Antenna device

Abstract

An array antenna (1) having element antennas (11) periodically arranged at element intervals (102a, 102b) along an element array axis (101a, 101b), and apertures (22) arranged at aperture intervals (104a, 104b) that are 1 / n (where n is an integer of 2 or more) of the element intervals (102a, 102b) along an aperture array axis (103a, 103b) in the same direction as the element array axis (101a, 101b), and a dielectric (21) arranged to face the array antenna (1) in a direction orthogonal to the element array axis (101a, 101b).

Description

Technical Field

[0001] The present disclosure relates to an antenna device including an array antenna.

Background Art

[0002] Conventionally, as an antenna device including a thin and broadband array antenna, a tightly coupled dipole array has been known (see, for example, Patent Document 1).

[0003] The tightly coupled dipole array described in this Patent Document 1 is composed of a feed line, a balun, a dipole, and a matching layer. Further, the balun is composed of an open stub and a short stub. In this tightly coupled dipole array, a high-frequency signal is fed by the feed line, and the dipole is differentially excited by the balun. Further, in this tightly coupled dipole array, a matching layer is provided above the dipole in order to operate the antenna in a broadband. Further, in this tightly coupled dipole array, generally, a dielectric having a low relative dielectric constant is used as the matching layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Thus, in the matching layer used for broadbanding, generally, a dielectric having a low relative dielectric constant is used. However, a dielectric having a low relative dielectric constant is expensive and difficult to obtain. Therefore, in an antenna device including a matching layer using such a dielectric having a low relative dielectric constant, an increase in manufacturing cost becomes a problem. Also, depending on the configuration of the antenna device, the relative permittivity of the matching layer required for a wide band varies. Therefore, depending on the configuration of the antenna device, there may be no dielectric having a desired relative permittivity, and narrowing the operating frequency band may become an issue.

[0006] The present disclosure has been made to solve the above-described problems, and an object thereof is to provide an antenna device that can achieve a wide bandwidth at low cost as compared with the prior art.

Means for Solving the Problems

[0007] The antenna device according to the present disclosure includes an array antenna having element antennas periodically arranged at a first interval along a first array axis, and a hole arranged at a second interval that is 1 / n (n is an integer of 2 or more) of the first interval along a second array axis that is in the same direction as the first array axis, and a dielectric arranged to face the array antenna in a direction orthogonal to the first array axis.

Effects of the Invention

[0008] According to the present disclosure, since it is configured as described above, it is possible to achieve a wide bandwidth at low cost as compared with the prior art.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. Embodiment 1. FIG. 1 is a perspective view showing a configuration example of an antenna device according to Embodiment 1. FIG. 2 is a top view showing a configuration example of the array antenna 1 in Embodiment 1. FIG. 3 is a top view showing a configuration example of the matching layer 2 in Embodiment 1.

[0011] As shown in FIGS. 1 to 3, the antenna device includes an array antenna 1 and a matching layer 2.

[0012] As shown in FIGS. 1 and 2, the array antenna 1 has a plurality of element antennas 11.

[0013] The element antennas 11 are periodically arranged at a predetermined element interval (first interval) 102a, 102b along element array axes (first array axes) 101a, 101b. FIG. 1 shows a case where the arrangement of the element antennas 11 is a square arrangement. That is, in FIG. 1, the element array axis 101a and the element array axis 101b are arranged to be orthogonal.

[0014] The matching layer 2 is arranged to face the array antenna 1 in a direction orthogonal (including the meaning of substantially orthogonal) to the element array axes 101a, 101b. In FIG. 1, the matching layer 2 is arranged above the array antenna 1. As shown in FIGS. 1 and 3, this matching layer 2 has a configuration in which a plurality of holes 22 are provided in a dielectric 21.

[0015] The holes 22 provided in the dielectric 21 are periodically arranged along the hole array axes (second array axes) 103a and 103b at a predetermined hole interval (second interval) 104a and 104b. The hole array axes 103a and 103b are array axes in the same (including substantially the same meaning) direction as the element array axes 101a and 101b. The hole intervals 104a and 104b are 1 / n (n is an integer of 2 or more) of the element intervals 102a and 102b. In FIG. 1, the case where the array of the holes 22 is a square array is shown. That is, in FIG. 1, the hole array axis 103a and the hole array axis 103b are arranged to be orthogonal. Further, in FIG. 1, the case where the shape of the hole 22 is circular is shown. Also, in FIG. 1, the case where the hole intervals 104a and 104b are 1 / 2 of the element intervals 102a and 102b is shown.

[0016] Generally, an array antenna is configured by arranging a large number of unit cells which are the minimum units. In the antenna device according to the first embodiment, the unit cell 10 is as shown in FIGS. 1 and 4, for example.

[0017] Next, the effects of the antenna device according to the first embodiment will be described. When the characteristic impedance in free space is defined as η, the characteristic impedance in the matching layer is inversely proportional to √(εr). Here, εr represents the relative permittivity of the matching layer. Therefore, by adjusting the relative permittivity or thickness of the matching layer 2, the input impedance seen from the matching layer to free space can be controlled. By adjusting this input impedance to a value suitable for broadbanding of the array antenna, broadbanding of the antenna device can be achieved. Also, even when controlling the phase excited in the element antenna and performing beam scanning in a wide-angle direction, by adjusting the input impedance seen from the matching layer to free space, matching design can be performed and the coverage area of the array antenna can be expanded.

[0018] Note that, in order to adjust the input impedance, the relative permittivity and thickness in the matching layer are used as parameters. Depending on the configuration of the antenna device, the relative permittivity and thickness in the matching layer required for broadbanding are different, and generally, a low relative permittivity is required.

[0019] Conventionally, as described in Patent Document 1, a dielectric with a low relative permittivity has been used as this matching layer. Since such a dielectric with a low relative permittivity is expensive and difficult to obtain, an increase in the manufacturing cost of the antenna device becomes an issue.

[0020] On the other hand, in the antenna device according to Embodiment 1, by using a dielectric 21 provided with a plurality of holes 22 as the matching layer 2, it is possible to lower the effective relative permittivity of the matching layer 2. By using such a dielectric 21 having holes 22, in the antenna device according to Embodiment 1, even if a dielectric having a relatively high relative permittivity generally used as the dielectric 21 is used, it is possible to realize a matching layer 2 with a low relative permittivity. As a result, in the antenna device according to Embodiment 1, the manufacturing cost can be improved compared to the conventional case.

[0021] In addition, depending on the configuration of the antenna device, there may be no dielectric having a desired relative permittivity required for broadbanding, and narrowing of the operating frequency band may become an issue. On the other hand, in the antenna device according to Embodiment 1, it is possible to control the effective permittivity in the matching layer 2 by adjusting the shape of the holes 22 provided in the dielectric 21. Thereby, in the antenna device according to Embodiment 1, it is possible to realize a matching layer 2 having an effective permittivity suitable for broadbanding. As a result, in the antenna device according to Embodiment 1, broadbanding can be achieved compared to the conventional case.

[0022] Further, if the hole intervals 104a and 104b are equal to the element intervals 102a and 102b, that is, when corresponding to n = 1, in order to obtain the matching layer 2 with a low effective dielectric constant, it is necessary to increase the size of the holes 22. In this case, the shape of the holes 22 may be about the wavelength. When the shape of the holes 22 is about the wavelength, frequency characteristics occur in the effective dielectric constant in the matching layer 2, and the antenna device may have a narrow bandwidth. Therefore, in the antenna device according to the first embodiment, the hole intervals 104a and 104b are set to an interval of 1 / n (where n is an integer of 2 or more) of the element intervals 102a and 102b. Thereby, in the antenna device according to the first embodiment, it is possible to make the shape of the holes 22 equal to or less than the wavelength, and it is possible to reduce the frequency characteristics of the effective dielectric constant in the matching layer 2.

[0023] In addition, in FIG. 3, the case where the shape of the holes 22 provided in the matching layer 2 is circular and the arrangement of the holes 22 is a square arrangement is shown. However, the shape and arrangement of the holes 22 are not limited to this. For example, FIG. 5 shows the case where the shape of the holes 22 provided in the matching layer 2 is rectangular. Further, for example, FIG. 6 shows the case where the shape of the holes 22 provided in the matching layer 2 is hexagonal. Thus, even when the shape of the holes 22 is not circular, the same effects as described above can be obtained. Further, for example, FIG. 7 shows the case where the arrangement of the holes 22 provided in the matching layer 2 is a triangular arrangement. Thus, even when the arrangement of the holes 22 is not a square arrangement, the same effects as described above can be obtained.

[0024] As described above, according to the first embodiment, the antenna device includes an array antenna 1 having element antennas 11 periodically arranged at element intervals 102a and 102b along element array axes 101a and 101b, and holes 22 arranged at hole intervals 104a and 104b that are 1 / n (n is an integer of 2 or more) of the element intervals 102a and 102b along hole array axes 103a and 103b that are in the same direction as the element array axes 101a and 101b, and a dielectric 21 disposed opposite to the array antenna 1 in a direction orthogonal to the element array axes 101a and 101b. Thereby, the antenna device according to the first embodiment can achieve broadband characteristics at a lower cost compared to the prior art. That is, in the antenna device according to the first embodiment, the dielectric 21 provided with a plurality of holes 22 is used as the matching layer 2. Thereby, in the antenna device according to the first embodiment, it is possible to reduce the effective relative permittivity in the matching layer 2. Therefore, in the antenna device according to the first embodiment, even when using a dielectric having a relatively high relative permittivity generally used as the dielectric 21, it is possible to realize a matching layer 2 having a low relative permittivity, and it is possible to improve the manufacturing cost compared to the prior art. In addition, in the antenna device according to the first embodiment, by adjusting the shape of the holes 22 provided in the dielectric 21, it is possible to control the effective permittivity in the matching layer 2. Therefore, in the antenna device according to the first embodiment, it is possible to realize a matching layer 2 suitable for broadband characteristics, and it is possible to achieve broadband characteristics compared to the prior art. In addition, in the antenna device according to the first embodiment, the hole intervals 104a and 104b are set to 1 / n (n is an integer of 2 or more) of the element intervals 102a and 102b. Thereby, in the antenna device according to the first embodiment, it is possible to make the shape of the holes 22 less than the wavelength, and it is possible to reduce the frequency characteristics of the effective permittivity in the matching layer 2.

[0025] Second Embodiment. FIG. 8 is a perspective view showing a configuration example of a unit cell 10 in the antenna device according to the second embodiment. FIG. 9 is an exploded perspective view showing a configuration example of the unit cell 10 in the antenna device according to the second embodiment. In the antenna device according to Embodiment 2, the case where a closely coupled dipole is applied as the element antenna 11 with respect to the antenna device according to Embodiment 1 is shown. Regarding other configuration examples in the antenna device according to Embodiment 2, they are the same as the configuration examples of the antenna device according to Embodiment 1, and the same reference numerals are given and the description thereof is omitted.

[0026] As shown in FIGS. 8 and 9, the element antenna 11 in Embodiment 2 has a metal plate 111 and a dielectric substrate 112.

[0027] The metal plate 111 is arranged along the element array axes 101a, 101b. A slot 113 is formed in this metal plate 111 to enable insertion of the dielectric substrate 112. In FIG. 8, the slot 113 is formed along the element array axis 101b.

[0028] The dielectric substrate 112 is inserted into the metal plate 111 by the slot 113 and is arranged in a direction orthogonal (including the meaning of substantially orthogonal) to the element array axes 101a, 101b (metal plate 111). In FIG. 8, the dielectric substrate 112 is arranged along the element array axis 101b.

[0029] Next, a configuration example of the dielectric substrate 112 will be described. FIG. 10 is a side view showing a configuration example of one layer of the dielectric substrate 112 in Embodiment 2, and FIG. 11 is a side view showing a configuration example of the other layer of the dielectric substrate 112 in Embodiment 2.

[0030] As shown in FIGS. 9 to 11, a power supply line 1121, a ground 1122, a balun 1123, a dipole 1124, and a coupling conductor pattern 1125 are formed on the dielectric substrate 112. Also, in FIGS. 9 to 11, the balun 1123 is composed of an open stub 11231 and a short stub 11232.

[0031] The power supply line 1121 is a metal conductor provided on one surface of the dielectric substrate 112. This power supply line 1121 is a line for supplying a high-frequency signal. The ground 1122 is a metal conductor provided on one surface of the dielectric substrate 112. The open stub 11231 is a metal conductor provided on one surface of the dielectric substrate 112. One end of this open stub 11231 is connected to one end of the power supply line 1121. The short stub 11232 is provided on the other surface of the dielectric substrate 112. The dipole 1124 is a metal conductor provided on the other surface of the dielectric substrate 112. The coupling conductor pattern 1125 is a conductor provided on one surface of the dielectric substrate 112 at a position overlapping two adjacent dipoles 1124 (see FIG. 13).

[0032] In this dielectric substrate 112, a high-frequency signal is supplied by the power supply line 1121, and the dipole 1124 is differentially excited by the balun 1123. Also, in this dielectric substrate 112, in order to enhance the coupling between adjacent dipoles 1124, the coupling conductor pattern 1125 is formed so as to overlap the dipole 1124 via the dielectric substrate 112.

[0033] Next, the effects of the antenna device according to the second embodiment will be described. FIG. 12 is a perspective view showing an example of the current distribution on the dipole 1124 when the coupling conductor pattern 1125 is not provided on the dielectric substrate 112. FIG. 13 is a perspective view showing an example of the current distribution on the dipole 1124 when the coupling conductor pattern 1125 is provided on the dielectric substrate 112. However, in FIGS. 12 and 13, the matching layer 2 is not shown.

[0034] As shown in FIG. 12, when the bonding conductor pattern 1125 is not provided on the dielectric substrate 112, the tip of the dipole 1124 is electrically open. Therefore, in this case, the current distribution 105 at the tip of the dipole 1124 becomes a low value, and resonance occurs at a frequency at which the dipole length is approximately 1 / 2 of the wavelength. As a result, the antenna device has narrow-band electrical characteristics.

[0035] On the other hand, as shown in FIG. 13, when the bonding conductor pattern 1125 is provided on the dielectric substrate 112, the adjacent dipoles 1124 are electromagnetically coupled by this bonding conductor pattern 1125, and the tip of the dipole 1124 is not electrically open. Therefore, in this case, not only at the frequency at which the dipole length is approximately 1 / 2 of the wavelength, but also a wide-band antenna that operates over a wide band is obtained.

[0036] In FIG. 9, the case where the balun 1123 is composed of the open stub 11231 and the short stub 11232 is shown. However, the configuration example of the balun 1123 is not limited to this. For example, as the balun 1123, even if a tapered balun in which the shape of the feeding line 1121 is changed in a tapered shape is used, the dipole 1124 can be excited differentially, and the same effect as described above can be obtained.

[0037] As described above, according to the second embodiment, the element antenna 11 includes a metal plate 111 arranged along the element array axes 101a and 101b, and a dielectric substrate 112 having a dipole 1124 that is a metal conductor on one surface and is inserted into the metal plate 111 and arranged in a direction orthogonal to the element array axes 101a and 101b. Further, the dielectric substrate 112 has a bonding conductor pattern 1125 that is a metal conductor at a position on the other surface that overlaps two adjacent dipoles 1124. Thereby, in addition to the effects in the first embodiment, the antenna device according to the second embodiment can be made more wide-band.

[0038] Embodiment 3. FIG. 14 is a perspective view showing a configuration example of a unit cell 10 in the antenna device according to Embodiment 3. FIG. 15 is an exploded perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 3. Further, FIG. 16 is a side view showing a configuration example of one layer of the dielectric substrate 112 in Embodiment 3, and FIG. 17 is a side view showing a configuration example of the other layer of the dielectric substrate 112 in Embodiment 3. In the antenna device according to Embodiment 3, a short-circuit conductor pattern 1126 is formed on the dielectric substrate 112 with respect to the antenna device according to Embodiment 2. Regarding other configuration examples in the antenna device according to Embodiment 3, they are the same as the configuration examples of the antenna device according to Embodiment 2, and the same reference numerals are given and the description thereof is omitted.

[0039] The short-circuit conductor pattern 1126 is a metal conductor provided on one surface of the dielectric substrate 112. One end of this short-circuit conductor pattern 1126 is connected to the bonding conductor pattern 1125, and the other end is connected to the ground 1122.

[0040] Next, the effects of the antenna device according to Embodiment 3 will be described. FIG. 18 is a side view showing an example of the current distribution on the balun 1123 when the short-circuit conductor pattern 1126 is not provided on the dielectric substrate 112. FIG. 19 is a side view showing an example of the current distribution on the balun 1123 when the short-circuit conductor pattern 1126 is provided on the dielectric substrate 112.

[0041] The balun 1123 is provided to differentially excite the dipole 1124. However, as shown in FIG. 18 for example, not only the differential mode but also a part of the common-mode current 106 is generated in the balun 1123. This common-mode current 106 resonates at a frequency at which the interval of the balun 1123 is approximately 1 / 2 of the wavelength, and due to this common-mode resonance, the dipole 1124 is not differentially excited. As a result, the electrical characteristics of the antenna device are significantly deteriorated.

[0042] As a method for reducing the influence of this common-mode resonance, it is known that connecting the dipole and the ground with a short-circuit conductor pattern is effective. However, when a short-circuit conductor pattern is connected to the dipole, the electrical characteristics of the dipole fluctuate.

[0043] Therefore, in the antenna device according to Embodiment 3, the short-circuit conductor pattern 1126 is used to connect the coupling conductor pattern 1125 and the ground 1122. As a result, for example, as shown in FIG. 19, current flows through the short-circuit conductor pattern 1126. Then, the common-mode current 106 is canceled by the current flowing through the short-circuit conductor pattern 1126, and the influence of the common-mode resonance is reduced. As a result, in the antenna device according to Embodiment 3, it is possible to suppress the deterioration of the electrical characteristics. Also, in the antenna device according to Embodiment 3, it is possible to suppress fluctuations in the electrical characteristics of the dipole 1124.

[0044] As described above, according to this Embodiment 3, the dielectric substrate 112 has, on the other surface, a short-circuit conductor pattern 1126 which is a metal conductor with one end connected to the coupling conductor pattern 1125 and the other end connected to the ground 1122. Thereby, in addition to the effects in Embodiment 2, the antenna device according to Embodiment 3 reduces the influence of the common-mode resonance and enables a wider bandwidth.

[0045] Embodiment 4. FIG. 20 is a perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 4. FIG. 21 is an exploded perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 4. Also, FIG. 22 is a side view showing a configuration example of one layer of the dielectric substrate 112 in Embodiment 4, and FIG. 23 is a side view showing a configuration example of the other layer of the dielectric substrate 112 in Embodiment 4. In the antenna device according to Embodiment 4, a resistor 1127 is interposed in the short-circuit conductor pattern 1126 with respect to the antenna device according to Embodiment 3. Regarding other configuration examples in the antenna device according to Embodiment 4, they are the same as the configuration examples of the antenna device according to Embodiment 3, and the same reference numerals are given and the description thereof is omitted.

[0046] The resistor 1127 is provided on one surface of the dielectric substrate 112. This resistor 1127 is interposed in the short-circuit conductor pattern 1126. In the antenna devices shown in FIGS. 20 to 23, the resistor 1127 is provided at the other end of the short-circuit conductor pattern 1126. That is, in the antenna devices shown in FIGS. 20 to 23, one end of the resistor 1127 is connected to the other end of the short-circuit conductor pattern 1126, and the other end of the resistor 1127 is connected to the ground 1122.

[0047] Next, the effects of the antenna device according to Embodiment 4 will be described. FIG. 24 is a side view showing an example of the current distribution when the resistor 1127 is not provided on the dielectric substrate 112. FIG. 24 is a side view showing an example of the current distribution when the resistor 1127 is provided on the dielectric substrate 112.

[0048] As shown in FIG. 24, when the coupling conductor pattern 1125 and the ground 1122 are connected by the short-circuit conductor pattern 1126, a loop current 107a flowing through the balun 1123 and a loop current 107b flowing through the short-circuit conductor pattern 1126 are formed. In this case, one loop current 107a excites the other loop current 107b, and this loop current 107b resonates. As a result, the antenna characteristics of the antenna device deteriorate.

[0049] Therefore, in the antenna device according to Embodiment 4, a resistor 1127 is interposed in the short-circuit conductor pattern 1126. Thereby, for example, as shown in FIG. 25, the loop current 107b flowing through the short-circuit conductor pattern 1126 is suppressed, and it becomes possible to reduce the influence of this loop resonance.

[0050] As described above, according to this Embodiment 4, a resistor 1127 is interposed in the short - circuit conductor pattern 1126. As a result, in addition to the effects in Embodiment 3, the influence of loop resonance in the antenna device according to Embodiment 4 is reduced, and a wider bandwidth can be achieved.

[0051] Embodiment 5. FIG. 26 is a perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 5. FIG. 27 is an exploded perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 5. Further, FIG. 28 is a side view showing a configuration example of one layer of the dielectric substrate 112 in Embodiment 5, and FIG. 29 is a side view showing a configuration example of the other layer of the dielectric substrate 112 in Embodiment 5. In the antenna device according to Embodiment 5, a plurality of holes 1128 are provided in the ground of the power - supply line 1121 with respect to the antenna device according to Embodiment 4. Regarding other configuration examples in the antenna device according to Embodiment 5, they are the same as the configuration examples of the antenna device according to Embodiment 4, and the same reference numerals are given and their descriptions are omitted.

[0052] The holes 1128 are provided in plurality on the other surface of the dielectric substrate 112 and in the ground of the power - supply line 1121.

[0053] Next, the effects of the antenna device according to Embodiment 4 will be described. In unbalanced lines such as microstrip lines, strip lines, or coplanar lines, which are typical power - supply lines, generally, the wider the distance between the signal line and the ground, the higher the characteristic impedance. Therefore, by providing holes in the ground of the signal line, the distance between the signal line and the ground is increased, and the characteristic impedance of the power - supply line can be increased. On the other hand, in this case, it is known that the input impedance of the tightly - coupled dipole coupled to the adjacent dipole is approximately 200Ω.

[0054] Therefore, in the antenna device according to Embodiment 5, a power supply line 1121 provided with a plurality of holes 1128 in the ground is used. As a result, it becomes possible to excite the dipole 1124 with a power supply line 1121 having a characteristic impedance close to the input impedance of the closely coupled dipole, that is, a power supply line 1121 having a high characteristic impedance. As a result, in the antenna device according to Embodiment 5, it becomes possible to configure a wider-band antenna.

[0055] As described above, according to this Embodiment 5, the dielectric substrate 112 has, on one surface, a power supply line 1121 for supplying a high-frequency signal for exciting the dipole 1124, and the power supply line 1121 is provided with a plurality of holes 1128 in the ground. As a result, in addition to the effects in Embodiment 4, the antenna device according to Embodiment 5 can be made wider-band.

[0056] Embodiment 6. FIG. 30 is a perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 6. FIG. 31 is an exploded perspective view showing a configuration example of the unit cell 10 in the antenna device according to Embodiment 6. In the antenna device according to Embodiment 6, a horizontally polarized wave element (first dielectric substrate) 112a and a vertically polarized wave element (second dielectric substrate) 112b are provided as the dielectric substrate 112 with respect to the antenna device according to Embodiment 5. Regarding other configuration examples in the antenna device according to Embodiment 6, they are the same as the configuration example of the antenna device according to Embodiment 5, and the same reference numerals are given and the description thereof is omitted.

[0057] Note that, in the metal plate 111 in Embodiment 5, a slot 113 having two sides is formed. In FIG. 30, one side of the slot 113 is formed along the element array axis 101a, and the other side is formed along the element array axis 101b.

[0058] The horizontally polarized wave element 112a is a substrate for radiating radio waves in the horizontal direction. In FIG. 30, the horizontally polarized wave element 112a is arranged along the element array axis 101b.

[0059] The vertical polarization element 112b is arranged so as to be orthogonal (including the meaning of substantially orthogonal) to this horizontal polarization element 112a, and is a substrate for radiating radio waves in the vertical direction. In FIG. 30, the vertical polarization element 112b is arranged along the element array axis 101a.

[0060] The horizontal polarization element 112a and the vertical polarization element 112b are each configured in the same manner as the dielectric substrate 112 in Embodiment 5.

[0061] In the antenna device according to Embodiment 6, by adopting such a configuration, in addition to the effects in Embodiment 5, it is possible to radiate radio waves of two orthogonal polarizations.

[0062] Next, the effects of the antenna device according to Embodiment 6 will be described. FIG. 32 is a diagram showing an example of the reflection coefficient analysis value (electromagnetic field analysis result) of the horizontal polarization element 112a. FIG. 33 is a diagram showing an example of the reflection coefficient analysis value (electromagnetic field analysis result) of the vertical polarization element 112b. In FIGS. 32 and 33, the horizontal axis and the vertical axis respectively show the frequency normalized by the low-frequency frequency fl and the reflection coefficient analysis value.

[0063] From FIGS. 32 and 33, it can be seen that there is no unnecessary resonance in the horizontal polarization element 112a and the vertical polarization element 112b, and a reflection characteristic of 6 times or more bandwidth (reflection coefficient ≦ -6 dB or less) is obtained, confirming the effectiveness of Embodiment 6.

[0064] Note that in the above, the case where the horizontal polarization element 112a and the vertical polarization element 112b are used as the dielectric substrate 112 with respect to the antenna device according to Embodiment 5 is shown. However, the present invention is not limited to this, and the horizontal polarization element 112a and the vertical polarization element 112b may be used as the dielectric substrate 112 with respect to the antenna device according to Embodiment 3 or the antenna device according to Embodiment 4, and the same effects as described above can be obtained.

[0065] As described above, according to the sixth embodiment, the dielectric substrate 112 includes a horizontally polarized element 112a and a vertically polarized element 112b that are arranged to be orthogonal to each other. Thereby, in addition to the effects in the third to fifth embodiments, the antenna device according to the sixth embodiment can radiate radio waves of two orthogonal polarizations.

[0066] Note that free combinations of the respective embodiments, modifications of any constituent elements of the respective embodiments, or omissions of any constituent elements in the respective embodiments are possible.

Industrial Applicability

[0067] The antenna device according to the present disclosure is low-cost and can be made broadband as compared with the conventional ones, and is suitable for use in an antenna device including an array antenna or the like.

Description of Reference Numerals

[0068] 1 Array antenna, 2 Matching layer, 10 Unit cell, 11 Element antenna, 21 Dielectric, 22 Hole, 111 Metal plate, 112 Dielectric substrate, 112a Horizontally polarized element (first dielectric substrate), 112b Vertically polarized element (second dielectric substrate), 113 Slot, 1121 Feeding line, 1122 Ground, 1123 Balun, 1124 Dipole, 1125 Coupling conductor pattern, 1126 Short-circuit conductor pattern, 1127 Resistor, 1128 Hole, 11231 Open stub, 11232 Short stub.

Claims

1. An array antenna having element antennas periodically arranged at a first interval along a first array axis, and a dielectric having holes arranged at a second interval which is 1 / n (n is an integer of 2 or more) of the first interval along a second array axis that is in the same direction as the first array axis, and being arranged to face the array antenna in a direction orthogonal to the first array axis A antenna device comprising.

2. The element antenna is a metal plate arranged along the first array axis, and a dielectric substrate having a dipole which is a metal conductor on one surface, and being inserted into the metal plate and arranged in a direction orthogonal to the first array axis The antenna device according to claim 1, characterized in that.

3. The dielectric substrate has, on the other surface, a coupling conductor pattern which is a metal conductor at a position overlapping two adjacent dipoles The antenna device according to claim 2, characterized in that.

4. The dielectric substrate has, on the other surface, a short-circuit conductor pattern which is a metal conductor having one end connected to the coupling conductor pattern and the other end connected to ground The antenna device according to claim 3, characterized in that.

5. A resistor is interposed in the short-circuit conductor pattern The antenna device according to claim 4, characterized in that.

6. The dielectric substrate has, on one surface, a feeding line for feeding a high-frequency signal for exciting the dipole, The feeding line has a plurality of holes provided in the ground The antenna device according to claim 5, characterized in that.

7. The dielectric substrate is a first dielectric substrate and a second dielectric substrate arranged to be orthogonal to each other The antenna device according to claim 4, characterized in that.

8. The dielectric substrate is a first dielectric substrate and a second dielectric substrate arranged to be orthogonal to each other The antenna device according to claim 5, characterized in that.

9. The dielectric substrate is a first dielectric substrate and a second dielectric substrate arranged to be orthogonal to each other The antenna device according to claim 6, characterized in that.

Images