On the other hand, the second widened portion 802 has a second dielectric block 91 and a second post wall 92.

[0139] The second dielectric block 91 is formed into a trapezoidal cube that is thicker than the first dielectric block 81. The second dielectric block 91 is a laminate of the dielectric layers 1A, 1B, 1C, 1D, 1E, 1F, and 1G in the dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectrics with no wiring layers L2 to L7 present at the interfaces between these dielectric layers 1A to 1G.

[0140] The second post wall 92 includes a plurality of conductive pillars M2 (second conductive pillars) penetrating the second dielectric block 91, and defines a second waveguide H2 within the second dielectric block 91. The second waveguide H2 has a path width that increases with increasing distance from the first waveguide H1. The second waveguide H2 is a dielectric waveguide that forms a transmission path for radio waves. The conductive pillars M2 form both side walls of the second waveguide H2.

[0141] Each conductive pillar M2 is a metal cylinder and connects two second conductor layers 93 and 94 that face each other in the thickness direction (Z-axis direction) across the second dielectric block 91. One second conductor layer 93 corresponds to the wiring layer L1 in FIG. 4, and the other second conductor layer 94 corresponds to the wiring layer L8 in FIG. 4. Each of the second conductor layers 93 and 94 is formed in a trapezoidal shape with one bottom surface facing the first waveguide H1, defines the top and bottom surfaces of the second waveguide H2, and is typically connected to ground potential. The second conductor layer 93 is electrically connected to the first conductor layer 83 via multiple interlayer connectors T2. Similarly, the second conductor layer 94 is electrically connected to the first conductor layer 84.

[0142] In the illustrated example, the conductive pillars M2 constituting the second post wall 92 are pillars having the same height as the conductive pillars M1 constituting the first post wall 82, and the upper and lower ends of the conductive pillars M2 are electrically connected to the second conductor layers 93 and 94 via interlayer connectors. However, the conductive pillars M2 may be pillars having a height equivalent to the opposing distance between the second conductor layers 93 and 94.

[0143] The conductive pillars M2 are linearly arranged along the two hypotenuses of the second conductor layers 93 and 94. In this embodiment, as shown in Fig. 37, the second post walls 92 are arranged on the same straight line as the first post walls 82. In order to confine the radio waves in the second waveguide H2 by the second post walls 92, the conductive pillars M2 are arranged at intervals of equal to or less than one-fourth the wavelength (0.66 mm) of the radio waves propagating through the second waveguide H2.

[0144] The size of each part of horn antenna 802 is not particularly limited, and for example, the distance along the Y-axis direction from feeding probe 41 to antenna opening 80s is 7.7 mm, the length along the X-axis direction of the base of the short side of horn portion 80 is 2.4 mm, the length along the X-axis direction of the base of the long side of horn portion 80 is 8 mm, the length along the Y-axis direction from the base of the short side of horn portion 80 to feeding portion 41 is 0.8 mm, the length of the hypotenuse of horn portion 80 is 8.6 mm, the length along the X-axis direction of dielectric multilayer substrate 1 is 7.5 mm, and the length along the Y-axis direction of dielectric multilayer substrate 1 is 14.35 mm.

[0145] 39 shows the results of a simulation showing the radiation characteristics of horn antenna 802 according to this example, where (A) is the voltage standing wave ratio (VSWR), the left side of (B) is the azimuth angle planar pattern, the right side of (B) is the elevation angle planar pattern, and (C) is a comparison of the radiation patterns of horn antenna 802 according to this example (Reference Example 2) and horn antenna 110 according to the comparative example (FIG. 9). Note that (B) is the radiation pattern at 60.5 GHz.

[0146] 39(A), with horn antenna 802 of this example, the reception frequency was 60.4 GHz, which was shifted to the higher frequency side than Reference Example 1. In addition, the receivable band was wider than that of the comparative example. Furthermore, as shown in FIG. 39(C), according to this example, the directivity of the main lobe was higher and the antenna gain was improved compared to the comparative example.

[0147] <Reference example 3> FIG. 40 is a schematic plan view showing a horn antenna 803 according to a reference example 3 of the present technology, and FIG. 41 is a side cross-sectional view of the horn antenna 803 at the center in the width direction (X-axis direction). The following mainly describes the configurations that differ from the second embodiment, and the same components as those in the second embodiment are given the same reference numerals and their description will be omitted or simplified.

[0148] Horn antenna 803 of this example differs from Reference Example 2 described above in that it has a dielectric section 51 that covers the opening of horn section 80. As in the sixth embodiment, dielectric section 51 is a laminate of dielectric layers 1A-1G in dielectric multilayer substrate 1 shown in Fig. 4, and is a layer made only of dielectric material with no wiring layers L2-L7 present at the interfaces between these dielectric layers 1A-1G. The tip surface in the Y-axis direction of dielectric section 51 forms antenna opening 80s. The length Ly of the dielectric portion 51 along the Y-axis direction is not particularly limited as long as it is at least λ / 2 or more. In this example, the length Ly is 1.5λ (4.0 mm), and the other portions are formed to have the same size as in the above-mentioned Reference Example 2.

[0149] Figures 42 and 43 show simulation results showing the radiation characteristics of horn antenna 803 according to this example. Figure 42(A) shows the voltage standing wave ratio (VSWR), the left side of Figure 42(B) shows the azimuth angle planar pattern, and the right side of Figure 42(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 60.5 GHz. Fig. 43(A) is a diagram showing a comparison of the radiation patterns of horn antenna 803 according to this example (Reference Example 3) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 43(B) is a diagram showing a comparison of the radiation patterns of horn antenna 803 according to this example (Reference Example 3) and horn antenna 802 according to Reference Example 2 described above.

[0150] As shown in FIG. 42(A), with horn antenna 803 of this example, the reception frequency is 59.4 GHz, and although the return loss increases, the receivable band is wider than that of the comparative example. Furthermore, as shown in FIG. 43(A), according to this example, the directivity of the main lobe was high and the antenna gain was greatly improved compared to the comparative example. Furthermore, as shown in FIG. 43(B), according to this example, the directivity of the main lobe was higher and the antenna gain was significantly improved compared to Reference Example 2.

[0151] <Reference example 4> FIG. 44 is a schematic plan view showing a horn antenna 804 according to a reference example 4 of the present technology, and FIG. 45 is a side cross-sectional view of the horn antenna 804 at the center in the width direction (X-axis direction). The following mainly describes the configurations that differ from the third embodiment, and the same configurations as the third embodiment are denoted by the same reference numerals and the description thereof will be omitted or simplified.

[0152] Horn antenna 804 of this example differs from Reference Example 3 in that it has a shielding layer 933 that covers first widened portion 801 of horn section 80. As in the fourth embodiment, shielding layer 933 is intended to suppress radio waves radiated from first conductor layer 83 and second conductor layer 93 by coupling between horn antenna 804 and the electric field formed by the transmission line of power feeding section 40.

[0153] The shield layer 933 is formed by extending the second conductor layer 93 to directly above the first widened portion 801 of the horn portion 80. The shield layer 933 is electrically connected to the first conductor layer 83 via a plurality of through holes (interlayer connections). The shield layer 933 is also connected to the ground potential and is composed of a wiring layer L1 electrically insulated from the signal line 43.

[0154] 46 and 47 show simulation results showing the radiation characteristics of horn antenna 804 according to this example. Fig. 46(A) shows the voltage standing wave ratio (VSWR), the left side of Fig. 46(B) shows the azimuth angle planar pattern, and the right side of Fig. 46(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 60.5 GHz. The length of feed probe 41 protruding from first conductor layer 83 into first waveguide H1 was set to 0.75 mm.

[0155] Fig. 47(A) is a diagram showing a comparison of the radiation patterns of horn antenna 804 according to this example (Reference Example 4) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 47(B) is a diagram showing a comparison of the radiation patterns of horn antenna 804 according to this example (Reference Example 4) and horn antenna 803 according to Reference Example 3 described above.

[0156] As shown in FIG. 46(A), with horn antenna 804 of this example, the reception frequency is 59.4 GHz, and although the return loss increases, the receivable band is wider than that of the comparative example. Furthermore, as shown in FIG. 47(A), according to this example, the directivity of the main lobe was high and the antenna gain was greatly improved compared to the comparative example. Furthermore, as shown in FIG. 47(B), according to this example, the directivity of the main lobe is higher than in Reference Example 3, and the antenna gain is slightly improved (0.5 dB).

[0157] <Reference example 5> FIG. 48 is a schematic plan view showing a horn antenna 805 according to Reference Example 5 of the present technology. The following mainly describes the configurations that differ from the second embodiment, and the same components as those in the second embodiment are given the same reference numerals and their description will be omitted or simplified.

[0158] Horn antenna 805 of this example differs from Reference Example 2 in that multiple air holes 85 are provided in first widened portion 801 of horn section 80. As with the second and third embodiments, air holes 85 are intended to suppress a decrease in antenna gain due to an impedance mismatch between the dielectric constituting the substrate and space.

[0159] In this example, the air hole 85 is a through-hole that passes through the formation area of ​​the first dielectric block 81 and the first conductor layers 83, 84 (see FIG. 38) that make up the first waveguide H1 in the Z-axis direction, and the inside is filled with air and communicates with the outside air. The air hole 85 is typically cylindrical, but the shape is not limited to this and may be, for example, elliptical, rectangular, or another cylindrical shape.

[0160] The opening width (diameter) of the air hole 85 is smaller than the wavelength λ of the radio waves propagating through the first dielectric block 81, and is preferably λ / 4 (0.66 mm in this example) or less. This makes it possible to prevent radio waves from leaking from the air hole 85.

[0161] The diameter, number of arrangements, and arrangement pattern of the air holes 85 can be set arbitrarily depending on the desired dielectric constant of the first waveguide H1. In this example, the diameter of the air holes 85 is 0.4 mm, and the air holes 85 are formed in the first waveguide H1 so that the porosity of the first waveguide H1 is 6.3%. In this case, the dielectric constant of the first waveguide H1 changes from 3.6 before the air holes 85 are formed to 3.37. In this case, the wavelength of 60 GHz radio waves propagating through the first waveguide H1 is 3.17 mm.

[0162] Figures 49 and 50 show simulation results showing the radiation characteristics of horn antenna 805 according to this example. Figure 49(A) shows the voltage standing wave ratio (VSWR), while the left side of Figure 49(B) shows the azimuth angle planar pattern and the right side of Figure 49(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 60.5 GHz. Fig. 50(A) is a diagram showing a comparison of the radiation patterns of horn antenna 805 according to this example (Reference Example 5) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 50(B) is a diagram showing a comparison of the radiation patterns of horn antenna 805 according to this example (Reference Example 5) and horn antenna 801 according to Reference Example 1 described above.

[0163] As shown in FIG. 49(A), with horn antenna 805 of this example, the reception frequency is 60.3 GHz, and the receivable band is wider than that of the comparative example. Furthermore, as shown in FIG. 50(A), according to this example, the directivity of the main lobe was higher and the antenna gain was improved compared to the comparative example. On the other hand, as shown in FIG. 50(B), according to this example, the directivity of the main lobe was low compared to Reference Example 1, and the antenna gain was slightly reduced.

[0164] <Reference example 6> FIG. 51 is a schematic plan view showing a horn antenna 806 according to Reference Example 6 of the present technology. The following mainly describes the configurations that differ from the second embodiment, and the same components as those in the second embodiment are given the same reference numerals and their description will be omitted or simplified.

[0165] Horn antenna 806 of this example differs from Reference Example 2 in that multiple air holes 95 are provided in second widened portion 802 of horn section 80. As with the second and third embodiments, air holes 95 are intended to suppress a decrease in antenna gain due to an impedance mismatch between the dielectric constituting the substrate and space.

[0166] In this example, the air hole 95 is a through-hole that passes through the formation area of ​​the second dielectric block 91 and the second conductor layers 93, 94 (see FIG. 38) that constitute the second waveguide H2 in the Z-axis direction, and the inside is filled with air and communicates with the outside air. The air hole 95 is typically cylindrical, but the shape is not limited to this and may be, for example, elliptical, rectangular, or another cylindrical shape.

[0167] The opening width (diameter) of the air hole 95 is smaller than the wavelength λ of the radio waves propagating through the second dielectric block 91, and is preferably λ / 4 (0.66 mm in this example) or less. This makes it possible to prevent radio waves from leaking from the air hole 95.

[0168] The diameter, number of arrangements, and arrangement pattern of the air holes 95 can be set arbitrarily depending on the desired dielectric constant of the second waveguide H2. In this example, the diameter of the air holes 95 is 0.4 mm, and the air holes 95 are formed in the second waveguide H2 so that the porosity of the second waveguide H2 is 12.24%. In this case, the dielectric constant of the second waveguide H2 changes from 3.6 before the air holes 95 are formed to 3.15. In this case, the wavelength of the 60 GHz radio waves propagating through the second waveguide H2 is 3.13 mm.

[0169] Figures 52 and 53 show simulation results showing the radiation characteristics of horn antenna 806 according to this example. Figure 52(A) shows the voltage standing wave ratio (VSWR), the left side of Figure 52(B) shows the azimuth angle planar pattern, and the right side of Figure 52(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 60.5 GHz. Fig. 53(A) is a diagram showing a comparison of the radiation patterns of horn antenna 806 according to this example (Reference Example 6) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 53(B) is a diagram showing a comparison of the radiation patterns of horn antenna 806 according to this example (Reference Example 6) and horn antenna 801 according to Reference Example 1 described above.

[0170] As shown in FIG. 52(A), with horn antenna 806 of this example, the reception frequency is 60.3 GHz, and the receivable band is wider than that of the comparative example. Furthermore, as shown in FIG. 53(A), according to this example, the directivity of the main lobe was higher and the antenna gain was improved compared to the comparative example. On the other hand, as shown in FIG. 53(B), according to this example, the directivity of the main lobe was low compared to Reference Example 1, and the antenna gain was slightly reduced.

[0171] <Reference example 7> FIG. 54 is a schematic plan view showing a horn antenna 807 according to Reference Example 7 of the present technology. The following mainly describes the configurations that differ from the second embodiment, and the same components as those in the second embodiment are given the same reference numerals and their description will be omitted or simplified.

[0172] Horn antenna 807 of this example differs from Reference Example 2 in that a plurality of air holes 85, 95 are provided in first and second widened portions 801, 802 of horn section 80. Air holes 85, 95 are formed in the same manner as in Reference Examples 5 and 6.

[0173] The diameter, number of arrangements, and arrangement pattern of the air holes 85, 95 can be set as desired depending on the desired dielectric constant of the first and second waveguides H1, H2. In this example, the diameter of the air holes 85, 95 is 0.4 mm, and the air holes 85, 95 are formed in the first and second waveguides H1, H2, respectively, so that the overall porosity of the first and second waveguides H1, H2 is 18.6%. In this case, the dielectric constant of the first and second waveguides H1, H2 changes from 3.6 before the air holes 95 were formed to 2.93. In this case, the wavelength of 60 GHz radio waves propagating through the first and second waveguides H1, H2 is 3.29 mm.

[0174] Figures 55 and 56 show simulation results showing the radiation characteristics of horn antenna 807 according to this example. Figure 55(A) shows the voltage standing wave ratio (VSWR), the left side of Figure 55(B) shows the azimuth angle planar pattern, and the right side of Figure 55(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 63.2 GHz. Fig. 56(A) is a diagram showing a comparison of the radiation patterns of horn antenna 807 according to this example (Reference Example 7) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 56(B) is a diagram showing a comparison of the radiation patterns of horn antenna 807 according to this example (Reference Example 7) and horn antenna 801 according to Reference Example 1 described above.

[0175] As shown in FIG. 55(A), with horn antenna 807 of this example, the reception frequency is 63.2 GHz, and the receivable band is wider than that of the comparative example. Furthermore, as shown in FIG. 56(A), according to this example, directivity in the left-right and up-down directions was enhanced compared to the comparative example, and the antenna gain in those directions was improved. On the other hand, as shown in FIG. 56(B), according to this example, the directivity of the main lobe deteriorated compared to Reference Example 1, and the antenna gain could not be improved.

[0176] <Reference example 8> FIG. 57 is a schematic cross-sectional side view showing a horn antenna 808 according to Reference Example 8 of the present technology and an enlarged view of its feed portion 40. The following mainly describes the configurations that differ from the fourth embodiment, and the same components as those in the fourth embodiment are given the same reference numerals and their description will be omitted or simplified.

[0177] In the horn antenna 808 of this example, the length of the feed probe 41 protruding from the first conductor layer 83 to the first waveguide H1 is different from that of Reference Example 4, and in this example, it is changed from 0.75 mm in Reference Example 4 to 0.65 mm (λ / 4 (0.66 mm) or less). By shortening the length of the feed probe 41, it is possible to expand the receiving frequency band, as will be described later.

[0178] Figures 58 and 59 show simulation results showing the radiation characteristics of horn antenna 808 according to this example. Figure 58(A) shows the voltage standing wave ratio (VSWR), the left side of Figure 58(B) shows the azimuth angle planar pattern, and the right side of Figure 58(B) shows the elevation angle planar pattern. Note that (B) is the radiation pattern at 60.5 GHz.

[0179] Fig. 59(A) is a diagram showing a comparison of the radiation patterns of horn antenna 808 according to this example (Reference Example 8) and horn antenna 110 according to the comparative example (Fig. 9) described above. Fig. 59(B) is a diagram showing a comparison of the radiation patterns of horn antenna 808 according to this example (Reference Example 8) and horn antenna 803 according to Reference Example 4 described above.

[0180] As shown in FIG. 58(A), with horn antenna 808 of this example, the reception frequency is 59.8 GHz, and the receivable band is significantly wider than that of Reference Example 4. Furthermore, as shown in FIG. 59(A), according to this example, the directivity of the main lobe was high and the antenna gain was greatly improved compared to the comparative example. On the other hand, as shown in FIG. 59(B), according to this example, the antenna gain was slightly improved (0.2 dB) compared to Reference Example 4, although there was no significant difference.

[0181] The present technology can also be configured as follows. (1) A waveguide section including a first dielectric block and a first post wall that defines a first waveguide extending in one axial direction and that includes a plurality of first conductive columns penetrating the first dielectric block; a horn portion including a first widening portion connected to one end of the waveguide portion in the uniaxial direction, the first widening portion having a second dielectric block thicker than the first dielectric block and a second post wall including a plurality of second conductive pillars penetrating the second dielectric block and defining a second waveguide whose path width increases with increasing distance from the first waveguide; A horn antenna comprising: (2) The horn antenna according to (1), the first dielectric block and the second dielectric block are formed of a common dielectric multilayer substrate; The first waveguide and the second waveguide are provided inside the dielectric multilayer substrate. Horn antenna. (3) The horn antenna according to (1) or (2) above, The waveguide section is The first conductive layer further includes two first conductive layers that face each other across the first dielectric block and are connected to the plurality of first conductive columns. Horn antenna. (4) The horn antenna according to (3) above, The first widening portion is two second conductor layers facing each other with the second dielectric block interposed therebetween and connected to the plurality of second conductive columns; an interlayer connection portion that electrically connects the first conductor layer and the second conductor layer, Horn antenna. (5) The horn antenna according to (4), The antenna further includes a conductive shield layer connected to the first conductor layer and the second conductor layer, and covering the waveguide portion and the horn portion. Horn antenna. (6) The horn antenna according to any one of (1) to (5) above, The horn portion is a third dielectric block connected to one end of the second dielectric layer in the uniaxial direction and having a thickness greater than that of the second dielectric block; a third post wall that defines a third waveguide, the third waveguide having a path width that increases with increasing distance from the second waveguide, the third post wall including a plurality of third conductive pillars that penetrate the third dielectric block; Horn antenna. (7) The horn antenna according to any one of (1) to (6) above, The waveguide section includes a plurality of air holes provided in the first dielectric block and having an opening width smaller than the wavelength of the electromagnetic wave propagating through the first dielectric. Horn antenna. (8) The horn antenna according to (6) or (7), The horn portion includes a plurality of air holes provided in at least one of the second dielectric block and the third dielectric block, the air holes having an opening width smaller than the wavelength of the electromagnetic wave propagating through the second dielectric block and the third dielectric block. Horn antenna. (9) The horn antenna according to (8), The horn portion further includes a dielectric lens portion provided on one end side in the axial direction and formed by a part of the plurality of air holes. Horn antenna. (10) The horn antenna according to any one of (1) to (9) above, The horn further includes a dielectric portion connected to one end of the horn portion in the axial direction, the length of the dielectric portion along the axial direction being equal to or greater than one-fourth the wavelength of the electromagnetic wave propagating through the second waveguide. Horn antenna. (11) The horn antenna according to (10), The dielectric portion has a plurality of air holes having an opening width smaller than the wavelength of the electromagnetic wave propagating through the dielectric portion, and a dielectric lens portion formed by a part of the plurality of air holes. Horn antenna. (12) The horn antenna according to any one of (1) to (11) above, The optical fiber further includes a power supply section having a signal line connected to the first waveguide. Horn antenna. (13) A dielectric multilayer substrate having a side surface portion forming an antenna aperture; a waveguide section provided inside the dielectric multilayer substrate, the waveguide section including two first conductor layers facing each other at a first interval in a thickness direction of the dielectric multilayer substrate, and a first post wall provided between the two first conductor layers and defining a first waveguide extending in a uniaxial direction perpendicular to the thickness direction of the dielectric multilayer substrate; a horn portion including a first widening portion provided between the waveguide portion and the side portion, the first widening portion having two second conductor layers facing each other at a second interval larger than the first interval in the thickness direction of the dielectric multilayer substrate, and a second post wall provided between the two second conductor layers and defining a second waveguide whose path width increases with increasing distance from the first waveguide; A horn antenna comprising: (14) a power supply unit; a horn portion including a first widening portion having a first dielectric block supporting the power supply portion and a first post wall defining a first waveguide including a plurality of first conductive pillars penetrating the first dielectric block and having a path width that increases with increasing distance from the power supply portion; A horn antenna comprising: (15) The horn antenna according to (14), The horn portion is The second widening section further includes a second dielectric block that is thicker than the first dielectric block, and a second post wall that includes a plurality of second conductive pillars that penetrate the second dielectric block and defines a second waveguide whose path width increases with increasing distance from the first waveguide. Horn antenna. (16) The horn antenna according to (15), the first dielectric block and the second dielectric block are formed of a common dielectric multilayer substrate; The first waveguide and the second waveguide are provided inside the dielectric multilayer substrate. Horn antenna. (17) The horn antenna according to (15) or (16) above, The first widened portion further includes two first conductor layers that face each other across the first dielectric block and are connected to the plurality of first conductive columns. Horn antenna. (18) The horn antenna according to (17), The second widening portion is two second conductor layers facing each other with the second dielectric block interposed therebetween and connected to the plurality of second conductive columns; an interlayer connection portion that electrically connects the first conductor layer and the second conductor layer, Horn antenna. (19) The horn antenna according to (18), The first widened portion is covered with a conductive shield layer connected to the first conductor layer and the second conductor layer. Horn antenna. (20) The horn antenna according to any one of (15) to (19) above, The horn portion includes a plurality of air holes provided in at least one of the first dielectric block and the second dielectric block, the air holes having an opening width smaller than the wavelength of the electromagnetic wave propagating through the first dielectric block and the second dielectric block. Horn antenna. [Explanation of symbols]

[0182] 1...Dielectric multilayer substrate 10...Waveguide section 11...First dielectric block 12...First post wall 13, 14...First conductor layer 15, 25, 35, 52...Air holes 20...Horn section 21...Second dielectric block 22...Second post wall 23, 24...Second conductor layer 31...Third dielectric block 32...Third post wall 33, 34...Third conductor layer 36, 53...Dielectric lens section 40...Power supply unit 41...Power supply probe 51...Dielectric part 100, 200, 300, 400, 500, 600...Horn antenna 201...First widening section 202...Second widening section 700...Antenna device

Claims

1. a waveguide section including a first dielectric block, a first post wall that defines a first waveguide extending in one axial direction and that includes a plurality of first conductive columns penetrating the first dielectric block, and two first conductor layers that face each other across the first dielectric block and are connected to the plurality of first conductive columns; a horn portion including a first widening portion connected to one end of the waveguide portion in the uniaxial direction, the first widening portion having a second dielectric block thicker than the first dielectric block, a second post wall defining a second waveguide including a plurality of second conductive columns penetrating the second dielectric block, the second waveguide having a path width increasing with increasing distance from the first waveguide, and two second conductor layers facing each other across the second dielectric block and connected to the plurality of second conductive columns; a conductive shield layer connected to the first conductor layer and the second conductor layer and covering the waveguide portion and the horn portion; A horn antenna comprising:

2. 2. The horn antenna of claim 1, the first dielectric block and the second dielectric block are formed of a common dielectric multilayer substrate, The first waveguide and the second waveguide are provided inside the dielectric multilayer substrate. Horn antenna.

3. 2. The horn antenna of claim 1, The first widened portion further includes an interlayer connection portion that electrically connects the first conductor layer and the second conductor layer. Horn antenna.

4. 2. The horn antenna of claim 1, The horn portion is a third dielectric block connected to one end of the second dielectric block in the uniaxial direction and having a thickness greater than that of the second dielectric block; a third post wall that defines a third waveguide, the third waveguide having a path width that increases with increasing distance from the second waveguide, the third post wall including a plurality of third conductive pillars that penetrate the third dielectric block; Horn antenna.

5. 2. The horn antenna of claim 1, The waveguide section includes a plurality of air holes provided in the first dielectric block and having an opening width smaller than the wavelength of the electromagnetic wave propagating through the first dielectric block. Horn antenna.

6. 5. The horn antenna according to claim 4, The horn portion includes a plurality of air holes provided in at least one of the second dielectric block and the third dielectric block, the air holes having an opening width smaller than the wavelength of the electromagnetic wave propagating through the second dielectric block and the third dielectric block. Horn antenna.

7. 7. The horn antenna of claim 6, The horn portion further includes a dielectric lens portion provided on one end side in the axial direction and formed by a part of the plurality of air holes. Horn antenna.

8. 2. The horn antenna of claim 1, a dielectric section connected to one end of the horn section in the axial direction, the dielectric section having a length along the axial direction that is equal to or greater than one-fourth the wavelength of the electromagnetic wave propagating through the second waveguide; Horn antenna.

9. 9. The horn antenna of claim 8, The dielectric portion has a plurality of air holes having an opening width smaller than the wavelength of the electromagnetic wave propagating through the dielectric portion, and a dielectric lens portion formed by a part of the plurality of air holes. Horn antenna.

10. 2. The horn antenna of claim 1, The optical fiber further includes a power supply section having a signal line connected to the first waveguide. Horn antenna.

11. a dielectric multilayer substrate having a side surface that forms an antenna opening; a waveguide section provided inside the dielectric multilayer substrate, the waveguide section including two first conductor layers facing each other at a first interval in a thickness direction of the dielectric multilayer substrate, and a first post wall provided between the two first conductor layers and defining a first waveguide extending in a uniaxial direction perpendicular to the thickness direction of the dielectric multilayer substrate; a horn portion including a first widening portion provided between the waveguide portion and the side portion, the first widening portion having two second conductor layers facing each other at a second interval larger than the first interval in a thickness direction of the dielectric multilayer substrate, and a second post wall provided between the two second conductor layers and defining a second waveguide whose path width increases with increasing distance from the first waveguide; a conductive shield layer connected to the first conductor layer and the second conductor layer and covering the waveguide portion and the horn portion; A horn antenna comprising:

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