JP2006197429A - Antenna directivity setting method, patch antenna, on-vehicle antenna and inner mirror device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an antenna directivity setting method capable of performing data communication satisfactorily without giving influence on an installation mode of a board, a patch antenna, an on-vehicle antenna and an inner mirror device for a vehicle. <P>SOLUTION: When setting the directivity of the patch antenna 10, a patch electrode 16 is provided, offset to the opposite side from an inclination direction perpendicular to a vertical direction to a board 12 with respect to the center position of a ground 14 in accordance with a desired orientation of the patch antenna 10 inclined from a direction perpendicular to the board 12 to the front of the vehicle and to over the vehicle. Consequently, the orientation of the patch antenna 10 is inclined to the opposite side from the direction where the patch electrode 16 is offset from the direction perpendicular to the board 12. Therefore, the orientation of the patch antenna 10 at the installation position can be adapted to the desired orientation so that data communication can be performed satisfactorily with a communication terminal such as an ETC (electronic toll collection) provided at a gate of a highway. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna directivity setting method applied to an antenna used in a communication terminal constituting a wireless communication system such as an automatic toll collection system for automatically paying a toll on a toll road by wireless communication, a patch antenna, etc. The present invention relates to a vehicle-mounted antenna and a vehicle inner mirror device including the same.

  A small patch antenna may be used as an antenna of a wireless communication terminal, and an example thereof is disclosed in Patent Document 1 below. The patch antenna includes a flat substrate, and, for example, a film-like patch electrode (for example, copper foil) having a smaller area than the substrate is formed at the center of the surface (one plate surface) of the substrate. Patch electrode) is formed. A film-like ground (for example, a ground made of copper foil) is entirely formed on the back surface (the other plate surface) opposite to the surface on which the patch electrode of the substrate is formed. This ground is electrically connected to the outer conductor of the coaxial cable for high-frequency signal transmission, for example, by soldering.

  Such a patch antenna is used in, for example, an ETC vehicle-mounted device constituting an automatic toll collection system (hereinafter referred to as ETC) that automatically pays a toll for toll roads by wireless communication. This ETC vehicle-mounted device is used by being attached to a vehicle such as an automobile.

  The patch antenna of the ETC on-vehicle device is, for example, erected in a state of being accommodated in a case in the on-vehicle state, and can transmit (radiate) radio waves to the front of the vehicle or receive from the front of the vehicle.

  When traveling on a toll road with a vehicle equipped with such an ETC on-vehicle device (for example, when passing through an interchange gate on a highway), a patch antenna is used to connect the ETC on-vehicle device and the gate side of the vehicle. This is a mechanism in which data is transmitted and received with a communication terminal by wireless communication.

  However, since the communication terminal on the gate side is installed at a position higher than the vehicle height, when the vehicle passes through the gate, the ETC on-vehicle device is located diagonally above the vehicle and above the vehicle. Must communicate with a communication terminal located in the direction. Therefore, when the directivity direction of the patch antenna is the front of the vehicle, there is a possibility that data transmission / reception may not be performed satisfactorily.

  In this case, the patch antenna is installed with the surface of the board diagonally upward at the patch antenna mounting position of the vehicle, so that the direction of the patch antenna is changed diagonally upward, or the array antenna is connected with a plurality of patch antennas. It is conceivable to take measures such as changing the directivity direction (that is, changing the antenna directivity itself) by configuring.

  However, if the above changes are made, for example, the case for accommodating the patch antenna may become large, and in this case, there arises a problem that the antenna portion of the ETC on-board unit becomes large. That is, there has been a drawback that such a change may be difficult due to design restrictions.

Therefore, measures to change the orientation of the patch antenna without changing the orientation of the board or configuring the array antenna that requires a larger installation area than a single patch antenna with multiple patch antennas. Was desired.
JP 2004-56498 A

  In view of the above problems, the present invention provides an antenna directivity setting method, a patch antenna, an in-vehicle antenna, and an inner mirror device for a vehicle that can satisfactorily perform data communication without being affected by the installation form of the substrate. With the goal.

  In the antenna directivity setting method according to the first aspect of the present invention, an area on the substrate is larger than an area of the ground on the surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface. An antenna directivity setting method in which a small film-like patch electrode is provided to face the ground through the substrate, and the patch electrode sets the directivity of a patch antenna that performs at least one of transmission and reception of radio waves. In order to incline the directivity direction of the patch antenna in a desired direction with respect to the direction perpendicular to the substrate, the opposite side of the inclination direction perpendicular to the vertical direction with respect to the center position of the ground The patch electrode is offset.

  According to the patch antenna handled by the antenna directivity setting method according to the first aspect of the invention, for example, at least one of transmission and reception of radio waves is performed by the patch electrode formed on the surface of the substrate. Thereby, data communication is performed with an external communication terminal.

  Here, in the antenna directivity setting method according to claim 1, the patch electrode is positioned relative to the center position of the ground according to the desired directivity direction (desired direction) of the patch antenna inclined from the direction perpendicular to the substrate. And offset to the opposite side of the tilt direction perpendicular to the vertical direction.

  Thereby, the directivity direction of the patch antenna is tilted from a direction perpendicular to the substrate to a desired direction. For this reason, the directivity direction and the desired direction at the attachment position of the patch antenna can be matched, and data communication can be performed favorably with an external communication terminal.

  In addition, the antenna directivity setting method includes, for example, multiple installations such that the substrate is tilted so that the direction perpendicular to the substrate is a desired direction at the patch antenna mounting position, or the directivity direction is aligned with the desired direction. Even if the array antenna is not configured by the patch antenna, the directivity direction can be aligned in a desired direction as described above, so that there is no restriction on the design of the patch antenna. That is, this antenna directivity setting method is not affected by the installation form of the board when setting the directivity direction.

  According to a second aspect of the present invention, there is provided a patch antenna having a film having an area on the substrate that is smaller than an area of the ground on a surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface. In a patch antenna in which a patch electrode is provided facing the ground through the substrate, and the patch electrode performs at least one of transmission and reception of radio waves, the patch electrode is perpendicular to the substrate with respect to the center position of the ground The patch electrode is offset in a direction orthogonal to the direction, so that the directivity direction of the patch antenna is inclined from the vertical direction to the opposite side to the offset direction.

  According to the patch antenna of the second aspect of the invention, at least one of transmission and reception of radio waves is performed by the patch electrode formed on the surface of the substrate. Thereby, data communication is performed with an external communication terminal.

  Here, in the patch antenna according to the second aspect, the patch electrode is provided offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground.

  As a result, the directivity direction of the patch antenna is tilted from the direction perpendicular to the substrate to the side opposite to the offset direction of the patch electrode. For this reason, the directivity direction at the attachment position of the patch antenna can be adapted to a desired direction, and data communication with an external communication terminal can be performed satisfactorily.

  In addition, this patch antenna can align the directivity direction to a desired direction as described above, without installing the board at an inclined position at the mounting position or configuring an array antenna with a plurality of patch antennas. Therefore, there is no restriction on the design of the patch antenna. That is, this patch antenna is not affected by the installation form of the substrate in aligning the directivity direction to a desired direction.

  An in-vehicle antenna according to a third aspect of the invention is provided at a predetermined position of a vehicle and has an area on the substrate on a surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface. In a vehicle-mounted antenna in which a film-like patch electrode smaller than the ground area is provided to face the ground through the substrate, and the patch electrode performs at least one of transmission and reception of radio waves, the center of the ground Since the patch electrode is offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the position, the directivity direction of the patch antenna is tilted from the vertical direction to the opposite side of the offset direction. It is characterized by that.

  According to the vehicle-mounted antenna according to the third aspect of the present invention, the substrate is formed on the surface of the substrate in a state where the substrate is provided at a predetermined position of the vehicle, for example, on the rear surface of the windshield glass, on the surface of the dashboard, or the like. The patch electrode performs at least one of transmission and reception of radio waves. As a result, data communication is performed with an external communication terminal (for example, an ETC communication terminal provided at a highway gate).

  Here, in the in-vehicle antenna according to the third aspect, the patch electrode is provided by being offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground.

  As a result, the directivity direction of the patch antenna is tilted from the direction perpendicular to the substrate to the side opposite to the offset direction of the patch electrode. For this reason, the directivity direction at the attachment position of the patch antenna can be adapted to a desired direction, and data communication with an external communication terminal can be performed satisfactorily.

  In addition, the in-vehicle antenna can align the directivity direction to a desired direction as described above, without installing the board at an inclination at the mounting position or configuring an array antenna with a plurality of patch antennas. Therefore, there is no restriction on the design of the in-vehicle antenna. In other words, the in-vehicle antenna is not affected by the installation form of the substrate when aligning the directivity direction to a desired direction, and can be provided in parallel without tilting the substrate on the back surface of the windshield glass, for example.

  According to a fourth aspect of the present invention, an inner mirror device for a vehicle includes a mirror body that is provided in a vehicle interior and holds a mirror for visually recognizing rearward in the vicinity of an opening end, and a vehicle interior side of a windshield glass of a vehicle. And a cover that covers the base end portion of the stay, and a film-like ground is formed on the back surface. On the surface of the substrate opposite to the back surface, a film-like patch electrode having an area on the substrate smaller than the area of the ground is provided facing the ground through the substrate, and the patch electrode A patch antenna that performs at least one of transmission and reception of radio waves is provided inside the cover, and a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground Said patch electrode that is provided with an offset, the orientation of the patch antenna is a direction which is the offset from the vertical direction is inclined to the opposite side, it is characterized.

  In the vehicle inner mirror device according to the fourth aspect of the invention, the base end portion of the stay is attached to the vehicle interior side of the windshield glass of the vehicle and is covered with the cover. The mirror body is supported by the tip of the stay. The mirror body holds a rear viewing mirror in the vicinity of the opening end. With such an inner mirror device, an occupant can visually recognize the rear of the vehicle.

  Further, in the inner mirror device for a vehicle, a patch antenna is provided inside the cover. In the patch antenna, at least one of transmission and reception of radio waves is performed by a patch electrode formed on the surface of the substrate. As a result, data communication is performed with an external communication terminal (for example, an ETC communication terminal provided at a highway gate).

  Here, in the patch antenna of the vehicle inner mirror device according to the fourth aspect, the patch electrode is provided by being offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground.

  As a result, the directivity direction of the patch antenna is tilted from the direction perpendicular to the substrate to the side opposite to the offset direction of the patch electrode. For this reason, the directivity direction at the position where the patch antenna is attached can be adapted to a desired direction. For example, when the inclined directivity direction is a diagonally upward direction in front of the vehicle and above the vehicle, Data communication can be performed satisfactorily with an ETC communication terminal provided in the network.

  In addition, the inner mirror device for a vehicle can be installed in the direction of the directional direction as described above even if the substrate is not inclined and installed at the patch antenna mounting position within the cover, or the array antenna is not configured by a plurality of patch antennas. Can be aligned in a desired direction. For this reason, there is no restriction on the design of the patch antenna, and thus the inner mirror device for a vehicle. That is, the inner mirror device for a vehicle is not affected by the installation form of the substrate when aligning the directivity direction of the patch antenna in a desired direction.

  As a result, the thickness of the cover (the dimension of the windshield glass from the surface on the vehicle interior side) can be reduced, and not only the data communication described above, but also the appearance from the vehicle interior, for example, is favorable and suitable. It is.

  As described above, the antenna directivity setting method, the patch antenna, the in-vehicle antenna, and the vehicle inner mirror device according to the present invention can satisfactorily perform data communication without being affected by the installation form of the substrate.

  A patch antenna 10 as an in-vehicle antenna according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 schematically shows the patch antenna 10 in a schematic diagram. The patch antenna 10 includes a flat substrate 12. The substrate 12 is made of a dielectric and is a thin plate having a substantially square shape when viewed from above as shown in FIG.

  As shown in FIG. 1B, a ground 14 is formed on the back surface 12 </ b> B (one plate surface) of the substrate 12. The ground 14 is a conductor formed in a film shape over the entire back surface 12B, and is, for example, a copper foil.

  On the other hand, a patch electrode 16 is provided on the front surface 12A (the other plate surface) of the substrate 12 so as to face the ground 14 through the substrate 12. The patch electrode 16 is a conductor formed in a film shape on the surface 12A of the substrate 12, and is, for example, a copper foil. The patch electrode 16 is formed in a substantially square shape when viewed from above as shown in FIG. 1A, and the area on the substrate 12 is smaller than the area of the ground 14.

  Such a patch electrode 16 is offset with respect to the center position of the ground 14 in a direction perpendicular to the direction perpendicular to the substrate 12 and a pair of side surfaces of the substrate 12 facing each other (see arrow X). Is provided. Here, an alternate long and two short dashes line in FIG. 1A indicates a virtual position when the patch electrode 16 is disposed in a direction perpendicular to the substrate 12 and facing the center position of the ground 14. In order to form the offset patch electrode 16 in this way, for example, the entire surface of the surface 12A of the substrate 12 is covered with a conductor such as a copper foil, and then the above-described offset of the conductors on the surface 12A is performed with the patch electrode. The patch electrode 16 is formed by peeling off other portions except the position where the 16 is formed. In this case, for example, the patch antenna 10 may be formed by using a printed circuit board whose front and back surfaces are covered with a conductor such as copper foil as the substrate 12 and subjecting the printed circuit board to the conductor stripping process as described above. .

  In such a patch antenna 10, the patch electrode 16 is offset from the surface 12 </ b> A of the substrate 12, so that the directing direction is perpendicular to the substrate 12 (see the arrow A <b> 1 indicated by the two-dot chain line in FIG. 1B). ) To the opposite side of the offset direction (arrow X direction) of the patch electrode 16 (see arrow A2 indicated by the solid line in FIG. 1B).

  Such a patch electrode 16 performs at least one of transmission and reception of radio waves.

  Here, the patch antenna 10 as described above is used in the vehicle inner mirror device 18 as shown in FIG. 2, for example. Hereinafter, in the present embodiment, the patch antenna 10 will be described as being used as an antenna that constitutes a part of the ETC on-vehicle device (the patch electrode 16 will be described as performing both transmission and reception of radio waves).

  The vehicle inner mirror device 18 includes a stay 22. A base end portion 22 </ b> B of the stay 22 is attached to the back surface 20 </ b> A of the windshield glass 20.

  The stay 22 has an intermediate portion protruding from the base end portion 22B toward the vehicle rear side and the vehicle lower side, and a distal end portion serving as a pivot mechanism 22A. A mirror body 24 having a substantially rectangular box shape is attached to the pivot mechanism 22A, is supported so as to be swingable with respect to the vehicle, and is capable of adjusting the angle. The mirror body 24 has an opening end 24A, and holds a mirror 26 for rearward viewing near the opening end 24A. Furthermore, the mirror main body 24 includes a transmission / reception module 32 that constitutes a part of the ETC vehicle-mounted device together with the patch antenna 10 therein.

  A wiring 34 is electrically connected to the transmission module 32. The wiring 34 is routed inside a cover 28 described later via the mirror main body 24 and the stay 22. The leading end of the wiring 34 is electrically connected to one end of the wiring 36 through the substrate 12. The wiring 36 is routed to the map lamp (not shown), for example, via the cover 28. Such wiring 34 and wiring 36 cooperate with each other to supply power to the transmission / reception module 32 (for example, supply power from the map lamp side), function as a ground line for the transmission / reception module 32, A predetermined signal is transmitted between 32 and a predetermined device on the other end side of the wiring 36.

  Furthermore, the stay 22 includes an antenna support portion 22C corresponding to the patch antenna 10, and is formed integrally with the base end portion 22B. The antenna support portion 22C is formed above the base end portion 22B in the vehicle.

  In such a vehicle inner mirror device 18, the base end portion 22 </ b> B and the antenna support portion 22 </ b> C of the stay 22 are covered with the cover 28. The cover 28 is formed in a substantially rectangular box shape, and one side surface thereof is opened corresponding to the windshield glass 20. The peripheral portion of the opened portion of the cover 28 is closely fixed to the back surface 20A of the windshield glass 20 by a fixing member (not shown), and thus the cover 28 is attached to the windshield glass 20.

  The above-described patch antenna 10 is provided inside the cover 28, and is disposed in the gap between the cover 28 and the windshield glass 20 without being exposed to the vehicle interior side by the cover 28. .

  The patch electrode 16 of the patch antenna 10 is offset to a position below the vehicle along the surface 12A of the substrate 12 with respect to the center position of the ground 14 (strictly speaking, obliquely downward in front of the vehicle and below the vehicle). (See arrow X corresponding to FIG. 1 in FIG. 2). For this reason, the directivity direction of the patch antenna 10 is set to a direction (an obliquely upward direction forward of the vehicle and above the vehicle; see arrow A2) that is steeper than a direction perpendicular to the substrate 12 (see arrow A1).

  Further, one end of a coaxial cable 38 for high-frequency signal transmission is connected to such a patch antenna 10. The outer conductor 38A of the coaxial cable 38 is electrically connected to the ground 14 of the patch antenna 10 by soldering, for example, and is electrically connected to the ground 14. As shown in FIG. 3, the center conductor 38B of the coaxial cable 38 penetrates the ground 14 and the substrate 12 so as not to conduct with the ground 14 (for example, the center conductor 38B of the ground 14 penetrates the center conductor 38B). An insulating film is formed in the through-hole, and the central conductor 38 penetrates the ground 14 and the substrate 12 in a state of being insulated from the ground 14). The tip of the central conductor 38B is electrically connected to the patch electrode 16 by, for example, soldering, and is electrically connected to the patch electrode 16. The other end portion of the coaxial cable 38 is electrically connected to the transmission / reception module 32 described above, whereby the coaxial cable 38 can supply power to the patch antenna 10 from the transmission / reception module 32.

  Next, the operation of the embodiment of the present invention will be described.

  In the vehicle inner mirror device 18, the base end portion 22 </ b> B of the stay 22 is attached to the back surface 20 </ b> A of the windshield glass 20 of the vehicle and covered with the cover 28. The mirror body 24 is supported by a pivot mechanism 22A that is the tip of the stay 22. The mirror body 24 holds a rear viewing mirror 26 in the vicinity of the opening end 24A. With such an inner mirror device 18, the occupant can visually recognize the rear of the vehicle.

  Further, in the vehicle inner mirror device 18, the patch antenna 10 is provided inside the cover 28. In the patch antenna 10, transmission and reception of radio waves are performed by the patch electrode 16 formed on the surface 12 </ b> A of the substrate 12. Thereby, data communication is performed with the ETC communication terminal provided at the gate of the expressway.

  Here, in the inner mirror device 18 for the vehicle, when setting the directivity of the patch antenna 10, the vehicle mirror is tilted from a direction perpendicular to the substrate 12 (here, a diagonally upward direction indicated by an arrow A1 in front of the vehicle and above the vehicle). The patch electrode 16 is perpendicular to the substrate 12 with respect to the center position of the ground 14 in accordance with a desired directivity direction of the patch antenna 10 (here, a diagonally upward direction indicated by an arrow A2 in front of and above the vehicle). It is offset and provided in a direction orthogonal to the direction (an obliquely downward direction indicated by an arrow X in front of the vehicle and below the vehicle).

  Thereby, the directivity direction of the patch antenna 10 is tilted from the direction perpendicular to the substrate 12 to the side opposite to the direction in which the patch electrode 16 is offset. For this reason, the directivity direction inside the cover 28 where the patch antenna 10 is attached (more specifically, on the antenna support portion 22C of the stay 22) is set to a desired direction (here, the inclined directivity direction is forward of the vehicle and (Slant upward direction indicated by an arrow A2 above the vehicle), and data communication can be satisfactorily performed with an ETC communication terminal provided at the gate of the expressway.

  In addition, the inner mirror device 18 for a vehicle can be installed in the cover 28 without tilting the substrate 12 at the position where the patch antenna 10 is attached or by configuring the array antenna with a plurality of patch antennas. Thus, the directivity direction can be aligned in a desired direction. For this reason, there is no restriction on the design of the patch antenna 10 and thus the vehicle inner mirror device 18. That is, the patch antenna 10 and the vehicle inner mirror device 18 are not affected by the installation form of the substrate 12 in aligning the directivity direction of the patch antenna 10 in a desired direction.

As a result, the thickness of the cover 28 (dimension from the back surface 20A of the windshield glass 20) can be reduced, and not only the data communication but also the appearance from the passenger compartment is good, which is preferable. is there.
(Modification)
Hereinafter, modifications of the patch antenna 10 will be described. The patch antenna 10 of this modification is not shown in FIG. 1 without the configuration in which the patch electrode 16 is formed at a position offset from the center position of the ground 14 in a direction perpendicular to the direction perpendicular to the substrate 12 (see FIG. 1). 4 (A) and 4 (B), a patch electrode 16 is formed at the center position of the substrate 12 (see the substrate 12 including the chain double-dashed line portion), and the substrate 12 and the ground 14 (or only the ground 14). ) Along the opposing direction of the pair of opposing side surfaces of the substrate 12 (see arrow Y), so that the patch electrode 16 is located on the substrate 12 with respect to the center position of the ground 14 (excluding the two-dot chain line portion). It is configured to be offset in a direction perpendicular to the direction perpendicular to the reference). Also in this case, the patch electrode 16 is directed from the direction perpendicular to the substrate 12 (see the arrow A1 indicated by the two-dot chain line in FIG. 4B) as in the above-described embodiment of the present invention. Can be tilted to the opposite side of the offset direction (opposite to the arrow Y) (see arrow A3 indicated by the solid line in FIG. 4B).

  Although the patch antenna 10 is provided on the vehicle inner mirror device 18 (more specifically, on the antenna support portion 22C of the stay 22 inside the cover 28), the present invention is not limited to this. For example, the patch antenna 10 may be provided on the back surface 20A of the windshield glass 20, the surface of the dashboard, or the like. When the patch antenna 10 is installed at such a position, the patch antenna 10 is not affected by the installation form of the substrate 12 in aligning the directivity direction to a desired direction as described above. For example, the windshield glass 20 The substrate 12 can be provided in parallel to the back surface 20A (on the surface in the case of a dashboard) without being inclined.

  In the present embodiment, the patch antenna 10 has been described as an antenna constituting a part of the ETC on-vehicle device, but the present invention is not limited to this. The patch antenna 10 is, for example, an antenna that forms part of a receiver of a VICS (road traffic information communication system), an antenna that forms part of an RKE (remote keyless entry device), or one of TPMS (tire pressure monitoring system). The present invention can be applied as various antennas such as an antenna constituting a part and an antenna constituting a part of a wireless communication system using Bluetooth.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the patch antenna which concerns on embodiment of this invention, (A) is the top view, (B) is a side view. It is a sectional side view which shows the outline of the inner mirror apparatus for vehicles provided with the patch antenna of FIG. It is an enlarged view corresponding to FIG. 2 which shows the connection part vicinity of a patch antenna and a coaxial cable. It is the schematic diagram corresponding to FIG. 1 of the modification of a patch antenna, (A) is the top view, (B) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Patch antenna 12 Board | substrate 12A Front surface 12B Back surface 14 Ground 16 Patch electrode 18 Inner mirror apparatus for vehicles 20 Windshield glass 22 Stay 22A Pivot mechanism (tip part of stay)
22B Base end (base end of stay)
24 Mirror body 26 Mirror 28 Cover

Claims (4)

A film-like patch electrode having an area on the substrate smaller than the area of the ground on the surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface is connected to the ground via the substrate. An antenna directivity setting method for setting the directivity of a patch antenna that is provided facing each other and the patch electrode performs at least one of transmission and reception of radio waves,
In order to incline the directivity direction of the patch antenna in a desired direction with respect to a direction perpendicular to the substrate, the patch is opposite to the inclination direction perpendicular to the vertical direction with respect to the center position of the ground. Electrode offset,
The antenna directivity setting method characterized by the above-mentioned. A film-like patch electrode having an area on the substrate smaller than the area of the ground on the surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface is connected to the ground via the substrate. In the patch antenna provided facing each other, the patch electrode performs at least one of transmission and reception of radio waves,
Since the patch electrode is offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground, the directing direction of the patch antenna is opposite to the direction offset from the vertical direction. Tilted to the side,
This is a patch antenna. A film-like patch electrode which is provided at a predetermined position of the vehicle and has a film-like ground on the back surface, the surface on the opposite side of the back surface having a smaller area on the substrate than the area of the ground In the in-vehicle antenna that is provided facing the ground through the substrate, and the patch electrode performs at least one of transmission and reception of radio waves,
Since the patch electrode is offset in a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground, the directing direction of the patch antenna is opposite to the direction offset from the vertical direction. Tilted to the side,
A vehicle-mounted antenna characterized by that. A mirror main body that is provided in the vehicle interior and holds a mirror for rearward viewing near the opening end; a stay that is attached to the vehicle interior side of the windshield glass of the vehicle and supports the mirror main body at the front end; A vehicle inner mirror device comprising: a cover that covers the base end portion of the stay;
A film-like patch electrode having an area on the substrate smaller than the area of the ground on the surface opposite to the back surface of the substrate on which a film-like ground is formed on the back surface is connected to the ground via the substrate. A patch antenna that is provided facing each other and in which the patch electrode performs at least one of transmission and reception of radio waves is provided inside the cover, and a direction perpendicular to the direction perpendicular to the substrate with respect to the center position of the ground The patch electrode is provided with an offset, so that the directivity direction of the patch antenna is inclined from the vertical direction to the side opposite to the offset direction,
An inner mirror device for a vehicle.

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