In-vehicle antenna device

Abstract

To easily control the directivity of a plane antenna.SOLUTION: The present invention includes: a first antenna for an electric wave of a first frequency band; and a second antenna for an electric wave of a second frequency band different from a first frequency band. At least a part of the element forming the second antenna resonates in the first frequency band.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an in-vehicle antenna device. [Background technology]

[0002] Patent Document 1 discloses an in-vehicle antenna device in which a planar antenna for GPS signals and an antenna for AM / FM are housed in an antenna case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-21856 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, depending on the configuration of the vehicle-mounted antenna device, it may be difficult to ensure the necessary directivity of the planar antenna.

[0005] One object of the present invention is to easily control the directivity of a planar antenna. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]

[0006] One aspect of the present invention is an in-vehicle antenna device comprising a first antenna that responds to radio waves in a first frequency band and a second antenna that responds to radio waves in a second frequency band different from the first frequency band, wherein at least a portion of the elements constituting the second antenna resonate in the first frequency band. Effect of the Invention

[0007] According to one aspect of the present invention, the directivity of a planar antenna can be easily controlled. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of an in-vehicle antenna device 10. FIG. [Diagram 2] FIG. 2 is an exploded perspective view of the patch antenna 30. [Diagram 3] 2A and 2B are a perspective view and a side view of a metal body 60A. [Figure 4] 2 is a diagram showing a configuration of an in-vehicle antenna device 10X. FIG. [Diagram 5] 1 is a graph showing an example of the relationship between the elevation angle and the average gain of the patch antenna 30 in the vehicle-mounted antenna device 10 and the vehicle-mounted antenna device 10X. [Figure 6] 13 is an explanatory diagram of the separation distance D and separation distance H between the patch antenna 30 and the resonator 61. FIG. [Figure 7] 13 is a graph showing an example of a relationship between a separation distance D and an average gain, and a relationship between a separation distance H and an average gain. [Figure 8] 11 is a diagram showing resonating units 61A to 61C of modified examples. FIG. [Figure 9] 13A and 13B are diagrams illustrating a resonating unit 61D and a resonating unit 61E according to modified examples. [Figure 10] 13 is a diagram showing a resonator unit 61F and a resonator unit 61G according to a modified example. FIG. [Figure 11] 11A and 11B are diagrams showing the configuration of an in-vehicle antenna device 80A, with FIG. 11A being a perspective view of the in-vehicle antenna device 80A and FIG. 11B being a side view of the in-vehicle antenna device 80A. [Figure 12] 12A and 12B are diagrams showing the configurations of an in-vehicle antenna device 80B and an in-vehicle antenna device 80C, with FIG. 12A being a side view of the in-vehicle antenna device 80B and FIG. 12B being a side view of the in-vehicle antenna device 80C. [Figure 13] 2 is a diagram showing a configuration of an in-vehicle antenna device 80X. FIG. [Figure 14] These are graphs showing the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C and the vehicle-mounted antenna device 80X, where FIG. 14A is a graph showing an example of the relationship between the elevation angle and the average gain, and FIG. 14B is a graph showing an example of the directivity at an elevation angle of 20°. [Figure 15] 10 is an explanatory diagram of a separation distance D between the patch antenna 30 and a resonator 91. FIG. [Figure 16] 13 is a graph showing an example of the relationship between the elevation angle and the average gain when the separation distance D is changed. [Figure 17] 17A and 17B are side and plan views showing a first example of the positional relationship, and FIG. 17C and FIG. 17D are side and plan views showing a second example of the positional relationship. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] At least the following points will become apparent from the description of this specification and the accompanying drawings.

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The same or equivalent components, members, etc. shown in each drawing are designated by the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0011] ==Configuration of the Vehicle-Mounted Antenna Device 10 of the First Embodiment== <Configuration Overview> Fig. 1 is a diagram showing the configuration of an in-vehicle antenna device 10 according to a first embodiment. Fig. 1 shows a perspective view of the in-vehicle antenna device 10 with a case 23 removed in the zenith direction (upward). First, an outline of the configuration of the in-vehicle antenna device 10 will be described below with reference to Fig. 1.

[0012] In Fig. 1, the front-rear direction of the vehicle on which the vehicle-mounted antenna device 10 is mounted is defined as the X direction, the left-right direction perpendicular to the X direction is defined as the Y direction, and the vertical direction perpendicular to the X and Y directions is defined as the Z direction. The front side from the driver's seat of the vehicle is defined as the +X direction, the right side is defined as the +Y direction, and the zenith direction (upward) is defined as the +Z direction. Hereinafter, in this embodiment, the front-rear, left-right, and up-down directions of the vehicle-mounted antenna device 10 are described as being the same as the front-rear, left-right, and up-down directions of the vehicle. Also, the case where the vehicle-mounted antenna device 10 is viewed in the -Z direction is defined as a "top view," and the case where the vehicle-mounted antenna device 10 is viewed in the +Y direction or the -Y direction is defined as a "side view."

[0013] The above definitions of directions and the like are common to other embodiments of this specification unless otherwise specified.

[0014] The vehicle-mounted antenna device 10 is an antenna device that is attached to the roof of a vehicle (not shown). The vehicle-mounted antenna device 10 has an antenna base 20, a case 23, a patch antenna 30, a patch antenna 31, and an antenna 32.

[0015] The antenna base 20 is a member that constitutes the bottom surface of the vehicle-mounted antenna device 10. The antenna base 20 includes, for example, an insulating base made of resin, and metal bases 21 and 22, and the metal bases 21 and 22 are attached to the insulating base with a plurality of screws (not shown). However, the insulating base may be made of a material other than resin as long as it has insulating properties, and may have a shape other than a plate shape.

[0016] The metal base 21 is a member that functions as the ground of the in-vehicle antenna device 10. The metal base 21 is formed, for example, in the shape of a metal plate. However, the metal base 21 may have a shape other than a plate as long as it is a metal member that functions as the ground. The patch antenna 30 is installed on the metal base 21.

[0017] The metal base 22 is a member that functions as the ground of the in-vehicle antenna device 10. The metal base 22 is formed, for example, in the shape of a metal plate. However, the metal base 22 may have a shape other than a plate as long as it is a metal member that functions as the ground. The patch antenna 31 and the antenna 32 are installed on the metal base 22.

[0018] In this embodiment, the metal base 21 and the metal base 22 are electrically connected by a metal plate (not shown). When the vehicle-mounted antenna device 10 is attached to the roof of a vehicle (not shown), the metal base 21, the metal base 22, and the roof are electrically connected. As a result, the metal base 21 and the metal base 22 function as the ground of the vehicle-mounted antenna device 10. Note that, in this embodiment, the metal base 21 and the metal base 22 are provided as separate bodies, but they may be provided as an integrated metal base. Even when such an integrated metal base is used, the metal base properly functions as the ground of the patch antenna 31 and the antenna 32 described later.

[0019] In the above description, the antenna base 20 of the vehicle-mounted antenna device 10 has the insulating base, the metal base 21, and the metal base 22 as members constituting the bottom surface of the vehicle-mounted antenna device 10 and members functioning as a ground. However, the vehicle-mounted antenna device 10 is not limited to these configurations.

[0020] For example, the antenna base 20 may have only the metal base 21 and the metal base 22, or may have only an integrated metal base instead of the metal base 21 and the metal base 22. The antenna base 20 may have an insulating base, a metal base 21, and a metal plate. The vehicle-mounted antenna device 10 may have an insulating base and an integrated metal base instead of the metal base 21 and the metal base 22. The vehicle-mounted antenna device 10 may have an insulating base, a metal base 21 and a metal base 22, and another metal base, or may have a metal plate instead of the metal base. The antenna base 20 may have an insulating base and a metal plate.

[0021] Therefore, in the in-vehicle antenna device 10 of this embodiment, the above-mentioned members can be freely combined as the member constituting the bottom surface of the in-vehicle antenna device 10 and the member functioning as the ground.

[0022] The case 23 is a member (housing) that covers the outside of the in-vehicle antenna device 10. In this embodiment, the case 23 is a housing for a general shark fin antenna, as shown in FIG.

[0023] The patch antenna 30 is a planar antenna compatible with radio waves in the 2.3 GHz band of the satellite digital audio radio service (SDARS), for example. In this embodiment, the patch antenna 30 receives radio waves in the 2.3 GHz band for SDARS. The communication standards and frequency bands compatible with the patch antenna 30 are not limited to those described above, and other communication standards and frequency bands may be used. The patch antenna 30 may also be compatible with radio waves in a plurality of frequency bands, and may at least either transmit or receive radio waves in a desired frequency band.

[0024] In the following description, the patch antenna 30 may be referred to as a "first antenna." Furthermore, the frequency band of radio waves that the patch antenna 30 supports may be referred to as a "first frequency band."

[0025] The patch antenna 30 will be described in detail later.

[0026] The patch antenna 31 is a planar antenna compatible with, for example, radio waves in the 1.5 GHz band of the Global Navigation Satellite System (GNSS). In this embodiment, the patch antenna 31 receives radio waves in the 1.5 GHz band for the GNSS. Note that the communication standards and frequency bands compatible with the patch antenna 31 are not limited to those described above, and other communication standards and frequency bands may be used. Furthermore, the patch antenna 31 may be compatible with radio waves in a plurality of frequency bands, and may at least either transmit or receive radio waves in a desired frequency band.

[0027] The antenna 32 is, for example, an antenna compatible with radio waves for AM / FM radio. In this embodiment, the antenna 32 receives radio waves for AM broadcasting of 522 kHz to 1710 kHz and radio waves for FM broadcasting of 76 MHz to 108 MHz. However, the antenna 32 may receive only either radio waves for AM broadcasting or radio waves for FM broadcasting. The communication standards and frequency bands compatible with the antenna 32 are not limited to those described above, and other communication standards and frequency bands may be used. Furthermore, the antenna 32 may at least either transmit or receive radio waves in a desired frequency band.

[0028] In the following description, the antenna 32 may be referred to as a "second antenna." Furthermore, the frequency band of radio waves that the antenna 32 supports may be referred to as a "second frequency band."

[0029] The antenna 32 will be described in detail later.

[0030] <Details of patch antenna 30 (first antenna)> Fig. 2 is an exploded perspective view of the patch antenna 30. Details of the patch antenna 30 will be described below with reference to Fig. 2 as well as Fig. 1 described above.

[0031] The patch antenna 30 has a substrate 70 , a dielectric member 72 , a radiating element 73 , a holding member 74 , and a metal body 75 .

[0032] The substrate 70 is a circuit board on which the dielectric member 72 is mounted. As shown in FIG.

[0033] The dielectric member 72 is a substantially quadrilateral plate-like member made of a dielectric material such as ceramic. As shown in Fig. 2, the front and rear surfaces of the dielectric member 72 are parallel to the X and Y directions, with the front surface of the dielectric member 72 facing the +Z direction and the rear surface of the dielectric member 72 facing the -Z direction. A pattern 71 is provided on the rear surface of the dielectric member 72. The pattern 71 is a conductor that functions as a ground conductor film (or a ground conductor plate). The rear surface of the dielectric member 72 is attached to the substrate 70 by, for example, an adhesive (not shown).

[0034] Here, "approximately quadrilateral" refers to a shape consisting of four sides, including, for example, a square or a rectangle, and at least some of the corners may be cut out at an angle relative to the sides. Furthermore, in the "approximately quadrilateral" shape, a notch (recess) or a protrusion (protrusion) may be provided on some of the sides. The shape of the dielectric member 72 is not limited to an approximately quadrilateral shape, and may be, for example, a circle or an ellipse. Furthermore, the dielectric member 72 may have a shape other than a plate shape.

[0035] The radiating element 73 is a conductive, substantially quadrilateral member having an area smaller than the front surface of the dielectric member 72. As shown in Fig. 2, the radiating element 73 is provided on the front surface of the dielectric member 72. The normal direction of the radiation surface of the radiating element 73 is the +Z direction. The shape of the radiating element 73 is not limited to a substantially quadrilateral shape, and may be, for example, a circle or an ellipse. In other words, the shape of the radiating element 73 may be any shape that is capable of at least one of receiving and transmitting a signal (radio wave) in a desired frequency band.

[0036] As shown in Fig. 2, the radiating element 73 has a feed point 78. The feed point 78 is a point where the feed line 77 shown in Fig. 2 is electrically connected to the radiating element 73. In this embodiment, a configuration in which only one feed line 77 is connected to the radiating element 73, that is, a single feed method is adopted. The radiating element 73 of the single feed method has, for example, a substantially rectangular shape with different vertical and horizontal lengths so that at least one of the desired circularly polarized waves can be transmitted and received. Note that the "substantially rectangular" shape is included in the above-mentioned "substantially quadrilateral".

[0037] However, in this embodiment, a configuration in which two feed lines 77 are connected to the radiating element 73, that is, a two-feed system, may be adopted. The radiating element 73 of the two-feed system has, for example, a substantially square shape with equal length and width so as to transmit and receive a desired circularly polarized wave. Note that the "substantially square" is a shape that falls within the above-mentioned "substantially quadrilateral".

[0038] 2, in the patch antenna 30 of this embodiment, a through hole 76 is formed penetrating the substrate 70 and the dielectric member 72. The through hole 76 is formed so that a feed line 77 is connected to a feed point 78 of the radiating element 73. In the dual-feed type radiating element 73, two through holes 76 are formed penetrating the substrate 70 and the dielectric member 72. In each of the through holes 76, the feed line 77 is connected to the feed point 78 of the radiating element 73.

[0039] The holding member 74 is a member that holds the metal body 75. The holding member 74 is made of resin and is provided on the front surface of the dielectric member 72 so as to surround the radiating element 73. However, the holding member 74 may be formed of a material other than resin as long as it can hold the metal body 75. Of the two sides parallel to the Y axis on the upper surface of the holding member 74, the side on the +X side is provided with a convex portion 74A extending in the +Z direction, and the side on the -X side is provided with a convex portion 74B and a convex portion 74C extending in the +Z direction. Each of the convex portions 74A to 74C is a protrusion having a substantially rectangular parallelepiped shape formed to determine the position of the metal body 75 relative to the holding member 74. However, each of the convex portions 74A to 74C does not have to be provided as a protrusion having a substantially rectangular parallelepiped shape as long as it can determine the position of the metal body 75 relative to the holding member 74. In addition, the holding member 74 does not have to be provided with the convex portions 74A to 74C. Moreover, the holding member 74 is not limited to a frame shape surrounding the entire circumference of the radiating element 73. For example, the metal body 75 may be attached to a protrusion provided in the case 23, or the metal body 75 may be fitted into a groove provided in the case 23. That is, the case 23 may also serve as the holding member 74.

[0040] The metal body 75 is a member that improves the radiation efficiency of the patch antenna 30 and controls the directivity by being capacitively coupled with the radiating element 73. The metal body 75 is a substantially square zenith plate (or zenith capacitive plate) held by the holding member 74, and of the two sides parallel to the Y axis, a recess 75A is provided on the +X side side, and a recess 75B and a recess 75C are provided on the -X side side. In this embodiment, the metal body 75 is disposed on the front surface of the holding member 74 in a state in which the protrusions 74A to 74C of the holding member 74 are fitted into the recesses 75A to 75C of the metal body 75. However, if the protrusions 74A to 74C are not provided on the holding member 74, the recesses 75A to 75C may not be provided on the metal body 75.

[0041] Although the metal body 75 has been described as having a substantially square plate shape, the present invention is not limited thereto and may be a substantially quadrilateral shape other than a substantially square shape, or may be a circular or elliptical shape. Furthermore, the metal body 75 may have a three-dimensional shape obtained by bending a plate-like metal plate. For example, the metal body 75 may be formed into an inverted V-shape, an inverted U-shape, a mountain shape (umbrella shape), or an arch shape by bending a metal plate. Furthermore, the metal body 75 may have a shape other than a plate shape.

[0042] <Details of Antenna 32 (Second Antenna)> Fig. 3A is a perspective view of a metal body 60A of a capacitive loading element 60 described later. Fig. 3B is a side view of a metal body 60A of a capacitive loading element 60 described later. In the following, details of the antenna 32 will be described with reference to Figs. 3A and 3B as well as Fig. 1 described above.

[0043] The antenna 32 includes a holder 40 , a helical element 50 , a capacitive loading element 60 , and a filter 100 .

[0044] Holder 40 is a member that holds helical element 50 and capacitance loading element 60. Holder 40 is provided on antenna base 20 as shown in Fig. 1. Holder 40 is formed of, for example, resin. However, holder 40 may be formed of a material other than resin as long as it can hold helical element 50 and capacitance loading element 60.

[0045] As shown in FIG. 1, the holder 40 has a support portion 41 and an attachment portion 42. The support portion 41 is a portion to which the helical element 50 is attached. The attachment portion 42 is a portion to which the capacitive loading element 60 is attached. The attachment portion 42 has a substantially trapezoidal cross section in which the X direction is the longitudinal direction and the width increases toward the lower side (-Z direction). However, the attachment portion 42 is not limited to the shape having the substantially trapezoidal cross section described above. For example, the cross-sectional shape of the attachment portion 42 when viewed from the front or rear may be a substantially quadrangular shape such as a substantially square or substantially rectangular shape, and the outer shape of the attachment portion 42 when viewed from the front or rear may be an inverted V shape, an inverted U shape, a mountain shape (umbrella shape), or an arch shape.

[0046] The helical element (hereinafter simply referred to as "coil") 50 is an element that resonates in a desired frequency band together with the capacitive loading element 60. The coil 50 is provided above the metal base 22 in a state where it is attached to the support part 41 of the holder 40, as shown in FIG. 1. One end of the coil 50 is electrically connected to the metal base 22, and the other end of the coil 50 is electrically connected to the capacitive loading element 60.

[0047] The capacitive loading element 60 is an element that resonates in a desired frequency band together with the coil 50. The capacitive loading element 60 is composed of metal bodies 60A-60D divided into four along the front-rear direction (longitudinal direction) as shown in Fig. 1. In the following description, the "metal body" refers to a metal member that is formed by processing, and includes, for example, a plate-shaped metal member such as a metal plate, as well as a metal member having a three-dimensional shape other than a plate shape.

[0048] As shown in FIG. 1, FIG. 3A, and FIG. 3B, each of the metal bodies 60A to 60D of this embodiment is formed by bending both ends of the Y-axis direction of the metal plate upward from both ends of the bottom surface that is approximately parallel to the central XY plane. In the following description, for each of the metal bodies 60A to 60D, the bottom surface portion that is approximately parallel to the central XY plane may be simply referred to as the "bottom surface portion". In addition, among the portions formed by bending both ends of the bottom surface portion upward, the left side may be simply referred to as the "left side surface portion" and the right side may be simply referred to as the "right side surface portion". Note that, in FIG. 3A and FIG. 3B, only the metal body 60A is shown among the metal bodies 60A to 60D, but the metal bodies 60B to 60D shown in FIG. 1 also have a bottom surface portion, a left side surface portion, and a right side surface portion, similar to the metal body 60A.

[0049] In this embodiment, the four metal bodies 60A-60D have the same length in the front-rear direction, but this is not limited to this. For example, the four metal bodies 60A-60D may have different lengths in the front-rear direction, or some of them may have the same length. Furthermore, each of the metal bodies 60A-60D has a shape with a bottom surface, but may include a metal body that does not have a bottom surface.

[0050] In the present embodiment, the capacitance loading element 60 has four metal bodies 60A to 60D, but is not limited thereto. For example, the capacitance loading element 60 may have one metal body, or may have a number of metal bodies other than four. The capacitance loading element 60 has a shape that is bent upward from both ends of the bottom surface at the center, but the shape is not limited thereto. For example, the capacitance loading element 60 may be bent downward from both ends. The outer shape of the capacitance loading element 60 when viewed from the front or rear may be, for example, an inverted V-shape, an inverted U-shape, a mountain shape (umbrella shape), or an arch shape.

[0051] The filter 100 is a member that electrically connects the four metal bodies 60A to 60D and has high impedance in the frequency band of radio waves corresponding to the patch antenna 30 and the patch antenna 31. In this embodiment, three filters 100 are provided. As shown in FIG. 1, each of the three filters 100 is provided in a gap between the metal body 60A and the metal body 60B on the left side surface, a gap between the metal body 60B and the metal body 60C on the left side surface, and a gap between the metal body 60C and the metal body 60D on the left side surface. The filter 100 is a circuit that resonates in parallel, for example, in the frequency band of radio waves corresponding to the patch antenna 30 and the patch antenna 31, and is configured to include a capacitor and a coil (not shown).

[0052] The installation position and number of the filters 100 in this embodiment are not limited to those shown in FIG. 1. The filters 100 may be arranged at positions that connect adjacent metal bodies among the metal bodies 60A to 60D. For this reason, the filters 100 may be provided, for example, at upper positions including the tops of the metal bodies 60A to 60D, or at lower positions including the bottoms. The filters 100 may be arranged only on the right side surface of the capacitance loading element 60. Furthermore, the filters 100 may be arranged alternately on the left side surface and the right side surface of the capacitance loading element 60.

[0053] As described above, the four metal bodies 60A to 60D are electrically connected via the filter 100 that has high impedance in the radio wave frequency band that the patch antennas 30 and 31 support. In addition, the coil 50 is designed to have high impedance in the radio wave frequency band that the patch antennas 30 and 31 support.

[0054] Since the filter 100 has low impedance in the AM / FM frequency bands, all of the metal bodies 60A-60D, together with the coil 50, operate as a single conductor for the AM / FM frequency bands. That is, the coil 50 and the capacitive loading element 60 operate as an antenna that resonates in the FM frequency band. In the following description, in the in-vehicle antenna device 10, a member that is provided to resonate in a desired frequency band may be referred to as an "element."

[0055] <Resonant section 61> Incidentally, the in-vehicle antenna device 10 of the present embodiment described above is a so-called composite antenna device having the patch antenna 30, the patch antenna 31, and the antenna 32. In such a composite antenna device, it is necessary to ensure the required characteristics for each antenna while taking into consideration electrical interference between the antennas. For example, in the patch antenna 30, the in-vehicle antenna device 10 of the present embodiment described above is capable of adjusting the size and position of elements (e.g., the dielectric member 72 and the radiating element 73) in order to ensure the required directivity while taking into consideration electrical interference with other antennas.

[0056] However, since the space inside the case 23 of the vehicle-mounted antenna device 10 is limited, there is a limit to ensuring the required directivity by adjusting the size and position of the elements in, for example, the patch antenna 30. Therefore, hereinafter, a vehicle-mounted antenna device 10 in which the directivity of the patch antenna 30 can be easily controlled will be described.

[0057] As described above, the capacitive loading element 60 including the metal body 60A resonates with the coil 50 in the FM frequency band (second frequency band). In this embodiment, the capacitive loading element 60 is provided with a resonating section 61 as shown in FIG. 1, FIG. 3A, and FIG. 3B. The resonating section 61 is a portion that resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. In this embodiment, the entire metal body 60A functions as the resonating section 61. Therefore, the metal body 60A is a part of an element of the antenna 32 (second antenna) that supports radio waves in the AM / FM frequency band (second frequency band), and by having the resonating section 61, resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports.

[0058] In this embodiment, the electrical length of the resonator 61 is formed so as to resonate in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. For example, the resonator 61 is formed with an electrical length equivalent to half the wavelength of the first frequency band. Here, "half the wavelength of the first frequency band" is not limited to an exact value, and may be any value that resonates in a desired frequency band. This is because the wavelength of the first frequency band is not necessarily expressed by an integer that is divisible, and the actual electrical length of the resonator 61 varies due to various factors. Note that the electrical length of the resonator 61 does not have to be formed so as to correspond to half the wavelength of the first frequency band, as long as it is formed so as to resonate in the first frequency band.

[0059] As shown in Figures 3A and 3B, the metal body 60A is provided with slits 62. The slits 62 are cuts (gaps) formed from the outer edge of the metal body 60A toward the inside. As shown in Figure 3B, three slits 62 aligned in the Z direction are provided on the left side surface of the metal body 60A. When viewed in the +Z direction, the three slits 62 are composed of a slit 62 formed in the -X direction, a slit 62 formed in the +X direction, and a slit 62 formed in the -X direction.

[0060] As a result, three folds 64 are provided on the left side surface of the metal body 60A as shown in FIG. 3B. The three folds 64 are provided on the +X direction side of the metal body 60A, the -X direction side of the metal body 60A, and the +X direction side of the metal body 60A when viewed in the +Z direction. As a result, the resonator 61 is formed by repeating horizontal folds 64 in the metal body 60A (i.e., in a meandering shape). In this embodiment, it is possible to form an electrical length that resonates in the first frequency band (for example, an electrical length equivalent to half the wavelength of the first frequency band) by adjusting the horizontal length of the slit 62, for example.

[0061] The number, positions, and extending direction of the slits 62 are not limited to those shown in Figures 3A and 3B. For example, one slit 62 may be provided in the metal body 60A. In this case, one fold 64 will be provided in the metal body 60A. Also, for example, a number other than three slits 62 may be provided in the metal body 60A. In this case, the number of folds 64 corresponding to the number of slits 62 will be provided.

[0062] Furthermore, in FIG. 3A and FIG. 3B, the slits 62 are provided only on the left side surface of the metal body 60A, but for example, the slits 62 may also be provided on the bottom surface of the metal body 60A.

[0063] In addition, in the side view shown in FIG. 3B, the direction in which the slit 62 extends is not limited to the horizontal direction, but may be the vertical direction. Here, the "horizontal direction" or "vertical direction" is not limited to a strict direction, but includes a direction shifted within a certain angle. This is because each part of the metal body 60A (bottom surface part, left side surface part, or right side surface part) is not necessarily provided parallel to the "horizontal direction" or "vertical direction". Also, in FIG. 3A and FIG. 3B, the slit 62 is provided so as to extend along the horizontal direction, but the slit 62 may be provided so as to be bent midway.

[0064] Therefore, as long as the electrical length of the resonating portion 61 of this embodiment is formed so as to resonate in the radio wave frequency band (first frequency band) corresponding to the patch antenna 30 (first antenna), the number, positions, extension directions, etc. of the above-mentioned slits 62 can be freely combined.

[0065] Just as slits 62 are provided on the left side surface of metal body 60A, slits 62 are also provided on the right side surface of metal body 60A. The number, position, extension direction, etc. of slits 62 are the same on the left side surface of metal body 60A and the right side surface of metal body 60A as shown in Fig. 3A. However, the number, position, extension direction, etc. of slits 62 may be different between the left side surface of metal body 60A and the right side surface of metal body 60A.

[0066] In the above description, the metal body 60A has the resonating portion 61, but this is not limited thereto. At least one of the metal bodies 60A to 60D constituting the capacitance loading element 60 may have the resonating portion 61. That is, for example, only the metal body 60B may have the resonating portion 61, or the metal body 60C and the metal body 60D may have the resonating portion 61. Furthermore, when the capacitance loading element 60 is a single metal body, the single metal body may have the resonating portion 61. Therefore, it is sufficient that at least a part of the elements constituting the antenna 32 (second antenna) resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports.

[0067] ==Configuration of Vehicle-Mounted Antenna Device 10X of Comparative Example== 4 is a diagram showing the configuration of an in-vehicle antenna device 10X of a comparative example. The in-vehicle antenna device 10X is an in-vehicle antenna device in which a resonator unit 61 is not provided in a capacitive loading element 60 of an antenna 32. The in-vehicle antenna device 10X has the same configuration as the in-vehicle antenna device 10 of the above-described embodiment, except that the resonator unit 61 is not provided.

[0068] Comparison of Characteristics Between Vehicle-Mounted Antenna Device 10 and Vehicle-Mounted Antenna Device 10X The following describes the results of calculating the elevation angle and average gain of the patch antenna 30 in the vehicle-mounted antenna device 10 and the vehicle-mounted antenna device 10X.

[0069] FIG. 5 is a graph showing an example of the relationship between the elevation angle and the average gain of the patch antenna 30 in the vehicle-mounted antenna device 10 and the vehicle-mounted antenna device 10X. In FIG. 5, the horizontal axis indicates the elevation angle, and the vertical axis indicates the average gain. In FIG. 5, the calculation results in the vehicle-mounted antenna device 10X are shown by a dashed line, and the calculation results in the vehicle-mounted antenna device 10 are shown by a solid line. Note that the square marks on the dashed line and the circles marks on the solid line indicate the positions of the numerical values ​​on the vertical axis relative to the numerical values ​​on the horizontal axis, and are shown by square marks and circles marks for convenience in order to distinguish between them. Note that in the following description, the average gain may be simply referred to as "gain".

[0070] As shown in FIG. 5, when comparing the gain of the vehicle-mounted antenna device 10X of the comparative example with the gain of the vehicle-mounted antenna device 10 of the present embodiment, the gain of the vehicle-mounted antenna device 10 of the present embodiment is higher than the gain of the vehicle-mounted antenna device 10X of the comparative example in the range of 20° to 65°. Therefore, the vehicle-mounted antenna device 10 of the present embodiment, as an antenna device that receives radio waves transmitted from a satellite, for example, has an improved average gain in at least a part of the elevation angle range from low elevation angle to medium elevation angle of the patch antenna 30, and has ideal directivity. Here, the elevation angle is set to 0° in the horizontal direction and 90° in the zenith angle. The low elevation angle refers to, for example, a range of 0° to 30°. The medium elevation angle refers to a range of 30° to 60°. The high elevation angle refers to a range of 60° to 90°.

[0071] Therefore, the directivity of the patch antenna 30 is improved in the vehicle-mounted antenna device 10, and as a result, incoming radio waves from, for example, a satellite can be efficiently received. In this manner, the vehicle-mounted antenna device 10 of this embodiment has the resonator 61, so that the directivity of the patch antenna 30 can be easily controlled.

[0072] The above describes the directivity of the patch antenna 30. Although detailed description is omitted, the vehicle-mounted antenna device 10 of this embodiment has another resonator 61, so that the directivity of the patch antenna 31 separate from the patch antenna 30 can also be easily controlled. In other words, the vehicle-mounted antenna device 10 of this embodiment can easily control the directivity of planar antennas such as the patch antenna 30 and the patch antenna 31.

[0073] == Distance between patch antenna 30 and resonator 61 == Here, in the top view and side view shown in Fig. 1, the patch antenna 30 and the resonator 61 do not overlap each other. When the patch antenna 30 and the resonator 61 are separated by a predetermined distance in the horizontal or vertical direction, the phase of the radio wave corresponding to the patch antenna 30 and the phase of the radio wave corresponding to the antenna 32 on which the resonator 61 is provided are constructive with each other. In the in-vehicle antenna device 10 of this embodiment, when the phases of the radio waves are separated by a distance at which they constructively interact with each other, the gain of the patch antenna 30 is further improved. Therefore, hereinafter, the separation distance at which the phase of the radio wave corresponding to the patch antenna 30 and the phase of the radio wave corresponding to the antenna 32 are constructive with each other will be examined.

[0074] FIG. 6 is an explanatory diagram of the separation distance D and the separation distance H.

[0075] 6, the separation distance D is the horizontal distance (X direction) between the patch antenna 30 and the resonator unit 61 of the antenna 32. Specifically, the separation distance D is the distance in the horizontal direction between the end of the patch antenna 30 closest to the resonator unit 61 and the end of the resonator unit 61 closest to the patch antenna 30.

[0076] 6, the separation distance H is the separation distance in the vertical direction (Z direction) between the patch antenna 30 and the resonator unit 61 of the antenna 32. Specifically, the separation distance H is the distance in the vertical direction between the end of the patch antenna 30 closest to the resonator unit 61 and the end of the resonator unit 61 closest to the patch antenna 30.

[0077] Fig. 7A is a graph showing an example of the relationship between the separation distance D and the average gain. Fig. 7B is a graph showing an example of the relationship between the separation distance H and the average gain.

[0078] In Fig. 7A, the horizontal axis indicates the separation distance D, and the vertical axis indicates the average gain of the patch antenna 30. In Fig. 7B, the horizontal axis indicates the separation distance H, and the vertical axis indicates the average gain of the patch antenna 30. In each of Figs. 7A and 7B, the calculation results for the patch antenna 30 at an elevation angle of 20° are indicated by a dashed line, and the calculation results for the patch antenna 30 at an elevation angle of 50° are indicated by a solid line. As a standard for the required gain of the patch antenna 30, the reference value of the average gain at an elevation angle of 50° is indicated by line A, and the reference value of the average gain at an elevation angle of 20° is indicated by line B.

[0079] 7A, if the separation distance D is 30 mm or more at an elevation angle of 50°, the average gain exceeds the reference value (line A), and it is found that the required gain of patch antenna 30 can be obtained. Moreover, with separation distance D being 30 mm or more and an elevation angle of 20°, the average gain is also greater than the reference value (line B).

[0080] 7B, if the separation distance H is 30 mm or more at an elevation angle of 50°, the average gain exceeds the reference value (line A), and it is found that the required gain of patch antenna 30 can be obtained. Also, if the separation distance D is 30 mm or more and the elevation angle is 20°, the average gain is still greater than the reference value (line B).

[0081] From the above, it can be seen that the necessary gain of the patch antenna 30 can be obtained by separating the patch antenna 30 and the resonator 61 by 30 mm or more in the horizontal or vertical direction. Here, 30 mm corresponds to one-quarter of the wavelength of the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. Therefore, in the in-vehicle antenna device 10 of this embodiment, it is desirable to separate the first antenna (patch antenna 30) and the resonator 61 by one-quarter of the wavelength of the first frequency band or more in the horizontal or vertical direction.

[0082] Here, "a quarter of the wavelength of the first frequency band" is not limited to an exact value, and may be any value that provides the necessary gain of the patch antenna 30. This is because the wavelength of the first frequency band is not necessarily expressed by an evenly divisible integer, and the actual electrical length of the resonator 61 varies due to various factors. In addition, the desired separation distance between the patch antenna 30 and the resonator 61 also varies depending on the reference value (line A, line B) of the required average gain of the patch antenna 30, so the first antenna (patch antenna 30) and the resonator 61 do not need to be separated by a quarter of the wavelength of the first frequency band or more in the horizontal or vertical direction.

[0083] ==Modifications of the resonating portion 61== 8A to 8C are diagrams showing resonating units 61A to 61C according to modified examples.

[0084] The above-mentioned resonating unit 61 is formed by repeating horizontal folds 64 in the metal body 60A. However, the shape of the resonating unit 61 is not limited to this. As in the resonating unit 61A shown in Fig. 8A, a slit 62 approximately parallel to the YZ plane may be provided so as to straddle the left side surface, bottom surface, and right side surface of the metal body 60A.

[0085] 8A, the metal body 60A has two slits 62 arranged side by side in the X direction. When viewed in the -X direction, the two slits 62 are configured with one slit 62 formed in the left side-bottom-right side direction and the other slit 62 formed in the right side-bottom-left side direction.

[0086] As a result, two folds 64 are provided on the metal body 60A as shown in Fig. 8A. The two folds 64 are provided on the left side surface and the right side surface. As a result, the resonator 61A is formed by repeating the folds 64 in the vertical direction on the metal body 60A. In the resonator 61A, it is possible to form an electrical length that resonates in the first frequency band (for example, an electrical length equivalent to half the wavelength of the first frequency band) by adjusting the length of the slits 62, for example.

[0087] The above-described resonating unit 61 and resonating unit 61A are formed with slits 62. However, forming the resonating unit with an electrical length that resonates in the first frequency band is not limited to just forming slits 62. As in resonating unit 61B and resonating unit 61C shown in Fig. 8B and Fig. 8C, slots 63 may be formed. The slots 63 are openings (holes or gaps) formed in the metal body 60A.

[0088] 8B, the resonator 61B is provided with slots 63 that are repeatedly folded back in the horizontal direction on the left and right side surfaces of the metal body 60A. The slots 63 on the left side surface and the slots 63 on the right side surface are connected on the bottom surface side of the metal body 60A.

[0089] As shown in FIG. 8C, the resonator unit 61C has a slot 63 formed across the left side, bottom and right side of the metal body 60A, and the slot 63 is folded back repeatedly in the vertical direction.

[0090] In the resonating portion 61B shown in FIG. 8B and the resonating portion 61C shown in FIG. 8C, an electrical length that resonates in the first frequency band (e.g., an electrical length equivalent to half the wavelength of the first frequency band) can be formed by adjusting the length of the slot 63, for example.

[0091] Figures 9A and 9B are diagrams showing a resonating unit 61D and a resonating unit 61E of modified examples, and Figures 10A and 10B are diagrams showing a resonating unit 61F and a resonating unit 61G of modified examples.

[0092] The above-mentioned resonator 61, resonator 61A to resonator 61C are provided on the metal body 60A having a shape bent upward from both ends of the bottom surface at the center. However, as shown in Fig. 9 and Fig. 10, the resonator may be provided on a mountain-shaped (umbrella-shaped) metal body as in the case of resonator 61D to resonator 61G. Note that a mountain-shaped (umbrella-shaped) metal body includes a configuration in which the upper edges of the left side surface and the right side surface are connected to each other, and the external shape of the metal body when viewed from the front or rear is an inverted V shape, an inverted U shape, an arch shape, or a substantially trapezoidal shape.

[0093] 9A is formed in a mountain-shaped (umbrella-shaped) metal body and has repeated horizontal folds 64 formed by slits 62. Resonator unit 61E shown in Fig. 9B is formed in a mountain-shaped (umbrella-shaped) metal body and has repeated vertical folds 64 formed by slits 62.

[0094] 10A is formed in a mountain-shaped (umbrella-shaped) metal body, and has a slot 63 that is repeatedly folded back in the horizontal direction. Also, the resonator unit 61G shown in Fig. 10B is formed in a mountain-shaped (umbrella-shaped) metal body, and has a slot 63 that is repeatedly folded back in the vertical direction.

[0095] In the resonating portion 61D and the resonating portion 61G shown in Figures 9A to 10B, an electrical length that resonates in the first frequency band (for example, an electrical length equivalent to half the wavelength of the first frequency band) can be formed by adjusting the length of the slit 62 or the slot 63.

[0096] In the above-described first embodiment, the in-vehicle antenna device 10 is a composite antenna device having the patch antenna 30 as the first antenna and the antenna 32 for AM / FM radio as the second antenna. Specifically, the capacitive loading element 60 of the antenna 32 resonates with the coil 50 in the FM frequency band (second frequency band), and further has a resonating section 61 that resonates in the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna).

[0097] However, the second antenna is not limited to an antenna for AM / FM radio, and may be an antenna compatible with other communication standards and frequency bands. For example, the second antenna may be an antenna for telematics, as in the in-vehicle antenna devices 80A to 80C described later.

[0098] ==Configuration of Vehicle-Mounted Antenna Devices 80A to 80C of Second Embodiment== <First Example of Vehicle-Mounted Antenna Device 80A> Fig. 11 is a diagram showing the configuration of an in-vehicle antenna device 80A, in which Fig. 11A is a perspective view of the in-vehicle antenna device 80A, and Fig. 11B is a side view of the in-vehicle antenna device 80A.

[0099] The vehicle-mounted antenna device 80A has an antenna base 20, a patch antenna 30, and an antenna 33A. In this embodiment, a member (housing) that covers the outside of the vehicle-mounted antenna device 80A, that is, a member corresponding to the case 23 in the vehicle-mounted antenna device 10 of the first embodiment shown in FIG. 1, is not shown.

[0100] The antenna base 20 of this embodiment is similar to the antenna base 20 in the vehicle-mounted antenna device 10 of the first embodiment, and therefore a detailed description thereof will be omitted. In addition, the patch antenna 30 of this embodiment is similar to the patch antenna 30 in the vehicle-mounted antenna device 10 of the first embodiment, and therefore a detailed description thereof will be omitted. In addition, in Figures 11A and 11B, illustration of members equivalent to the holding member 74 and the metal body 75 in the patch antenna 30 shown in Figure 2 is omitted.

[0101] The antenna 33A is an antenna for telematics. The antenna 33A is an antenna that supports, for example, radio waves in the 700 MHz to 2.7 GHz band used in LTE (Long Term Evolution) and the Sub-6 band used in 5G (fifth generation mobile communication system), that is, radio waves in the frequency band from 3.6 GHz to less than 6 GHz. However, the communication standards and frequency bands supported by the antenna 33A are not limited to those described above, and other communication standards and frequency bands may be used.

[0102] The antenna 33A may be an antenna that supports radio waves in a frequency band used for, for example, V2X (Vehicle to Everything: vehicle-to-vehicle communication, road-to-vehicle communication), Wi-Fi (registered trademark), Bluetooth (registered trademark), and DAB. Furthermore, the antenna 33A may be an antenna for keyless entry or a smart entry.

[0103] The antenna 33A may be an antenna compatible with MIMO (Multiple-Input Multiple-Output) communication. In this case, the vehicle-mounted antenna device 80A further includes an antenna similar to the antenna 33A, so that the vehicle-mounted antenna device 80A is compatible with MIMO communication. In the vehicle-mounted antenna device 80A that performs MIMO communication, data is transmitted from each of the multiple antennas that constitute the vehicle-mounted antenna device 80A, and the data is simultaneously received by the multiple antennas.

[0104] Therefore, the in-vehicle antenna device 80A of this embodiment is a composite antenna device having the patch antenna 30 and the antenna 33 A. In the in-vehicle antenna device 80A, similarly to the in-vehicle antenna device 10 of the first embodiment, the directivity of the patch antenna 30 can be easily controlled by having a resonator 91 described later.

[0105] In addition, unlike the vehicle-mounted antenna device 10 of the first embodiment, in the following description, the antenna 33A of the vehicle-mounted antenna device 80A may be referred to as a "second antenna." Also, the frequency band of radio waves supported by the antenna 33A may be referred to as a "second frequency band."

[0106] The antenna 33A (second antenna) has an element 90A that resonates in a frequency band (second frequency band) of radio waves that the antenna 33A supports. The element 90A is provided with a resonating portion 91 as shown in Figs. 11A and 11B. The resonating portion 91 is a portion that resonates in a frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. In this embodiment, as shown by the dashed lines in Figs. 11A and 11B, a part of the element 90A formed in a meandering shape functions as the resonating portion 91. Therefore, the resonating portion 91 is a part of the element 90A of the antenna 33A (second antenna) that supports radio waves in the frequency band (second frequency band) for telematics, and resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports.

[0107] Specifically, the electrical length of the resonator 91 is formed so as to resonate in a frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. For example, the resonator 91 is formed with an electrical length equivalent to a quarter of the wavelength of the first frequency band. Here, "a quarter of the wavelength of the first frequency band" is not limited to an exact value, and may be any value that resonates in a desired frequency band. This is because the wavelength of the first frequency band is not necessarily expressed by an integer that is divisible, and the actual electrical length of the resonator 91 varies due to various factors. Note that the electrical length of the resonator 91 does not have to be formed so as to correspond to a quarter of the wavelength of the first frequency band, as long as it is formed so as to resonate in the first frequency band.

[0108] As shown in Fig. 11B, the element 90A is provided with a slit 92. The slit 92 is a cut (gap) formed from the outer edge of the element 90A toward the inside. As shown in Fig. 11B, the element 90A is provided with two slits 92. In the side view shown in Fig. 11B, the two slits 92 are composed of a slit 92 formed in the -Z direction from the upper end of the element 90A and bending and extending in the +X direction, and a slit 92 formed in the -X direction.

[0109] 11B, two folds 93 are provided in a portion of element 90A. When viewed in the +Z direction, the two folds 93 are provided on the +X direction side and the -X direction side of element 90A. As a result, the resonating portion 91 is formed by repeating horizontal folds 93 in element 90A (i.e., in a meandering shape). In this embodiment, it is possible to form an electrical length that resonates in the first frequency band (for example, an electrical length equivalent to a quarter of the wavelength of the first frequency band) by adjusting the horizontal length of the slit 92, for example.

[0110] The number, positions, and extending direction of the slits 92 are not limited to those shown in Fig. 11B. For example, one slit 92 may be provided in the element 90A. In this case, one fold 93 is provided in the slit 92. Also, for example, a number other than two slits 92 may be provided in the element 90A. In this case, the number of folds 93 corresponding to the number of slits 92 is provided.

[0111] In addition, in the side view shown in Fig. 11B, the direction in which the slits 92 extend is not limited to the horizontal direction, but may be the vertical direction. In Fig. 11B, one of the slits 92 is bent halfway, but it may be provided so as to extend only along the horizontal direction. The resonating portion 91 may be formed by repeatedly folding back in the vertical direction in the element 90A. Furthermore, in the element 90A, a slot may be formed instead of a slit.

[0112] Therefore, as long as the electrical length of the resonating portion 91 of this embodiment is formed so as to resonate in the radio wave frequency band (first frequency band) corresponding to the patch antenna 30 (first antenna), the number, positions, extension directions, etc. of the above-mentioned slits 92 or slots can be freely combined.

[0113] In addition, as long as the resonating portion 91 resonates in the first frequency band, a part of the element 90A does not have to be formed in a meandering shape. For example, in the in-vehicle antenna device 80B and the in-vehicle antenna device 80C described later, the width of the antenna element is formed to a predetermined length that resonates in the first frequency band.

[0114] Fig. 12 is a diagram showing the configurations of an in-vehicle antenna device 80B and an in-vehicle antenna device 80C. Fig. 12A is a side view of the in-vehicle antenna device 80B, and Fig. 12B is a side view of the in-vehicle antenna device 80C.

[0115] <Second Example of Vehicle-Mounted Antenna Device 80B> The vehicle-mounted antenna device 80B has an antenna base 20, a patch antenna 30, and an antenna 33B which is an antenna for telematics. The configuration of the vehicle-mounted antenna device 80B is the same as that of the vehicle-mounted antenna device 80A, except that the shape of the antenna 33B is different from that of the antenna 33A in the vehicle-mounted antenna device 80A described above. Therefore, only the details of the antenna 33B will be described below.

[0116] In the following description, the antenna 33B of the in-vehicle antenna device 80B may be referred to as a "second antenna." Also, the frequency band of radio waves that the antenna 33B supports may be referred to as a "second frequency band."

[0117] The antenna 33B (second antenna) has an element 90B that resonates in a frequency band (second frequency band) of radio waves that the antenna 33B supports. In the in-vehicle antenna device 80B, the width W1 of the element 90B is formed with an electrical length equivalent to a quarter of the wavelength of the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. This allows a part of the element 90B to function as a resonating unit 91 that resonates in the first frequency band. Therefore, the resonating unit 91 is a part of the element 90B of the antenna 33B (second antenna) that supports radio waves in the frequency band (second frequency band) for telematics, and resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports.

[0118] It should be noted that element 90B of antenna 33B, which is an antenna for telematics, is not limited to the shape shown in FIG. 12A, and may have another shape as shown in FIG. 12B.

[0119] <Third Example of Vehicle-Mounted Antenna Device 80C> The vehicle-mounted antenna device 80C has an antenna base 20, a patch antenna 30, and an antenna 33C that is an antenna for telematics. The configuration of the vehicle-mounted antenna device 80C is the same as that of the vehicle-mounted antenna device 80B, except that the shape of the antenna 33C is different from the shape of the antenna 33B in the vehicle-mounted antenna device 80B described above. Therefore, only the details of the antenna 33C will be described below.

[0120] In the following description, the antenna 33C of the in-vehicle antenna device 80C may be referred to as a "second antenna." Also, the frequency band of radio waves supported by the antenna 33C may be referred to as a "second frequency band."

[0121] Antenna 33C has element 90C that resonates in the frequency band (second frequency band) of radio waves that antenna 33C (second antenna) supports. Compared to element 90B of antenna 33B shown in Fig. 12A, element 90C of antenna 33C has an upper end that is formed at an angle.

[0122] In addition, in the in-vehicle antenna device 80C, the width W2 of the element 90C is formed with an electrical length equivalent to a quarter of the wavelength of the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna). As a result, a part of the element 90C functions as a resonator 91 that resonates in the first frequency band. Therefore, the resonator 91 is a part of the element 90C of the antenna 33C (second antenna) that supports radio waves in the frequency band (second frequency band) for telematics, and resonates in the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna).

[0123] Here, using an in-vehicle antenna device 80X as a comparative example described later, a comparison will be made between the characteristics of the patch antenna 30 in the in-vehicle antenna device 80X and the characteristics of the patch antenna 30 in an in-vehicle antenna device 80C as a third example of this embodiment.

[0124] ==Configuration of Vehicle-Mounted Antenna Device 80X of Comparative Example== Fig. 13 is a diagram showing a configuration of an in-vehicle antenna device 80X as a comparative example. As shown in Fig. 13, the in-vehicle antenna device 80X is an in-vehicle antenna device having only a patch antenna 30. Therefore, in the following description, the in-vehicle antenna device 80X may be referred to as a "single patch antenna model."

[0125] In other words, the in-vehicle antenna device 80X is an in-vehicle antenna device obtained by removing the antenna 33C from the in-vehicle antenna device 80C described above. The in-vehicle antenna device 80X has the same configuration as the in-vehicle antenna device 80C of the third example of the present embodiment described above, except that the antenna 33C is not provided.

[0126] Comparison of Characteristics Between Vehicle-Mounted Antenna Device 80C and Vehicle-Mounted Antenna Device 80X The following describes the results of calculating the characteristics of the patch antenna 30 in the in-vehicle antenna device 80C and the in-vehicle antenna device 80X.

[0127] Fig. 14 is a graph showing characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C and the vehicle-mounted antenna device 80X. Fig. 14A is a graph showing an example of the relationship between the elevation angle and the average gain, and Fig. 14B is a graph showing an example of the directivity at an elevation angle of 20°.

[0128] In Fig. 14A, the horizontal axis indicates the elevation angle, and the vertical axis indicates the average gain. In Fig. 14A, the calculation results for the vehicle-mounted antenna device 80X are shown by a dashed line, and the calculation results for the vehicle-mounted antenna device 80C are shown by a solid line. Note that the circles on the dashed lines and the triangles on the solid lines indicate the positions of the values ​​on the vertical axis relative to the values ​​on the horizontal axis, and are shown as circles and triangles for convenience in order to distinguish between them. Note that in the following description, the average gain may be simply referred to as "gain".

[0129] 14A and 14B, when the gain of the in-vehicle antenna device 80X of the comparative example is compared with the gain of the in-vehicle antenna device 80C of this embodiment, the gain of the in-vehicle antenna device 80C of this embodiment is higher than the gain of the in-vehicle antenna device 80X of the comparative example, particularly in the low elevation angle range. Therefore, the in-vehicle antenna device 80C of this embodiment, as an antenna device that receives radio waves transmitted from a satellite, for example, has an improved average gain in at least a part of the elevation angle range from low to medium elevation angles of the patch antenna 30, and has ideal directivity.

[0130] Therefore, the directivity of the patch antenna 30 is improved in the in-vehicle antenna device 80C of this embodiment, and as a result, incoming radio waves from, for example, a satellite can be efficiently received. In this manner, the in-vehicle antenna device 80C of this embodiment has the resonator 91, and thus can easily control the directivity of the patch antenna 30. Although detailed verification will not be described, the in-vehicle antenna device 80A and the in-vehicle antenna device 80B described above also have the resonator 91, and thus can easily control the directivity of the patch antenna 30.

[0131] 11B, 12A, and 12B, the patch antenna 30 and the resonator 91 in each of the in-vehicle antenna devices 80A to 80C of this embodiment do not overlap with each other in side views. Although not shown, the patch antenna 30 and the resonator 91 in each of the in-vehicle antenna devices 80A to 80C of this embodiment also do not overlap with each other in top view.

[0132] As in the in-vehicle antenna device 10 of the first embodiment described above, in the in-vehicle antenna devices 80A to 80C of the present embodiment, the patch antenna 30 and the resonator 91 are spaced apart from each other by a predetermined distance in the horizontal or vertical direction. At this time, the phase of the radio wave corresponding to the patch antenna 30 and the phase of the radio wave corresponding to the antennas 33A to 33C in which the resonator 91 is provided are reinforced with each other. Therefore, hereinafter, the separation distance at which the phase of the radio wave corresponding to the patch antenna 30 and the phase of the radio wave corresponding to the antenna 33C among the antennas 33A to 33C are reinforced with each other will be examined.

[0133] FIG. 15 is an explanatory diagram of the separation distance D between the patch antenna 30 and the resonator 91. As shown in FIG.

[0134] The separation distance D is the separation distance in the horizontal direction (X direction) between the patch antenna 30 and the resonator unit 91 of the antenna 33C in a side view as shown in Fig. 15. Specifically, the separation distance D is the distance in the horizontal direction between the end of the patch antenna 30 closest to the resonator unit 91 and the end of the resonator unit 91 closest to the patch antenna 30.

[0135] FIG. 16 is a graph showing an example of the relationship between the elevation angle and the average gain when the separation distance D is changed.

[0136] In FIG. 16, the horizontal axis indicates the elevation angle, and the vertical axis indicates the average gain. In FIG. 16, the calculation results for the vehicle-mounted antenna device 80X of the comparative example are shown by a broken line, and the calculation results for the vehicle-mounted antenna device 80C of this embodiment when the separation distance D is changed are shown by a plurality of solid lines. The calculation results when the separation distance D is changed to 8 mm, 16 mm, 32 mm, 64 mm, 128 mm, and 256 mm are shown by using △ marks and □ marks on the solid lines. Note that these △ marks and □ marks on the solid lines indicate the position of the numerical values ​​on the vertical axis relative to the numerical values ​​on the horizontal axis, and are shown by △ marks and □ marks for convenience in order to distinguish them. Note that in the following description, the average gain may be simply referred to as "gain".

[0137] 16, when the separation distance D is 8 mm, the gain of the vehicle-mounted antenna device 80C is lower than the gain of the vehicle-mounted antenna device 80X (patch antenna only model, circle mark), especially in the low elevation angle range. On the other hand, when the separation distance D is 16 mm, 32 mm, 64 mm, 128 mm, and 256 mm, the gain of the vehicle-mounted antenna device 80C is higher than the gain of the vehicle-mounted antenna device 80X (patch antenna only model, circle mark), at least in the low elevation angle range.

[0138] This shows that when the separation distance D is 16 mm or more, the characteristics of the patch antenna 30 of the in-vehicle antenna device 80C are improved compared to a model of a single patch antenna. Here, 16 mm corresponds to one-eighth of the wavelength of the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. Therefore, in the in-vehicle antenna device 80C of this embodiment, it is desirable that the first antenna (patch antenna 30) and the resonator 91 are separated in the horizontal direction by one-eighth or more of the wavelength of the first frequency band.

[0139] As shown in Fig. 16, when the separation distance D is 128 mm, the gain of the vehicle-mounted antenna device 80C is slightly higher than the gain of the vehicle-mounted antenna device 80X (patch antenna only model, circle mark). However, when the separation distance D is 256 mm, the graph of the vehicle-mounted antenna device 80C and the graph of the vehicle-mounted antenna device 80X (patch antenna only model) are almost the same. In other words, when the separation distance D is 256 mm, it can be seen that the gain of the vehicle-mounted antenna device 80C is almost the same as the gain of the vehicle-mounted antenna device 80X (patch antenna only model).

[0140] As a result, when the separation distance D is greater than 128 mm, the characteristics of the patch antenna 30 of the in-vehicle antenna device 80C are substantially the same as those of a patch antenna alone model. Here, 128 mm corresponds to one wavelength in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. Therefore, in the in-vehicle antenna device 80C of this embodiment, the separation distance in the horizontal direction between the first antenna (patch antenna 30) and the resonator 91 is set to one wavelength or less in the first frequency band, which is particularly advantageous since it improves the characteristics of the patch antenna 30.

[0141] ==Other== Fig. 17 is a diagram showing another example of the positional relationship between the patch antenna 30 and the resonator 61. Fig. 17A and Fig. 17B are a side view and a plan view showing a first example of the positional relationship, and Fig. 17C and Fig. 17D are a side view and a plan view showing a second example of the positional relationship.

[0142] 1, the patch antenna 30 and the resonator unit 61 do not overlap each other when viewed from above or from the side. However, the patch antenna 30 and the resonator unit 61 do not need to be non-overlapping each other when viewed from above or from the side, and the patch antenna 30 and the resonator unit 61 may be non-overlapping each other when viewed from either the above or from the side.

[0143] In a first example of the positional relationship, the patch antenna 30 and the resonator unit 61 overlap each other in the side view shown in Fig. 17A. However, the patch antenna 30 and the resonator unit 61 do not overlap each other in the top view shown in Fig. 17B. Note that the dashed lines shown in Fig. 17A are auxiliary lines to indicate that the patch antenna 30 and the resonator unit 61 overlap each other.

[0144] In a second example of the positional relationship, the patch antenna 30 and the resonator 61 do not overlap each other in the side view shown in Fig. 17C, while the patch antenna 30 and the resonator 61 overlap each other in the top view shown in Fig. 17D. Note that the dashed lines shown in Fig. 17C are auxiliary lines to indicate that the patch antenna 30 and the resonator 61 overlap each other.

[0145] Even when the patch antenna 30 and the resonator unit 61 do not overlap each other in either the top view or the side view, as in the first and second examples of positional relationships, the directivity of the patch antenna 30 can be controlled even more easily.

[0146] ==Summary== The vehicle-mounted antenna device 10 of this embodiment has been described above. The vehicle-mounted antenna device 10 includes, for example, a patch antenna 30 (first antenna) that supports radio waves in the 2.3 GHz band (first frequency band) for SDARS, and an antenna 32 (second antenna) that supports radio waves in a frequency band different from the first frequency band, for example, a 522 kHz to 1710 kHz band for AM broadcasting and a 76 MHz to 108 MHz band for FM broadcasting (second frequency band). At least a part (for example, the metal body 60A) of an element (for example, the capacitive loading element 60) constituting the second antenna resonates in the first frequency band. According to the vehicle-mounted antenna device 10 of this embodiment, the directivity of the planar antenna (for example, the patch antenna 30) can be easily controlled.

[0147] The vehicle-mounted antenna devices 80A to 80C of the present embodiment have been described. The vehicle-mounted antenna devices 80A to 80C include, for example, a patch antenna 30 (first antenna) that supports radio waves in the 2.3 GHz band (first frequency band) for SDARS, and antennas 33A to 33C (second antennas) that support radio waves in a frequency band (second frequency band) for telematics that is different from the first frequency band, as shown in Fig. 11 and Fig. 12. At least a part of the elements (for example, elements 90A to 90C) that constitute the second antenna resonates in the first frequency band. According to the vehicle-mounted antenna devices 80A to 80C of the present embodiment, the directivity of the planar antenna (for example, the patch antenna 30) can be easily controlled.

[0148] Also, at least a part (e.g., metal body 60A) of an element (e.g., capacitive loading element 60) has a resonating portion 61 formed with an electrical length that resonates in the first frequency band, as shown in, for example, Figures 3, 8, 9, and 10. This makes it possible to easily control the directivity of the planar antenna (e.g., patch antenna 30).

[0149] Moreover, the electrical length of the resonator 61 is half the wavelength of the first frequency band, which makes it possible to easily control the directivity of the planar antenna (for example, the patch antenna 30).

[0150] 3, 8, 9, and 10, the resonator unit 61 has at least one fold 64. This allows the resonator unit 61 to have an electrical length that resonates in the first frequency band.

[0151] 3, 8, 9, and 10, the resonator unit 61 has a gap (slit 62 or slot 63) extending in at least one of the horizontal and vertical directions. This allows the resonator unit 61 to have an electrical length that resonates in the first frequency band.

[0152] 3, 8B, 9A, and 10A, the resonator unit 61 is formed by repeatedly folding back in the horizontal direction, so that the resonator unit 61 can have an electrical length that resonates in the first frequency band.

[0153] 1 and 6, the patch antenna 30 (first antenna) and the resonator 61 do not overlap each other in top and side views. This makes it easier to control the directivity of the planar antenna (for example, the patch antenna 30).

[0154] 17, the patch antenna 30 (first antenna) and the resonator 61 do not overlap each other in a top or side view. This makes it easier to control the directivity of the planar antenna (for example, the patch antenna 30).

[0155] 1 and 6, the patch antenna 30 (first antenna) and the resonator 61 are spaced apart by a predetermined distance in the horizontal or vertical direction. This makes it easier to control the directivity of the planar antenna (e.g., the patch antenna 30).

[0156] Moreover, the predetermined distance is equal to or greater than a quarter of the wavelength of the first frequency band, which makes it easier to control the directivity of the planar antenna (eg, patch antenna 30).

[0157] Moreover, the second frequency band is lower than the first frequency band, which makes it possible to easily control the directivity of the planar antenna (for example, the patch antenna 30).

[0158] In this embodiment, "vehicle-mounted" means that it can be placed on a vehicle, and therefore includes not only those that are attached to a vehicle, but also those that are brought into a vehicle and used within the vehicle. In addition, the antenna device of this embodiment is used in a "vehicle" that is a vehicle with wheels, but is not limited to this, and may be used in, for example, an aircraft such as a drone, a probe, a construction machine without wheels, an agricultural machine, a ship, or other moving object.

[0159] The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. Furthermore, the present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof. [Explanation of symbols]

[0160] 10,10X,80A~80C,80X Vehicle-mounted antenna device 20 Antenna Base 21,22 Metal base 23 cases 30 Patch antenna (first antenna) 31 Patch Antenna 32 Antenna (2nd Antenna) 33A~33C Antenna (2nd Antenna) 40 Holder 41 Pillar section 42 Mounting part 50 Helical element (coil) 60 Capacitive load element 60A~60D Metal body 61 Resonance part 62 Slit 63 Slots 64 Turn Around 70 Substrate 71 Patterns 72 Dielectric Materials 73 Radiating element 74 Retaining member 74A~74C Convex part 75 Metal body 75A~75C Recess 76 Through hole 77 Power line 78 Power supply point 90A~90C Element 91 Resonance section 92 Slit 93 Turn Around 100 Filters

Claims

1. A substrate; a first antenna corresponding to a first frequency band that is a circularly polarized wave; a second antenna having a rectangular plate shape corresponding to a second frequency band which is linearly polarized, a portion of the second antenna extending from the power supply portion is disposed at an angle to the substrate; One side of the second antenna has a length that resonates in the first frequency band. Antenna device.

2. the one side of the second antenna is substantially parallel to a radiation surface of the first antenna, A length equivalent to approximately one-quarter of the wavelength of the first frequency band, 2. The antenna device according to claim 1.

3. The first frequency band is a lower frequency band than the second frequency band.

2. The antenna device according to claim 1.

4. The entire second antenna is disposed at an angle to the substrate.

2. The antenna device according to claim 1.

5. The side of the second antenna that is farthest from the substrate has a length equivalent to approximately one-quarter of the wavelength of the first frequency band.

2. The antenna device according to claim 1.

Images