JP7809574B2 - Antenna device and wireless terminal - Google Patents

Description

The present invention relates to an antenna device and a wireless terminal.

Various types of antennas have been proposed for wireless communication (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Publication No. 9-107219 Japanese Patent Application Publication No. 8-18332

An array antenna, which consists of multiple antenna elements, can perform beamforming by adjusting the phase of each antenna element. However, the direction in which the beam can be steered by adjusting the phase of each antenna element is limited to directions approaching the axis of the array of antenna elements. Therefore, while the beam can be steered in any direction if the antenna elements are arranged vertically and horizontally, if the antenna elements can only be arranged in a single row due to installation space constraints, for example, the beam cannot be steered in any direction. Therefore, if an array antenna is placed in a location where it is difficult to arrange antenna elements in multiple rows, such as the edge of a thin smartphone, it may not be possible to avoid interference with the beam caused by parts of the user's body, such as the face or head, using beamforming with phase adjustment.

One aspect of the disclosed technology aims to provide an antenna device and wireless terminal that can adjust the beam direction.

One aspect of the disclosed technology is exemplified by the following antenna device.
An antenna device detachable from a wireless terminal, the antenna device having a planar, directional radiating element connected to a feed point,
a planar, non-powered conductor element disposed on the radiation surface side of the radiating element and spaced apart from the radiating element;
The conductor element is formed so that the length of the longest line segment formed on the conductor element by connecting any two points on the conductor element is within a range of 0.1 to 0.4 times the length of the effective wavelength in the dielectric of the radio wave used for wireless communication, and is arranged at an angle to the radiating element so that their planes are not parallel to each other.
Antenna device.

The disclosed technology allows the beam direction to be adjusted.

FIG. 1 is a first diagram showing a main part of an antenna device according to an embodiment. FIG. 2 is a second diagram showing the main part of the antenna device according to the embodiment. FIG. 3 is a first diagram showing a main part of an antenna device according to a comparative example. FIG. 4 is a second diagram showing a main part of an antenna device according to a comparative example. FIG. 5 is a two-dimensional schematic diagram showing the simulation results of the radiation pattern formed in the antenna device according to the comparative example. FIG. 6 is a diagram showing a two-dimensional schematic representation of a simulation result of a radiation pattern formed in the antenna device according to the embodiment. FIG. 7 is a three-dimensional schematic diagram showing the simulation results of the radiation pattern formed in the antenna device according to the embodiment. FIG. 8 is a diagram showing a two-dimensional radiation pattern of the antenna device according to the embodiment. FIG. 9 is a diagram showing the relationship between the gain and angle in the peak direction of the radiation pattern and the angle θ1. FIG. 10 is a first diagram showing the main part of the modified example. FIG. 11 is a second diagram showing the main part of the modified example. FIG. 12 is a two-dimensional schematic diagram showing the simulation results of the radiation pattern formed in the antenna device according to the modified example. FIG. 13 is a three-dimensional schematic diagram showing the simulation results of the radiation pattern formed in the antenna device according to the modified example. FIG. 14 is a first diagram showing a two-dimensional radiation pattern of an antenna device according to a modified example. FIG. 15 is a second diagram showing a two-dimensional radiation pattern of the antenna device according to the modified example. FIG. 16 is a diagram showing the relationship between the gain and angle in the peak direction of the radiation pattern and the angle θ2. FIG. 17 is a diagram showing the relationship between the angle and the gain of each stacked patch. FIG. 18 is a diagram showing the simulation results regarding the distance between the patch antenna and the stacked patch and the size of the stacked patch. FIG. 19 is a diagram illustrating an example of a smartphone. FIG. 20 is a diagram illustrating an example of attachment and detachment of an external device. FIG. 21 is a diagram showing a first example of the internal structure of the external device. FIG. 22 is a diagram showing an example of a processing flow relating to beam direction control in the antenna device. FIG. 23 is a diagram showing a second example of the internal structure of the external device. FIG. 24 is a diagram showing the relative positional relationship between the patch antenna, the first stacked patch, and the second stacked patch in the second example. FIG. 25 is a first diagram showing the radiation pattern of the antenna device in this verification. FIG. 26 is a second diagram showing the radiation pattern of the antenna device in this verification. FIG. 27 is a diagram showing the relationship between the gain and angle in the peak direction of the radiation pattern and the angle θ4. FIG. 28 is a diagram showing a modified example of the external device.

<Embodiment>
The configurations of the embodiments described below are merely examples, and the disclosed technology is not limited to the configurations of the embodiments.

An antenna device according to an embodiment has, for example, the following configuration: That is, an antenna device detachable from a wireless terminal, the antenna device including a planar radiating element connected to a feeding point and a ground arranged with a dielectric between the radiating element and the ground, the antenna device further including a planar, non-powered conductor element arranged at a distance from the radiating element on the radiation surface side of the radiating element, the conductor element being formed so that the length of the longest line segment formed on the conductor element connecting any two points on the conductor element is within a range of 0.1 to 0.4 times the effective wavelength in the dielectric of radio waves used for wireless communication, and the conductor element is arranged at an angle to the radiating element so that the planes are non-parallel to each other.

With the above antenna device, the parasitic conductive element is tilted relative to the radiating element, allowing the beam direction to be changed from the front direction of the radiating element to another direction.

The above-mentioned antenna device will now be described in detail. Figure 1 is a first diagram showing the main parts of the antenna device according to the embodiment. Figure 2 is a second diagram showing the main parts of the antenna device according to the embodiment. Figure 1 shows a perspective view of the antenna device 1 seen from an angle. Figure 2 shows a view of the antenna device 1 seen from the side (Y-axis direction). Although the directions of the X-axis, Y-axis, and Z-axis are shown in Figures 1 and 2, hereinafter, the X-axis direction will be referred to as the front-to-rear direction of the antenna device 1, the Y-axis direction will be referred to as the left-to-right direction of the antenna device 1, and the Z-axis direction will be referred to as the up-to-down direction of the antenna device 1.

As shown in Figures 1 and 2, the antenna device 1 includes a ground 2, a dielectric 3 laminated on the ground 2, a patch antenna 4 formed on the surface of the dielectric 3, and a stacked patch 5 (an example of a "conductor element" as used herein) spaced apart from the patch antenna 4.

The ground 2 is at the same potential as the reference potential of the electronic circuit built into the wireless terminal in which the antenna device 1 is installed. Therefore, the ground 2 serves as the electrical ground for the antenna device 1. As shown in Figure 1, the ground 2 has a roughly rectangular plate-like appearance when viewed overall. However, the antenna device 1 shown in Figure 1 shows only the essential parts of the antenna device 1, and the antenna device 1 is not limited to having a ground 2 of this type. The antenna device 1 including the ground 2 may, for example, be part of a circuit board that constitutes the entire wireless terminal in which the antenna device 1 is installed.

Dielectric 3 is a dielectric layer laminated on the surface of ground 2, and as shown in Figure 1, has a flat, generally rectangular shape. Dielectric 3 is made of a material that generates dielectric polarization when placed in an electric field, and specific examples include electrical insulators such as glass epoxy resin, ABS resin, polycarbonate resin, silicone rubber, and thermoplastic polyurethane elastomer.

The patch antenna 4 is a planar radiating element connected to a feed point. The patch antenna 4 emits radio waves using harmonics fed from a high-frequency circuit via the feed point, and receives radio waves transmitted from an external source. An appropriate matching circuit may be provided at the feed point. The patch antenna 4 has dimensions and a shape that allow it to resonate at a specific design frequency.

The stacked patch 5 is a planar, non-powered conductive element disposed on the radiation surface side of the patch antenna 4 at a distance from the patch antenna 4. Examples of such stacked patches 5 include a plate-shaped conductor such as a metal. The size of the stacked patch 5 is determined according to the wavelength of the radio waves used in the antenna device 1. For example, if the effective wavelength of the radio waves used in the antenna device 1 is _λg , the stacked patch 5 is preferably a rectangular plate-shaped element in which the length of the longest line segment formed by connecting any two points on the stacked patch 5 is _0.1λg to _0.4λg . Furthermore, the pitch interval between adjacent stacked patches 5 is preferably within the range of _0.3λg to _0.7λg .

For example, when wireless communication is performed using the antenna device 1, the effective wavelength _λg can be determined by the following formula (1) when the relative dielectric constant at the location where the stacked patch 5 is arranged is _εr .

In the above formula (1), c is the speed of light and f is the frequency. When the antenna device 1 performs wireless communication using radio waves in the millimeter wave band (frequency 24 to 300 GHz), the effective wavelength _λg is 0.32 mm or more and 12.5 mm or less according to formula (1). Therefore, when the antenna device 1 performs wireless communication using radio waves in the millimeter wave band, it is preferable that the stacked patch 5 be a plate-like square with the longest line segment having a length of 0.032 to 5 mm.

The stacked patch 5 is arranged at an angle relative to the patch antenna 4 so that their planes are not parallel to each other. Also, as shown in FIG. 2, the stacked patch 5 is arranged at a position where an imaginary central axis perpendicularly penetrating the plane passes through the center of the patch antenna 4. Therefore, the imaginary central axis perpendicularly penetrating the plane of the stacked patch 5 is tilted at a predetermined angle θ1 with respect to the front direction of the patch antenna 4. Therefore, with the antenna device 1 of this embodiment, the beam is directed not in the front direction of the patch antenna 4, but in an oblique direction inclined from the front direction of the patch antenna 4.

To verify the effects of the antenna device 1 of this embodiment, a simulation was performed using an electromagnetic field simulator, and the simulation results are described below. Figure 3 is a first diagram showing the main parts of an antenna device according to a comparative example. Figure 4 is a second diagram showing the main parts of an antenna device according to a comparative example. Figure 3 shows a perspective view of the antenna device 101 as seen from an angle. Figure 4 shows a view of the antenna device 101 as seen from the side.

As shown in Figures 3 and 4, the antenna device 101 of the comparative example has a configuration in which the stacked patch 5 is omitted from the antenna device 1. Therefore, like the antenna device 1, the antenna device 101 has a ground 102, a dielectric 103 stacked on the ground 102, and a patch antenna 104 formed on the surface of the dielectric 103, but does not have anything equivalent to the stacked patch 5.

In this simulation, the electric fields formed by antenna device 1 and antenna device 101 were simulated and compared. In this simulation, the angle θ1 of antenna device 1 was set to 45 degrees. Figure 5 is a two-dimensional schematic diagram showing the simulation results of the radiation pattern formed by antenna device 101 according to the comparative example. Figure 6 is a two-dimensional schematic diagram showing the simulation results of the radiation pattern formed by antenna device 1 according to the embodiment. Figure 5 shows the radiation pattern when antenna device 101 is viewed from the side. Figure 6 shows the radiation pattern when antenna device 1 is viewed from the side.

As can be seen from the radiation pattern shown in Figure 5, in the antenna device 101 according to the comparative example, the beam radiation direction is aligned with the front direction of the patch antenna 4. On the other hand, as can be seen from the radiation pattern shown in Figure 6, in the antenna device 1 according to the embodiment, the beam radiation direction is not aligned with the front direction of the patch antenna 4, but is oriented diagonally downward from the front direction of the patch antenna 4.

Figure 7 is a three-dimensional schematic diagram showing the results of a simulation of the radiation pattern formed by the antenna device 1 according to the embodiment. The X, Y, and Z axes shown in Figure 7 correspond to the X, Y, and Z axes in Figures 1 and 2. That is, Figure 7 shows a three-dimensional radiation pattern when the X axis is in the front direction of the patch antenna 4, the Y axis is in the direction directly to the side of the antenna device 1, and the Z axis is in the direction directly above the antenna device 1. As can be seen from the radiation pattern in Figure 7, the point with the highest gain is located slightly below the X axis on the paper surface of Figure 7. Furthermore, since the point with high gain is near the XZ plane, it can be seen that in the antenna device 1, the beam is directed slightly below the front direction of the patch antenna 4 and does not spread in the left-right direction.

Figure 8 shows the two-dimensional radiation pattern of the antenna device 1 according to the embodiment. As shown in Figure 8, the gain peaks at 10.1 dBi at an angle of 18 degrees downward from the X-axis direction.

The simulation results shown above show that by placing the stacked patch 5 in front of the patch antenna 4 at an angle to the patch antenna 4, it is possible to change the direction of the beam that would normally be directed in the front direction of the patch antenna 4.

Next, a simulation was performed on the relationship between the gain and angle in the peak direction of the radiation pattern and the angle θ1, and the results are shown below. Figure 9 is a diagram showing the relationship between the gain and angle in the peak direction of the radiation pattern and the angle θ1. In Figure 9, the horizontal axis represents the tilt angle θ1 of the stacked patch 5 relative to the front direction of the patch antenna 4, the left vertical axis represents the gain in the peak direction of the radiation pattern, and the right vertical axis represents the angle in the peak direction of the radiation pattern. Of the two data lines shown in Figure 9, the solid data line represents the left vertical axis (gain in the peak direction), and the dashed data line represents the right vertical axis (angle in the peak direction).

As can be seen from the graph in Figure 9, when the tilt angle θ1 of the stacked patch 5 relative to the front direction of the patch antenna 4 is changed between 0 and 60 degrees, the angle of the peak direction changes within a range of 0 to approximately 20 degrees. Furthermore, even when the tilt angle θ1 of the stacked patch 5 relative to the front direction of the patch antenna 4 is changed between 0 and 60 degrees, the gain in the peak direction remains 9 dBi or more, and it can be seen that there is almost no decrease in peak gain, especially when the tilt angle θ1 is between 0 and 45 degrees.

Therefore, in this embodiment, even if the tilt angle θ1 of the stacked patch 5 relative to the front direction of the patch antenna 4 is changed between 0 and 60 degrees, it is possible to change the beam direction without practically interfering with the peak gain. Furthermore, as shown in Figure 9, the peak direction angle has an upper limit when θ1 is set to approximately 45 degrees, and as θ1 is increased beyond approximately 45 degrees, the peak direction angle gradually decreases, so it can be said that the practical range for changing θ1 is between 0 and 45 degrees.

<Modification>
In the above embodiment, only one stacked patch 5 corresponds to one patch antenna 4, but two, three or more stacked patches 5 may be provided corresponding to one patch antenna 4. Fig. 10 is a first diagram showing the main parts of a modified example. Fig. 11 is a second diagram showing the main parts of the modified example. In this modified example, the same components as those in the above embodiment are denoted by the same reference numerals, and their description will be omitted.

Similar to the stacked patch 5 in the above embodiment, the first stacked patch 5A and the second stacked patch 5B are both planar, non-powered conductive elements arranged at a distance from the patch antenna 4 on the radiation surface side of the patch antenna 4. In this modification, a plurality of stacked patches corresponding to the patch antenna 4 are arranged in order in the radiation direction of the patch antenna 4. In this modification, of the two stacked patches (5A, 5B), the one closer to the patch antenna 4 is referred to as the first stacked patch 5A, and the one farther from the patch antenna 4 is referred to as the second stacked patch 5B. When three or more stacked patches corresponding to one patch antenna 4 are provided, they are preferably referred to as the first, second, third, ... nth stacked patches in order from the one closest to the patch antenna 4.

The first stacked patch 5A and the second stacked patch 5B are both tilted relative to the patch antenna 4 so that their planes are non-parallel. Furthermore, as shown in FIG. 11 , the first stacked patch 5A and the second stacked patch 5B are both positioned so that their imaginary central axes, which run vertically through their planes, pass through the center of the patch antenna 4. Therefore, the imaginary central axis running vertically through the plane of the first stacked patch 5A is tilted at a predetermined angle θ1 with respect to the front direction of the patch antenna 4. Furthermore, the imaginary central axis running vertically through the plane of the second stacked patch 5B is tilted at a predetermined angle θ2 with respect to the front direction of the patch antenna 4. Therefore, the antenna device 1 of this modified example can direct the beam in a more oblique direction than the embodiment.

A simulation was also performed on this modified example using an electromagnetic field simulator, and the simulation results are described below. In this simulation, the electric field formed by the antenna device 1 related to the modified example was simulated under two calculation conditions: angle θ1 was 45 degrees, and angle θ2 was 15 degrees and 60 degrees.

Figure 12 is a two-dimensional schematic diagram showing the results of a simulation of the radiation pattern formed by the antenna device 1 according to the modified example. Figure 12 shows the radiation pattern when the antenna device 1 according to the modified example is viewed from the side. Figure 12 also shows the simulation results when the angle θ2 is set to 60 degrees. As can be seen from the radiation pattern shown in Figure 12, the radiation direction of the antenna device 1 according to this modified example is more oblique than that of the above embodiment.

Figure 13 is a three-dimensional schematic diagram showing the results of a simulation of the radiation pattern formed by an antenna device 1 according to a modified example. The X-axis, Y-axis, and Z-axis shown in Figure 13 correspond to the X-axis, Y-axis, and Z-axis in Figure 11. Figure 13 also shows the radiation pattern according to the modified example and the radiation pattern according to the comparative example side by side. (A), (B), and (C) in Figure 13 show the results of a simulation in which the beam directions in the XY plane are staggered by adjusting the phase between each of the four antenna devices 1. Figure 13 (A) shows a state in which beamforming by phase adjustment is not performed by aligning the phases of the four antenna devices 1. Figures 13 (B) and (C) show a state in which the beams are tilted slightly toward the Y-axis by beamforming by phase adjustment by adjusting the phases of the four antenna devices 1. As can be seen from the radiation pattern according to the modified example in Figure 13, the point with the highest gain is located below the X-axis on the paper surface of Figure 13. On the other hand, as can be seen from the radiation pattern for the comparative example in Figure 13, the point with the highest gain is located on the XY plane. This shows that while in the comparative example, beamforming through phase adjustment only allowed adjustment of the beam direction in the XY plane, in the modified example, it is possible to adjust the beam direction not only in the XY plane but also in the XZ plane (the same applies to the embodiment).

Figure 14 is the first diagram showing the two-dimensional radiation pattern of the antenna device 1 according to the modified example. Figure 14 shows the simulation results when angle θ1 is 45 degrees and angle θ2 is 15 degrees. As shown in Figure 14, the gain peaks at 11.1 dBi at an inclination angle of 13 degrees downward from the X-axis direction.

Figure 15 is a second diagram showing the two-dimensional radiation pattern of the antenna device 1 according to the modified example. Figure 15 shows the simulation results when angle θ1 is 45 degrees and angle θ2 is 60 degrees. As shown in Figure 15, the gain peaks at 9.35 dBi at an inclination angle of 30 degrees downward from the X-axis direction.

The simulation results shown above show that the antenna device 1 of this modified example is capable of directing the beam in a more oblique direction than the embodiment.

Next, a simulation was performed on the relationship between the gain and angle in the radiation pattern peak direction and the angle θ2, and the results are shown below. In this simulation, the angle θ1 was set to 45 degrees. Figure 16 is a diagram showing the relationship between the gain and angle in the radiation pattern peak direction and the angle θ2. In Figure 16, the horizontal axis represents the tilt angle θ2 of the second stacked patch 5B relative to the front direction of the patch antenna 4, the left vertical axis represents the gain in the radiation pattern peak direction, and the right vertical axis represents the angle in the radiation pattern peak direction. The correspondence between the two data lines in Figure 16 and the vertical axes on both the left and right sides is the same as in Figure 9.

As can be seen from the graph in Figure 16, when the tilt angle θ2 of the second stacked patch 5B relative to the front direction of the patch antenna 4 is changed between 0 and 90 degrees, the angle in the peak direction changes within a range of 0 to approximately 30 degrees. It can also be seen that the gain in the peak direction is 8 dBi or more even when the tilt angle θ2 of the second stacked patch 5B relative to the front direction of the patch antenna 4 is changed between 0 and 90 degrees.

Therefore, in this modified example, even if the tilt angle θ2 of the second stacked patch 5B relative to the front direction of the patch antenna 4 is changed between 0 and 90 degrees, it is possible to change the beam direction without practically interfering with the peak gain. Furthermore, as shown in Figure 16, the peak direction angle has an upper limit when θ2 is set to approximately 60 degrees, and as θ2 is increased beyond approximately 60 degrees, the peak direction angle gradually decreases. Therefore, when θ1 is 45 degrees, the practical range for changing θ2 is between 0 and 60 degrees.

Next, in this modified example, we conducted a simulation to verify the effects of varying the angles θ1 and θ2, and the results are shown below. Figure 17 shows the relationship between the angle and gain of each stacked patch. In this verification, as shown in Figure 17, the angle θ1 was changed to seven levels: -45 degrees, -30 degrees, -15 degrees, 0 degrees, 15 degrees, 30 degrees, and 45 degrees, and the angle θ2 was changed to 11 levels: -75 degrees, -60 degrees, -45 degrees, -30 degrees, -15 degrees, 0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, and 75 degrees. The table in Figure 17 shows the gain and difference between the modified example and the comparative example for each radiation direction.

As can be seen from the table in Figure 17, in this modified example, by setting angles θ1 and θ2 to various values, it is possible to obtain a higher gain over a wider range of radiation directions than in the comparative example. The radiation direction and angles θ1 and θ2 are not limited to the patterns in the table shown in Figure 17, but it can be seen that in the radiation direction range from -90 degrees to 90 degrees, the gain is improved by approximately 4 dB on average compared to the comparative example.

The distance between the patch antenna 4 and the stacked patch 5 and the size of the stacked patch 5 are significantly related to the gain of the antenna device 1. Therefore, the following describes verification results regarding the distance between the patch antenna 4 and the stacked patch 5 and the size of the stacked patch 5. FIG. 18 is a diagram showing simulation results regarding the distance between the patch antenna 4 and the stacked patch 5 and the size of the stacked patch 5. FIG. 18 is a graph showing the relationship between the length of the longest line segment of the stacked patch 5 and the gain when θ1 is set to 0 degrees in the antenna device 1 according to the embodiment and the distance between the patch antenna 4 and the stacked patch 5 is changed in three steps: 1/10 of the effective wavelength _λg , 1/7 of _λg , and 1/4 of _λg . In the graph of FIG. 18, the vertical axis represents the actual gain (dBi), and the horizontal axis represents the length of the longest line segment of the stacked patch 5. As can be seen from the graph of FIG. 18, the length of the longest line segment of the stacked patch 5 has a greater impact on the actual gain than the distance between the patch antenna 4 and the stacked patch 5. Furthermore, it can be seen that the effect of improving the working gain is significant if the length of the longest line segment of the stacked patch 5 is in the range of _0.1λg to _0.4λg . When the effective wavelength is 0.32 mm, _0.1λg is 0.032 mm, and _0.4λg is 0.0128 mm. When the effective wavelength is 12.5 mm, _0.1λg is 1.25 mm, and _0.4λg is 5 mm. These results show that it is preferable to arrange the stacked patch 5, first stacked patch 5A, and second stacked patch 5B with these dimensions and positions.

<Application example>
The antenna device 1 of the above-described embodiment and modified examples can be applied, for example, as follows. FIG. 19 is a diagram showing an example of a smartphone. The smartphone 11 is a portable wireless terminal. The smartphone 11 is equipped with a display, an exterior, a CPU (Central Processing Unit), and the like. The above-described embodiment and modified examples are suitable for a smartphone 11 in which a patch antenna 4 is disposed on the edge of the smartphone 11, which is thin when viewed from the outside, as shown in FIG. 19 . As shown in FIG. 19 , the smartphone 11 is provided with the patch antenna 4, ground 2, and dielectric 3 of the antenna device 1 of the above-described embodiment and modified examples, but does not include anything equivalent to the stacked patch 5, first stacked patch 5A, or second stacked patch 5B. In this case, in a smartphone 11 in which four patch antennas 4 are arranged in a row, the beam direction can be adjusted in the XY plane by adjusting the phase of each patch antenna 4, but the beam direction cannot be adjusted in the XZ plane. For such a smartphone 11, the antenna device 1 of the above-described embodiment and modified examples can be configured as follows.

Figure 20 is a diagram illustrating the attachment and detachment of an external device. The external device 12 contains a built-in component equivalent to the stacked patch 5 in the above embodiment, or the first stacked patch 5A and second stacked patch 5B in the modified example. By attaching such an external device 12 near the patch antenna 4 of the smartphone 11, it is possible to configure the antenna device 1 according to the above embodiment or modified example.

<First example of external device>
FIG. 21 is a diagram showing a first example of the internal structure of the external device 12. FIG. 21 illustrates an antenna device 1 corresponding to the above-described modified example. For example, as shown in the enlarged view of FIG. 21 , the external device 12 includes a plate PA on which first stacked patches 5A are arranged, a support member 8A (an example of the "movable part" herein) that supports the plate PA, a plate PB on which second stacked patches 5B are arranged, and a support member 8B (an example of the "movable part" herein) that supports the plate PB. The support members 8A and 8B are rotatable by a drive shaft 7 directly connected to a drive unit 6. While FIG. 21 shows a single rod-shaped drive shaft 7, the drive shaft 7 has a double-tube structure, with an inner tube connected to the support member 8A and an outer tube connected to the support member 8B. Therefore, the drive unit 6 can adjust the angles of the support members 8A and 8B separately. If the angles of the support members 8A and 8B are manually adjustable, the drive unit 6 may be omitted.

The plate PA on which the first stacked patches 5A are arranged and the plate PB on which the second stacked patches 5B are arranged are lined up in order in the radiation direction of the patch antennas 4 arranged on the plate PA. The plate PA is arranged closer to the plate P4 than the plate PB.

The drive unit 6 includes a minute motor, a transmission, a control circuit, and the like. The drive unit 6 operates based on commands sent wirelessly or via a wired connection from a control device in the smartphone 11, and adjusts the angle of the plates PA and PB relative to the plate P4, as shown in FIGS. 21A to 21C. The drive mechanism of the drive unit 6 may be a MEMS (Micro Electro Mechanical System) formed by a semiconductor manufacturing process, or may be assembled from parts manufactured by ordinary machining. The wireless connection method used for the drive unit 6 may be, for example, Bluetooth (registered trademark), a type of short-range wireless communication, or another connection method. The drive unit 6
The wired connection method used may be, for example, a USB (Universal Serial Bus) or other connection methods.

Figure 22 shows an example of a processing flow related to beam direction control in the antenna device 1. The processing flow shown in Figure 22 may be executed primarily by a control device within the smartphone 11, or may be executed primarily by a control device separately provided within the external device 12.

When it is detected wirelessly or wired that the external device 12 has been attached to the smartphone 11 (S101), it is confirmed whether millimeter waves are being used (S102). The power to the external device 12 may be turned on by the user operating a power switch provided on the external device 12, or may be turned on by power from the smartphone 11 when the external device 12 is connected to the smartphone 11 via a wired connection. The smartphone 11 may also notify the user that the external device 12 has been attached.

When the smartphone 11 equipped with the external device 12 is located in an area where, for example, 5G communication (fifth-generation mobile communication system) using millimeter waves is provided, the smartphone 11 confirms the presence of millimeter waves. Once the presence of millimeter waves is confirmed, the drive unit 6 then begins changing the orientation (angle) of the plates PA and PB relative to the plate P4 (S103). Then, a search is performed for the orientation that maximizes the received power (S104). Once the optimization of the angles of the plates PA and PB relative to the plate P4 is completed and the received power of the millimeter waves increases, the external device 12 notifies the user that the received power has increased (S105). Examples of notification methods include displaying an icon or animation on the smartphone 11 screen, generating a notification sound from the smartphone 11 or the external device 12, or turning on an indicator light on the external device 12. Receiving such a notification, the user can experience the benefits of the external device 12. Furthermore, the communication speed of the smartphone 11 is improved.

<Second example of external device>
The external attachment device 12 can be modified, for example, as follows. FIG. 23 is a diagram showing a second example of the internal structure of the external attachment device 12. For example, as shown in the enlarged view of FIG. 23 , the external attachment device 12 includes a plate PA on which first stacked patches 5A are arranged, a support member 8A that supports the plate PA, a plate PB on which second stacked patches 5B are arranged, a support member 8B that supports the plate PB, a plate PC on which third stacked patches 5C are arranged, and a support member 8C that supports the plate PC. The support member 8B is rotatably attached to the support member 8A. The support member 8C is rotatably attached to the support member 8B. That is, the rotation axes of the support members 8B and 8C are located at different positions from the rotation axis of the support member 8A.

The external device 12 can also be configured in this way. Even in this configuration, it is possible to change the beam direction of the antenna device 1. In this second example, as in the first example, the angles of the plates PA, PB, and PC relative to the plate P4 may be automatically adjustable by a driving device, or may be manually adjustable without using the driving device.

In this second example, because the support member 8B is rotatably attached to the support member 8A, the imaginary central axis passing through the center of the second stacked patch 5B passes through the center of the first stacked patch 5A, not through the center of the patch antenna 4. In other words, this second example has a configuration similar to a multi-joint structure. Therefore, we also performed a simulation to examine the effect when the imaginary central axis takes such a configuration, and the results are shown below.

Figure 24 shows the relative positional relationship between the patch antenna 4, the first stacked patch 5A, and the second stacked patch 5B in the second example. Similar to the above-described modification, the first stacked patch 5A and the second stacked patch 5B are tilted relative to the patch antenna 4 so that their planes are non-parallel. Also, similar to the above-described modification, the first stacked patch 5A is positioned so that its imaginary central axis, which runs perpendicularly through its plane, passes through the center of the patch antenna 4. However, unlike the above-described modification, the second stacked patch 5B is positioned so that its imaginary central axis, which runs perpendicularly through its plane, passes through the center of the first stacked patch 5A. Therefore, in this simulation, the tilt angle of the plane of the first stacked patch 5A relative to a plane perpendicular to the front direction of the patch antenna 4 (a plane parallel to the radiation plane of the patch antenna 4) is defined as θ3. Also, the tilt angle of the plane of the second stacked patch 5B relative to a plane perpendicular to the front direction of the patch antenna 4 (a plane parallel to the radiation plane of the patch antenna 4) is defined as θ4.

Figure 25 is the first diagram showing the radiation pattern of the antenna device 1 used in this verification. Figure 25 shows the simulation results when angle θ3 is 45 degrees and angle θ4 is 15 degrees. As shown in Figure 25, the gain peaks at 10.4 dBi at an inclination angle of 19 degrees downward from the X-axis direction.

Figure 26 is the second diagram showing the radiation pattern of the antenna device 1 used in this verification. Figure 26 shows the simulation results when angle θ3 is 45 degrees and angle θ4 is 60 degrees. As shown in Figure 26, the gain peaks at 9.5 dBi at an inclination angle of 29 degrees downward from the X-axis direction.

Figure 27 shows the relationship between the gain and angle in the direction of the peak of the radiation pattern and angle θ4. In Figure 27, the tilt angle θ4 is shown on the horizontal axis, the gain in the direction of the peak of the radiation pattern is shown on the left vertical axis, and the angle in the direction of the peak of the radiation pattern is shown on the right vertical axis. The angle θ3 is 45 degrees. The correspondence between the two data lines in Figure 27 and the vertical axes on both the left and right sides is the same as in Figures 9 and 16.

As can be seen from the graph in Figure 27, when the tilt angle θ4 of the second stacked patch 5B relative to the front direction of the patch antenna 4 is changed between 0 and 90 degrees, the angle in the peak direction changes within a range of 0 to approximately 30 degrees. It can also be seen that the gain in the peak direction is 8 dBi or more even when the tilt angle θ4 of the second stacked patch 5B is changed between 0 and 90 degrees.

Therefore, when the virtual central axis passing vertically through the second stacked patch 5B is positioned at a position passing through the center of the first stacked patch 5A, it can be seen that even if the inclination angle θ4 is changed between 0 degrees and 90 degrees, the beam direction can be changed without causing any practical problems to the peak gain.

Figure 28 is a diagram showing a modified example of the external device 12. For example, as shown in Figure 28, the external device 12 may have plates PA, PB, and PC that can be rotated around hinges 9 and inserted and removed inside and outside the external device 12. In this configuration, when it is desired to change the beam direction with the first stacked patches 5A, 5B, and 5C, the multi-joint structure can be extended from inside the external device 12. Therefore, when it is not necessary to change the beam direction with the first stacked patches 5A, 5B, and 5C, the multi-joint structure can be stored inside the external device 12, allowing the external device 12 to be kept compact.

<Other Modifications>
The above-described embodiment, modified examples, and application examples may be modified as appropriate. For example, the smartphone 11 may be provided with a plurality of antenna devices 1, the entire antenna device 1 may be built into the smartphone 11, or the entire configuration of the antenna device 1 including the patch antenna 4 may be configured as a single antenna device separate from the wireless device. Furthermore, the first application example may omit the support member 8B and the plate PB and realize a configuration equivalent to the antenna device 1 of the embodiment.

1, 101... Antenna device 2, 102... Ground 3, 103... Dielectric 4, 104... Patch antenna 5... Stacked patch 5A... First stacked patch 5B... Second stacked patch 5C... Third stacked patch 6... Driving device 7... Driving shaft 9... Hinges 8A, 8B, 8C... Support member P4, PA, PB, PC... Plate 11... Smartphone 12... External device

Claims (11)

a radiating element array in which a plurality of radiating elements having directivity are arranged in a line;
a conductor element array in which a plurality of planar, non-powered conductor elements are arranged in a line on the radiation surface side of the radiating element and spaced apart from the radiating element,
The conductor element is formed so that the length of the longest line segment formed on the conductor element by connecting any two points on the conductor element is within a range of 0.1 to 0.4 times the length of the effective wavelength in the dielectric of the radio wave used for wireless communication, and is arranged at an angle with respect to the radiating element so that their planes are non-parallel to each other.
Antenna device. a plurality of pairs of the radiating element and the conductive element are arranged along a predetermined imaginary straight line;
The conductive elements of each set are inclined in a direction different from the extension direction of the virtual line relative to the radiating element.
The antenna device according to claim 1 . The conductive elements of each set are arranged at positions such that the pitch between the conductive elements of the adjacent set is within a range of 0.3 to 0.7 times the effective wavelength.
The antenna device according to claim 2 . the conductive element is arranged such that the distance between the center of the radiating element and the center of the conductive element is one-tenth of the effective wavelength.
The antenna device according to any one of claims 1 to 3. a plurality of the conductive elements corresponding to a specific radiating element are arranged in the radiation direction of the specific radiating element;
5. The antenna device according to claim 1. the conductive element is arranged at a position where a virtual central axis perpendicularly penetrating a plane passes through the center of the radiating element or another conductive element arranged on the side of the radiating element,
6. An antenna device according to claim 1. It is characterized in that it is detachable from the wireless terminal.
7. An antenna device according to claim 1. a movable portion capable of changing an inclination angle of the conductive element relative to the radiating element;
8. An antenna device according to claim 1. the movable portion changes the tilt angle so as to increase the received power of the radio wave at the antenna device.
9. The antenna device according to claim 8. and a notification unit that notifies a user of an increase in received power when the tilt angle is changed by the movable unit.
10. The antenna device according to claim 9. An antenna device comprising: an antenna device according to any one of claims 1 to 10 ;
Wireless terminal.