JP2024003909A - antenna device - Google Patents

Abstract

To provide an antenna device and so forth which have, both at the same time, preferable irradiation range of electromagnetic waves and gain.SOLUTION: An antenna device includes: an array antenna module including a plurality of antenna elements; and a reflector having a curved surface. The array antenna module and the reflector are disposed along a first axis. When an axis intersecting the first axis is defined as a second axis, and an axis intersecting the first axis and the second axis is defined as a third axis, then the reflector has the curved surface which is curved at a first curvature in a direction along the second axis and also curved at a second curvature, smaller than the first curvature, in a direction along the third axis.SELECTED DRAWING: Figure 1

Description

The present invention relates to an antenna device and the like.

Conventionally, antenna devices with various configurations are known. For example, Patent Document 1 discloses an antenna device that includes a reflecting mirror installed on a mechanical rotational drive mechanism and a plurality of array antennas each installed at the focal point of the reflecting mirror on the rotational drive mechanism. .

JP2007-251663A

In the method of Patent Document 1, the gain is improved by configuring one direction (horizontal direction) of the reflecting mirror with a curved surface, and by configuring the other orthogonal direction (vertical direction) with a straight line, the gain is improved by the array antenna. A beam scan is performed. However, in the method of Patent Document 1, since the vertical plane is formed of a straight line, the only element for improving the gain is the horizontal parabolic plane, and it is difficult to improve the overall gain with respect to the size of the antenna device.

According to some aspects of the present disclosure, it is possible to provide an antenna device and the like that achieve both electromagnetic wave irradiation range and gain.

One aspect of the present disclosure includes an array antenna module including a plurality of antenna elements, and a reflecting mirror having a curved surface, wherein the array antenna module and the reflecting mirror are arranged along a first axis, and the reflecting mirror is defined by a first curvature in the direction along the second axis, where an axis that intersects the first axis is a second axis, and an axis that intersects the first axis and the second axis is a third axis. The present invention relates to an antenna device having the curved surface that is curved and curved by a second curvature smaller than the first curvature in the direction along the third axis.

1 is a configuration example of an antenna device according to a first embodiment. 1 is a configuration example of an antenna device according to a first embodiment. FIG. 3 is a diagram illustrating the positional relationship between a reflecting mirror, an array antenna module, and a focal point. FIG. 2 is a diagram illustrating the configuration of a signal system of an antenna device. It is a structural example of the antenna device of 2nd Embodiment. It is a structural example of the antenna device of 2nd Embodiment. This is an example of the positional relationship between the reflector and the array antenna module, and the main radiation direction. This is an example of the positional relationship between the reflector and the array antenna module, and the main radiation direction. This is an example of the positional relationship between the reflector and the array antenna module, and the main radiation direction. It is an example of a structure of the drive mechanism which moves a reflecting mirror. It is a structural example of the antenna device of 4th Embodiment. It is a structural example of the antenna device of 4th Embodiment. It is a structural example of the antenna device of 4th Embodiment.

This embodiment will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description will be omitted. Note that this embodiment described below does not unduly limit the content described in the claims. Furthermore, not all of the configurations described in this embodiment are essential configuration requirements of the present disclosure.

1. First Embodiment 1.1 Antenna Device FIGS. 1 and 2 are diagrams showing the configuration of an antenna device 1 according to this embodiment. As shown in FIGS. 1 and 2, the antenna device 1 includes an array antenna module 21 and a reflector 22. Note that the configuration of the antenna device 1 is not limited to that shown in FIGS. 1 and 2, and various modifications such as adding other configurations are possible.

The array antenna module 21 emits or receives electromagnetic waves. The array antenna module 21 is, for example, a primary radiator of the antenna device 1.

Reflector 22 reflects electromagnetic waves. The reflecting mirror 22 includes a curved surface 22S that is a reflecting surface. Specifically, the curved surface 22S corresponds to the surface of the reflecting mirror 22 on the array antenna module 21 side.

As shown in FIGS. 1 and 2, in the following description, the axis connecting the array antenna module 21 and the reflecting mirror 22 will be referred to as a first axis AX1. In other words, the array antenna module 21 and the reflecting mirror 22 are arranged along the first axis AX1. Further, an axis that intersects with the first axis AX1 is defined as a second axis AX2, and an axis that intersects with the first axis AX1 and the second axis AX2 is defined as a third axis AX3. Specifically, the first axis AX1, the second axis AX2, and the third axis AX3 may be orthogonal to each other. In FIGS. 1 and 2, the direction of the arrow is the positive direction of each axis, and the opposite direction is the negative direction of each axis, but the positive and negative directions of each axis may be switched.

For example, the plane defined by the first axis AX1 and the third axis AX3 is a horizontal plane, and the second axis AX2 is a vertical axis. However, as will be described later using FIG. 11, the plane defined by the first axis AX1 and the second axis AX2 may be a horizontal plane, and the third axis AX3 may be an axis corresponding to the vertical direction. Further, any one of the first to third axes AX1 to AX3 is not limited to being aligned with the vertical direction, and any one of the axes may be an axis inclined with respect to the vertical direction. Also, any one of the three planes defined by any two of the first axis AX1 to the third axis AX3 may coincide with the horizontal plane, or all three planes may coincide with the horizontal plane. It may also be a plane that is tilted.

1.2 Array Antenna Module The array antenna module 21 converts the input intermediate frequency (IF) signal into a radio frequency (RF) signal, performs signal processing on the RF signal, and converts the processed RF signal into a radio frequency (RF) signal. Converts into electromagnetic waves and emits electromagnetic waves.

The array antenna module 21 also receives electromagnetic waves, converts the received electromagnetic waves into RF signals, performs signal processing on the RF signals, frequency converts the processed RF signals into IF signals, and converts the received electromagnetic waves into RF signals. Output.

As illustrated in FIG. 2, the array antenna module 21 includes a substrate 81 and a plurality of antenna elements 100 provided on the substrate 81. Furthermore, the array antenna module 21 may include configurations not shown in FIG. 2, such as an RF integrated circuit (RFIC) and a shield.

The shield and RFIC are attached to the back surface of the substrate 81, for example. A shield covers the RFIC. This can suppress unnecessary electromagnetic waves from being emitted from the RFIC and unnecessary electromagnetic waves from being received by the RFIC.

In FIG. 2, 16 antenna elements 100 arranged on the substrate 81 are illustrated as the antenna elements 100. Each antenna element 100 is, for example, a patch antenna. Note that although FIG. 2 illustrates 16 antenna elements 100 arranged in a 4×4 arrangement, the arrangement and number of antenna elements are not limited to this. For example, the array antenna module 21 may be composed of antenna elements 100 arranged on one straight line. Moreover, the number of antenna elements 100 included in the array antenna module 21 may be 15 or less, or may be 17 or more.

Antenna element 100 emits or receives electromagnetic waves. Each of the antenna elements 100 can radiate or receive electromagnetic waves of two orthogonal polarizations. Thereby, multiple input/multiple output (MIMO) communication can be performed using the plurality of antenna elements 100. Furthermore, IF signals obtained from electromagnetic waves of two orthogonal polarizations can be combined, and the gain of the antenna element 100 can be increased. One of the two orthogonal polarized waves is horizontally polarized, and the other of the two orthogonal polarized waves is vertically polarized. However, one of the two orthogonal polarized waves may be a polarized wave other than the horizontal polarized wave, and the other of the two orthogonal polarized waves may be a polarized wave other than the vertically polarized wave. For example, one of the two orthogonal polarized waves may be a polarized wave tilted by +45 degrees from the horizontal direction, and the other of the two orthogonal polarized waves may be a polarized wave tilted by -45 degrees from the horizontal direction. Good too.

Furthermore, the array antenna module 21 may include a wiring section (not shown) that includes wiring that electrically connects the RFIC and each of the antenna elements 100 to each other. The wiring electrically connects the RFIC and the feeding point for horizontal polarization of each of the antenna elements 100 to each other, and the wiring that electrically connects the RFIC and the feeding point for vertical polarization of each of the antenna elements 100 to each other. including wiring to connect to.

1.3 Reflector As shown in FIGS. 1 and 2, the curved surface 22S of the reflector 22 is curved in the direction along the second axis AX2 and curved in the direction along the third axis AX3. For example, when the first line 22La is a line along the second axis AX2 on the curved surface 22S, the first line 22La is a curved line. The first line 22La corresponds to the cross-sectional shape of the curved surface 22S on a plane defined by the first axis AX1 and the second axis AX2. Furthermore, when a line in the direction along the third axis AX3 on the curved surface 22S is defined as the second line 22Lb, the second line 22Lb is a curved line. The second line 22Lb corresponds to the cross-sectional shape of the curved surface 22S on a plane defined by the first axis AX1 and the third axis AX3.

Although FIG. 1 shows an example in which the first line 22La and the second line 22Lb are curves passing through the origin (the intersection of the first axis AX1 to the third axis AX3 in FIG. 1), there is no limitation to this. Not done. For example, in this embodiment, the cross-sectional shape of the curved surface 22S based on a plane parallel to the plane defined by the first axis AX1 and the second axis AX2 may be the first line 22La. Further, the cross-sectional shape of the curved surface 22S taken by a plane parallel to the plane defined by the first axis AX1 and the third axis AX3 may be the second line 22Lb. Even in this case, in the reflecting mirror 22 of this embodiment, the first line 22La is a curved line, and the second line 22Lb is a curved line.

In the method of the present embodiment, the reflecting mirror 22 is curved with a first curvature in the direction along the second axis AX2, and with a second curvature smaller than the first curvature in the direction along the third axis AX3. It has a curved surface 22S. In other words, in the curved surface 22S, the curvature of the first line 22La is larger than the curvature of the second line 22Lb. According to the method of this embodiment, the shape of the reflecting mirror 22 can be curved in both directions of the second axis AX2 and the third axis AX3. Therefore, compared to the method using a reflecting mirror in which one side (for example, in the vertical direction) is linear, as in Patent Document 1, the degree of convergence of the electromagnetic waves reflected by the reflecting mirror 22 can be increased, making it possible to increase the gain. become.

Note that the first curvature here is the curvature of the first line 22La. For example, when the curvature of the first line 22La differs depending on the position, the curvature of the first line 22La at the reference point may be used as the first curvature. For example, when the first line 22La corresponds to a parabolic shape (parabola) as described later, the curvature at the apex of the parabola (the point that takes the extreme value) may be used as the first curvature. Similarly, for the second curvature, the curvature at the reference point of the second line 22Lb may be used as the second curvature. Note that the reference point here is not limited to the vertex, but may be the point where the curvature is maximum, the intersection of the first line 22La and the second line 22Lb, or any other point. There may be.

In the method of this embodiment, by making the first curvature of the first line 22La and the second curvature of the second line 22Lb different, the direction along the second axis AX2 and the direction along the third axis AX3 are This makes it possible to vary the characteristics regarding reflection of electromagnetic waves on the curved surface 22S. The details will be described later using FIG. 3, but for example, in the elevation direction, high-intensity electromagnetic waves are radiated in the main radiation direction MRD, and in the horizontal direction, electromagnetic waves are irradiated over a wide range by beam scanning using the array antenna module 21. It becomes possible to do the following.

Here, the curve having the first curvature (first line 22La) may have a shape corresponding to a parabolic shape. In other words, the first line 22La may have a shape corresponding to a parabola. The shape corresponding to a parabola may be the parabola itself, or may include a curve whose difference from the parabola is less than a predetermined value. In this way, the first line 22La has a shape that converges the parallel electromagnetic waves incident on the first line 22La at one point (focal point) on the optical axis, making it easy to converge the electromagnetic waves and gain gain. can be improved.

Furthermore, the curve having the second curvature (second line 22Lb) may also have a shape corresponding to a parabolic shape. In other words, the second line 22Lb may have a shape corresponding to a parabola. In this way, the second line 22Lb has a shape that converges the parallel electromagnetic waves incident on the second line 22Lb at one point (focal point) on the optical axis, making it easy to converge the electromagnetic waves and gain gain. can be improved.

For example, when the shape of a parabola is defined as y ² =4ax, the first line 22La has a shape corresponding to y ² =4a ₁ x, and the second line 22Lb has a shape corresponding to y ² =4a ₂ x. There may be. Here, by setting a ₁ <a ₂ , it becomes possible to provide a difference between the first curvature and the second curvature. For example, since the radius of curvature at the apex of the parabola y ² =4ax is proportional to a, the curvature at the apex is inversely proportional to a. Therefore, by setting a _{1 <a 2 , it becomes possible to set both the first line 22La and the second line 22Lb to be parabolic curves, and to set the first curvature>} the second curvature.

However, the curve having the second curvature (second line 22Lb) is not limited to the parabolic shape, and may have other shapes. For example, for the second line 22Lb, the arrival position on the optical axis of parallel electromagnetic waves incident on the second line 22Lb differs depending on the incident position (parallel electromagnetic waves do not converge to one point on the optical axis). ) characteristics. Even in this case, since the reflecting mirror 22 has a curved shape instead of a linear shape in the direction along the third axis AX3, it is possible to improve the gain compared to the conventional method such as Patent Document 1.

1.4 Relationship between the focal point of the reflecting mirror and the array antenna module As described above, in the antenna device 1 of this embodiment, the first curvature and the second curvature are different. This makes it possible to adjust the positional relationship between the focal point and the array antenna module 21. For example, by placing the array antenna module 21 at the focal point of the first line 22La, high-intensity electromagnetic waves are radiated in the main radiation direction, while placing the array antenna module 21 at a position different from the focal point of the second line 22Lb. This makes it possible to perform beam scanning using the array antenna module 21 in the direction along the third axis AX3. The same applies when the antenna device 1 receives electromagnetic waves, and it becomes possible to perform beam scanning while increasing the gain. A detailed explanation will be given below using FIG. 3.

FIG. 3 is a diagram illustrating the positional relationship of the reflecting mirror 22, the array antenna module 21, and the focal point of the reflecting mirror 22. In FIG. 3, the first focal point 22Fa represents the focal point of the first line 22La, and the second focal point 22Fb represents the focal point of the second line 22Lb. For example, as described above, when the first line 22La has a shape corresponding to y ² =4a ₁ x, the distance from the vertex of the first line 22La to the first focal point 22Fa corresponds to a ₁ . Further, when the second line 22Lb has a shape corresponding to y ² =4a ₂ x, the distance from the vertex of the second line 22La to the second focal point 22Fb corresponds to a ₂ . As mentioned above, since a ₁ < a ₂ from the relationship between the first curvature and the second curvature, the apex of the second line 22Lb is smaller than the distance from the apex of the first line 22La to the first focal point 22Fa. The distance from the second focal point 22Fb to the second focal point 22Fb is set to be long. Here, the apex of the first line 22La and the apex of the second line 22Lb are, for example, the origin in FIGS. 1 and 2 (the point where the three axes of the illustrated first axis AX1 to third axis AX3 intersect). .

Further, as described above, the second line 22Lb may be a curve different from the parabolic shape. In this case, the parallel electromagnetic waves incident on the second line 22Lb may not converge to one point on the optical axis, but may reach different points depending on the reflection position (the focus may not become one). In this case, the focal point determined by the second line 22Lb may be determined by a plurality of points on the optical axis that electromagnetic waves incident parallel to the second line 22Lb can reach, for example. For example, the focal point determined by the second line 22Lb may be a set of the plurality of points. Alternatively, the focus determined by the second line 22Lb may be the center of gravity of the plurality of points, any one of the plurality of points, or another point determined from the plurality of points. It may be a point.

As shown in FIG. 3, the array antenna module 21 may be placed at a position corresponding to a focal point determined by a curved line having a first curvature. The curve having the first curvature is the first line 22La, and the focus determined by the curve having the first curvature is the first focus 22Fa. Note that, as shown in FIG. 2, when the array antenna module 21 includes a plurality of antenna elements 100, the first focal point 22Fa may be set at the position of any one of the plurality of antenna elements 100. Alternatively, the first focal point 22Fa may be set at a position determined based on the positions of the plurality of antenna elements 100. The position determined based on the positions of the plurality of antenna elements 100 may be, for example, the position of the center of gravity of the plurality of antenna elements 100, or may be any position within a region including the plurality of antenna elements 100. You can. Moreover, the array antenna module 21 may be arranged at a position other than the above, where the distance between the first focal point 22Fa and the antenna element 100 is equal to or less than a predetermined value.

In this way, the electromagnetic waves irradiated from the array antenna module 21 are reflected by the curved surface of the reflecting mirror 22 in the direction along the second axis AX2, so that the electromagnetic waves are reflected in parallel along the main radiation direction MRD of the parabolic curve. It becomes an electromagnetic wave. The main radiation direction MRD represents the direction in which electromagnetic waves radiated from the array antenna module 21 travel after being reflected by the parabolic curve. Note that "parallel" here is not limited to strictly matching the main radiation direction MRD, but includes "substantially parallel" in which the amount of deviation with respect to the main radiation direction MRD is equal to or less than a predetermined threshold. Further, parallel electromagnetic waves radiated from the outside to the antenna device 1 are reflected by the curved surface of the reflecting mirror 22 in the direction along the second axis AX2, and thereby converge in the same phase at a position corresponding to the array antenna module 21. . Therefore, it becomes possible to increase the gain in transmitting and receiving electromagnetic waves.

Note that in this case, beam scanning using the array antenna module 21 is not performed. The beam scan here refers to an electronic beam scan that changes the beam direction of the antenna device 1 by changing at least one of the phase and amplitude of each antenna element 100 included in the plurality of antenna elements 100, for example. . Since electronic beam scanning is not performed, the beam irradiation direction when viewed within the plane defined by the first axis AX1 and the second axis AX2 is the main radiation direction MRD, and other directions within the plane The beam may not be irradiated. For example, when the second axis AX2 is a vertical axis, in this embodiment, the elevation angle of the beam may be the main radiation direction MRD.

Further, the distance from the reflecting mirror 22 to the focal point determined by the curve having the second curvature may be longer than the distance from the reflecting mirror 22 to the array antenna module 21. The curve having the second curvature is the second line 22Lb, and the focus determined by the curve having the second curvature is the second focus 22Fb. For example, when considering the antenna element 100 that is placed farthest from the reflector 22 among the plurality of antenna elements 100, the distance from the reflector 22 to the second focal point 22Fb is longer than the distance from the reflector 22 to the antenna element 100. (Figure 3). In this way, it becomes possible to make the position of the array antenna module 21 and the position of the second focal point 22Fb different. In this case, the electromagnetic waves radiated from the array antenna module 21 are not parallel to the main radiation direction MRD, but proceed in a direction according to the reflection position. As a result, by performing electronic beam scanning using the array antenna module 21, multiple beams with different directions are radiated within the plane defined by the first axis AX1 and the third axis AX3 (in a horizontal plane in a narrow sense). It becomes possible to do so. The same goes for receiving electromagnetic waves, and it becomes possible to receive electromagnetic waves in a wide range in the horizontal direction with high intensity.

As described above, in the method of the present embodiment, electromagnetic waves approximately parallel to the main radiation direction MRD are irradiated using a parabolic curve in the direction along the second axis AX2 on the curved surface 22S of the reflecting mirror 22. Gain can be increased. Furthermore, in the method of the present embodiment, the degree of convergence of electromagnetic waves is determined by using the second line 22Lb, which is a curved line (parabolic curve in a narrow sense), in the direction along the third axis AX3 on the curved surface 22S of the reflecting mirror 22. While increasing the height, beam scanning can be used to irradiate a wide range of beams. In other words, it is possible to increase the gain of the antenna device 1 as a whole while ensuring a wide beam range.

As described above, in the antenna device 1 of this embodiment, the electromagnetic wave in the elevation direction becomes the main radiation direction MRD of the parabolic curve, and the irradiation range in the elevation direction may be narrower than the irradiation range in the horizontal direction. . This point is allowed in this embodiment.

For example, the antenna device 1 of this embodiment is suitable for home routers and the like that are often used in a fixed position. The home router here is customer premises equipment (CPE) that connects to an external network using a mobile communication network such as 5G, and also constructs a LAN using WiFi (registered trademark). Good too. The antenna device 1 of this embodiment is, for example, a device that communicates with a 5G base station.

In this case, the location of the 5G base station does not change frequently, so once the CPE location, attitude, and beam irradiation direction settings are completed, it is assumed that the settings will not be changed frequently. Ru. Therefore, the narrow width in the elevation direction is unlikely to be a disadvantage. Furthermore, there are various possible installation locations for the 5G base station, such as a steel tower, the roof of a building, and indoors, but the width of the change in height is, for example, about several tens of meters. Therefore, it is less necessary for the antenna device 1 mounted on the CPE to search a wider range in the elevation direction than in the horizontal direction, and from this point of view as well, the narrow width in the elevation direction is unlikely to be a disadvantage. For the above reasons, this embodiment may be configured to emit electromagnetic waves parallel to the main radiation direction MRD in the elevation direction, and emit electromagnetic waves in a wide range using beam scanning in the horizontal direction.

However, as will be described later using the third embodiment and the fourth embodiment, it is possible to use the drive mechanism 60 or the second drive mechanism to further widen the irradiation direction of electromagnetic waves. Furthermore, the antenna device 1 of this embodiment is not limited to CPE, and can be widely applied to antenna devices 1 for various uses.

1.5 Signal System FIG. 4 is a block diagram of the signal system of the antenna device of the first embodiment. Note that FIG. 4 illustrates five antenna elements 101, 102, 103, 104, and 105 out of the 16 antenna elements 100. The same applies to the wiring of other antenna elements 100 in the array antenna module 21.

As illustrated in FIG. 4, the antenna device 1 includes a circuit board 15, a flexible printed circuit board (FPC) 16, and an RFIC 17.

The circuit board 15 is placed, for example, on a top surface 51S of a rotary table 51, which will be described later with reference to FIGS. 9 to 11. The FPC 16 is placed along the top surface 51S of the rotary table 51 and the surface of a base 73, which will be described later with reference to FIGS. 9 to 11. The RFIC 17 is provided in the array antenna module 21.

One end of the FPC 16 is connected to the circuit board 15. The other end of the FPC 16 is connected to the RFIC 17. Thereby, the FPC 16 electrically connects the circuit board 15 and the RFIC 17 to each other. Thereby, the FPC 16 can transmit signals from the circuit board 15 to the RFIC 17 and from the RFIC 17 to the circuit board 15. All or part of the FPC 16 may be replaced with other types of transmission lines. For example, all or part of the FPC 16 may be replaced with a coaxial cable, coaxial tube, waveguide, or the like.

As illustrated in FIG. 4, the circuit board 15 includes a baseband circuit 111 and an RF control circuit 112.

The RF control circuit 112 generates a control signal and outputs the generated control signal. The FPC 16 transmits the output control signal from the RF control circuit 112 to the RFIC 17. The RFIC 17 selects an antenna element to be used from the plurality of antenna elements 100 (including, for example, antenna elements 101, 102, 103, 104, and 105) according to the transmitted control signal. The selected antenna element may be one antenna element or a combination of two or more antenna elements. Further, the RFIC 17 converts the electromagnetic waves to be radiated or received by the plurality of antenna elements 100 into horizontally polarized electromagnetic waves and/or vertically polarized electromagnetic waves according to the transmitted control signal. Thereby, the RF control circuit 112 controls the RFIC 17, and controls the antenna element to be used and the polarization of the electromagnetic waves to be radiated or received by the antenna element to be used.

When causing the antenna element 100 to radiate horizontally polarized electromagnetic waves, the RFIC 17 selects a horizontally polarized feeding point of the antenna element 100 and supplies an RF signal to each of the horizontally polarized feeding points. In the example of FIG. 4, the feed points for horizontal polarization are feed points 101H, 102H, 103H, 104H, and 105H for horizontal polarization of antenna elements 101, 102, 103, 104, and 105. Further, when the antenna element 100 emits vertically polarized electromagnetic waves, the RFIC 17 selects a vertically polarized feeding point of the antenna element 100 and supplies RF signals to the selected vertically polarized feeding points, respectively. . In the example of FIG. 4, the feed points for vertical polarization are feed points 101V, 102V, 103V, 104V, and 105V for vertical polarization of antenna elements 101, 102, 103, 104, and 105.

When the antenna element 100 receives horizontally polarized electromagnetic waves, the RFIC 17 selects a horizontally polarized feeding point of the antenna element 100, and receives the RF signal from each of the selected horizontally polarized feeding points. . When the antenna element 100 receives vertically polarized electromagnetic waves, the RFIC 17 selects a vertically polarized feeding point of the antenna element 100, and receives the RF signal from each of the selected vertically polarized feeding points. .

When the antenna device 1 emits electromagnetic waves, the baseband circuit 111 generates a baseband signal and outputs the generated baseband signal. Further, the RF control circuit 112 generates an IF signal from the output baseband signal and outputs the generated IF signal. Further, the FPC 16 transmits the output IF signal from the RF control circuit 112 to the RFIC 17. In addition, the RFIC 17 converts the frequency of the transmitted IF signal into an RF signal, performs signal processing on the RF signal, and supplies the processed RF signal to the selected feeding point of the selected antenna element. do. The signal processing performed is amplification, phase shift, etc.

When the antenna device 1 receives electromagnetic waves, the RFIC 17 receives the RF signal from the selected feeding point of the selected antenna element, performs signal processing on the supplied RF signal, and performs signal processing. The frequency of the RF signal subjected to this process is converted into an IF signal, and the IF signal is output. The signal processing performed is amplification, phase shift, etc. Further, the FPC 16 transmits the output IF signal from the RFIC 17 to the RF control circuit 112. Further, the RF control circuit 112 generates a baseband signal from the transmitted IF signal and outputs the generated baseband signal. The output baseband signal is input to the baseband circuit 111.

2. Second Embodiment FIGS. 5 and 6 are diagrams showing the configuration of an antenna device 1 according to this embodiment. As shown in FIGS. 5 and 6, the antenna device 1 includes an array antenna module 21 and a reflector 22. In addition to the curved surface 22S described above in the first embodiment, the reflecting mirror 22 according to the present embodiment has a second curved surface different from the curved surface 22S in at least one of the positive direction and the negative direction of the third axis AX3 of the curved surface 22S. have 5 and 6, both the second curved surface 22Sb provided in the positive direction of the third axis AX3 of the curved surface 22S and the second curved surface 22Sc provided in the negative direction of the third axis AX3 of the curved surface 22S are illustrated. However, either one may be omitted.

In this way, the width of the reflecting mirror 22 in the direction along the third axis AX3 can be made wider than when only the curved surface 22S is used. Therefore, within the plane defined by the first axis AX1 and the third axis AX3 (horizontal plane in a narrow sense), the radiation range of the reflected wave by the reflecting mirror 22 can be made wider. Similarly, when the array antenna module 21 receives electromagnetic waves, it is possible to receive electromagnetic waves in a wide range.

Here, the second curved surfaces 22Sb and 22Sc may be curved with a curvature corresponding to the first curvature in the direction along the second axis AX2. The curvature corresponding to the first curvature may be a curvature that matches the first curvature, or may be a curvature whose difference from the first curvature is equal to or less than a predetermined threshold. In this way, the electromagnetic waves radiated from the array antenna module 21 and reflected by the second curved surface 22Sb or 22Sc also become electromagnetic waves parallel to the main radiation direction MRD in the direction corresponding to the second axis AX2 (for example, the elevation direction). radiated as. Therefore, it becomes possible to increase the gain. Similarly, it is possible to improve the gain when the array antenna module 21 receives electromagnetic waves.

Further, the second curved surfaces 22Sb and 22Sc may have a linear shape in the direction along the third axis AX3. For example, the third line 22Lc, which is a line along the third axis AX3, of the second curved surface 22Sb may be a straight line. The third line 22Lc corresponds to the cross-sectional shape of the second curved surface 22Sb, for example, on a plane defined by the first axis AX1 and the third axis AX3. Similarly, of the second curved surface 22Sc, the fourth line 22Ld, which is a line in the direction along the third axis AX3, may be a straight line. The fourth line 22Ld corresponds to the cross-sectional shape of the second curved surface 22Sc, for example, on a plane defined by the first axis AX1 and the third axis AX3. The third line 22Lc and the fourth line 22Ld may be lines parallel to the third axis AX3 or may be lines inclined with respect to the third axis AX3.

In this way, within the plane defined by the first axis AX1 and the third axis AX3, the electromagnetic waves radiated from the array antenna module 21 and reflected by the second curved surface 22Sb or 22Sc will have a direction depending on the reflection position. Change. Therefore, by performing beam scanning using the array antenna module 21, for example, it becomes possible to radiate the beam over a wide range in the horizontal plane. In particular, by making the third line 22Lc and the fourth line 22Ld straight, it becomes easier to increase the width of the reflecting mirror 22 in the direction along the third axis AX3, so that the direction of irradiation of electromagnetic waves is made wider. Is possible. For example, the antenna device 1 of this embodiment can widen the radiation range of the beam in the horizontal plane compared to the case where the reflecting mirror 22 illustrated in the first embodiment is used.

Further, the second curved surface 22Sb may be curved with a third curvature smaller than the second curvature in the direction along the third axis AX3. For example, the third line 22Lc may be a curved line having a third curvature. Similarly, the second curved surface 22Sc may be curved with a third curvature smaller than the second curvature in the direction along the third axis AX3. For example, the fourth line 22Ld may be a curved line having a third curvature.

In this case, it becomes possible to converge the electromagnetic waves along the third curve while expanding the width of the reflecting mirror 22 in the direction along the third axis AX3, so it is possible to achieve both the width of the electromagnetic wave irradiation direction and the gain. Become. For example, the larger the third curvature, the greater the contribution to improving the gain, and the smaller the third curvature (the closer it is to a straight line), the greater the contribution to expanding the beam radiation range.

3. Third Embodiment As described above using the first embodiment and the second embodiment, the reflecting mirror 22 corresponds to a parabolic shape in the direction along the second axis AX2, and has a first focal point that is the focal point of the parabolic shape. The array antenna module 21 may be arranged at a position corresponding to 22Fa. In this case, the electromagnetic waves are radiated in the main radiation direction MRD in the direction corresponding to the second axis AX2. In this embodiment, the irradiation direction of electromagnetic waves is adjusted by adjusting the main radiation direction MRD.

7A to 7C are diagrams illustrating the positional relationship between the reflecting mirror 22 and the array antenna module 21 and the relationship between the main radiation direction MRD. Note that although FIGS. 7A to 7C describe an example in which the first axis AX1 to the third axis AX3 do not move even when the reflecting mirror 22 moves, at least one The direction of the two axes may change. FIG. 7A is similar to the example described above in the first embodiment, for example, and the main radiation direction MRD is along the first axis AX1. For example, when the first axis AX1 is a horizontal axis, the main radiation direction MRD corresponds to the horizontal direction.

On the other hand, FIG. 7B is a diagram showing an example of the relationship when the reflecting mirror 22 is moved in the direction D1 in FIG. 7A. Also in FIG. 7B, the array antenna module 21 is arranged at a position corresponding to the first focal point 22Fa, which is the focal point of the first line 22La, for example. In this way, the main radiation direction MRD according to the first line 22La changes compared to the state shown in FIG. 7A. In the example of FIG. 7B, by moving the reflecting mirror 22 in the negative direction of the second axis AX2, the main radiation direction MRD is tilted in the positive direction of the second axis AX2 compared to the example of FIG. 7A. For example, if the positive direction of the second axis AX2 is vertically upward, by switching from the state shown in FIG. 7A to FIG. 7B, it is possible to change the main radiation direction MRD to a direction having an upward angle with respect to the horizontal direction. become.

Similarly, FIG. 7C is a diagram showing an example of the relationship when the reflecting mirror 22 is moved in the direction D2 in FIG. 7A. Also in FIG. 7C, the array antenna module 21 is arranged at a position corresponding to the first focal point 22Fa, which is the focal point of the first line 22La, for example. In the example of FIG. 7C, by moving the reflecting mirror 22 in the positive direction of the second axis AX2, the main radiation direction MRD is tilted in the negative direction of the second axis AX2 compared to the example of FIG. 7A. For example, if the positive direction of the second axis AX2 is vertically upward, by switching from the state shown in FIG. 7A to FIG. 7C, it is possible to change the main radiation direction MRD to a direction having a downward angle with respect to the horizontal direction. become.

The antenna device 1 of this embodiment may include a drive mechanism 60 that changes the main radiation direction MRD according to a curved line having a first curvature by moving the reflecting mirror 22. FIG. 8 is a diagram showing an example of the drive mechanism 60. As shown in FIG. 8 , the array antenna module 21 may include the rotary table 51 and be fixed to the upper surface 51S of the rotary table 51 by a base 73 . Further, the drive mechanism 60 may include a fixed part 61 fixed to the upper surface 51S of the rotating table 51, and a movable part 62 that rotates about an axis parallel to the third axis AX3. Note that the rotating table 51 will be described later in the fourth embodiment. Further, instead of the rotary table 51 in FIG. 8, a flat plate that does not rotate may be used.

The movable part 62 is, for example, a disc-shaped or cylindrical member driven by a motor or the like. The motor here may be a motor that continuously rotates the movable part 62, or a stepping motor that rotates the movable part 62 by a predetermined amount. Moreover, the movable part 62 may be configured to be manually rotated based on a user's operation.

The movable portion 62 contacts the reflecting mirror 22 at the end on the positive direction side of the first axis AX1. Specifically, the movable part 62 comes into contact with a contact surface (a surface not facing the array antenna module 21) of the reflecting mirror 22 that is the surface opposite to the curved surface 22S shown in FIG. 1 etc. . Here, the contact surfaces of the movable portion 62 and the reflecting mirror 22 may each have a concave portion and a convex portion. By fitting the concave portion of the movable portion 62 and the convex portion of the contact surface, and the convex portion of the movable portion 62 and the concave portion of the contact surface, the movable portion 62 rotated about an axis parallel to the third axis AX3. In this case, the reflector 22 moves in a direction along the second axis. For example, in the example of FIG. 8, when the movable part 62 rotates clockwise, the reflecting mirror 22 moves in the direction D1 of FIG. 7A, and when the movable part 62 rotates counterclockwise, the reflecting mirror 22 moves in the 7A in direction D2.

However, the movable portion 62 and the reflecting mirror 22 are not limited to having a concave portion and a convex portion. For example, at least one of the surface of the movable portion 62 and the contact surface of the reflecting mirror 22 may be made of a member having a large coefficient of friction. Even in this case, when the movable part 62 rotates about an axis parallel to the third axis AX3, the reflecting mirror 22 moves in the direction D1 or D2 due to friction with the movable part 62.

In this way, by using the drive mechanism 60, it becomes possible to adjust the irradiation direction (in a narrow sense, the elevation direction) of electromagnetic waves in the direction along the second axis AX2. Therefore, it becomes possible to appropriately transmit and receive electromagnetic waves between the antenna device 1 and a communication target device (for example, a 5G base station).

Note that FIG. 8 is an example of the drive mechanism 60, and the specific configuration of the drive mechanism 60 that moves the reflecting mirror 22 can be modified in various ways.

4. Fourth Embodiment FIGS. 9 and 10 are diagrams showing the configuration of an antenna device 1 according to this embodiment. As shown in FIGS. 9 and 10, the antenna device 1 includes an array antenna module 21, a reflecting mirror 22, and a rotating table 51. Although FIGS. 9 and 10 illustrate the reflecting mirror 22 described above using FIGS. 1 and 2, the reflecting mirror 22 described above using FIGS. 5 and 6 may also be used. Further, the antenna device 1 may further include the drive mechanism 60 described above using FIG. 8.

The upper surface 51S of the rotary table 51 is a surface corresponding to a plane defined by the first axis AX1 and the third axis AX3, and is a horizontal plane in a narrow sense. The rotating table 51 rotates within a horizontal plane. The reflecting mirror 22 is coupled to the top surface 51S of the rotary table 51 directly or via a support (for example, the drive mechanism 60 shown in FIG. 8) that is not shown. The array antenna module 21 is coupled to a base 73, and the base 73 is coupled to the top surface 51S of the rotary table 51. Thereby, when the rotary table 51 rotates, the array antenna module 21 and the reflecting mirror 22 rotate about the rotation axis 13R while maintaining their positional relationship.

The antenna device 1 includes a second drive mechanism (not shown) that rotates the rotary table 51 about the rotation axis 13R. For example, the rotating table 51 may be connected to a column, and the second drive mechanism may be a mechanism that rotates the column around the rotation axis 13R. The support column here is, for example, a member whose center corresponds to the rotating shaft 13R. For example, the second drive mechanism may include a movable part that rotates around a rotation axis in a direction along the second axis AX2 and whose end portion contacts the support column, and a motor (including a stepping motor) that rotates the movable part. good. Further, the movable part of the second drive mechanism may rotate the rotary table 51 by contacting the side surface or the lower surface (the surface opposite to the upper surface 51S) of the rotary table 51. In addition, various mechanisms for rotating the rotary table 51 are known, and these can be widely applied as the second drive mechanism of this embodiment.

As described above, the antenna device 1 of this embodiment may include the second drive mechanism that rotates the reflecting mirror 22 around the rotation axis (for example, the rotation axis 13R) parallel to the second axis AX2. In this way, the direction of irradiation of electromagnetic waves on the plane defined by the first axis AX1 and the third axis AX3 can be adjusted by rotating the rotary table 51. Therefore, for example, it becomes possible to irradiate electromagnetic waves over a wide range in the horizontal direction. For example, in addition to the above-mentioned electronic beam scanning, it is possible to perform mechanical beam scanning in which the rotating table 51 changes the radiation direction of the beam.

In addition, although the example in which the upper surface 51S of the rotary table 51 is a surface along the plane defined by the first axis AX1 and the third axis AX3 has been described above, the present invention is not limited to this. FIG. 11 is a diagram showing another configuration of the antenna device 1 of this embodiment. As shown in FIG. 11, the upper surface 51S of the rotary table 51 may be a surface along a plane defined by the first axis AX1 and the second axis AX2. For example, the second axis AX2 may correspond to the horizontal direction, and the third axis AX3 may correspond to the vertical direction.

In the example of FIG. 11, of the curved surface 22S, the fifth line 22Le, which is a line in the direction along the second axis AX2, is the curve of the first curvature, and the fifth line, which is the line in the direction along the third axis AX3, is the curve of the first curvature. The line 22Lf of No. 6 is the curve of the second curvature. The first curvature and the second curvature are as described above. For example, the array antenna module 21 is arranged at a position corresponding to the focal point of the fifth line 22Le, and is not arranged at a position corresponding to the focal point of the sixth line 22Lf.

In the example of FIG. 11, for example, in the horizontal direction, electromagnetic waves are irradiated in the main radiation direction MRD, and in the vertical direction (elevation angle direction), electromagnetic waves are irradiated over a wide range by beam scanning using the array antenna module 21. Further, the rotating table 51 rotates about the rotating shaft 13R. In this case, the rotation axis 13R is an axis in a direction along the third axis AX3 (an axis parallel to it in a narrow sense). That is, the antenna device 1 of this embodiment may include a second drive mechanism that rotates the reflecting mirror 22 around a rotation axis (for example, the rotation axis 13R) parallel to the third axis AX3. The configuration example of the second drive mechanism is as described above.

By using the antenna device 1 shown in FIG. 11, it becomes possible to switch the main radiation direction MRD within the horizontal plane, so that electromagnetic waves can be irradiated over a wide range in the horizontal direction by mechanical beam scanning. Furthermore, since electronic beam scanning can be used in the vertical direction, it becomes possible to transmit and receive electromagnetic waves over a wide range while improving the gain using the curve (sixth line 22Lf).

Although this embodiment has been described in detail as above, those skilled in the art will easily understand that many modifications can be made without substantively departing from the novelty and effects of this embodiment. . Therefore, all such modifications are intended to be included within the scope of the present disclosure. For example, a term that appears at least once in the specification or drawings together with a different term with a broader or synonymous meaning may be replaced by that different term anywhere in the specification or drawings. Furthermore, all combinations of this embodiment and modifications are also included within the scope of the present disclosure. Further, the configuration and operation of the antenna device, array antenna module, etc. are not limited to those described in this embodiment, and various modifications are possible.

DESCRIPTION OF SYMBOLS 1... Antenna device, 13R... Rotation axis, 15... Circuit board, 16... Flexible printed circuit board (FPC), 17... RFIC, 21... Array antenna module, 22... Reflector, 22Fa... First focal point, 22Fb... Second focal point , 22La...first line, 22Lb...second line, 22Lc...third line, 22Ld...fourth line, 22Le...fifth line, 22Lf...sixth line, 22S...curved surface, 22Sb, 22Sc ...Second curved surface, 51...Rotary table, 51S...Top surface, 60...Drive mechanism, 61...Fixed part, 62...Movable part, 73...Base, 81...Substrate, 100, 101-105...Antenna element, 101H-105H... Feeding point for horizontal polarization, 101V to 105V... Feeding point for vertical polarization, 111... Baseband circuit, 112... RF control circuit, AX1... 1st axis, AX2... 2nd axis, AX3... 3rd axis, D1, D2...direction, MRD...main radiation direction

Claims (10)

an array antenna module including a plurality of antenna elements;
a reflecting mirror having a curved surface;
including;
the array antenna module and the reflector are arranged along a first axis;
The reflective mirror is
When an axis intersecting the first axis is a second axis, and an axis intersecting the first axis and the second axis is a third axis, the curved surface is curved by a first curvature in the direction along the second axis. and an antenna device having the curved surface curved by a second curvature smaller than the first curvature in the direction along the third axis. In claim 1,
In the antenna device, the curve having the first curvature has a shape corresponding to a parabolic shape. In claim 2,
The array antenna module includes:
An antenna device disposed at a position corresponding to a focal point determined by the curve having the first curvature. In any one of claims 1 to 3,
The distance from the reflecting mirror to the focal point determined by the curve having the second curvature is longer than the distance from the reflecting mirror to the array antenna module. In claim 4,
In the antenna device, the curve having the second curvature has a shape corresponding to a parabolic shape. In any one of claims 1 to 3,
In the antenna device, the reflecting mirror has a second curved surface different from the curved surface in at least one of a positive direction and a negative direction of the third axis of the curved surface. In claim 6,
The second curved surface is curved with a curvature corresponding to the first curvature in the direction along the second axis, and has a linear shape in the direction along the third axis. In claim 6,
The second curved surface is curved with a curvature corresponding to the first curvature in the direction along the second axis, and curved with a third curvature smaller than the second curvature in the direction along the third axis. antenna device. In any one of claims 1 to 3,
The antenna device further includes a drive mechanism that changes the main radiation direction according to the curved line having the first curvature by moving the reflecting mirror. In any one of claims 1 to 3,
The antenna device further includes a second drive mechanism that rotates the reflecting mirror around a rotation axis parallel to the second axis or the third axis.

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