JP2006074697A - Directional antenna, directivity control method therefor, and antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a directional antenna which can be mounted on a small-sized device and can freely change the direction of radiation, and to provide a directivity control method therefor and an antenna system. <P>SOLUTION: In the directional antenna which includes a power feeding patch 2 and at least one parasitic path 3 disposed around the power feeding path and in which the direction of electromagnetic wave radiation is changed by grounding a current induced in the parasitic patch 3, the parasitic patch 3 comprises GND short-circuiting lines 4a, 4b1, 4b2, 4b3 for grounding at positions different from the center of an exciting direction, and each of the GND short-circuiting lines comprises a switch for changing over whether or not the parasitic patch 3 and the ground are to be electrically connected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a directional antenna capable of freely selecting a beam emission direction, a method for controlling the directivity, and an antenna system using the directional antenna.

  In recent years, satellite communication and mobile communication have been actively performed, and the importance of directional antennas has attracted attention.

  In satellite communication mobile communication, the relative position of the transmitting side and the receiving side changes, so when using a directional antenna, it is necessary to detect the direction in which the communication partner is located and point the antenna in that direction. .

  When an omnidirectional antenna is used, it is not necessary to change the direction of the antenna. However, since it has drawbacks such as poor radiation efficiency and noise, it is rarely used in practice.

  As a prior art relating to satellite communication, there is a “satellite broadcast receiving antenna automatic tracking device” disclosed in Patent Document 1. The invention disclosed in Patent Document 1 detects the direction of transmission or reception by mechanically moving an antenna and tracks a communication partner.

  As conventional techniques related to mobile communication, there are an “antenna pointing system” disclosed in Patent Document 2 and a “directional antenna tracking device” disclosed in Patent Document 3. The invention disclosed in Patent Document 2 is a system that tracks a communication partner using a gyro and geomagnetism. The invention disclosed in Patent Document 3 is a system for tracking a communication partner by mechanically moving an antenna while constantly checking the position of a moving body using a gyro, GPS, and geomagnetism.

  However, in the field of mobile communication, downsizing of the device is required, so that it is actually difficult to apply the inventions disclosed in the above patent documents.

In order to solve such a problem, Non-Patent Document 1 proposes a method of providing directivity by using a patch antenna and dropping a parasitic patch portion to GND. FIG. 12 shows an antenna to which the method disclosed in Non-Patent Document 1 is applied. This antenna tilts the radiation direction by the interaction between the phase of the current excited by the parasitic patch on the opposite side and the phase of the current of the feeding patch by dropping the current induced in the parasitic patch to GND.
JP-A-9-321517 Japanese Examined Patent Publication No. 7-58854 Japanese Patent Laid-Open No. 10-10220 DVThiel, Electronics Letters, vol.33 No.1, pp7-8

However, in this method, although directivity is obtained, the direction is only one predetermined direction, and directivity in an arbitrary direction cannot be changed.
Further, since the current induced in the parasitic patch is dropped to GND at a single point, the residual current of the parasitic patch is large, which hinders the beam radiation direction from being greatly inclined.

  Thus, a directional antenna that can be mounted on a small device and whose radiation direction can be freely changed has not been provided.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a directional antenna that can be mounted on a small device and whose radiation direction can be freely changed, a directivity control method thereof, and an antenna system.

In order to achieve the above object, as a first aspect, the present invention includes a power supply patch and at least one non-power supply patch arranged around the power supply patch, and grounds a current induced in the non-power supply patch. The parasitic patch has a plurality of short-circuit wires for grounding the parasitic patch at a location different from the center of the excitation direction. The present invention provides a directional antenna comprising a switch for switching whether or not to electrically connect a parasitic patch and a ground.
Since there are a plurality of positions where the parasitic patch is dropped to GND except for the center of the excitation direction of the parasitic patch, the radiation direction of the electromagnetic wave can be tilted in an arbitrary direction from the direction perpendicular to the surface on which the patches are arranged.

In the first aspect of the present invention, the parasitic patch is preferably electrically connected to the ground by two or more short-circuit wires. By connecting two or more portions of the non-feeding patch to the GND at the same time, it is possible to tilt the radiation direction of the electromagnetic wave more than before.
In addition to this, it is preferable that a plurality of short-circuit lines for electrically connecting the parasitic patch to the ground are provided on one end side in the excitation direction of the parasitic patch. In this way, it is possible to tilt the radiation direction of the electromagnetic wave more than before.
Alternatively, it is preferable that at least one short-circuit line for electrically connecting the parasitic patch to the ground is provided at both ends in the excitation direction of the parasitic patch. More preferably, two or more short-circuits that are electrically connected to the ground are provided at both ends of the parasitic patch in the excitation direction. In addition, it is preferable that the short-circuit line that electrically connects the parasitic patch with the ground is disposed so as not to overlap the excitation direction of the parasitic patch. If short-circuit wires are disposed at both ends in the excitation direction, the distance between the short-circuit wires is widened, so that it is easy to dispose a switch. Moreover, it becomes possible to incline the radiation direction of electromagnetic waves larger than before.

  In order to achieve the above object, the present invention provides, as a second aspect, a directional antenna having a power supply patch and at least one power supply patch disposed around the power supply patch. A short-circuit wire having a switch for switching whether or not to electrically connect the parasitic patch to the ground and to ground a current induced in the parasitic patch; and to connect two or more parasitic patches to the ground Thus, the present invention provides a directional antenna characterized in that the radiation direction of electromagnetic waves changes by connecting the two. In this way, it is possible to tilt the radiation direction of the electromagnetic wave more than before.

  Moreover, in order to achieve the said objective, this invention is a method of controlling the directivity direction of the directional antenna concerning the structure in any one of the said 1st aspect of the said invention as 3rd aspect, Comprising: The antenna directivity control method is characterized in that the radiation direction of electromagnetic waves is controlled by changing the position and the number of short-circuit lines used for connecting to the ground by switching of the switches. According to this aspect, the radiation direction of electromagnetic waves can be tilted in an arbitrary direction from the direction perpendicular to the surface on which the patches are arranged.

  In order to achieve the above object, the present invention provides, as a fourth aspect, a method for controlling the directivity direction of a directional antenna according to the second aspect of the present invention, in which a parasitic patch connected to the ground is provided. The antenna directivity control method is characterized by controlling the radiation direction of electromagnetic waves by changing the position and number of the antennas. According to this aspect, the radiation direction of electromagnetic waves can be tilted in an arbitrary direction from the direction perpendicular to the surface on which the patches are arranged.

  In order to achieve the above object, the present invention provides, as a fifth aspect, an antenna system using a directional antenna according to any one of the first aspect of the present invention, wherein a parasitic patch is provided. It is an object of the present invention to provide an antenna system having means for controlling the radiation direction of electromagnetic waves by changing the position and number of short-circuit lines used for connection to a ground by switching a switch. According to this aspect, the radiation direction of electromagnetic waves can be tilted in an arbitrary direction from the direction perpendicular to the surface on which the patches are arranged.

  In order to achieve the above object, the present invention provides, as a sixth aspect, an antenna system using the directional antenna according to the second aspect of the present invention, wherein the position of the parasitic patch connected to the ground is And an antenna system having means for controlling the radiation direction of electromagnetic waves by changing the number of the antenna systems. According to this aspect, the radiation direction of electromagnetic waves can be tilted in an arbitrary direction from the direction perpendicular to the surface on which the patches are arranged.

  ADVANTAGE OF THE INVENTION According to this invention, the directional antenna which can be mounted in a small apparatus and can change a radiation direction freely, its directional control method, and an antenna system can be provided.

[Principle of the Invention]
The present invention provides directivity by dropping the non-feed patch of the patch antenna to GND.
The control of the radiation direction is performed by adjusting the position of dropping to GND and the number of dropping positions to control the residual current. More specifically, the remaining current is reduced by dropping the non-powered patches to GND at two or more locations at the same time, and the directivity is controlled by changing the number of the non-powered patches dropped to GND.

  The patch antenna has a structure in which a conductor patch is formed on a dielectric, and the other side of the patch across the dielectric is a conductor GND (referred to as a ground plane or a ground plane). The patch is fed from the back via a coaxial cable.

  Hereinafter, preferred embodiments of the present invention based on the above principle will be described. In the drawings used for the description, some elements are exaggerated or omitted for easy explanation. Specifically, the patch antenna is omitted from the dielectric and ground plane among the components, and only the patch pattern is shown. It should be noted that a switch is provided on a GND short-circuit line (not shown) that is a line for dropping the non-powered patch to GND, and whether or not to drop the non-powered patch to the GND level can be switched by switching the switch. Yes.

  In the following description, a coordinate system as shown in FIG. 8 is used. The position in the space is represented by three-axis orthogonal coordinates of XYZ, where the rotation angle from the X-axis direction to the Y-axis direction is φ, and the rotation angle from the Z-axis to the XY plane is θ. The positive direction of the Z axis represents the zenith direction, and the XY plane represents the horizontal plane.

[First Embodiment]
A first embodiment in which the present invention is suitably implemented will be described. FIG. 1 shows a configuration of a directional antenna according to this embodiment.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 1A shows a configuration in which the non-feeding patches 3 are arranged on both sides in the Y-axis direction with the feeding patch 2 as the center. The parasitic patch 3 is provided with GND short-circuit lines 4a, 4b1, 4b2, and 4b3. Each GND short-circuit line is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for the sake of simplification of explanation, the GND short-circuit line is not shown in the parasitic patch 3 on the lower side in the drawing.
By switching a switch (not shown), each of the GND short-circuit lines 4a, 4b1, 4b2, and 4b3 is in a state where at least one of them is short-circuited to a ground plate (not shown) or neither is short-circuited to the ground plate.
When none of the GND short-circuit lines 4a, 4b1, 4b2, and 4b3 is short-circuited to the ground plane (when all the GND short-circuit lines are floating from GND), the radiation direction of electromagnetic waves is a direction perpendicular to the XY plane (Z-axis) Direction, ie, zenith direction).
When the GND short-circuit line 4a is short-circuited to the ground plane by switching a switch (not shown), the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative direction of the Y-axis in the configuration shown in FIG. This is a phenomenon that occurs due to the correlation between the phase of the induced current of the parasitic patch 3 on the side that is not dropped to GND and the phase of the induced current of the feeder patch 2 by dropping one side of the parasitic patch to GND.

  There is a correlation between the phase of the induced current of the feed patch 2 and the phase of the induced current of the parasitic patch 3 even when both the parasitic patches 3 are insulated from the ground plane or both are short-circuited to the ground plane. However, since the parasitic patches 3 are arranged symmetrically with respect to the feeding patch 2, the influence of the induced current of each parasitic patch 3 cancels out, and the radiation direction of the electromagnetic wave becomes the zenith direction. In other words, when the symmetry of the phase of the induced current of the parasitic patch 3 centered on the feeding patch 2 is broken, the radiation direction of the electromagnetic wave is inclined from the zenith direction.

As the parasitic patch 3 is short-circuited at a position near the end portion in the excitation direction, the induced current is likely to drop to GND. Therefore, when the GND short-circuit line 4b1 is short-circuited to the ground plane, the induced current is more likely to drop to GND than when the GND short-circuit line 4a is short-circuited to the ground plane. For this reason, the radiation direction of the electromagnetic wave when the GND short-circuit line 4b1 is short-circuited to the ground plane has a larger inclination from the zenith direction (inclination in the Y-axis minus direction) than when the GND short-circuit line 4a is short-circuited to the ground plane.
On the other hand, when the GND short-circuit lines 4b2 and 4b3 are short-circuited to the ground plane, the induced current is less likely to drop to GND than when the GND short-circuit line 4a is short-circuited to the ground plane. For this reason, the radiation direction of the electromagnetic waves when the GND short-circuit lines 4b2 and 4b3 are short-circuited to the ground plane is smaller in inclination from the zenith direction (inclination in the Y-axis minus direction) than when the GND short-circuit line 4a is short-circuited to the ground plane. Become.

  If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the non-feeding patch 3 on the lower side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

FIG. 1B shows a configuration in which the non-feeding patches 3 are arranged on both sides in the X-axis direction with the feeding patch 2 as the center. Even in this configuration, the electromagnetic wave depends on whether one of the parasitic patches 3 is short-circuited to the ground plane and whether the GND short-circuiting wires 4a, 4b1, 4b2, and 4b3 are used to short-circuit the parasitic patch 3 to the ground plane. The radiation direction can be adjusted.
However, in the case of this structure, when the GND short-circuit wire 4a is short-circuited to the ground plane, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative side of the X axis. Further, the radiation direction of the electromagnetic wave when the GND short-circuit line 4b1 is short-circuited with the ground plane has a greater inclination from the zenith direction (slope toward the X-axis minus direction) than when the GND short-circuit line 4a is short-circuited with the ground plane. Further, the radiation direction of the electromagnetic wave when the GND short-circuit lines 4b2 and 4b3 are short-circuited to the ground plane is smaller from the zenith direction (slope to the X-axis minus direction) than when the GND short-circuit line 4a is short-circuited to the ground plane. .
If the radiation direction of the electromagnetic wave is inclined to the X axis plus side, the parasitic patch 3 on the lower side in the figure (not shown) may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  Note that, here, the configuration of four GND short-circuit lines has been described as an example, but this number and the position where it is arranged can be arbitrarily set.

  Moreover, although the case where any one of the GND short-circuit lines 4a, 4b1, 4b2, and 4b3 is short-circuited to a ground plate (not shown) has been described here, two or more of them may be short-circuited to the ground plate at the same time.

[Second Embodiment]
A second embodiment in which the present invention is suitably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 2A shows a configuration in which the non-feeding patches 3 are arranged on both sides in the Y-axis direction with the feeding patch 2 as the center. The parasitic patch 3 is provided with a GND short-circuit line 5. Each GND short-circuit line is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for the sake of simplification of explanation, the GND short-circuit line is not shown in the parasitic patch 3 on the lower side in the drawing.
The GND short-circuit line 5 short-circuits the parasitic patch 3 and a ground plane (not shown) when a switch (not shown) is ON.
When all the GND short-circuit line switches are OFF (when all the GND short-circuit lines are floating from GND), the radiation direction of the electromagnetic wave is a direction perpendicular to the XY plane (Z-axis direction, that is, the zenith direction).
When any switch of the GND short-circuit line 5 is turned ON, in the configuration shown in FIG. 2A, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative direction of the Y axis. As in the case of the first embodiment, by dropping one side of the non-feeding patch to GND, the phase of the induced current of the non-feeding patch 3 on the side not dropped to GND and the phase of the induced current of the feeding patch 2 It is a phenomenon that arises from the mutual relationship.

When the number of GND short-circuit lines 5 to be short-circuited with the ground plane is increased, the induced current of the parasitic patch 3 is likely to fall to GND. For this reason, when the number of the GND short-circuit lines 5 to be short-circuited with the ground plane is increased, the electromagnetic wave radiation direction is greatly inclined from the zenith direction to the Y-axis minus direction.
Conversely, if the number of GND short-circuit lines 5 to be short-circuited with the ground plane is reduced, the induced current of the parasitic patch 3 is less likely to fall to GND. For this reason, if the number of the GND short-circuit lines 5 to be short-circuited with the ground plane is reduced, the inclination of the electromagnetic wave in the radiation direction (the inclination from the zenith direction to the Y-axis minus direction) becomes small.

  If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the non-feeding patch 3 on the lower side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

FIG. 2B shows a configuration in which the non-feeding patches 3 are arranged on both sides in the X-axis direction with the feeding patch 2 as the center. Also in this configuration, the radiation direction of the electromagnetic wave can be adjusted depending on whether one of the parasitic patches 3 is short-circuited to the ground plane and how many GND short-circuiting wires 5 are used to short-circuit the parasitic patch 3 to the ground plane.
However, in the case of this structure, if the number of the GND short-circuit lines 5 to be short-circuited with the ground plane is increased, the inclination is greatly inclined from the zenith direction to the X-axis minus direction. Further, when the number of GND short-circuit lines 5 to be short-circuited with the ground plane is reduced, the inclination of the electromagnetic wave radiation direction (inclination from the zenith direction to the Y-axis minus direction) becomes small.
If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the parasitic patch 3 on the left side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  Note that, here, the configuration of four GND short-circuit lines has been described as an example, but this number and the position where it is arranged can be arbitrarily set.

[Third Embodiment]
A third embodiment in which the present invention is preferably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction indicated by an arrow in FIG. 3 (Y-axis direction).

FIG. 3A shows a configuration in which the non-feeding patches 3 are arranged on both sides in the Y-axis direction with the feeding patch 2 as the center. The parasitic patch 3 is provided with a GND short-circuit line 6. Each GND short-circuit line is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for simplification of explanation, a GND short-circuit line is not shown in the lower parasitic patch 3 in the figure.
The GND short-circuit lines 6 are respectively provided at both ends of the parasitic patch 3 in the excitation direction, and short-circuit the parasitic patch 3 and the ground plane (not shown) when a switch (not shown) is ON.
When all the GND short-circuit line switches are OFF (when all the GND short-circuit lines are floating from GND), the radiation direction of the electromagnetic wave is a direction perpendicular to the XY plane (Z-axis direction, that is, the zenith direction).
When any switch of the GND short-circuit line 6 is turned ON, in the configuration shown in FIG. 2A, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative direction of the Y axis. As in the case of the first embodiment, by dropping one side of the non-feeding patch to GND, the phase of the induced current of the non-feeding patch 3 on the side not dropped to GND and the phase of the induced current of the feeding patch 2 It is a phenomenon that arises from the mutual relationship.

  The closer the GND short-circuit line is to the periphery of the parasitic patch, particularly the end in the excitation direction, the easier it is to drop the induced current of the parasitic patch 3 to GND. Therefore, the current induced in the parasitic patch 3 is efficiently dropped to GND by the GND short-circuit line 6 provided at the excitation direction end of the parasitic patch 3. For this reason, the radiation direction of electromagnetic waves is greatly inclined from the zenith direction to the Y axis minus direction. Furthermore, when both the GND short-circuit lines 6 are short-circuited to the ground plane, the current induced in the parasitic patch 3 is more efficiently dropped to GND, and the inclination in the Y-axis minus direction increases.

  If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the non-feeding patch 3 on the lower side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

FIG. 3B shows a configuration in which the non-feeding patches 3 are arranged on both sides in the X-axis direction with the feeding patch 2 as the center. Also in this configuration, the radiation direction of the electromagnetic wave can be adjusted depending on whether one of the parasitic patches 3 is short-circuited to the ground plane and how many GND short-circuiting wires 6 are used to short-circuit the parasitic patch 3 to the ground plane.
In the case of this structure, the inclination in the radial direction is an inclination from the zenith direction to the X-axis minus direction, and the inclination increases when both the GND short-circuit lines 6 are short-circuited to the ground plane. If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the parasitic patch 3 on the left side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  Here, the configuration in which one GND short-circuit line is arranged at both ends in the excitation direction has been described as an example, but two or more GND short-circuit lines may be arranged at both ends in the excitation direction.

[Fourth Embodiment]
A fourth embodiment in which the present invention is preferably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 4A shows a configuration in which the non-feeding patches 3 are arranged on both sides in the Y-axis direction with the feeding patch 2 as the center. The parasitic patch 3 is provided with a GND short-circuit line 7. Each GND short-circuit line 7 is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for the sake of simplification of explanation, the GND short-circuit line is not shown in the parasitic patch 3 on the lower side in the drawing.
Three GND short-circuit lines 7 are provided at both ends of the parasitic patch 3 in the excitation direction, respectively, and short-circuit the parasitic patch 3 and the ground plane (not illustrated) when a switch (not illustrated) is ON.
When all the GND short-circuit line switches are OFF (when all the GND short-circuit lines are floating from GND), the radiation direction of the electromagnetic wave is a direction perpendicular to the XY plane (Z-axis direction, that is, the zenith direction).
When any switch of the GND short-circuit line 7 is turned ON, in the configuration shown in FIG. 4A, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative direction of the Y axis. As in the case of the first embodiment, by dropping one side of the non-feeding patch to GND, the phase of the induced current of the non-feeding patch 3 on the side not dropped to GND and the phase of the induced current of the feeding patch 2 It is a phenomenon that arises from the mutual relationship.

  As the number of GND short-circuit lines increases, the induced current of the parasitic patch 3 tends to drop to GND. In the present embodiment, since six GND short-circuit lines are provided in the parasitic patch 3, when the switches of the six GND short-circuit lines are turned on as shown in FIG. In comparison, the current induced in the parasitic patch 3 is more efficiently dropped to GND. For this reason, the inclination of the radial direction in the negative Y-axis direction increases.

  If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the non-feeding patch 3 on the lower side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

FIG. 4B shows a configuration in which the non-feeding patches 3 are arranged on both sides in the X-axis direction with the feeding patch 2 as the center. Also in this configuration, the radiation direction of the electromagnetic wave can be adjusted depending on whether one of the parasitic patches 3 is short-circuited to the ground plane and how many GND short-circuiting wires 7 are used to short-circuit the parasitic patch 3 to the ground plane.
In the case of this structure, the inclination in the radial direction is an inclination from the zenith direction to the X-axis minus direction, and increasing the number of GND short-circuit lines 7 to be short-circuited with the ground plane increases the inclination in the radial direction. If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the parasitic patch 3 on the left side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  Here, the configuration in which the number of GND short-circuit lines is six has been described as an example, but this number and the position where it is arranged can be arbitrarily set.

[Fifth Embodiment]
A fifth embodiment in which the present invention is preferably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 5A shows a configuration in which the non-feeding patches 3 are arranged on both sides in the Y-axis direction with the feeding patch 2 as the center. The parasitic patch 3 is provided with a GND short-circuit line 8. Each GND short-circuit wire 8 is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for the sake of simplification of explanation, the GND short-circuit line is not shown in the parasitic patch 3 on the lower side in the drawing.
Two GND short lines 8 are provided at both ends of the parasitic patch 3 in the excitation direction, respectively, and short-circuit the parasitic patch 3 and the ground plane (not illustrated) when a switch (not illustrated) is ON. Each GND short-circuit line 8 is arranged so as not to overlap the excitation direction (in other words, the X coordinate is different).
When all the GND short-circuit line switches are OFF (when all the GND short-circuit lines are floating from GND), the radiation direction of the electromagnetic wave is a direction perpendicular to the XY plane (Z-axis direction, that is, the zenith direction).
When any switch of the GND short-circuit line 7 is turned ON, in the configuration shown in FIG. 5A, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the negative direction of the Y axis. As in the case of the first embodiment, by dropping one side of the non-feeding patch to GND, the phase of the induced current of the non-feeding patch 3 on the side not dropped to GND and the phase of the induced current of the feeding patch 2 It is a phenomenon that arises from the mutual relationship.

  When the GND short-circuit lines are provided so as not to overlap with each other in the excitation direction, even if the parasitic patches 3 are short-circuited to the ground plane using the same number of GND short-circuit lines, the induced current of the parasitic patches 3 tends to drop to GND. Therefore, as compared with the first to third embodiments, the current induced in the parasitic patch 3 is more efficiently dropped to GND. For this reason, the inclination of the radial direction in the negative Y-axis direction increases.

  If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the non-feeding patch 3 on the lower side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

FIG. 5B shows a configuration in which the non-feeding patches 3 are arranged on both sides in the X-axis direction with the feeding patch 2 as the center. Also in this configuration, the radiation direction of the electromagnetic wave can be adjusted depending on whether one of the parasitic patches 3 is short-circuited to the ground plane and how many GND short-circuit wires 8 are used to short-circuit the parasitic patch 3 to the ground plane.
In the case of this structure, the inclination in the radial direction is an inclination from the zenith direction to the X axis minus direction. If the radiation direction of the electromagnetic wave is inclined to the Y axis plus side, the parasitic patch 3 on the left side in the drawing (not shown) may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  Note that, here, the configuration of four GND short-circuit lines has been described as an example, but this number and the position where it is arranged can be arbitrarily set.

[Sixth Embodiment]
A sixth embodiment in which the present invention is preferably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at a power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 6 shows a configuration in which a non-feeding patch 3 is arranged around a feeding patch 2 to form a matrix antenna. Each parasitic patch 3 is provided with a GND short-circuit line 9. The GND short-circuit line 9 is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for simplification of explanation, only the parasitic patch 3 on the upper side in the drawing is shown in (a), and the GND short-circuiting wire 9 for feeding the non-feeding patch 3 on the right side in the drawing is shown in (b).
When the switches of the GND short-circuit wires 9 of all the parasitic patches 3 are OFF (when all the GND short-circuit wires are floating from the GND), the electromagnetic wave radiation direction is a direction perpendicular to the XY plane (Z-axis direction, that is, Zenith direction).

  As shown in FIG. 6A, when the switch of the GND short-circuit wire 9 of the parasitic patch 3 on the Y axis plus side is turned ON, the radiation direction of the electromagnetic wave is inclined from the zenith direction to the minus direction of the Y axis. As in the case of the first embodiment, the phase of the induced current of the parasitic patch 3 on the side not to be dropped to GND and the feeding patch 2 are reduced by dropping the parasitic patch 3 around the feeding patch 2 to GND. This is a phenomenon that occurs from the correlation of the phases of the induced current.

  Similarly, as shown in FIG. 6B, when the switch of the GND short-circuit wire 9 of the parasitic patch 3 on the X axis plus side is turned ON, the radiation direction of the electromagnetic wave is from the zenith direction to the minus direction of the X axis. Lean to.

  If the electromagnetic wave radiation direction is inclined to the Y-axis plus side, the GND short-circuit wire 9 of the parasitic patch 3 on the Y-axis minus side may be short-circuited to the ground plane in the same manner as described above. If the electromagnetic wave radiation direction is inclined to the Y-axis plus side, the GND short-circuit wire 9 of the parasitic patch 3 on the X-axis minus side may be short-circuited to the ground plane in the same manner as described above.

  As described above, the directional antenna according to the present embodiment can tilt the radiation direction of the electromagnetic wave from the zenith direction to the X axis direction or the Y axis direction by an arbitrary angle θ.

  By dropping the induced currents of the three parasitic patches 3 to GND, the inclination of the radiation direction of the electromagnetic wave can be increased compared to the case where only the induced current of one parasitic patch 3 is dropped to GND.

  Here, the configuration in which one GND short-circuit line 9 is provided in each parasitic patch 3 has been described as an example, but this number and the position where it is arranged can be arbitrarily set.

[Seventh Embodiment]
A seventh embodiment in which the present invention is preferably implemented will be described.
The patch antenna according to the present embodiment has a configuration in which a feeding patch 2 and a parasitic patch 3 are arranged in an XY plane. The power supply patch 2 is supplied with power at the power supply point 1 and is excited in a direction (Y-axis direction) indicated by an arrow in FIG.

FIG. 7 shows a configuration in which a non-feeding patch 3 is arranged around a feeding patch 2 to form a matrix antenna. Each parasitic patch 3 is provided with a GND short-circuit line 10. The GND short-circuit line 10 is short-circuited to a ground plate (not shown) via a switch (not shown). Here, for the sake of simplification of explanation, only the parasitic patch 3 on the upper and right sides in the drawing shows the short-circuit line 10.
When the switches of the GND short-circuit wires 10 of all the parasitic patches 3 are OFF (when all the GND short-circuit wires are floating from GND), the electromagnetic wave radiation direction is a direction perpendicular to the XY plane (Z-axis direction, that is, Zenith direction).

  As shown in FIG. 7, when the switch of the GND short-circuit wire 10 of the non-feeding patch 3 on the right, upper and diagonally right of the feeding patch 2 is turned on, the radiation direction of the electromagnetic wave is the X-axis minus direction from the zenith direction. And the Y axis minus direction. This is a phenomenon that occurs due to the correlation between the phase of the induced current of the non-feeding patch 3 and the phase of the induced current of the feeding patch 2 that are not dropped to GND.

  If the radiation direction of the electromagnetic wave is inclined to the opposite side, the GND short-circuit wire 10 of the non-feeding patch 3 on the left, lower and lower left of the feeding patch 2 may be short-circuited with the ground plane in the same manner as described above. Similarly, if the radiation direction of the electromagnetic wave is inclined in the intermediate direction between the X-axis minus direction and the Y-axis plus direction, the GND short-circuit wire 10 of the non-feeding patch 3 on the right side, the lower side and the lower right side of the feeding patch 2 is used as the ground plane. What is necessary is just to short-circuit. Furthermore, if the radiation direction of the electromagnetic wave is inclined in the intermediate direction between the X axis plus direction and the Y axis minus direction, the GND short-circuit wire 10 of the parasitic patch 3 on the left, upper and upper left of the electrostatic patch is short-circuited to the ground plane. Just do it.

  Other than the above example, the radiation direction of the electromagnetic wave can be set to an arbitrary direction by changing the position and the number of the parasitic patches 3 to be short-circuited with the ground plane. That is, θ and φ, which are inclination components of the electromagnetic wave radiation direction, can be set to arbitrary values.

Each of the above embodiments is an example of a preferred embodiment of the present invention, and the present invention is not limited to this.
For example, in the first to fifth embodiments, the configuration in which a total of three feeding patches and non-feeding patches are arranged has been described as an example, but the number of patches is arbitrary.
In the sixth embodiment and the seventh embodiment, the antenna having the 3 × 3 matrix configuration has been described as an example. However, the directivity can be achieved even in a 5 × 5 matrix or more. There is no problem with the controls.
Thus, the present invention can be variously modified.

It is a figure which shows the structure of the antenna concerning 1st Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 2nd Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 3rd Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 4th Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 5th Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 6th Embodiment which implemented this invention suitably. It is a figure which shows the structure of the antenna concerning 7th Embodiment which implemented this invention suitably. It is a figure which shows the definition of a coordinate system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding point 2 Feeding patch 3 Non-feeding patch 4a, 4b1, 4b2, 4b3, 5, 6, 7, 8, 9, 10 GND short circuit line

Claims (11)

A directional antenna having a feeding patch and at least one parasitic patch arranged around the feeding patch, wherein a radiation direction of electromagnetic waves is changed by grounding a current induced in the parasitic patch;
The parasitic patch includes a plurality of short-circuit wires for grounding the parasitic patch at a location different from the center of the excitation direction,
Each short-circuit line includes a switch that switches whether to electrically connect the parasitic patch and the ground.   The directional antenna according to claim 1, wherein the parasitic patch is electrically connected to a ground through the two or more short-circuit wires.   The directional antenna according to claim 2, wherein a plurality of short-circuit lines electrically connecting the parasitic patch to the ground are provided on one end side in the excitation direction of the parasitic patch.   3. The directional antenna according to claim 2, wherein at least one short-circuit line that electrically connects the parasitic patch to the ground is provided at both ends of the parasitic patch in the excitation direction.   5. The directional antenna according to claim 4, wherein two or more short-circuits for electrically connecting the parasitic patch to the ground are provided at both ends in the excitation direction of the parasitic patch.   6. The directional antenna according to claim 4, wherein a short-circuit line that electrically connects the parasitic patch to the ground is disposed so as not to overlap an excitation direction of the parasitic patch. A directional antenna having a feeding patch and at least one parasitic patch arranged around the feeding patch,
The parasitic patch includes a short-circuit line including a switch that switches whether to electrically connect the parasitic patch to the ground and to ground the current induced in the parasitic patch.
A directional antenna characterized in that the radiation direction of electromagnetic waves is changed by electrically connecting two or more parasitic patches to the ground. A method for controlling a directivity direction of a directional antenna according to any one of claims 1 to 6,
An antenna directivity control method, comprising: controlling a radiation direction of an electromagnetic wave by changing a position and a number of the short-circuit line used for connecting the parasitic patch to a ground by switching the switch. A method for controlling a directivity direction of a directional antenna according to claim 7,
An antenna directivity control method, comprising: controlling a radiation direction of an electromagnetic wave by changing a position and a number of the non-feeding patches connected to a ground. An antenna system using the directional antenna according to any one of claims 1 to 7,
An antenna system comprising: means for controlling a radiation direction of an electromagnetic wave by changing a position and a number of the short-circuit line used for connecting the parasitic patch to a ground by switching the switch. An antenna system using the directional antenna according to claim 7,
An antenna system comprising means for controlling the radiation direction of electromagnetic waves by changing the position and number of the parasitic patches connected to the ground.

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