Antenna device
By forming a patch antenna on a dielectric substrate and placing a cavity above it to expand the radiation direction, the problem of difficulty in miniaturizing and reducing cost in the antenna device in the prior art is solved, and the wide-angle radiation direction and low-cost effects are achieved.
Patent Information
- Application Number
- CN202480005323.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-17
- Filing Date
- 2024-05-30
- Publication Date
- 2025-07-11
AI Technical Summary
The existing antenna devices using dielectric substrates are difficult to achieve a wide-angle radiation direction that is miniaturized and low-cost, and require complex electronic circuits and large spatial configurations.
A patch antenna is formed on the dielectric substrate and a cavity is arranged above it. The electromagnetic field distribution of the cavity affects the expansion radiation direction, achieving wide-angle radiation direction, avoiding the need for arraying and complex electronic circuits.
The antenna device is miniaturized and reduced in cost, while maintaining the radiation direction of wide angles, reducing space requirements and component costs.
Smart Images
Figure CN120303827A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an antenna device composed of a dielectric substrate. Background Art
[0002] In mobile communications such as 5G and 6G, in order to transmit and receive high-frequency radio waves in various environments such as inside and outside buildings, an antenna device is required to have a wide-angle radiation directivity capable of transmitting and receiving radio waves in multiple directions. In order to meet such a requirement, the following method is known: an array antenna in which a plurality of antenna elements are arranged in an array is configured to achieve a wide-angle radiation directivity as a whole. For example, Patent Document 1 discloses the following technique: in an array antenna in which a plurality of antennas are arranged in an array, a phase difference is given to each antenna for beamforming, and a wide-angle radiation directivity can be obtained.
[0003] Prior Art Documents
[0004] Patent Documents
[0005] Japanese Patent No. 6818757 Gazette Summary of the Invention
[0006] Problems to be Solved by the Invention
[0007] In recent antenna devices, from the viewpoint of miniaturization and weight reduction, a structure using a dielectric substrate is widely used. For example, if a patch antenna is formed on a dielectric substrate, it is easy to miniaturize the antenna device, but it is difficult to achieve a wide-angle radiation directivity. As described above, in order to achieve a wide-angle radiation directivity of the antenna device, it is necessary to arrange a plurality of antennas such as patch antennas in an array on the dielectric substrate to form an array antenna.
[0008] However, an array antenna using a dielectric substrate requires a space for arranging a plurality of antennas, resulting in an increase in size, making it difficult to miniaturize the antenna device. In addition, it is necessary to form a complex electronic circuit for giving a phase difference for beamforming to a plurality of antennas, resulting in an increase in both component cost and installation cost, and the dimensional tolerance during the production of the dielectric substrate also becomes strict.
[0009] As described above, in the case of configuring an antenna device using a dielectric substrate by the above-described conventional method, it is difficult to achieve a wide-angle radiation directivity in a small size and at low cost.
[0010] The present invention has been completed to solve the above problems, and in the case of configuring an antenna device using a dielectric substrate, an antenna device is realized that can maintain a wide-angle radiation directivity by arranging only one patch antenna and can miniaturize and reduce the cost of the antenna device.
[0011] Means for Solving the Problems
[0012] In order to solve the above problems, the antenna device (1) of the present invention is an antenna device formed using a dielectric substrate, and is configured to include: a patch antenna (20) formed on a predetermined conductor layer of the dielectric substrate; a cavity (12) formed in a dielectric layer (11) disposed above the predetermined conductor layer of the dielectric substrate, and having a shape surrounding the patch antenna when viewed from above in a plan view in the thickness direction (first direction (Z)) of the dielectric substrate; and ground conductors (21, 22, 23) disposed opposite to the dielectric layer with the predetermined conductor layer interposed therebetween in the first direction.
[0013] The antenna device of the present invention is configured such that in an antenna device using a dielectric substrate, a patch antenna having a predetermined conductor layer and a ground conductor directly below the patch antenna are formed, and a cavity is formed in the dielectric layer laminated above the patch antenna, and the cavity has a shape surrounding the patch antenna when viewed from above in the first direction. With such a configuration, the radio waves radiated from the patch antenna via the power supply structure are affected by the electromagnetic field distribution on the dielectric surface of the side surface of the upper cavity, so that the radiation direction is expanded and the radiation directivity is broadened. Therefore, it is not necessary to increase the space for arranging a plurality of antennas in an array shape or to use a complex electronic circuit for phase control during beam forming, and the miniaturization and low cost of the antenna device can be easily achieved.
[0014] In the present invention, the patch antenna and the cavity can each be set to have various shapes when viewed from above in the first direction. For example, a patch antenna and a cavity having a rectangular shape when viewed from above in the first direction, and a patch antenna and a cavity having a circular shape can be adopted. In addition, the height of the cavity along the first direction is preferably set in the range of 0.7λ to 0.8λ with respect to the wavelength λ of the operating frequency in the dielectric substrate. Further, it is preferable that the outer edge portion of the cavity is set to be larger than the outer edge portion of the patch antenna by a distance in the range of 0.03λ to 0.07λ when viewed from above in the first direction.
[0015] In the present invention, the patch antenna and the cavity can be symmetrically arranged with respect to the center of the dielectric substrate when viewed from above in the first direction. Thereby, the antenna device can obtain a symmetric radiation directivity in all directions from approximately the center in the substrate plane.
[0016] In the present invention, the ground conductor can be formed on a plurality of conductor layers connected to each other via a plurality of via conductors extending in the first direction. Thereby, the area of the ground conductor can be enlarged to strengthen the grounding and improve the antenna characteristics.
[0017] In the present invention, a power supply structure for supplying one or both of a horizontally polarized wave and a vertically polarized wave can be provided in a patch antenna. Thus, at least both the radio wave of the horizontally polarized wave and the radio wave of the vertically polarized wave can be transmitted and received by one patch antenna, and the radio wave of the horizontally polarized wave and the radio wave of the vertically polarized wave can be appropriately used separately according to the usage situation.
[0018] Effects of the Invention
[0019] According to the present invention, a single patch antenna is arranged on a dielectric substrate, and a cavity is arranged above it. Therefore, an antenna device can be realized which avoids the enlargement and high cost caused by the array of the antenna device, and has excellent usability due to the wide-angle radiation directivity. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 is a perspective view of the antenna device 1 of the present embodiment viewed obliquely from above.
[0021] Figure 2 is Figure 1 a sectional structure view of the A-A section of the antenna device 1.
[0022] Figure 3 is a top view of the antenna device 1 of the present embodiment viewed from above.
[0023] Figure 4 is a view for explaining the conductor structure of the lower part of the antenna device 1 of the present embodiment.
[0024] Figure 5 is a view for comparing and showing the radiation directivity in the XZ plane of the antenna device 1 of the present embodiment and the antenna device of the comparative example.
[0025] Figure 6 is a view for comparing and showing the radiation directivity in the YZ plane of the antenna device 1 of the present embodiment and the antenna device of the comparative example.
[0026] Figure 7 is a view for comparing and showing the reflection characteristics of the antenna device 1 of the present embodiment and the antenna device of the comparative example.
[0027] Figure 8 is a perspective view of the antenna device 1 to which a modification of the present invention is applied, viewed obliquely from above.
[0028] Figure 9 is a top view of the antenna device 1 of this modification viewed from above.
[0029] Figure 10 is a view for comparing and showing the radiation directivity in the XZ plane of the antenna device 1 of this modification and the antenna device of the comparative example.
[0030] Figure 11 It is a diagram showing the radiation directivities in the YZ plane, comparing the antenna device 1 of this modification example and the antenna device of the comparative example. Detailed implementation manners
[0031] Hereinafter, with reference to Figures 1 to 11 Preferred implementation manners of the present invention will be described. In this implementation manner, an antenna device embodying the present invention will be described. However, the implementation manner described below is an example of a manner applying the present invention, and the present invention is not limited by the content of this implementation manner.
[0032] Using Figures 1 to 4 The structure of the antenna device 1 of an embodiment of this implementation manner will be described. Figure 1 It is a perspective view of the antenna device 1 observed from obliquely above. Figure 2 It is Figure 1 The sectional structure diagram of the A-A section of the antenna device 1. Figure 3 It is a top view of the antenna device 1 observed from above. Figure 4 It is a diagram for explaining the conductor structure of the lower part of the antenna device 1. In addition, in Figures 1 to 4 for ease of explanation, the X direction, Y direction, and Z direction (the first direction of the present invention) orthogonal to each other are respectively indicated by arrows.
[0033] The antenna device 1 of this implementation manner is constituted by using a dielectric substrate made of a dielectric material. The dielectric substrate has a structure in which a lower dielectric layer 10 and an upper dielectric layer 11 are laminated. A patch antenna 20 is formed at the center of the surface of the lower dielectric layer 10, and a cavity 12 is formed at the center of the upper dielectric layer 11. That is, in the dielectric layer 11, the part of the cavity where the central dielectric material is removed in a rectangular shape becomes the cavity 12. In addition, in the lower dielectric layer 10, a three-layered ground conductor 21, 22, 23 is disposed below the patch antenna 20.
[0034] As Figure 2 and Figure 3 shown, when observed from the Z direction in a top view, both the upper and lower dielectric layers 10 and 11 have a rectangular planar shape of the same size. The patch antenna 20 has a rectangular planar shape with a size sufficiently smaller than that of the dielectric layer 11, and the cavity 12 has a rectangular planar shape slightly larger than that of the patch antenna 20. That is, in a top view, the cavity 12 surrounds the patch antenna 20, and thus, the patch antenna 20 faces the air inside the cavity 12 directly above, and has a structure in which the patch antenna 20 is exposed to the outside.
[0035] In Figure 2In the figure, the height Z1 in the Z direction of the lower dielectric layer 10 and the height Z2 in the Z direction of the upper dielectric layer 11 (the height Z2 of the cavity 12) are shown. It can be seen that Z2 is set to be larger than Z1. Additionally, in Figure 3 the figure, the length X1 in the X direction and the length Y1 in the Y direction of the upper and lower dielectric layers 10 and 11, and the length X2 in the X direction and the length Y2 in the Y direction of the cavity 12 are shown respectively. As described above, X1 and Y1 are set to be larger than X2 and Y2. Additionally, the size of the patch antenna 20 is set to be slightly smaller than X2 and Y2. In Figures 1 to 4 the figure, a case is illustrated in which the dielectric layers 10 and 11 and the cavity 12 are all square in planar shape and X1 = Y1, X2 = Y2 are set.
[0036] In the present embodiment, specific dimensional conditions such as the above X1, X2, Y1, Y2, Z1, Z2, etc. need to be appropriately determined according to the operating frequency band, antenna characteristics, etc. For example, when envisioning an operating frequency of 28 GHz, as a setting example of the dimensional conditions, for the dielectric layers 10 and 11, X1 = Y1 = 7.6 mm, Z1 = 0.6 mm, Z2 = 3.3 mm can be cited, and for the cavity 12, X2 = Y2 = 2.35 mm can be cited. Additionally, the height of the cavity 12 is the same as Z2, and the size of the patch antenna 20 is slightly smaller than X2 and Y2, about 2 mm. Generally, the lower the operating frequency band, the larger the dimensional parameters need to be set, and the higher the operating frequency band, the smaller the dimensional parameters need to be set.
[0037] Next, Figure 4 the conductor structure of the antenna device 1 will be described. In Figure 4 the figure, in a state where the upper dielectric layer 11 is removed, only the region of the lower dielectric layer 10 is shown. In addition to the patch antenna 20 and the ground conductors 21, 22, 23, a plurality of via conductors 30, 31, 32 extending in the stacking direction in the dielectric layer 10 are also shown. First, the three-layer ground conductors 21, 22, 23 are arranged in the order of the ground conductor 21, the ground conductor 22, and the ground conductor 23 from the lower layer side. The ground conductors 21, 22, 23 are each formed to extend substantially over the entire rectangular region of the dielectric layer 10. The three-layer ground conductors 21, 22, 23 are electrically connected to each other via a plurality of via conductors 30. In this way, the relatively large-area ground conductors 21, 22, 23 are arranged opposite to the patch antenna 20 above, so the grounding of the antenna device 1 is strengthened, which is effective for improving the antenna characteristics.
[0038] Additionally, as Figure 4 shown, two via conductors 31, 32 that function as power supply lines are connected to the patch antenna 20. A high-frequency signal of a horizontally polarized wave is supplied to one via conductor 31, and a high-frequency signal of a vertically polarized wave is supplied to the other via conductor 32. InFigure 3 The patch antenna 20 shown has an upper end portion 31a of a via conductor 31 for a horizontally polarized wave and an upper end portion 32a of a via conductor 32 for a vertically polarized wave, which are connected to the patch antenna 20 at positions offset from the center of the patch antenna 20 in the horizontal and vertical directions, respectively. The lower ends of the respective via conductors 31 and 32 are connected to a pair of pads (not shown) on the bottom surface of the dielectric layer 10, forming a structure that enables power supply to a pair of power supply lines from the outside. With such a structure, the antenna device 1 can radiate either or both of a horizontally polarized wave and a vertically polarized wave via the power supply structure.
[0039] When a high-frequency signal is supplied to the antenna device 1 of the present embodiment from the outside, the radio wave is radiated substantially upward in the Z direction. In this case, according to the conventional general structure, Figure 4 the entire area above the patch antenna 20 on the surface of the dielectric layer 10 having the structure shown is air. In contrast, in the present embodiment, the difference is that there is a cavity 12 above the patch antenna 20. In the present embodiment, the function of the cavity 12 is to make the radiation directivity of the antenna device 1 wide-angle. Conventionally, it has been difficult to achieve a wide-angle radiation directivity by providing only one patch antenna 20. According to the antenna device 1 of the present embodiment, mainly by the effect of providing the cavity 12, a wide-angle radiation directivity can be obtained, and the verification results regarding this will be described later.
[0040] Hereinafter, Figures 5 to 7 will be used to describe the verification results of the antenna characteristics related to the antenna device 1 of the present embodiment. Here, for comparison with the antenna device 1 of the present embodiment, an antenna device having a structure without the upper dielectric layer 10 and the cavity 12 was used as a comparative example, and the antenna characteristics were compared. This comparative example has Figure 4 such a structure that the patch antenna 20 is disposed at the uppermost part of the dielectric layer 10. In addition, the dimensional parameters of the comparative example are substantially the same as the corresponding parts of the antenna device 1 of the present embodiment.
[0041] Figure 5 and Figure 6 are diagrams showing the radiation directivity of the antenna device 1 of the present embodiment and the antenna device of the comparative example for comparison. Figure 5 represents the directivity in the XZ plane, Figure 6 represents the directivity in the YZ plane. These are the results of verifying the directivity of the radio wave radiated from the patch antenna 20 by inputting a signal with a frequency of 28 GHz and performing simulation. In Figure 5 and Figure 6 , the radiation directivity (solid line) of the present embodiment and the radiation directivity (dashed line) of the comparative example are shown overlapping.
[0042] As shown in Figure 5 andFigure 6 As shown, when the radiation directivity is above the Z direction in the radiation direction, the gain becomes a peak, and in the XZ plane and the YZ plane, the radiation direction deviates from the Z direction and the gain decreases. At this time, in Figure 5 and Figure 6 , if the range of the angle at which the gain becomes half of the peak value is obtained as the half-value width, in the case of the comparative example, the half-value width becomes about 90°, whereas in the case of the present embodiment (solid line), the half-value width exceeds 180° and becomes more than twice that of the comparative example. Therefore, based on the results of Figure 5 and Figure 6 , it is verified that the antenna device 1 according to the present embodiment can obtain a radiation directivity with a wider angle.
[0043] In addition, Figure 7 is a diagram showing the reflection characteristics in comparison between the antenna device 1 of the present embodiment and the antenna device of the comparative example. The reflection characteristics are obtained by using simulation corresponding to the frequency to obtain the VSWR (Voltage Standing Wave Ratio) representing the relationship between the input signal and the reflected signal. In Figure 7 , the VSWR of the present embodiment (solid line) and the VSWR of the comparative example (dashed line) are overlapped and shown.
[0044] As Figure 7 shown, regarding the reflection characteristics, near the frequency of 28 GHz, the VSWR becomes the minimum value, and from here, the VSWR deteriorates more and more toward the low-frequency side and the high-frequency side. Moreover, in the present embodiment, the frequency range with good VSWR is relatively wide, whereas in the case of the comparative example, the frequency range with good VSWR becomes relatively narrow. Specifically, in the present embodiment, the frequency range where the VSWR is 2 or less is more than 4 times that of the comparative example. Therefore, based on the results of Figure 7 , it is verified that the antenna device 1 of the present embodiment can obtain good reflection characteristics in a relatively wide frequency range.
[0045] Next, the antenna device 1 to which a modified example of the present invention is applied will be described using Figure 8 and Figure 9 . In the above-described embodiment, the antenna device 1 in which the patch antenna 20 and the cavity 12 have a rectangular planar shape when viewed from the Z direction has been described, but in the antenna device 1 of this modified example, the shapes of the patch antenna 20a and the cavity 12a are changed. Figure 8 is a perspective view of the antenna device 1 of this modified example viewed from obliquely above, Figure 9 is a top view of the antenna device 1 viewed from above Figure 8 . Here, Figure 8 and Figure 9 are the same as Figure 1 andFigure 3 Correspondingly, regarding Figure 2 and Figure 4 , it is substantially the same for this modification example, and thus is omitted.
[0046] As Figure 8 and Figure 9 shown, in the antenna device 1 of this modification example, the differences in the structures of Figure 1 and Figure 3 are that both the patch antenna 20a and the cavity 12a have a circular planar shape when viewed from above in the Z direction. That is, the cavity 12a is formed by removing the central dielectric material in a circular shape in the upper dielectric layer 11, and the patch antenna 20a is formed in a circular shape at the center of the surface of the lower dielectric layer 10. In addition, in Figure 8 and Figure 9 , the upper and lower dielectric layers 10, 11 have a rectangular planar shape in the same way as Figure 1 and Figure 3 . Additionally, in the same way as Figure 2 , a three-layered ground conductor 21, 22, 23 is arranged in the lower dielectric layer 10. Similarly, Figure 4 shown, the arrangement of the power supply structure, the upper end portions 31a and the lower end portions 32a of the through-hole conductors 31, 32 for horizontal polarization waves and vertical polarization waves ( Figure 9 ) is also the same as that in the above-described embodiment.
[0047] As Figure 9 shown, when viewed from above in the Z direction, the circular cavity 12a is set to a diameter D, and the circular patch antenna 20a is set to a diameter slightly smaller than the diameter D. That is, when viewed from above, the cavity 12a is arranged to surround the patch antenna 20a, which is the same as the case of Figure 3 . In addition, in the dimensional conditions of this modification example, the heights Z1, Z2 in the Z direction of the dielectric layers 10, 11 respectively ( Figure 2 ) and the lengths X1 in the X direction and the lengths Y1 in the Y direction of the upper and lower dielectric layers 10, 11 are the same as those in the above-described embodiment. Regarding Figure 9 the diameter D, similar to other dimensional conditions, it needs to be appropriately determined according to the operating frequency band, antenna characteristics, etc.
[0048] Figure 10 and Figure 11 are diagrams regarding the antenna device 1 of this modification example, showing the radiation directivities similar to those of Figure 5 and Figure 6 . Signals with an input frequency of 28 GHz are used, and the results of verifying the directivity of the radio waves radiated from the patch antenna 20a through simulation are shown. In Figure 10 and Figure 11In [the figure], the radiation directivity (solid line) of this modification example is overlapped and shown together with Figure 5 and Figure 5 the radiation directivities (dashed lines) of the same comparative examples. Figure 10 and Figure 11 The radiation directivities of [the elements] are substantially the same as those of Figure 5 and Figure 6 which verifies that even when the structure of this modification example is adopted, the effect of obtaining a radiation directivity with a wider angle can be achieved. In addition, regarding the reflection characteristics of this modification example, substantially the same results as those of Figure 7 can also be obtained, and the illustration thereof is omitted here.
[0049] As described above, by adopting the structure of the antenna device 1 to which the present invention is applied, good antenna characteristics including a wide-angle radiation directivity can be achieved. That is, compared with the radiation directivity with a relatively narrow angle in the conventional structure where the patch antenna 20 is disposed on the surface of the dielectric layer 10, in the embodiment including the above modification example (hereinafter referred to as this embodiment), by the effect of providing the cavity 12 in the dielectric layer 11 laminated on the upper part of the dielectric layer 10, the wide-angleization of the radiation directivity can be achieved. It can be assumed that the radio wave radiated upward in the Z direction from the patch antenna 20 generates an electromagnetic field distribution on the dielectric surfaces of the four side surfaces constituting the cavity 12, and when it propagates in the Z direction to the upper opening of the cavity 12, it expands in multiple directions and the radiation directivity is wide-angleized.
[0050] According to the conventional structure, in order to achieve a radiation directivity with a wider angle, the following method is required: an array antenna in which a plurality of antennas are arranged in an array is configured, and the phases of the respective antennas are controlled by beamforming. In contrast, in the case of the antenna device 1 of this embodiment, a wide-angle radiation directivity can be obtained only by one patch antenna 20 without configuring an array antenna. Therefore, there is no need for a space for arranging a plurality of antennas, nor a complicated electronic circuit for giving a phase difference to each antenna. Therefore, in addition to the superiority of the above-described antenna performance, the antenna device 1 of this embodiment is smaller than the dielectric substrate when arrayed by the conventional structure, which is suitable for miniaturization of the antenna device 1. Along with this, the dimensional tolerance during the production of the dielectric substrate can also be alleviated, and the component cost and the mounting cost can be reduced, enabling cost reduction.
[0051] In addition, in this embodiment, when achieving good antenna characteristics including a wide-angle radiation directivity, as described above, appropriate setting of the dimensional parameters is important. That is, the dimensional parameters of the antenna device 1 are not limited to Figures 1 to 4Rather than the configuration, it is preferably set to a wavelength λ corresponding to the operating frequency in the dielectric substrate. This wavelength λ is the wavelength considering the wavelength shortening effect in the dielectric substrate. Specifically, the height of the cavity 12 along the Z direction is preferably such that, with respect to the wavelength λ of the operating frequency in the dielectric substrate, the height Z2 of the upper dielectric layer 11 (the height of the cavity 12) is set within the range of 0.7λ to 0.8λ. Additionally, it is preferable to set the lengths X2 and Y2 of the cavity 12 in the X and Y directions to a distance within the range of 0.03λ to 0.07λ greater than the lengths of the rectangle of the patch antenna 20 in the X and Y directions. Such conditions of the dimensional parameters are preferable settings to ensure the desired antenna characteristics such as wide-angle radiation directivity and good reflection characteristics in the antenna device 1.
[0052] In addition, in the present embodiment, as Figure 3 shown, the case where the patch antenna 20 and the cavity 12 have rectangular and circular planar shapes when viewed from above in the Z direction is illustrated, but it is not limited to rectangular and circular shapes, and different planar shapes can also be used. For example, even if the patch antenna 20 and the cavity 12 have a polygonal planar shape other than rectangular, the present invention can be applied. In this case, the effects of the antenna device 1 to which the present invention is applied can also be obtained. Moreover, in the present embodiment, the case where the patch antenna 20 and the cavity 12 are symmetrically arranged with respect to the center of the dielectric substrates 10 and 11 when viewed from above in the Z direction is illustrated, but the present invention can also be applied even if the arrangement is asymmetric with respect to the center.
[0053] The content of the present invention has been specifically described based on the present embodiment, but the present invention is not limited to the above-described embodiment, and modifications can be made without departing from the gist thereof. That is, as long as the basic configuration of the antenna device 1 described Figures 1 to 4 can achieve the effects of the present invention, the present invention can be widely applied to various antenna devices 1 with other configurations and shapes. For example, regarding the shape, power supply method, size, etc. of the patch antenna 20, various modifications can be made as long as the effects of the present invention can be obtained.
[0054] Reference Numeral Explanation
[0055] 1, antenna device; 10, 11, dielectric layer; 12, 12a, cavity; 20, 20a, patch antenna; 21, 22, 23, ground conductor; 33, 31, 32, via conductor.
Claims
1. An antenna device is formed using a dielectric substrate, and is characterized in that: The antenna device includes: A patch antenna formed on a predetermined conductor layer of the dielectric substrate; A cavity formed in a dielectric layer disposed above the predetermined conductor layer of the dielectric substrate, and having a shape surrounding the patch antenna when viewed from above in a plan view in the thickness direction of the dielectric substrate, i.e., the first direction; And A ground conductor disposed opposite to the dielectric layer with the predetermined conductor layer therebetween in the first direction.
2. The antenna device according to claim 1, characterized in that: The patch antenna and the cavity each have a rectangular shape when viewed from above in the first direction.
3. The antenna device according to claim 1, characterized in that: The patch antenna and the cavity each have a circular shape when viewed from above in the first direction.
4. The antenna device according to claim 1, characterized in that: The height of the cavity along the first direction is set in a range of 0.7λ to 0.8λ with respect to the wavelength λ of the operating frequency in the dielectric substrate.
5. The antenna device according to claim 1, characterized in that: When viewed from above in the first direction, the outer edge portion of the cavity is set to a distance in a range that is 0.03λ to 0.07λ larger than the outer edge portion of the patch antenna.
6. The antenna device according to claim 1, characterized in that: When viewed from above in the first direction, the patch antenna and the cavity are symmetrically arranged with respect to the center of the dielectric substrate.
7. The antenna device according to claim 1, characterized in that: The ground conductor is formed of a plurality of conductor layers interconnected by a plurality of via conductors extending along the first direction.
8. The antenna device according to claim 1, characterized in that: A power supply structure for supplying one or both of a horizontally polarized wave and a vertically polarized wave is provided on the patch antenna.