Antenna Device

Abstract

To provide an antenna device capable of radiating a circular polarization with a simple structure.SOLUTION: An antenna device comprises: a substrate 20 containing a dielectric body; a patch part 30 arranged on the substrate; and a via conductor 40, a first ground plate 50, a second ground plate 60, and a transmission path 70, which are connected to the patch part. The via conductor is offset to a Y direction from a center of the patch part. The first ground plate includes a penetration hole 51 into which the via conductor is inserted, and is arranged onto the substrate so as to be opposite to the patch part in a Z direction. The second ground plate is arranged on the substrate so as to be opposite to the first ground plate on the side opposite to the patch part in the Z direction. The transmission path is arranged on the substrate so as to be positioned between the first ground plate and the second ground plate, and is extended to a X direction from the via conductor so as to be connected to the via conductor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The disclosure herein relates to an antenna device. [Background technology]

[0002] Patent Document 1 discloses an antenna device having a patch portion. The contents of the prior art documents are incorporated by reference as explanations of technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-358530 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, circular polarization is achieved by providing two notches (perturbation elements) in the patch section. However, when used as an antenna for the millimeter wave band, for example, the size of the perturbation element becomes comparable to the manufacturing error. Since the manufacturing error is thus large compared to the size of the patch section, it is difficult to provide an antenna device that exhibits desired characteristics. In the above-mentioned respects, or in other respects not mentioned, further improvements are required in the antenna device.

[0005] One disclosed object is to provide an antenna device capable of radiating circularly polarized waves with a simple structure. Another disclosed object is to provide an antenna device capable of radiating circularly polarized waves in the millimeter wave band. [Means for solving the problem]

[0006] Antenna device disclosed herein One of teeth, A substrate (20) including a dielectric material; A patch portion (30) disposed on a substrate; a via conductor (40) disposed on the substrate, extending in a thickness direction of the substrate, and connected to the patch portion at a position shifted a predetermined distance in a first direction perpendicular to the thickness direction from a center (30c) of the patch portion in a plan view in the thickness direction; a first ground plate (50) having a through hole (51) through which the via conductor is inserted and disposed on the substrate so as to face the patch portion in the plate thickness direction; a second base plate (60) disposed on the substrate so as to face the first base plate on the opposite side to the patch portion in the plate thickness direction; A transmission line (70) is disposed on the substrate so as to be located between the first ground plane and the second ground plane in the thickness direction of the substrate, and is connected to the via conductor and extends from the via conductor in a second direction perpendicular to the thickness direction and the first direction. (However, this does not include the case where multiple patch parts are lined up in the first direction when viewed in a plan view in the plate thickness direction.) And, it is equipped with. Another disclosed antenna device is: A substrate (20) including a dielectric material; A patch portion (30) disposed on the substrate; a via conductor (40) disposed on the substrate, extending in a thickness direction of the substrate, and connected to the patch portion at a position shifted a predetermined distance in a first direction perpendicular to the thickness direction from a center (30c) of the patch portion in a plan view in the thickness direction; a first ground plate (50) having a through hole (51) through which the via conductor is inserted and disposed on the substrate so as to face the patch portion in the plate thickness direction; a second base plate (60) disposed on the substrate so as to face the first base plate on the opposite side to the patch portion in the plate thickness direction; The substrate is provided with a transmission line (70) disposed on the substrate so as to be located between the first ground plane and the second ground plane in the plate thickness direction, connected to the via conductor and extending from the via conductor in a second direction perpendicular to the plate thickness direction and the first direction.

[0007] According to the disclosed antenna device, a circularly polarized wave can be radiated without a perturbation element such as a notch due to the relationship between the extension direction of the transmission line that employs a so-called stripline structure and the offset direction of the via conductor with respect to the center of the patch section. In other words, a circularly polarized wave can be radiated with a simple structure. Since there is no need to provide a perturbation element in the patch section, the desired characteristics can be exhibited in the millimeter wave band, that is, a circularly polarized wave can be radiated.

[0008] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The claims and the reference characters in parentheses in this section are merely illustrative of the corresponding relationships with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become more apparent by referring to the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] 1 is a plan view showing an antenna device according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 1 is a diagram showing an electric field intensity distribution. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] 11 is a diagram showing the relationship between the diameter of a via conductor and the circular polarization ratio. FIG. [Figure 8] FIG. [Figure 9] FIG. 11 is a cross-sectional view showing an antenna device according to a second embodiment. [Figure 10] FIG. 2 is a diagram showing a surface on which transmission lines are arranged on a substrate. [Figure 11] FIG. [Figure 12] FIG. 11 is a cross-sectional view showing an antenna device according to a third embodiment. [Figure 13] FIG. 2 is a diagram showing a surface on which transmission lines are arranged on a substrate. [Figure 14] FIG. [Figure 15] FIG. [Figure 16] FIG. [Figure 17] 13 is a diagram showing an antenna device according to a fourth embodiment. FIG. [Figure 18] FIG. [Figure 19] 13 is a diagram illustrating an antenna device according to a fifth embodiment. [Figure 20] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0011] (First embodiment) The antenna device of this embodiment is configured to transmit and / or receive radio waves at a predetermined operating frequency. The antenna device is suitable for transmitting and / or receiving radio waves in the millimeter wave band, for example. The antenna device may be used in a millimeter wave radar, for example. In the case of a millimeter wave radar, millimeter waves in the 24 GHz band, 76 GHz band, 79 GHz band, etc., can be used. The antenna device may be mounted on a moving object, such as a vehicle or an aircraft. The antenna device may be used in a security system, a surveillance system, etc.

[0012] <Antenna device> First, the structure of the antenna device will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a plan view of the antenna device of this embodiment, seen from the patch portion side in the thickness direction of the substrate. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1.

[0013] As shown in Figs. 1 to 3, the antenna device 10 includes a substrate 20, a patch unit 30, a via conductor 40, a first ground plate 50, a second ground plate 60, and a transmission line 70. The antenna device 10 is configured on a printed circuit board. In other words, an antenna is mounted on the printed circuit board. The substrate 20 is an insulating base material of the printed circuit board. The elements other than the substrate 20, that is, the patch unit 30, the via conductor 40, the first ground plate 50, the second ground plate 60, and the transmission line 70, are conductor elements of the printed circuit board.

[0014] In the following, the thickness direction of the substrate 20 is defined as the Z direction, and the offset direction of the via conductor relative to the center of the patch section, which is a direction perpendicular to the Z direction, is defined as the Y direction. The direction perpendicular to the Z direction and the Y direction is defined as the X direction. Unless otherwise specified, the shape viewed in plan from the Z direction, that is, the shape along the XY plane defined by the X direction and the Y direction, is referred to as the planar shape. The Z direction corresponds to the thickness direction, the Y direction corresponds to the first direction, and the X direction corresponds to the second direction.

[0015] The substrate 20 is configured to include a dielectric material such as resin. By using the substrate 20, a wavelength shortening effect due to the dielectric material can be expected. The substrate 20 may be made of, for example, only resin, a combination of resin with glass cloth or nonwoven fabric, or a material containing ceramic. The substrate 20 functions as a holding unit that holds the patch unit 30, the via conductors 40, the first ground plane 50, the second ground plane 60, and the transmission line 70 in a predetermined positional relationship.

[0016] The substrate 20 has one surface 20a and a back surface 20b that is the surface opposite to the surface 20a in the Z direction. The substrate 20 has side surfaces 20c, 20d, 20e, and 20f that are perpendicular to the surface 20a and the back surface 20b. The side surface 20c is the surface opposite to the side surface 20d in the X direction. The side surface 20e is the surface opposite to the side surface 20f in the Y direction.

[0017] As described later, in this embodiment, the patch unit 30 is disposed on one surface 20a of the substrate 20, and the second ground plane 60 is disposed on the back surface 20b. The patch unit 30 is disposed biased toward the side surface 20d in the X direction. The via conductors 40, the first ground plane 50, and the transmission line 70 are disposed inside the substrate 20. The printed circuit board is a multilayer substrate in which conductor elements are disposed in multiple layers on an insulating base material. The substrate 20 is configured by laminating multiple insulating layers including a dielectric material.

[0018] As an example, the substrate 20 is formed by stacking three insulating layers 21, 22, and 23. The insulating layer 21 forms one surface 20a of the substrate 20. The insulating layer 23 forms a back surface 20b of the substrate 20. The insulating layer 22 is an intermediate layer disposed between the insulating layers 21 and 23 in the Z direction. The substrate 20 has a generally rectangular shape in plan view with the X direction as the longitudinal direction. The printed circuit board may have only the patch portion 30, the via conductor 40, the first ground plate 50, the second ground plate 60, and the transmission line 70 as conductors, or may further have circuit elements other than the above-mentioned conductor elements.

[0019] The patch unit 30 is a radiating element. The patch unit 30 is a conductor made of copper or the like. The patch unit 30 is sometimes referred to as an antenna element. The patch unit 30 is disposed facing the first ground plate 50 so as to have a predetermined distance between the patch unit 30 and the first ground plate 50 in the Z direction. The patch unit 30 of this embodiment is disposed on one surface 20a of the substrate 20, that is, on the upper surface of the insulating layer 21, as described above. The patch unit 30 is disposed at a position closer to the side surface 20d than the side surface 20c in the X direction. The patch unit 30 is formed, for example, by patterning a metal foil disposed on the substrate 20. The direction perpendicular to the plate surface of the patch unit 30 is approximately parallel to the Z direction.

[0020] The patch unit 30 of this embodiment is substantially square in plan. The planar shape of the patch unit 30 is not limited to a square. The planar shape of the patch unit 30 is preferably a shape that is line-symmetrical with respect to two mutually orthogonal straight lines as axes of symmetry, that is, a two-way line-symmetrical shape. A two-way line-symmetrical shape refers to a shape that is line-symmetrical with respect to a certain straight line as an axis of symmetry, and is also line-symmetrical with respect to another straight line that is orthogonal to the straight line. Examples of two-way line-symmetrical shapes include a square, a rectangle, a circle (a perfect circle), an ellipse, a regular hexagon, a regular octagon, and a rhombus. It is more preferable that the patch unit 30 is a point-symmetrical shape such as a circle, a square, a rectangle, or a parallelogram.

[0021] The size of the patch unit 30 is appropriately designed so as to operate at the operating frequency. For example, when the operating frequency is 76 GHz, the wavelength (λ) of the radio wave at the operating frequency is calculated by (300 [mm / s] / 76 [GHz]) / square root of the dielectric constant of the substrate 20. The length of one side of the patch unit 30, which is substantially square in plan view, may be, for example, about 1 / 2 the wavelength, or about n times the 1 / 2 wavelength, where n is an integer of 2 or more.

[0022] The via conductor 40 is a conductor that electrically connects the patch unit 30 and the transmission line 70. The via conductor 40 is a part of a conductor for feeding power to the patch unit 30. The via conductor 40 is formed by disposing a conductor in a hole (a so-called via) formed in the substrate 20. The via conductor 40 is a columnar conductor disposed on the substrate 20. The via conductor 40 may be referred to as a metal via, a feeding via, a feeding element, etc.

[0023] The via conductor 40 extends in the Z direction. In this embodiment, the via conductor 40 (hole) penetrates the insulating layers 21 and 22 in the substrate 20. One end of the via conductor 40 is connected to the patch section 30, and the other end is connected to the transmission line 70. The antenna device 10 may include one via conductor 40, or may include multiple via conductors 40 arranged in parallel. An appropriate selection can be made depending on the size of the antenna device 10 (patch section 30).

[0024] The via conductor 40 is offset in the Y direction with respect to the center 30c of the patch unit 30. That is, the via conductor 40 is connected to the patch unit 30 at a position shifted a certain distance in the Y direction from the center 30c. The center 30c corresponds to the center of gravity of the patch unit 30. In the patch unit 30 that is substantially square in plan, the center 30c corresponds to the intersection of two diagonals of the patch unit 30. In this way, by offsetting the via conductor 40 with respect to the center 30c, impedance matching can be obtained.

[0025] The first ground plate 50 and the second ground plate 60 are connected to a ground line of a power supply circuit (not shown) to provide a ground potential (earth potential) in the antenna device 10. Hereinafter, the first ground plate 50 and the second ground plate 60 may be referred to as ground plates 50, 60. The ground plates 50, 60 are conductors made of copper or the like. The ground plates 50, 60 are formed, for example, by patterning a metal foil arranged on the substrate 20. The direction perpendicular to the plate surfaces of the ground plates 50, 60 is also approximately parallel to the Z direction.

[0026] In a plan view, the area of ​​each of the ground plates 50, 60 is larger than the area of ​​the patch unit 30. Each of the ground plates 50, 60 has a size that can contain the entire patch unit 30. Each of the ground plates 50, 60 preferably has a size required for stable operation of the antenna device 10. The ground plates 50, 60 of this embodiment are substantially rectangular in plan view. Each of the ground plates 50, 60 substantially coincides with the substrate 20 in a plan view. Each side of the ground plates 50, 60 has a length that is, for example, one or more times the wavelength of radio waves at the operating frequency, i.e., one or more wavelengths.

[0027] In this embodiment, the planar shape of the substrate 20 and the ground planes 50 and 60 is rectangular as an example, but it may be square or another polygonal shape. It may also be circular (including elliptical). In the case of a circular shape, it is preferable that the ground planes 50 and 60 are formed to have a diameter larger than a circle of one wavelength.

[0028] The first ground plate 50 is disposed inside the substrate 20 as described above. The first ground plate 50 is disposed facing the patch unit 30 so as to have a predetermined distance between the patch unit 30 in the Z direction. The first ground plate 50 of this embodiment is interposed between the insulating layers 21 and 22. The first ground plate 50 is disposed on the insulating layer 22. The first ground plate 50 has a through hole 51 through which the via conductor 40 is inserted. The through hole 51 is provided so as to include the via conductor 40 in a plan view. The first ground plate 50 is provided away from the via conductor 40. The first ground plate 50 is disposed so as to surround the via conductor 40. The first ground plate 50 faces a portion of the patch unit 30 excluding a portion overlapping with the through hole 51 in a plan view. The first ground plate 50 faces a portion of the transmission line 70 excluding a portion overlapping with the through hole 51 in a plan view.

[0029] The second ground plate 60 is disposed on the substrate 20 so as to face the first ground plate 50 on the opposite side to the patch unit 30 in the Z direction. The second ground plate 60 is disposed so that the first ground plate 50 is located between the patch unit 30. The second ground plate 60 of this embodiment is disposed on the rear surface 20b of the substrate 20, that is, the lower surface of the insulating layer 23. The second ground plate 60 is provided on almost the entire surface of the rear surface 20b. The second ground plate 60 is disposed so as to include the patch unit 30, the via conductor 40, and the transmission line 70 in a plan view. The second ground plate 60 faces the transmission line 70 over the entire length of the transmission line 70.

[0030] The transmission line 70 is a conductor for feeding power to the patch unit 30 through the via conductor 40. A current input to the transmission line 70 propagates through the via conductor 40 to the patch unit 30, exciting the patch unit 30. The transmission line 70 is disposed on the substrate 20 so as to be located between the ground plates 50, 60 in the Z direction. The transmission line 70 is sandwiched between the two ground plates 50, 60 and covered with the substrate 20 including a dielectric, forming a so-called stripline structure.

[0031] The transmission line 70 extends in the X direction. The transmission line 70 is connected to the via conductor 40 and extends from the via conductor 40 to the side surface 20c of the substrate 20. The end of the transmission line 70 opposite to the end connected to the via conductor 40 is exposed from the side surface 20c to enable power feeding. A signal line of a power feeding circuit (not shown) is connected to the transmission line 70.

[0032] The transmission line 70 of this embodiment is interposed between the insulating layers 22 and 23. The transmission line 70 is disposed on the insulating layer 23. The transmission line 70 is also formed, for example, by patterning a metal foil disposed on the substrate 20. The transmission line 70 faces the ground plates 50 and 60 in the Z direction. The transmission line 70 faces the second ground plate 60 over its entire length. The transmission line 70 faces the first ground plate 50 over most of its entire length.

[0033] <Operation of the antenna device> Next, the operation of the antenna device 10 will be described with reference to Figs. 4 to 6. Figs. 4 to 6 all show the results of an electromagnetic field simulation. Fig. 4 shows the electric field strength distribution. Fig. 4(a) shows the electric field strength distribution of a reference example, and Fig. 4(b) shows the electric field strength distribution of this example. Fig. 4 shows the maximum electric field strength when the operating frequency is 77 GHz. Figs. 5 and 6 show the current distribution (magnetic field strength distribution). Fig. 6 shows a state in which the phase of the high frequency signal is shifted by about 90 degrees from that of Fig. 5.

[0034] In the reference example shown in FIG. 4(a), elements that are the same as or related to the elements of this embodiment are indicated by adding r to the end of the reference numerals of this embodiment. In the antenna device 10r of the reference example, a microstrip line structure is adopted as the transmission line 70r. A patch section 30r is arranged on one surface of a substrate 20r, and a transmission line 70r is arranged on the back surface. A ground plate 50r is arranged between the patch section 30r and the transmission line 70r in the Z direction. A via conductor 40r electrically connects the patch section 30r and the transmission line 70r through a through hole 51r of the ground plate 50r.

[0035] The antenna device 10 of this example shown in FIG. 4(b) has the same structure as the antenna device 10 described above. The antenna device 10 of this example is different from the antenna device 10r of the reference example in that it includes a second ground plate 60 and that a substrate 20 (dielectric) is also disposed between the ground plates 50 and 60. Thus, in this example, a stripline structure is adopted for the transmission line 70. The other configurations are the same as those of the antenna device 10r. That is, also in the reference example, the via conductor 40r is offset in the Y direction with respect to the center of the patch section 30r. Also, the transmission line 70r extends in the X direction from the via conductor 40r.

[0036] 4, in this example, the second ground plane 60 is disposed on the back side of the via conductor 40 and the transmission line 70, and therefore the electric field strength on the back side of the via conductor 40 is higher than in the reference example. That is, in this example, the electric field penetrates more to the back side of the via conductor 40 than in the reference example.

[0037] Due to this electric field leakage, for example, at the timing shown in Fig. 5, the current flowing through the via conductor 40 in the X direction is biased. Specifically, as shown in the upper part of Fig. 5, the magnetic field strength on the anti-feed side (the side closer to side 20d) is higher than the magnetic field strength on the feed side (the side closer to side 20c). This causes a potential difference, and the current flowing through the patch unit 30 becomes predominant in the direction perpendicular to the direction of the main polarization, which is the offset direction of the via conductor 40, that is, in the X direction, as shown in the lower part of Fig. 5.

[0038] On the other hand, as shown in Fig. 6, at a timing when the phase is shifted by about 90 degrees, the bias of the current flowing through the via conductor 40 in the X direction is smaller as shown in the upper part of Fig. 6 compared to Fig. 5. Therefore, the current flowing through the patch unit 30 is predominantly in the same direction as the direction of the main polarization, that is, in the Y direction, as shown in the lower part of Fig. 6.

[0039] Although not shown, at a timing when the phase is shifted by approximately 180 degrees from Fig. 5, the current flowing through the patch unit 30 is predominantly in the X direction, which is the opposite direction to Fig. 5. At a timing when the phase is shifted by approximately 270 degrees from Fig. 5, the current flowing through the patch unit 30 is predominantly in the Y direction, which is the opposite direction to Fig. 6.

[0040] In this way, in the patch section 30, a current flowing in the X direction and a current flowing in the Y direction are continuously generated. Therefore, a circularly polarized wave is generated. In the reference example shown in FIG. 4(a), the electric field does not flow around the back side of the via conductor 40r much, so a phenomenon similar to that of the antenna device 10 of the present embodiment could not be confirmed. It should be noted that not only in the configuration shown in FIG. 4(a) but also in a configuration in which the transmission line 70r is arranged on the same plane as the patch section 30r and the via conductor 40r is eliminated, a phenomenon similar to that of the antenna device 10 of the present embodiment could not be confirmed.

[0041] <Via conductor diameter and circular polarization ratio> Next, the relationship between the diameter of the via conductor 40 and the circular polarization ratio will be described with reference to FIG. 7. FIG. 7 also shows the results of an electromagnetic field simulation. λ in FIG. 7 indicates the wavelength of radio waves at the operating frequency. The circular polarization ratio is the difference (dB) between the gain (dBi) of left-handed circular polarization and the gain (dBi) of right-handed circular polarization. The circular polarization ratio is sometimes called the polarization ratio. Left-handed circular polarization is sometimes called left-handed polarization, and right-handed circular polarization is sometimes called right-handed polarization.

[0042] As shown in FIG. 7, when the diameter of the via conductor 40 is λ×1 / 16 or more, the difference between left-handed circular polarization and right-handed circular polarization becomes significant. In other words, the circular polarization ratio can be improved. The circular polarization ratio increases as the diameter of the via conductor 40 increases. In this embodiment, the diameter of the via conductor 40 is set to λ×1 / 16 or more. This allows the antenna device 10 to radiate radio waves with a high circular polarization ratio. In other words, it is possible to radiate left-handed circular polarization or right-handed circular polarization.

[0043] Fig. 8 shows the results of an electromagnetic field simulation. Fig. 8 shows the directivity when the diameter of the via conductor 40 is λ×1 / 4. As shown in Fig. 8, the antenna device 10 has directivity in the Z direction.

[0044] <Summary of the First Embodiment> In this embodiment, as described above, a stripline structure is adopted for the transmission line 70. Moreover, the transmission line 70 is extended in a direction perpendicular to the offset direction of the via conductor 40 with respect to the center 30c of the patch unit 30. This allows the antenna device 10 to radiate a circularly polarized wave without providing a perturbation element such as a notch. In other words, it is possible to radiate a circularly polarized wave with a simple structure.

[0045] Since no perturbation element is provided in the patch unit 30, manufacturing errors that would occur if a perturbation element were provided do not become an issue even in the millimeter wave band. Therefore, the antenna device 10 can exhibit the desired characteristics even in the millimeter wave band, that is, can radiate a circularly polarized wave.

[0046] In this embodiment, the diameter of the via conductor 40 is λ×1 / 16 or more, which can improve the circular polarization ratio, thereby enabling good transmission and reception (communication).

[0047] The position of the patch unit 30 in the Y direction is not particularly limited. For example, it may be arranged so as to be biased toward the side surface 20e, or toward the side surface 20f. It may also be arranged at a position that is approximately equidistant from the side surfaces 20e and 20f.

[0048] Although an example in which the transmission line 70 extends in the X direction toward the side surface 20c has been shown, the present invention is not limited to this example, and the transmission line 70 may extend in the X direction toward the side surface 20d.

[0049] Second embodiment This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used.

[0050] Fig. 9 shows the antenna device 10 of this embodiment. Fig. 9 corresponds to Fig. 2. Fig. 10 shows the arrangement surface of the substrate 20 on which the transmission line 70 is arranged, that is, the upper surface of the insulating layer 23. In Fig. 10, the through hole 51 of the first base plate 50 is indicated by a dashed line.

[0051] 9 and 10, the transmission line 70 has a land 71. The land 71 is provided at a connection portion of the transmission line 70 with the via conductor 40. The land 71 is formed continuously and integrally with other portions of the transmission line 70, for example, by patterning a metal foil. The land 71 has, for example, a substantially circular shape in plan view.

[0052] The land 71 is provided so as to enclose the via conductor 40 in a plan view in the Z direction. As a result, the diameter of the land 71 is larger than the diameter of the via conductor 40. The diameter of the land 71 is longer than the width of the portion of the transmission line 70 excluding the land 71. In other words, in the direction perpendicular to the extension direction of the transmission line 70 (Y direction), the width of the transmission line 70 is widest at the land 71.

[0053] <Summary of the second embodiment> When the area of ​​the patch unit 30 is constant, increasing the diameter of the via conductor 40 can improve the circular polarization ratio, but the opposing area (capacitor) between the patch unit 30 and the first ground plate 50 decreases, resulting in a decrease in gain. In this embodiment, the transmission line 70 has a land 71. By having the land 71, it is possible to improve the circular polarization ratio while suppressing a decrease in gain, even without increasing the diameter of the via conductor 40.

[0054] Fig. 11 shows the results of an electromagnetic field simulation. Fig. 11 shows the directivity of a configuration in which the land 71 is provided. The diameter of the via conductor 40 is set to λ / 8. As shown in Fig. 11, the antenna device 10 has directivity in the Z direction. In addition, the antenna device 10 has a circular polarization ratio equivalent to that of the antenna device 10 without the land 71 and with a via conductor 40 having a diameter of λ / 4 (see Fig. 8).

[0055] Third embodiment This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used.

[0056] Fig. 12 shows the antenna device 10 of this embodiment. Fig. 12 corresponds to Fig. 2. Fig. 13 shows the arrangement surface of the substrate 20 on which the transmission line 70 is arranged, that is, the upper surface of the insulating layer 23. Fig. 13 corresponds to Fig. 10. In Fig. 13, the through hole 51 of the first base plate 50 is also shown by a dashed line.

[0057] 12 and 13, the antenna device 10 further includes a plurality of short-circuiting portions 80 disposed on the substrate 20. The short-circuiting portions 80 are conductors connected to the ground plates 50 and 60, respectively. The multiple short-circuiting portions 80 are disposed so as to surround the via conductor 40 in a plan view.

[0058] The short circuit portion 80 of this embodiment is provided as a via conductor in which a conductor is disposed in a hole (via) formed in the substrate 20. The multiple short circuit portions 80 are disposed in the insulating layers 22 and 23 of the substrate 20. Each short circuit portion 80 extends in the Z direction, with one end connected to the first ground plane 50 and the other end connected to the second ground plane 60. The multiple short circuit portions 80 are disposed on the circumference of a virtual circle (not shown) centered on the via conductor 40 in a plan view. The multiple short circuit portions 80 are disposed such that the intervals between adjacent short circuit portions 80 are substantially equal, except for the portion overlapping with the transmission line 70. The intervals between adjacent short circuit portions 80 are λ / 4 or less. The short circuit portion 80 may be referred to as a short circuit element, a short circuit via, or the like.

[0059] <Summary of the third embodiment> According to this embodiment, the shielding effect of the short-circuit portion 80 can prevent the electric field that wraps around the back side of the via conductor 40 from leaking out to the surroundings. This can improve the gain. Also, the circular polarization ratio can be increased.

[0060] <Modification> The antenna device 10 may include a land 71 together with a plurality of short-circuit portions 80, as shown in Fig. 14 and Fig. 15, for example. Fig. 14 corresponds to Fig. 12, and Fig. 15 corresponds to Fig. 13. In the example shown in Fig. 14 and Fig. 15, a land 81 that electrically connects the plurality of short-circuit portions 80 is provided on the same plane as the transmission line 70. The plurality of short-circuit portions 80 and the land 81 are arranged so as to surround the via conductor 40 and the land 71 in a plan view. The land 81 has a substantially C-shape in plan view, and the transmission line 70 is arranged in the gap portion of the C shape.

[0061] Fig. 16 shows the results of an electromagnetic field simulation of the configuration shown in Fig. 14 and Fig. 15. Here again, the diameter of the via conductor 40 is set to λ / 8. As shown in Fig. 16, the antenna device 10 has directivity in the Z direction. In addition, the antenna device 10 has the land 71, does not have the short-circuit portion 80, and exhibits a higher circular polarization ratio than the antenna device 10 having the via conductor 40 with a diameter of λ / 8 (see Fig. 11). Furthermore, the gain is also improved.

[0062] (Fourth embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used.

[0063] Fig. 17 shows the arrangement surface of the substrate 20 on which the transmission line 70 is arranged, that is, the upper surface of the insulating layer 23, in the antenna device 10 of this embodiment. Fig. 17 corresponds to Fig. 10. In Fig. 17 as well, the through hole 51 of the first base plate 50 is indicated by a dashed line.

[0064] As shown in Fig. 17, the antenna device 10 has a similar configuration to the preceding embodiment (see Fig. 15). Unlike the preceding embodiment, the transmission line 70 of the antenna device 10 has a transmission line 701 extending from the via conductor 40 in the X direction, and a transmission line 702 extending from the via conductor 40 in the opposite direction to the transmission line 701. The transmission line 701 corresponds to a first transmission line, and the transmission line 702 corresponds to a second transmission line. Then, it is possible to switch between power supply to the patch unit 30 by the transmission line 701 and power supply to the patch unit 30 by the transmission line 702.

[0065] In this embodiment, the transmission line 701 extends in the X direction from the via conductor 40 toward the side surface 20c. The transmission line 702 extends in the X direction from the via conductor 40 toward the side surface 20d. The end of the transmission line 701 on the side surface 20c side forms a first port (Port1) for power supply, and the end of the transmission line 702 on the side surface 20d side forms a second port (Port2) for power supply. Power supply to the first port and the second port can be switched. When power is supplied to the first port of the first and second ports, a current flows through the patch unit 30 via the transmission line 701 and the via conductor 40. When power is supplied to the second port of the first and second ports, a current flows through the patch unit 30 via the transmission line 702 and the via conductor 40. In this way, the power supply direction can be switched. The other configurations are the same as those described in the preceding embodiment.

[0066] The antenna device 10 may further include a power supply control unit 90 for switching power supply. The power supply control unit 90 controls power supply to the multiple transmission lines 70. At least some of the elements constituting the power supply control unit 90 may be mounted on the substrate 20. The power supply control unit 90 has, for example, switches 901 and 902 and a switch control unit 903. The switch 901 is connected to a first port of the transmission line 701, and switches the connection state between the transmission line 701 and the power supply circuit between conduction and cut-off. When the switch 901 is turned on, the transmission line 701 is brought into a conduction state with the power supply circuit, and a current is input from the power supply circuit to the transmission line 701. When the switch 901 is turned off, power supply from the power supply circuit to the transmission line 701 is cut off.

[0067] The switch 902 is connected to a second port of the transmission line 702, and switches the connection state between the transmission line 702 and the power supply circuit between conductive and cut-off. When the switch 902 is turned on, the transmission line 702 is brought into a conductive state with the power supply circuit, and a current is input from the power supply circuit to the transmission line 702. When the switch 902 is turned off, the power supply from the power supply circuit to the transmission line 702 is cut off. For example, a MOSFET or the like can be used as the switches 901 and 902. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor.

[0068] The switch control unit 903 controls the on / off of the switches 901 and 902. The switch control unit 903 controls the on / off of all the switches 901 and 902 in response to an instruction signal from the outside, so that one of the switches 901 and 902 is turned on and the other is turned off.

[0069] 18 shows the results of an electromagnetic field simulation of the above-mentioned antenna device 10. Here again, the diameter of the via conductor 40 is set to λ / 8. In both cases of feeding power to Port 1 and feeding power to Port 2, the antenna device 10 has directivity in the Z direction. When feeding power to Port 1, left-handed circularly polarized waves become dominant, and when feeding power to Port 2, right-handed circularly polarized waves become dominant.

[0070] <Summary of the Fourth Embodiment> According to this embodiment, in addition to achieving the effects described in the preceding embodiments, it is possible to switch between left-handed circularly polarized waves and right-handed circularly polarized waves.

[0071] The configuration of the antenna device 10 is not limited to the example shown in FIG. 17. It can be combined with any of the configurations shown in the preceding embodiments. For example, in a configuration that does not include the land 71 and the short-circuiting unit 80, the transmission lines 701 and 702 and the power supply control unit 90 may be provided. In a configuration that includes the land 71 and does not include the short-circuiting unit 80, the transmission lines 701 and 702 and the power supply control unit 90 may be provided. In a configuration that includes the short-circuiting unit 80 and does not include the land 71, the transmission lines 701 and 702 and the power supply control unit 90 may be provided.

[0072] Fifth embodiment This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used.

[0073] Fig. 19 shows the arrangement surface of the substrate 20 on which the transmission line 70 is arranged, that is, the upper surface of the insulating layer 23, in the antenna device 10 of this embodiment. Fig. 19 corresponds to Fig. 10. In Fig. 19 as well, the through hole 51 of the first base plate 50 is indicated by a dashed line.

[0074] As shown in Fig. 19, the antenna device 10 has a similar configuration to the preceding embodiment (see Fig. 15). Unlike the preceding embodiment, the antenna device 10 includes a transmission line 75 extending in the Y direction from the via conductor 40 in addition to the transmission line 70. The transmission line 75 is located between the ground plates 50 and 60 in the Z direction. The transmission line 70 corresponds to the third transmission line, and the transmission line 75 corresponds to the fourth transmission line. Then, it is possible to switch between power supply to the patch unit 30 by the transmission line 70 and power supply to the patch unit 30 by the transmission line 75.

[0075] In this embodiment, the transmission line 75 extends in the Y direction from the via conductor 40 toward the side surface 20f. The end of the transmission line 70 on the side surface 20c forms a first port (Port1) for power supply, and the end of the transmission line 75 on the side surface 20f forms a second port (Port2) for power supply. Power supply to the first port and the second port can be switched. When power is supplied to the first port of the first and second ports, a current flows through the patch unit 30 via the transmission line 70 and the via conductor 40. When power is supplied to the second port of the first and second ports, a current flows through the patch unit 30 via the transmission line 75 and the via conductor 40. In this way, the power supply direction can be switched. The other configurations are the same as those described in the preceding embodiment.

[0076] The antenna device 10 may further include a power supply control unit 91 for switching the power supply, as in the fourth embodiment. The power supply control unit 91 controls the power supply to the transmission lines 70 and 75. At least some of the elements constituting the power supply control unit 91 may be mounted on the substrate 20. The power supply control unit 91 has, for example, switches 911 and 912 and a switch control unit 913. The switch 911 is connected to a first port of the transmission line 70, and switches the connection state between the transmission line 70 and the power supply circuit between conduction and cut-off. When the switch 911 is turned on, the transmission line 70 is brought into a conduction state with the power supply circuit, and a current is input from the power supply circuit to the transmission line 70. When the switch 911 is turned off, power supply from the power supply circuit to the transmission line 70 is cut off.

[0077] The switch 912 is connected to the second port of the transmission line 75, and switches the connection state between the transmission line 75 and the power feed circuit between conductive and cut-off. When the switch 912 is turned on, the transmission line 75 is brought into a conductive state with the power feed circuit, and a current is input from the power feed circuit to the transmission line 75. When the switch 912 is turned off, the power supply from the power feed circuit to the transmission line 75 is cut off.

[0078] The switch control unit 913 controls the on / off of the switches 911 and 912. The switch control unit 913 controls the on / off of all the switches 911 and 912 in response to an external instruction signal so that one of the switches 911 and 912 is turned on and the other is turned off.

[0079] 20 shows the results of an electromagnetic field simulation of the above-mentioned antenna device 10. Here again, the diameter of the via conductor 40 is set to λ / 8. When power is fed to Port 1, the antenna device 10 has directivity in the Z direction. The antenna device 10 radiates a circularly polarized wave. When power is fed to Port 2, the antenna device 10 has directivity in the Z direction. The antenna device 10 radiates a linearly polarized wave.

[0080] <Summary of the Fifth Embodiment> According to this embodiment, in addition to achieving the effects described in the preceding embodiments, it is possible to switch between circular polarization and linear polarization.

[0081] The configuration of the antenna device 10 is not limited to the example shown in FIG. 19. It can be combined with any of the configurations shown in the preceding embodiments. For example, in a configuration that does not include the land 71 and the short-circuiting portion 80, the transmission lines 70 and 75 and the power supply control portion 91 may be provided. In a configuration that includes the land 71 and does not include the short-circuiting portion 80, the transmission lines 70 and 75 and the power supply control portion 91 may be provided. In a configuration that includes the short-circuiting portion 80 and does not include the land 71, the transmission lines 70 and 75 and the power supply control portion 91 may be provided.

[0082] Although an example in which the transmission line 70 extends in the X direction toward the side surface 20c has been shown, the present invention is not limited thereto. The transmission line 70 may extend in the X direction toward the side surface 20d. Although an example in which the transmission line 75 extends in the Y direction toward the side surface 20f has been shown, the present invention is not limited thereto. The transmission line 75 may extend in the Y direction toward the side surface 20e.

[0083] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and / or elements of the embodiments. The disclosure includes the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0084] The disclosure in the specification and drawings is not limited by the claims. The disclosure in the specification and drawings includes the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification and drawings without being bound by the claims.

[0085] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, there are no intervening elements or layers. Other words used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0086] Spatially relative terms such as "inside," "outside," "back," "below," "low," "top," "top," and the like are utilized herein to facilitate the description of the relationship of one element or feature to another element or feature as depicted in the figures. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "directly below" other elements or features would be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this specification would be interpreted accordingly. [Explanation of symbols]

[0087] Reference Signs List 10...antenna device, 20...substrate, 20a...one side, 20b...rear side, 20c, 20d, 20e, 20f...side, 21, 22, 23...insulating layer, 30...patch portion, 30c...center, 40...via conductor, 50...first ground plate, 51...through hole, 60...second ground plate, 70, 701, 702, 75...transmission line, 71...land, 80...short circuit portion, 81...land, 90, 91...power supply control portion, 901, 902, 911, 912...switch, 903, 913...switch control portion

Claims

1. A substrate (20) including a dielectric material; A patch portion (30) disposed on the substrate; a via conductor (40) disposed on the substrate, extending in a thickness direction of the substrate, and connected to the patch portion at a position shifted a predetermined distance in a first direction perpendicular to the thickness direction from a center (30c) of the patch portion in a plan view in the thickness direction; a first ground plate (50) having a through hole (51) through which the via conductor is inserted and disposed on the substrate so as to face the patch portion in the plate thickness direction; a second base plate (60) disposed on the substrate so as to face the first base plate on the opposite side to the patch portion in the plate thickness direction; A transmission line (70) is disposed on the substrate so as to be located between the first ground plane and the second ground plane in the plate thickness direction, and is connected to the via conductor and extends from the via conductor in a second direction perpendicular to the plate thickness direction and the first direction (excluding a case where a plurality of patch portions are arranged in the first direction when viewed in a plan view in the plate thickness direction). An antenna device comprising:

2. A substrate (20) including a dielectric material; A patch portion (30) disposed on the substrate; a via conductor (40) disposed on the substrate, extending in a thickness direction of the substrate, and connected to the patch portion at a position shifted a predetermined distance in a first direction perpendicular to the thickness direction from a center (30c) of the patch portion in a plan view in the thickness direction; a first ground plate (50) having a through hole (51) through which the via conductor is inserted and disposed on the substrate so as to face the patch portion in the plate thickness direction; a second base plate (60) disposed on the substrate so as to face the first base plate on the opposite side to the patch portion in the plate thickness direction; a transmission line (70) disposed on the substrate so as to be located between the first ground plane and the second ground plane in the plate thickness direction, connected to the via conductor, and extending from the via conductor in a second direction perpendicular to the plate thickness direction and the first direction; An antenna device comprising:

3. An antenna device as described in claim 1 or claim 2, wherein the transmission line extends in a straight line along the second direction from the via conductor to the end of the substrate.

4. If the wavelength of the radio wave at the operating frequency is λ, then The antenna device according to any one of claims 1 to 3, wherein the via conductor has a diameter of λ×1 / 16 or more.

5. The antenna device according to any one of claims 1 to 4, wherein the transmission line has a land (71) at a connection portion with the via conductor, the land (71) being arranged so as to include the via conductor in a plan view in the plate thickness direction.

6. The transmission line includes a first transmission line (701) extending from the via conductor in the second direction, and a second transmission line (702) extending from the via conductor in a direction opposite to the first transmission line, 6. The antenna device according to claim 1, wherein the power supply to the patch unit via the first transmission line and the power supply to the patch unit via the second transmission line are switchable.

7. A fourth transmission line (75) is disposed on the substrate separately from the third transmission line, which is the transmission line, so as to be located between the first ground plane and the second ground plane in the plate thickness direction, and is connected to the via conductor and extends from the via conductor in the first direction; 6. The antenna device according to claim 1, wherein the power supply to the patch unit via the third transmission line and the power supply to the patch unit via the fourth transmission line are switchable.

8. The antenna device according to any one of claims 1 to 7, further comprising a plurality of short-circuiting portions (80) connected to the first ground plane and the second ground plane, respectively, and arranged on the substrate so as to surround the via conductor in a plan view in the plate thickness direction.

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