Composite antenna device

Abstract

The composite antenna device is capable of receiving signals of a plurality of frequency bands, and is provided with: an antenna base; a first antenna which is mounted on the antenna base, has a radiating element, and is capable of receiving a signal of a first frequency band; a second antenna capable of receiving a signal of a second frequency band lower than the first frequency band; and the second antenna has capacitance loading elements arranged at intervals in the height direction with respect to the antenna base, and the capacitance loading elements include at least one cutout that does not overlap the radiating element of the first antenna in a plan view. And a second antenna disposed in the vicinity of the radiating element so that the radiating element is positioned on an extension line in the longitudinal direction of the capacitance loading element, and provided so as to intersect the longitudinal direction to control the directivity of the first antenna.

Description

[0001] This invention application is a divisional application of the invention application with an international application date of March 11, 2022, an international application number of PCT / JP2022 / 011078, a national application number of 202280025485.2 entering the Chinese national phase, and an invention name of “Vehicle-mounted Antenna Device”. Technical Field

[0002] The present invention relates to a composite antenna arrangement. Background Art

[0003] Patent Document 1 discloses a vehicle-mounted antenna device in which a planar antenna for GPS signals and an antenna for AM / FM are housed in an antenna case.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-21856 Summary of the Invention

[0007] However, due to the structure of the vehicle-mounted antenna device, it is difficult to ensure the directivity required of the planar antenna.

[0008] One example of an object of the present invention is to facilitate control of the directivity of a planar antenna. Other objects of the present invention will become apparent from the description of this specification.

[0009] One embodiment of the present invention is a vehicle-mounted antenna device comprising: a first antenna for responding to radio waves in a first frequency band; and a second antenna for responding to radio waves in a second frequency band different from the first frequency band, wherein at least a portion of an oscillator constituting the second antenna resonates in the first frequency band.

[0010] Effects of the Invention

[0011] According to one embodiment of the present invention, the directivity of a planar antenna can be easily controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a diagram showing the structure of the vehicle-mounted antenna device 10 .

[0013] Figure 2 It is an exploded perspective view of the patch antenna 30 .

[0014] Figure 3 It is a perspective view of the metal body 60A and a side view of the metal body 60A.

[0015] Figure 4 It is a diagram showing the structure of a vehicle-mounted antenna device 10X.

[0016] Figure 5 Graphs 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.

[0017] Figure 6 1 and 2 are explanatory diagrams of the separation distance D and the separation distance H between the patch antenna 30 and the resonant portion 61 .

[0018] Figure 7 Graphs showing an example of the relationship between the separation distance D and the average gain, and the relationship between the separation distance H and the average gain.

[0019] Figure 8 1 and 2 are diagrams showing resonating parts 61A to 61C according to modified examples.

[0020] Figure 9 1 and 2 are diagrams showing a resonating portion 61D and a resonating portion 61E according to a modified example.

[0021] Figure 10 1 and 2 are diagrams showing a resonating portion 61F and a resonating portion 61G according to a modified example.

[0022] Figure 11 1 is a diagram showing the structure of a vehicle-mounted antenna device 80A. Figure 11 A is a perspective view of a vehicle-mounted antenna device 80A. Figure 11 B is a side view of the vehicle-mounted antenna device 80A.

[0023] Figure 12 1 is a diagram showing the structure of a vehicle-mounted antenna device 80B and a vehicle-mounted antenna device 80C. Figure 12 A is a side view of the vehicle-mounted antenna device 80B. Figure 12 B is a side view of the vehicle-mounted antenna device 80C.

[0024] Figure 13 It is a diagram showing the structure of a vehicle-mounted antenna device 80X.

[0025] Figure 14 Graphs showing the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C and the vehicle-mounted antenna device 80X. Figure 14 A is a graph showing an example of the relationship between elevation angle and average gain. Figure 14 B is a graph showing an example of directivity at an elevation angle of 20 degrees.

[0026] Figure 15 3 is an explanatory diagram of the separation distance D between the patch antenna 30 and the resonant portion 91 .

[0027] Figure 16 This is a graph showing an example of the relationship between the elevation angle and the average gain when the separation distance D is changed.

[0028] Figure 17 is a diagram showing another example of the positional relationship between the patch antenna 30 and the resonant portion 61. Figure 17 A and Figure 17 B is a side view and a top view showing the first example of the positional relationship. Figure 17 C and Figure 17 D is a side view and a top view showing a second example of the positional relationship.

[0029] Description of Reference Numerals

[0030] 10, 10X, 80A~80C, 80X vehicle-mounted antenna devices

[0031] 20 Antenna base

[0032] 21, 22 Metal base

[0033] 23 housing

[0034] 30 Patch antenna (first antenna)

[0035] 31 Patch Antenna

[0036] 32 antenna (2nd antenna)

[0037] 33A~33C Antenna (Second Antenna)

[0038] 40 Cage

[0039] 41 Pillar Department

[0040] 42 Installation

[0041] 50 Helical element (coil)

[0042] 60 Capacitor loading element

[0043] 60A~60D metal body

[0044] 61 Resonance section

[0045] 62 Slit

[0046] 63 slots

[0047] 64 Turn Back

[0048] 70 substrate

[0049] 71 Pattern

[0050] 72 Dielectric components

[0051] 73 Radiating Elements

[0052] 74 Holding components

[0053] 74A~74C convex part

[0054] 75 Metal Body

[0055] 75A~75C concave part

[0056] 76 through hole

[0057] 77 Feeder

[0058] 78 Feed Points

[0059] 90A~90C Vibrator

[0060] 91 Resonance section

[0061] 92 Slit

[0062] 93 Turn back

[0063] 100 filters. DETAILED DESCRIPTION

[0064] At least the following matters can be understood from the description of this specification and the accompanying drawings.

[0065] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The same or equivalent components and members shown in the respective drawings are denoted by the same reference numerals, and duplicate descriptions will be omitted as appropriate.

[0066] ==Structure of Vehicle-Mounted Antenna Device 10 According to First Embodiment==

[0067] <Structure Overview>

[0068] Figure 1 1 is a diagram showing the structure of the vehicle-mounted antenna device 10 according to the first embodiment. Figure 1 The following is a perspective view of the vehicle-mounted antenna device 10 after the housing 23 is removed toward the zenith (upward). Figure 1 The outline of the structure of the vehicle-mounted antenna device 10 will be described.

[0069] exist Figure 1In the diagram, the front-to-back direction of the vehicle on which the vehicle-mounted antenna device 10 is mounted is referred to as the X direction, the left-to-right direction perpendicular to the X direction is referred to as the Y direction, and the vertical direction perpendicular to the X and Y directions is referred to as the Z direction. Furthermore, as viewed from the driver's seat of the vehicle, the front side is referred to as the +X direction, the right side is referred to as the +Y direction, and the zenith direction (upward) is referred to as the +Z direction. In the following description of this embodiment, the front-to-back, left-to-right, and up-to-down directions of the vehicle-mounted antenna device 10 are assumed to be the same as those of the vehicle. Furthermore, viewing the vehicle-mounted antenna device 10 from the -Z direction is referred to as "top view," and viewing the vehicle-mounted antenna device 10 from the +Y or -Y directions is referred to as "side view."

[0070] In addition, the definitions of the above-mentioned directions and the like are common to other embodiments of the present specification, unless otherwise specified.

[0071] The vehicle-mounted antenna device 10 is mounted on the roof of a vehicle (not shown) and includes an antenna base 20 , a housing 23 , a patch antenna 30 , a patch antenna 31 , and an antenna 32 .

[0072] The antenna base 20 forms the bottom surface of the vehicle-mounted antenna device 10. The antenna base 20 comprises, for example, a resin insulating base, a metal base 21, and a metal base 22. The metal bases 21 and 22 are attached to the insulating base using a plurality of screws (not shown). However, as long as the insulating base is insulating, it may be formed of materials other than resin and may have a shape other than plate.

[0073] The metal base 21 serves as the grounding portion of the vehicle-mounted antenna device 10. The metal base 21 is formed, for example, into a metal plate. However, as long as the metal base 21 functions as the grounding portion, it may have a shape other than a plate. A patch antenna 30 is mounted on the metal base 21.

[0074] The metal base 22 functions as the ground portion of the vehicle-mounted antenna device 10. The metal base 22 is formed, for example, into a metal plate. However, as long as the metal base 22 functions as a ground portion, it may have a shape other than a plate. The patch antenna 31 and antenna 32 are mounted on the metal base 22.

[0075] In this embodiment, the metal base 21 and the metal base 22 are electrically connected via a metal plate not shown. In addition, when the vehicle-mounted antenna device 10 is mounted on the roof of a vehicle not shown, the metal base 21 and the metal base 22 are electrically connected to the roof. Thus, the metal base 21 and the metal base 22 function as a ground portion of the vehicle-mounted antenna device 10. In addition, in this embodiment, although the metal base 21 and the metal base 22 are provided separately, they may also be provided as an integrated metal base. Even when such an integrated metal base is used, the metal base will appropriately function as a ground portion of the patch antenna 31 and the antenna 32 described later.

[0076] In the above description, the antenna base 20 of the vehicle-mounted antenna device 10, which constitutes the bottom surface of the vehicle-mounted antenna device 10 and functions as a ground portion, includes an insulating base, a metal base 21, and a metal base 22. However, the vehicle-mounted antenna device 10 is not limited to these structures.

[0077] For example, the antenna base 20 may include only the metal base 21 and the metal base 22, or may include only an integrated metal base in place of the metal base 21 and the metal base 22. Alternatively, the antenna base 20 may include an insulating base, the metal base 21, and a metal plate. Alternatively, the vehicle-mounted antenna device 10 may include an insulating base and an integrated metal base in place of the metal base 21 and the metal base 22. Furthermore, the vehicle-mounted antenna device 10 may include an insulating base, the metal base 21 and the metal base 22, and another metal base, or may include a metal plate in place of the metal base. Alternatively, the antenna base 20 may include both an insulating base and a metal plate.

[0078] Therefore, the vehicle-mounted antenna device 10 of the present embodiment can freely combine the above-mentioned components as the component constituting the bottom surface of the vehicle-mounted antenna device 10 and the component functioning as the ground portion.

[0079] The housing 23 is a component (shell) that covers the outside of the vehicle-mounted antenna device 10. Figure 1 As shown, the housing 23 is a typical shell of a shark fin antenna.

[0080] The patch antenna 30 is, for example, a planar antenna that supports radio waves in the 2.3 GHz band of the Satellite Digital Audio Radio Service (SDARS). In this embodiment, the patch antenna 30 receives radio waves in the 2.3 GHz band used by SDARS. Furthermore, the communication standards and frequency bands supported by the patch antenna 30 are not limited to those described above; other communication standards and frequency bands are also possible. Furthermore, the patch antenna 30 can support radio waves in multiple frequency bands, as long as it can perform at least one of transmission and reception of radio waves in the desired frequency band.

[0081] 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.”

[0082] Note that the patch antenna 30 will be described in detail later.

[0083] The patch antenna 31 is, for example, a planar antenna that supports 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 used by the GNSS. Furthermore, the communication standards and frequency bands supported by the patch antenna 31 are not limited to those described above; other communication standards and frequency bands are also possible. Furthermore, the patch antenna 31 can support radio waves in multiple frequency bands, as long as it can perform at least one of transmitting and receiving radio waves in the desired frequency band.

[0084] Antenna 32 is, for example, an antenna that supports radio waves for AM / FM radio. In this embodiment, antenna 32 receives radio waves for AM broadcasts in the 522kHz to 1710kHz range and radio waves for FM broadcasts in the 76MHz to 108MHz range. However, antenna 32 may also receive only one of AM and FM broadcasts. Furthermore, the communication standards and frequency bands supported by antenna 32 are not limited to those described above and may also support other communication standards and frequency bands. Furthermore, antenna 32 only needs to be able to transmit or receive radio waves in the desired frequency band.

[0085] 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.”

[0086] Note that the antenna 32 will be described in detail later.

[0087] <Details of Patch Antenna 30 (First Antenna)>

[0088] Figure 23 is an exploded perspective view of the patch antenna 30. Figure 1 and Figure 2 The patch antenna 30 will be described in detail.

[0089] The patch antenna 30 includes a substrate 70 , a dielectric member 72 , a radiating element 73 , a holding member 74 , and a metal body 75 .

[0090] The substrate 70 is a circuit substrate for providing a dielectric component 72. Figure 2 As shown, the substrate 70 is mounted on the metal base 21 .

[0091] The dielectric member 72 is a substantially square plate-shaped member formed of a dielectric material such as ceramic. Figure 2 As shown, the front and back surfaces of dielectric member 72 are parallel to the X and Y directions. The front surface of dielectric member 72 faces the +Z direction, and the back surface of dielectric member 72 faces the -Z direction. A pattern 71 is provided on the back surface of dielectric member 72. Pattern 71 is a conductor that functions as a grounded conductor film (or grounded conductor plate). The back surface of dielectric member 72 is attached to substrate 70 using, for example, an adhesive (not shown).

[0092] Here, "substantially quadrilateral" refers to a shape consisting of four sides, including, for example, a square and a rectangle. For example, at least some corners may be cut off obliquely relative to the sides. Furthermore, within a "substantially quadrilateral" shape, a portion of the sides may have a notch (a recessed portion) or a protrusion (a protruding portion). Furthermore, the shape of dielectric member 72 is not limited to a substantially quadrilateral; for example, a circular or elliptical shape may also be employed. Furthermore, dielectric member 72 may have shapes other than a plate.

[0093] The radiation element 73 is a conductive, substantially quadrilateral member having a smaller area than the front surface of the dielectric member 72. Figure 2 As shown, radiating element 73 is provided on the front surface of dielectric member 72. Furthermore, the normal direction of the radiating surface of radiating element 73 is the +Z direction. Furthermore, the shape of radiating element 73 is not limited to a substantially rectangular shape; for example, a circular or elliptical shape is also possible. In other words, radiating element 73 may be of any shape as long as it can transmit or receive signals (radio waves) in the desired frequency band.

[0094] In addition, if Figure 2 As shown, the radiating element 73 has a feed point 78. The feed point 78 is Figure 2The point where feeder line 77 is electrically connected to radiating element 73 is shown. In this embodiment, a single feeder line 77 is connected to radiating element 73, i.e., a single feed method is employed. For example, radiating element 73 in a single feed method has a generally rectangular shape with varying lengths in the vertical and horizontal directions, enabling at least one of transmission and reception of desired circularly polarized waves. Note that the term "generally rectangular" encompasses the aforementioned "generally quadrilateral" shape.

[0095] However, in this embodiment, a dual-feed configuration may also be employed, in which two feeder lines 77 are connected to the radiating element 73. The dual-feed radiating element 73 may have, for example, a substantially square shape with equal lengths in both directions, enabling transmission and reception of desired circularly polarized waves. Note that a "substantially square" shape is included within the "substantially quadrilateral" described above.

[0096] In the patch antenna 30 of this embodiment, as Figure 2 As shown, a through hole 76 is formed through the substrate 70 and the dielectric member 72. The through hole 76 is formed so that a feed line 77 is connected to a feeding point 78 of the radiating element 73. Furthermore, in a dual-feed radiating element 73, two through holes 76 are formed through the substrate 70 and the dielectric member 72. Furthermore, a feed line 77 is connected to the feeding point 78 of the radiating element 73 in each through hole 76.

[0097] The holding member 74 is a member that holds the metal body 75. It is made of resin and is mounted on the front surface of the dielectric member 72, surrounding the radiating element 73. However, as long as the holding member 74 can hold the metal body 75, it can be made of materials other than resin. Of the two sides of the upper surface of the holding member 74 parallel to the Y axis, the +X side has a protrusion 74A extending in the +Z direction, and the -X side has protrusions 74B and 74C extending in the +Z direction. Protrusions 74A through 74C are generally rectangular parallelepiped projections formed to position the metal body 75 relative to the holding member 74. However, as long as protrusions 74A through 74C can respectively position the metal body 75 relative to the holding member 74, they do not need to be generally rectangular parallelepiped projections. Furthermore, the holding member 74 does not need to have protrusions 74A through 74C. Furthermore, the holding member 74 is not limited to a frame shape that entirely surrounds the radiating element 73. For example, the metal body 75 may be mounted on a protrusion provided in the housing 23 or may be fitted into a groove provided in the housing 23. In other words, the housing 23 may also serve as the holding member 74.

[0098] The metal body 75 is a component that improves the radiation efficiency of the patch antenna 30 and controls its directivity through capacitive coupling with the radiating element 73. The metal body 75 is a roughly square zenith plate (or zenith capacitor plate) held by the holding member 74. Of the two sides parallel to the Y-axis, a recess 75A is provided on the +X side, and recesses 75B and 75C are provided on the -X side. In this embodiment, the metal body 75 is positioned on the front surface of the holding member 74, with the protrusions 74A to 74C of the holding member 74 respectively engaged with the recesses 75A to 75C of the metal body 75. However, if the holding member 74 does not have the protrusions 74A to 74C, the metal body 75 does not need to have the recesses 75A to 75C.

[0099] Furthermore, while the metal body 75 is configured as a substantially square plate, this is not limiting and may also be a substantially quadrilateral other than a substantially square, or may be circular or elliptical. Furthermore, the metal body 75 may be a three-dimensional shape formed by bending a plate-like metal sheet. For example, the metal body 75 may be configured as an inverted V-shape, an inverted U-shape, a mountain shape (umbrella shape), or an arch shape by bending the metal sheet. Furthermore, the metal body 75 may have a shape other than a plate.

[0100] <Details of Antenna 32 (Second Antenna)>

[0101] Figure 3 A is a perspective view of a metal body 60A of a capacitance loading element 60 to be described later. Figure 3 B is a side view of the metal body 60A of the capacitance loading element 60 described later. Figure 1 and Figure 3 A and Figure 3 B will now explain the details of the antenna 32.

[0102] Antenna 32 has a holder 40 , a helical element 50 , a capacitive loading element 60 , and a filter 100 .

[0103] The retaining frame 40 is a component for retaining the spiral element 50 and the capacitor loading element 60. Figure 1 As shown, the holder 40 is provided on the antenna base 20. The holder 40 is formed of, for example, resin. However, as long as the holder 40 can hold the helical element 50 and the capacitor loading element 60, it may be formed of a material other than resin.

[0104] like Figure 1As shown, the retaining frame 40 has a support portion 41 and a mounting portion 42. The support portion 41 is a portion for mounting the spiral element 50. The mounting portion 42 is a portion for mounting the capacitor loading element 60. In addition, the mounting portion 42 has a substantially trapezoidal cross-section with the X direction as the longitudinal direction and the left and right widths widening toward the lower side (-Z direction). However, the mounting portion 42 is not limited to the above-mentioned shape with a substantially trapezoidal cross-section. For example, the cross-sectional shape when observing the mounting portion 42 from the front or rear may also be a roughly square, a roughly rectangular or other roughly quadrilateral, and the outer shape when observing the mounting portion 42 from the front or rear may also be an inverted V-shape, an inverted U-shape, a mountain shape (umbrella shape), or an arch shape.

[0105] The spiral element (hereinafter referred to as "coil") 50 is an element that resonates in a desired frequency band together with the capacitance loading element 60. Figure 1 As shown, the coil 50 is mounted on the support 41 of the holder 40 and is provided above the metal base 22 . 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 capacitance loading element 60 .

[0106] The capacitance loading element 60 is an element that resonates with the coil 50 in a desired frequency band. Figure 1 As shown, the capacitor loading element 60 is composed of four metal bodies 60A to 60D divided along the front-to-back direction (lengthwise direction). In the following description, "metal body" is formed by processing a metal part. For example, in addition to plate-shaped metal parts such as metal plates, it also includes metal parts with three-dimensional shapes other than plate shapes.

[0107] like Figure 1 、 Figure 3 A and Figure 3 As shown in FIG. 3B , the metal bodies 60A to 60D of this embodiment are formed by bending the two ends of the metal plate in the Y-axis direction upward from the two ends of the bottom surface roughly parallel to the XY plane in the center. In the following description, regarding each metal body 60A to 60D, the bottom surface portion roughly parallel to the XY plane in the center is sometimes referred to as the "bottom surface portion". In addition, the left side of the portion formed by bending from the two ends of the bottom surface portion upward is sometimes referred to as the "left side surface portion", and the right side is sometimes referred to as the "right side surface portion". In addition, although Figure 3 A and Figure 3 B shows only the metal body 60A among the metal bodies 60A to 60D, but Figure 1 The metal bodies 60B to 60D shown in the figure also have a bottom surface, a left surface, and a right surface, similarly to the metal body 60A.

[0108] In this embodiment, the four metal bodies 60A to 60D have the same length in the front-to-back direction, but this is not limiting. For example, the four metal bodies 60A to 60D may have different lengths in the front-to-back direction, or some of them may have the same length. Furthermore, while the metal bodies 60A to 60D each have a bottom portion, they may also include metal bodies without a bottom portion.

[0109] In addition, in the present embodiment, although the capacitor loading element 60 is configured to have four metal bodies 60A to 60D, it is not limited to this. For example, the capacitor loading element 60 may also have one metal body, or may have multiple metal bodies other than four. In addition, although the capacitor loading element 60 has a shape that is bent upward from both ends of the central bottom surface, the shape is not limited to this. For example, the capacitor loading element 60 may also be bent downward from both ends. In addition, the outer shape of the capacitor loading element 60 when viewed from the front or rear may also be, for example, an inverted V-shape, an inverted U-shape, a mountain shape (umbrella shape), or an arch shape.

[0110] The filter 100 is a component that electrically connects the four metal bodies 60A to 60D and provides high impedance in the frequency band of the radio waves of the patch antenna 30 and the patch antenna 31. In this embodiment, there are three filters 100. Figure 1 As shown, three filters 100 are provided in the gaps between metal bodies 60A and 60B on the left side of the face, the gap between metal bodies 60B and 60C on the left side of the face, and the gap between metal bodies 60C and 60D on the left side of the face. Filters 100 are circuits that exhibit parallel resonance, for example, in the frequency band of radio waves supported by patch antennas 30 and 31, and are configured to include capacitors and coils (not shown).

[0111] In addition, the installation position and number of the filter 100 of this embodiment are not limited to Figure 1 The filter 100 only needs to be arranged at a position that connects adjacent metal bodies 60A to 60D. Therefore, the filter 100 can be arranged at an upper position including the top or a lower position including the bottom of the metal bodies 60A to 60D. In addition, the filter 100 can also be arranged only on the right side of the capacitor loading element 60. Furthermore, the filter 100 can also be arranged alternately on the left and right sides of the capacitor loading element 60.

[0112] As described above, the four metal bodies 60A to 60D are electrically connected via the filter 100 having high impedance in the frequency band of radio waves supported by the patch antennas 30 and 31. The coil 50 is designed to have high impedance in the frequency band of radio waves supported by the patch antennas 30 and 31.

[0113] Because filter 100 has low impedance in the AM / FM frequency band, all metal bodies 60A-60D operate as a single conductor along with coil 50 within the AM / FM frequency band. In other words, coil 50 and capacitor-loading element 60 operate as an antenna that resonates in the FM frequency band. In the following description, components of vehicle-mounted antenna device 10 designed to resonate in the desired frequency band may be referred to as "elements" or "diodes."

[0114] <Resonating Section 61>

[0115] However, the vehicle-mounted antenna device 10 of the present embodiment described above is a so-called composite antenna device comprising a patch antenna 30, a patch antenna 31, and an antenna 32. In such composite antenna devices, it is necessary to ensure the required characteristics of each antenna while taking into account electrical interference between the antennas. For example, the vehicle-mounted antenna device 10 of the present embodiment described above allows for adjustment of the size and position of the oscillator (e.g., the dielectric member 72 and the radiating element 73) in order to ensure the required directivity while taking into account electrical interference with other antennas in the patch antenna 30.

[0116] However, due to the limited space within the housing 23 of the vehicle-mounted antenna device 10, there are limits to ensuring the necessary directivity by adjusting the size and position of the oscillator in, for example, the patch antenna 30. Therefore, the following describes a vehicle-mounted antenna device 10 that can easily control the directivity of the patch antenna 30.

[0117] As described above, the capacitance loading element 60 including the metal body 60A resonates in the FM frequency band (second frequency band) together with the coil 50. In this embodiment, Figure 1 、 Figure 3 A and Figure 3 As shown in FIG. 2B , the capacitance loading element 60 includes a resonant portion 61. The resonant portion 61 is a portion that resonates in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports. Furthermore, in this embodiment, the entire metal body 60A functions as the resonant portion 61. Therefore, the metal body 60A is part of the vibrator of the antenna 32 (second antenna) that supports radio waves in the AM / FM frequency band (second frequency band), and the presence of the resonant portion 61 allows the metal body 60A to resonate in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) supports.

[0118] Furthermore, in this embodiment, the electrical length of the resonating portion 61 is formed so as to resonate in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) responds to. For example, the resonating portion 61 is formed with an electrical length equivalent to one-half the wavelength of the first frequency band. Here, "one-half the wavelength of the first frequency band" is not limited to an exact value; any value that resonates in the desired frequency band is sufficient. This is because the wavelength of the first frequency band is not necessarily expressed as a divisible integer, and the actual electrical length of the resonating portion 61 varies due to various factors. Furthermore, as long as the electrical length of the resonating portion 61 is formed so as to resonate in the first frequency band, it does not need to be formed to be equivalent to one-half the wavelength of the first frequency band.

[0119] like Figure 3 A and Figure 3 As shown in FIG. 3B , a slit 62 is provided on the metal body 60A. The slit 62 is a notch (gap) formed from the outer edge of the metal body 60A toward the inner side. Figure 3 As shown in FIG. 2B , three slits 62 are arranged along the Z direction on the left side of the metal body 60A. When viewed in the +Z direction, the three slits 62 are composed of a slit 62 formed along the -X direction, a slit 62 formed along the +X direction, and a slit 62 formed along the -X direction.

[0120] Therefore, if Figure 3 As shown in FIG. 2B , three folds 64 are provided on the left side of the metal body 60A. When viewed sequentially in the +Z direction, the three folds 64 are located on the +X side of the metal body 60A, the -X side of the metal body 60A, and the +X side of the metal body 60A. Thus, the resonating portion 61 is formed by repeatedly (i.e., in a serpentine shape) making horizontal folds 64 on the metal body 60A. In this embodiment, the horizontal length of the slit 62 can be adjusted to achieve 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).

[0121] In addition, the number, position and extension direction of the slits 62 are not limited to Figure 3 A and Figure 3 B. For example, a single slit 62 may be provided in the metal body 60A. In this case, a single fold 64 is provided in the metal body 60A. Alternatively, for example, a plurality of slits 62 other than three may be provided in the metal body 60A. In this case, the number of folds 64 corresponding to the number of slits 62 is provided.

[0122] In addition, Figure 3 A and Figure 3 In B, the slit 62 is provided only on the left side surface of the metal body 60A, but the slit 62 may be provided on the bottom surface of the metal body 60A, for example.

[0123] In addition, Figure 3 In the side view shown in B, the extending direction of the slit 62 is not limited to the horizontal direction, but can also be the vertical direction. Here, the "horizontal direction" or "vertical direction" is not limited to a strict direction, but includes directions deviating within a specified angle. This is because the various parts of the metal body 60A (bottom face, left face or right face) are not necessarily arranged parallel to the "horizontal direction" or "vertical direction". In addition, Figure 3 A and Figure 3 In B, the slit 62 is provided so as to extend in the horizontal direction, but the slit 62 may be provided so as to be bent midway.

[0124] Therefore, as long as the electrical length of the resonating portion 61 of this embodiment is formed to resonate in the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna), the number, position, and extending direction of the slits 62 can be freely combined.

[0125] In addition, similarly to the case where the slit 62 is provided on the left side surface of the metal body 60A, the slit 62 is also provided on the right side surface of the metal body 60A. Figure 3 As shown in FIG. 1A , the number, position, and extending direction of the slits 62 are the same on the left side and the right side of the metal body 60A. However, the number, position, and extending direction of the slits 62 may be different on the left side and the right side of the metal body 60A.

[0126] In the above description, although it is described that the metal body 60A has the resonance part 61, it is not limited to this. It is sufficient as long as at least one of the metal bodies 60A to 60D constituting the capacitor loading element 60 has the resonance part 61. That is to say, for example, only the metal body 60B may have the resonance part 61, or the metal body 60C and the metal body 60D may have the resonance part 61. Furthermore, in the case where the capacitor loading element 60 is a metal body, one metal body may also have the resonance part 61. Therefore, it is sufficient as long as at least a part of the vibrator constituting the antenna 32 (the second antenna) resonates in the frequency band (the first frequency band) of the radio waves to which the patch antenna 30 (the first antenna) responds.

[0127] ==Structure of Vehicle-Mounted Antenna Device 10X of Comparative Example==

[0128] Figure 4 This figure shows the structure of a vehicle-mounted antenna device 10X according to a comparative example. Vehicle-mounted antenna device 10X does not include a resonating portion 61 in the capacitance-loading element 60 of antenna 32. Vehicle-mounted antenna device 10X has the same structure as vehicle-mounted antenna device 10 according to the present embodiment, except that the resonating portion 61 is not included.

[0129] ==Comparison of Characteristics between the Vehicle-Mounted Antenna Device 10 and the Vehicle-Mounted Antenna Device 10X==

[0130] Hereinafter, calculation results of 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 will be described.

[0131] Figure 5 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 5 In the figure, the horizontal axis represents the elevation angle and the vertical axis represents the average gain. Figure 5 In the figure, the calculation results for the vehicle-mounted antenna device 10X are shown by a dotted line, and the calculation results for the vehicle-mounted antenna device 10 are shown by a solid line. The □ marks on these dotted lines and the ● marks on these solid lines indicate the position of the values ​​on the vertical axis relative to the values ​​on the horizontal axis. These are indicated by □ and ● marks for convenience and to distinguish them. In the following description, the average gain may be simply referred to as "gain."

[0132] like Figure 5 As shown, when the gain of the vehicle-mounted antenna device 10X of the comparative example is compared 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 that of the vehicle-mounted antenna device 10X of the comparative example within the range of 20° to 65°. Therefore, the vehicle-mounted antenna device 10 of the present embodiment improves the average gain of the patch antenna 30 within at least a portion of the elevation angle range from low to medium, thereby exhibiting ideal directivity, for example, as an antenna device for receiving radio waves transmitted from a satellite. Here, the elevation angle is defined as 0° in the horizontal direction and 90° at the zenith angle. For example, a low elevation angle refers to a range of 0° to 30°. A medium elevation angle refers to a range of 30° to 60°. Furthermore, a high elevation angle refers to a range of 60° to 90°.

[0133] Therefore, in the vehicle-mounted antenna device 10, the directivity of the patch antenna 30 is improved, and as a result, incoming radio waves from a satellite can be efficiently received. In this way, the vehicle-mounted antenna device 10 of this embodiment can easily control the directivity of the patch antenna 30 by including the resonant portion 61.

[0134] The directivity of the patch antenna 30 has been described above. Although detailed explanation is omitted, the vehicle-mounted antenna device 10 of this embodiment also facilitates control of the directivity of the patch antenna 31, which is different from the patch antenna 30, by including the additional resonant portion 61. In other words, the vehicle-mounted antenna device 10 of this embodiment facilitates control of the directivity of planar antennas such as the patch antenna 30 and the patch antenna 31.

[0135] ==Distance between patch antenna 30 and resonant portion 61==

[0136] Here, in Figure 1 In the top and side views shown, the patch antenna 30 and the resonating portion 61 do not overlap. Furthermore, when the patch antenna 30 and the resonating portion 61 are separated by a predetermined distance in the horizontal or vertical direction, the phases of the radio waves handled by the patch antenna 30 and the phases of the radio waves handled by the antenna 32, which includes the resonating portion 61, mutually reinforce each other. In the vehicle-mounted antenna device 10 of this embodiment, the gain of the patch antenna 30 is further improved when the separation distance at which the phases of the radio waves handled by the patch antenna 30 and the phases of the radio waves handled by the antenna 32 are mutually reinforced. Therefore, the following examines the separation distance at which the phases of the radio waves handled by the patch antenna 30 and the phases of the radio waves handled by the antenna 32 are mutually reinforced.

[0137] Figure 6 It is an explanatory diagram of the separation distance D and the separation distance H.

[0138] In such Figure 6 In the side view shown, separation distance D is the horizontal (X-direction) separation distance between patch antenna 30 and resonating portion 61 of antenna 32. Specifically, separation distance D is the horizontal distance between the end of patch antenna 30 closest to resonating portion 61 and the end of resonating portion 61 closest to patch antenna 30.

[0139] In such Figure 6 In the side view shown, separation distance H is the vertical (Z-direction) separation distance between patch antenna 30 and resonating portion 61 of antenna 32. Specifically, separation distance H is the vertical distance between the end of patch antenna 30 closest to resonating portion 61 and the end of resonating portion 61 closest to patch antenna 30.

[0140] Figure 7 A is a graph showing an example of the relationship between the separation distance D and the average gain. Figure 7 B is a graph showing an example of the relationship between the separation distance H and the average gain.

[0141] exist Figure 7 In A, the horizontal axis represents the separation distance D, and the vertical axis represents the average gain of the patch antenna 30. Figure 7 In B, the horizontal axis represents the separation distance H, and the vertical axis represents the average gain of the patch antenna 30. Figure 7 A and Figure 7 In Figure B, the calculation results for patch antenna 30 at an elevation angle of 20° are indicated by a dashed line, and the calculation results for patch antenna 30 at an elevation angle of 50° are indicated by a solid line. Furthermore, as a reference for the gain required for patch antenna 30, line A indicates a reference value for the average gain at an elevation angle of 50°, and line B indicates a reference value for the average gain at an elevation angle of 20°.

[0142] like Figure 7 As shown in A, when the separation distance D is set to 30 mm or more at an elevation angle of 50°, the average gain exceeds the reference value (line A), and the gain required by patch antenna 30 can be obtained. Furthermore, when the separation distance D is set to 30 mm or more, the average gain exceeds the reference value (line B) even at an elevation angle of 20°.

[0143] In addition, if Figure 7 As shown in B, at an elevation angle of 50°, if the separation distance H is set to 30 mm or more, the average gain exceeds the reference value (line A), and the gain required by patch antenna 30 can be obtained. In addition, when the separation distance D is set to 30 mm or more, the average gain exceeds the reference value (line B) even at an elevation angle of 20°.

[0144] Therefore, as can be seen from the above, the patch antenna 30 and the resonant portion 61 can obtain the required gain by being separated 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 vehicle-mounted antenna device 10 of this embodiment, the first antenna (patch antenna 30) and the resonant portion 61 are preferably separated by one-quarter of the wavelength of the first frequency band in the horizontal or vertical direction.

[0145] Here, "one-quarter the wavelength of the first frequency band" is not limited to an exact value; it can be any value that achieves the gain required by patch antenna 30. This is because the wavelength of the first frequency band is not necessarily expressed as a divisible integer, and the actual electrical length of resonant section 61 varies depending on various factors. Furthermore, the preferred separation distance between patch antenna 30 and resonant section 61 also varies depending on the reference value (A line, B line) of the average gain required for patch antenna 30. Therefore, the separation between the first antenna (patch antenna 30) and resonant section 61 in the horizontal or vertical direction does not need to be greater than one-quarter the wavelength of the first frequency band.

[0146] ==Modification of Resonating Section 61==

[0147] Figure 8 A~ Figure 8 C is a diagram showing resonating parts 61A to 61C according to a modified example.

[0148] The resonating portion 61 is formed by repeatedly forming horizontal folds 64 on the metal body 60A. However, the resonating portion 61 is not limited to this shape. Figure 8 As in the resonating portion 61A shown in FIG. 1A , a slit 62 substantially parallel to the YZ plane may be provided across the left side, bottom, and right side of the metal body 60A.

[0149] like Figure 8 As shown in FIG. 6A , a metal body 60A is provided with two slits 62 arranged in the X direction. When viewed in the -X direction, the two slits 62 are formed in the direction of the left side, bottom side, and right side, and the slits 62 are formed in the direction of the right side, bottom side, and left side.

[0150] Therefore, if Figure 8 As shown in FIG. 1A , two folds 64 are formed on the metal body 60A. These folds 64 are provided on the left and right sides of the metal body. Thus, the resonating portion 61A is formed by repeatedly forming folds 64 in the vertical direction on the metal body 60A. In the resonating portion 61A, the length of the slit 62 can be adjusted, for example, to achieve 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).

[0151] The above-mentioned resonating portion 61 and resonating portion 61A are formed with the slit 62. However, in order to form the resonating portion with an electrical length that resonates in the first frequency band, it is not limited to forming the slit 62. Figure 8 B and Figure 8 A slit 63 may be formed as in the resonating portion 61B and the resonating portion 61C shown in FIG. C. The slit 63 is an opening (hole or gap) formed in the metal body 60A.

[0152] like Figure 8 As shown in FIG. 2B , the resonator 61B has horizontally folded slits 63 on the left and right sides of the metal body 60A. The slits 63 on the left and right sides are connected to each other on the bottom side of the metal body 60A.

[0153] like Figure 8 As shown in FIG. 3C , the resonance portion 61C is provided with a slit 63 extending across the left side, bottom, and right side of the metal body 60A. The slit 63 repeatedly folds in the vertical direction.

[0154] exist Figure 8 The resonance part 61B shown in B and Figure 8 In the resonance portion 61C shown in C, the length of the slot 63 can be adjusted to form an electrical length that resonates in the first frequency band (for example, an electrical length corresponding to half the wavelength of the first frequency band).

[0155] Figure 9 A and Figure 9 B is a diagram showing a resonating portion 61D and a resonating portion 61E according to a modified example. Figure 10 A and Figure 10 B is a diagram showing a resonating portion 61F and a resonating portion 61G according to a modified example.

[0156] The resonating portion 61 and the resonating portion 61A to the resonating portion 61C are provided on a metal body 60A having a shape bent upward from both ends of the bottom surface at the center. Figure 9 and Figure 10 As shown in the resonating parts 61D to 61G, the resonating parts may also be provided on a mountain-shaped (umbrella-shaped) metal body. It should be noted that the mountain-shaped (umbrella-shaped) metal body includes a structure in which the upper edges of the left and right sides are connected, and the outer shape of the metal body when viewed from the front or rear is an inverted V-shape, an inverted U-shape, an arch, or a substantially trapezoidal shape.

[0157] Figure 9 The resonating portion 61D shown in A is formed on a mountain-shaped (umbrella-shaped) metal body and is obtained by repeatedly forming horizontal folds 64 using slits 62. Figure 9 The resonating portion 61E shown in B is formed on a mountain-shaped (umbrella-shaped) metal body and is obtained by repeatedly forming folds 64 in the vertical direction using slits 62 .

[0158] in addition, Figure 10 The resonating portion 61F shown in A is formed on a mountain-shaped (umbrella-shaped) metal body and has a narrow groove 63 that repeatedly folds back in the horizontal direction. Figure 10 The resonating portion 61G shown in B is formed on a mountain-shaped (umbrella-shaped) metal body, and has a slit 63 formed therein which repeatedly folds back in the vertical direction.

[0159] exist Figure 9 A~ Figure 10 In the resonating portion 61D and the resonating portion 61G shown in FIG. 3B , the length of the slit 62 or the slot 63 can be adjusted to form an electrical length that resonates in the first frequency band (for example, an electrical length corresponding to half the wavelength of the first frequency band).

[0160] In the first embodiment described above, a composite antenna device, namely, a vehicle-mounted antenna device 10, was described, comprising a patch antenna 30 as a first antenna and an AM / FM radio antenna 32 as a second antenna. Specifically, the capacitance loading element 60 of the antenna 32 resonates with the coil 50 in the FM frequency band (the second frequency band) and includes a resonating portion 61 that resonates in the frequency band (the first frequency band) of radio waves that the patch antenna 30 (the first antenna) supports.

[0161] However, the second antenna is not limited to an antenna for AM / FM radio, and may be an antenna corresponding to other communication standards and frequency bands. For example, as in the vehicle-mounted antenna devices 80A to 80C described later, the second antenna may be an antenna for telematics.

[0162] ==Structure of Vehicle-Mounted Antenna Devices 80A to 80C According to Second Embodiment==

[0163] <First Example of Vehicle-Mounted Antenna Device 80A>

[0164] Figure 11 : is a diagram showing the structure of a vehicle-mounted antenna device 80A. Figure 11 A is a perspective view of a vehicle-mounted antenna device 80A. Figure 11 B is a side view of the vehicle-mounted antenna device 80A.

[0165] The vehicle-mounted antenna device 80A includes an antenna base 20, a patch antenna 30, and an antenna 33A. In this embodiment, the vehicle-mounted antenna device 80A does not include a component (housing) that covers the outside, that is, a component that corresponds to a housing. Figure 1 FIG. 1 is a diagram showing components of the housing 23 in the vehicle-mounted antenna device 10 according to the first embodiment.

[0166] Since the antenna base 20 of this embodiment is the same as the antenna base 20 of the vehicle-mounted antenna device 10 of the first embodiment, detailed description thereof will be omitted. In addition, since the patch antenna 30 of this embodiment is also the same as the patch antenna 30 of the vehicle-mounted antenna device 10 of the first embodiment, detailed description thereof will be omitted. Figure 11 A and Figure 11 In B, the equivalent of Figure 2 Illustration of components of the holding member 74 and the metal body 75 in the patch antenna 30 shown.

[0167] Antenna 33A is a telematics antenna. For example, antenna 33A supports radio waves in the 700 MHz to 2.7 GHz frequency band used in LTE (Long Term Evolution) and the Sub-6 frequency band used in 5G (fifth-generation mobile communication systems), that is, radio waves in the 3.6 GHz to less than 6 GHz frequency band. However, the communication standards and frequency bands supported by antenna 33A are not limited to the above and may also support other communication standards and frequency bands.

[0168] Antenna 33A may be an antenna compatible with radio waves in the frequency band used in, for example, V2X (Vehicle to Everything), Wi-Fi (registered trademark), Bluetooth (registered trademark), or DAB. Furthermore, antenna 33A may be an antenna for keyless entry or smart entry.

[0169] Alternatively, antenna 33A may be an antenna compatible with MIMO (Multiple-Input Multiple-Output) communications. In this case, by further including an antenna identical to antenna 33A, vehicle-mounted antenna device 80A supports MIMO communications. In vehicle-mounted antenna device 80A performing MIMO communications, data is transmitted individually from the multiple antennas comprising vehicle-mounted antenna device 80A, and data is received simultaneously by the multiple antennas.

[0170] Therefore, the vehicle-mounted antenna device 80A of this embodiment is a composite antenna device including the patch antenna 30 and the antenna 33A. In this vehicle-mounted antenna device 80A, similar to the vehicle-mounted antenna device 10 of the first embodiment, the directivity of the patch antenna 30 can also be easily controlled by including the resonant portion 91 described below.

[0171] In addition, unlike the vehicle-mounted antenna device 10 of the first embodiment, the antenna 33A of the vehicle-mounted antenna device 80A is sometimes referred to as the "second antenna" in the following description. In addition, the frequency band of radio waves supported by the antenna 33A is sometimes referred to as the "second frequency band."

[0172] The antenna 33A (second antenna) includes a vibrator 90A that resonates in the frequency band (second frequency band) of radio waves to which the antenna 33A corresponds. Figure 11 A and Figure 11 As shown in FIG. 3B , a resonant portion 91 is provided on the vibrator 90A. The resonant portion 91 is a portion that resonates in the frequency band (first frequency band) of radio waves to which the patch antenna 30 (first antenna) corresponds. Figure 11 A and Figure 11 As shown by the dotted line in B, a portion of the oscillator 90A formed in a meandering shape functions as a resonating portion 91. Therefore, the resonating portion 91 is a portion of the oscillator 90A of the antenna 33A (second antenna) that responds to radio waves in the frequency band for telematics (the second frequency band), and resonates in the frequency band (the first frequency band) of radio waves that the patch antenna 30 (first antenna) responds to.

[0173] Specifically, the electrical length of the resonating portion 91 is formed so as to resonate in the frequency band (first frequency band) of radio waves that the patch antenna 30 (first antenna) responds to. For example, the resonating portion 91 is formed with an electrical length equivalent to one-quarter of the wavelength of the first frequency band. Here, "one-quarter of the wavelength of the first frequency band" is not limited to an exact value; any value that resonates in the desired frequency band is sufficient. This is because the wavelength of the first frequency band is not necessarily expressed as a divisible integer, and the actual electrical length of the resonating portion 91 varies depending on various factors. Furthermore, as long as the electrical length of the resonating portion 91 is formed so as to resonate in the first frequency band, it does not need to be formed to be equivalent to one-quarter of the wavelength of the first frequency band.

[0174] like Figure 11 As shown in FIG. 3B , a slit 92 is provided on the vibrator 90A. The slit 92 is a notch (gap) formed from the outer edge of the vibrator 90A toward the inside. Figure 11 As shown in FIG. 3B , two slits 92 are provided on the vibrator 90A. Figure 11 In the side view shown in B, the two slits 92 are composed of a slit 92 formed in the -Z direction from the upper end of the vibrator 90A and extending in the +X direction and a slit 92 formed in the -X direction.

[0175] Therefore, if Figure 11 As shown in Figure 2B, two folds 93 are provided on a portion of vibrator 90A. When viewed sequentially in the +Z direction, the two folds 93 are located on the +X side and -X side of vibrator 90A. Thus, resonating portion 91 is formed by repeatedly forming horizontal folds 93 (i.e., a serpentine shape) on vibrator 90A. In this embodiment, the horizontal length of slit 92 can be adjusted to achieve an electrical length that resonates in the first frequency band (e.g., an electrical length equivalent to one-quarter of the wavelength of the first frequency band).

[0176] In addition, the number, position and extension direction of the slits 92 are not limited to Figure 11 Case B. For example, one slit 92 may be provided in vibrator 90A. In this case, one fold 93 is provided in slit 92. Alternatively, for example, two or more slits 92 may be provided in vibrator 90A. In this case, the number of folds 93 provided corresponds to the number of slits 92.

[0177] In addition, Figure 11 In the side view shown in B, the extending direction of the slit 92 is not limited to the horizontal direction, but can also be the vertical direction. Figure 11 In Figure 1, a single slit 92 is bent midway, but it can also be extended only in the horizontal direction. Furthermore, the resonating portion 91 can be formed by repeatedly forming vertical bends in the vibrator 90A. Furthermore, a slot can be formed in the vibrator 90A instead of a slit.

[0178] Therefore, as long as the electrical length of the resonant portion 91 of this embodiment is formed to resonate in the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna), the number, position, and extending direction of the slits 92 or slots can be freely combined.

[0179] Furthermore, as long as the resonating portion 91 resonates in the first frequency band, the oscillator 90A need not be partially formed in a meandering shape. For example, in the vehicle-mounted antenna devices 80B and 80C described below, the width of the antenna oscillator is formed to a predetermined length that resonates in the first frequency band.

[0180] Figure 12 : is a diagram showing the structure of the vehicle-mounted antenna device 80B and the vehicle-mounted antenna device 80C. Figure 12 A is a side view of the vehicle-mounted antenna device 80B. Figure 12 B is a side view of the vehicle-mounted antenna device 80C.

[0181] <Second Example of Vehicle-Mounted Antenna Device 80B>

[0182] The vehicle-mounted antenna device 80B includes an antenna base 20, a patch antenna 30, and an antenna 33B, which serves as a telematics antenna. The structure of the vehicle-mounted antenna device 80B is identical to that of the vehicle-mounted antenna device 80A, except that the shape of the antenna 33B differs from that of the antenna 33A in the vehicle-mounted antenna device 80A described above. Therefore, the following description will focus solely on the details of the antenna 33B.

[0183] In the following description, the antenna 33B of the vehicle-mounted antenna device 80B may be referred to as a “second antenna.” The frequency band of radio waves supported by the antenna 33B may also be referred to as a “second frequency band.”

[0184] Antenna 33B (second antenna) includes a vibrator 90B that resonates in the frequency band (second frequency band) of radio waves that antenna 33B supports. Furthermore, in vehicle-mounted antenna device 80B, the width W1 of vibrator 90B is formed to have an electrical length equivalent to one-quarter of the wavelength of the frequency band (first frequency band) of radio waves that patch antenna 30 (first antenna) supports. Consequently, a portion of vibrator 90B functions as a resonant portion 91 that resonates in the first frequency band. Therefore, resonant portion 91 is a portion of vibrator 90B of 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 patch antenna 30 (first antenna) supports.

[0185] In addition, the oscillator 90B of the antenna 33B used for telematics is not limited to Figure 12 The shape shown in A, such as Figure 12 As shown in B, it can also have other shapes.

[0186] <Third Example Vehicle-Mounted Antenna Device 80C>

[0187] The vehicle-mounted antenna device 80C includes an antenna base 20, a patch antenna 30, and an antenna 33C, which serves as a telematics antenna. The structure of the vehicle-mounted antenna device 80C is identical to that of the vehicle-mounted antenna device 80B, except that the shape of the antenna 33C differs from that 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.

[0188] In the following description, the antenna 33C of the vehicle-mounted antenna device 80C may be referred to as a “second antenna.” The frequency band of radio waves supported by the antenna 33C may also be referred to as a “second frequency band.”

[0189] The antenna 33C includes a vibrator 90C that resonates in the frequency band (second frequency band) of radio waves to which the antenna 33C (second antenna) corresponds. Figure 12 Compared with the antenna element 90B shown in A, the upper end of the antenna element 90B is formed obliquely.

[0190] Furthermore, in the vehicle-mounted antenna device 80C, the width W2 of the vibrator 90C is formed to an electrical length equivalent to one-quarter of the wavelength of the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna). Consequently, a portion of the vibrator 90C functions as a resonant portion 91 that resonates in the first frequency band. Therefore, the resonant portion 91 is a portion of the vibrator 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).

[0191] Here, a comparison between the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80X and the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C of the third example of the present embodiment will be described using a vehicle-mounted antenna device 80X of a comparative example described later.

[0192] ==Structure of Vehicle-Mounted Antenna Device 80X of Comparative Example==

[0193] Figure 13 FIG is a diagram showing the structure of a vehicle-mounted antenna device 80X according to a comparative example. Figure 13 As shown, the vehicle-mounted antenna device 80X is a vehicle-mounted antenna device having only the patch antenna 30. Therefore, in the following description, the vehicle-mounted antenna device 80X may be referred to as a "patch antenna full model."

[0194] In other words, the vehicle-mounted antenna device 80X is obtained by removing the antenna 33C from the vehicle-mounted antenna device 80C. The vehicle-mounted antenna device 80X has the same structure as the vehicle-mounted antenna device 80C of the third example of the present embodiment, except that the antenna 33C is not provided.

[0195] ==Comparison of Characteristics between the Vehicle-Mounted Antenna Device 80C and the Vehicle-Mounted Antenna Device 80X==

[0196] Hereinafter, calculation results of the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C and the vehicle-mounted antenna device 80X will be described.

[0197] Figure 14 Graphs showing the characteristics of the patch antenna 30 in the vehicle-mounted antenna device 80C and the vehicle-mounted antenna device 80X. Figure 14 A is a graph showing an example of the relationship between elevation angle and average gain. Figure 14 B is a graph showing an example of directivity at an elevation angle of 20 degrees.

[0198] exist Figure 14 In A, the horizontal axis represents the elevation angle and the vertical axis represents the average gain. Figure 14 In Figure A, the calculation results for vehicle-mounted antenna device 80X are shown by a dotted line, while the calculation results for vehicle-mounted antenna device 80C are shown by a solid line. The circles on these dotted lines and the triangles on these solid lines indicate the positions of the values ​​on the vertical axis relative to the values ​​on the horizontal axis. These circles and triangles are used to distinguish them and for convenience. In the following description, average gain may be simply referred to as "gain."

[0199] like Figure 14 A and Figure 14 As shown in Figure B, when the gain of the vehicle-mounted antenna device 80X of the comparative example is compared with the gain of the vehicle-mounted antenna device 80C of the present embodiment, the gain of the vehicle-mounted antenna device 80C of the present embodiment is higher than that of the vehicle-mounted antenna device 80X of the comparative example, particularly in the low elevation angle range. Therefore, the vehicle-mounted antenna device 80C of the present embodiment, for example, as an antenna device for receiving radio waves transmitted from a satellite, improves the average gain of the patch antenna 30 in at least a portion of the low to medium elevation angle range, thereby exhibiting ideal directivity.

[0200] Therefore, in the vehicle-mounted antenna device 80C of this embodiment, the improved directivity of the patch antenna 30 results in, for example, efficient reception of incoming radio waves from a satellite. Thus, the vehicle-mounted antenna device 80C of this embodiment, by including the resonant portion 91, can easily control the directivity of the patch antenna 30. Furthermore, although detailed verification is omitted, the vehicle-mounted antenna devices 80A and 80B described above also easily control the directivity of the patch antenna 30 by including the resonant portion 91.

[0201] Here, in Figure 11 B. Figure 12 A and Figure 12In the side view shown in FIG. B, the patch antenna 30 and the resonant portion 91 of the vehicle-mounted antenna devices 80A to 80C of this embodiment do not overlap each other. Although not shown, the patch antenna 30 and the resonant portion 91 of the vehicle-mounted antenna devices 80A to 80C of this embodiment also do not overlap each other in a plan view.

[0202] Similar to the vehicle-mounted antenna device 10 of the first embodiment described above, in the vehicle-mounted antenna devices 80A to 80C of this embodiment, the patch antenna 30 and the resonating portion 91 are also separated by a predetermined distance in the horizontal or vertical direction. In this case, the phase of the radio waves handled by the patch antenna 30 and the phase of the radio waves handled by the antennas 33A to 33C equipped with the resonating portion 91 mutually reinforce each other. Therefore, the following will verify the separation distance at which the phase of the radio waves handled by the patch antenna 30 and the phase of the radio waves handled by antenna 33C of the antennas 33A to 33C mutually reinforce each other.

[0203] Figure 15 3 is an explanatory diagram of the separation distance D between the patch antenna 30 and the resonant portion 91 .

[0204] In such Figure 15 In the side view shown, separation distance D is the horizontal (X-direction) separation distance between patch antenna 30 and resonating portion 91 of antenna 33C. Specifically, separation distance D is the horizontal distance between the end of patch antenna 30 closest to resonating portion 91 and the end of resonating portion 91 closest to patch antenna 30.

[0205] Figure 16 This is a graph showing an example of the relationship between the elevation angle and the average gain when the separation distance D is changed.

[0206] exist Figure 16 In the figure, the horizontal axis represents the elevation angle and the vertical axis represents the average gain. Figure 16 In the figure, the calculation results for the comparative example vehicle-mounted antenna device 80X are shown by a dotted line, while the calculation results for the vehicle-mounted antenna device 80C according to the present embodiment, when the separation distance D is varied, are shown by multiple solid lines. Furthermore, the calculation results for varying the separation distance D to 8 mm, 16 mm, 32 mm, 64 mm, 128 mm, and 256 mm are shown using triangle and square marks on the solid lines. Furthermore, the triangle and square marks on these solid lines indicate the position of the values ​​on the vertical axis relative to the values ​​on the horizontal axis and are used for convenience and to distinguish them. In the following description, the average gain may be simply referred to as "gain."

[0207] like Figure 16As shown, when the separation distance D is 8 mm, the gain of vehicle-mounted antenna device 80C is lower than the gain of vehicle-mounted antenna device 80X (whole patch antenna model, marked with a circle), particularly 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 vehicle-mounted antenna device 80C is higher than the gain of vehicle-mounted antenna device 80X (whole patch antenna model, marked with a circle), at least in the low elevation angle range.

[0208] As can be seen from this, when the separation distance D is 16 mm or greater, the characteristics of the patch antenna 30 of the vehicle-mounted antenna device 80C are improved compared to the full-size patch antenna model. Here, 16 mm corresponds to one-eighth of the wavelength of the radio frequency band (first frequency band) supported by the patch antenna 30 (first antenna). Therefore, in the vehicle-mounted antenna device 80C of this embodiment, the first antenna (patch antenna 30) and the resonant portion 91 are preferably separated horizontally by at least one-eighth of the wavelength of the first frequency band.

[0209] In addition, if Figure 16 As shown, when the separation distance D is 128 mm, the gain of vehicle-mounted antenna device 80C is slightly higher than the gain of vehicle-mounted antenna device 80X (whole-patch antenna model, marked with a circle). However, when the separation distance D is 256 mm, the graph of vehicle-mounted antenna device 80C and the graph of vehicle-mounted antenna device 80X (whole-patch antenna model) are substantially consistent. In other words, when the separation distance D is 256 mm, the gain of vehicle-mounted antenna device 80C and the gain of vehicle-mounted antenna device 80X (whole-patch antenna model) are substantially the same.

[0210] Therefore, when the separation distance D is greater than 128 mm, the characteristics of the patch antenna 30 of the vehicle-mounted antenna device 80C are substantially the same as those of the overall patch antenna model. Here, 128 mm corresponds to one wavelength of the frequency band (first frequency band) of radio waves supported by the patch antenna 30 (first antenna). Therefore, in the vehicle-mounted antenna device 80C of this embodiment, setting the horizontal separation distance between the first antenna (patch antenna 30) and the resonating portion 91 to less than one wavelength of the first frequency band improves the characteristics of the patch antenna 30, which is particularly advantageous.

[0211] ==Other==

[0212] Figure 17 : is a diagram showing another example of the positional relationship between the patch antenna 30 and the resonant portion 61. Figure 17 A and Figure 17 B is a side view and a top view showing the first example of the positional relationship. Figure 17 C and Figure 17D is a side view and a top view showing a second example of the positional relationship.

[0213] In the above Figure 1 In the illustrated vehicle-mounted antenna device 10, the patch antenna 30 and the resonating portion 61 do not overlap in either plan or side view. However, the patch antenna 30 and the resonating portion 61 do not need to overlap in both plan and side view; they may also not overlap in either view.

[0214] In the first example of positional relationship, Figure 17 When viewed from the side as shown in A, the patch antenna 30 and the resonant portion 61 overlap each other. Figure 17 In the plan view shown in B, the patch antenna 30 and the resonant portion 61 do not overlap each other. Figure 17 The dotted line indicated by A is an auxiliary line for indicating that the patch antenna 30 and the resonating portion 61 overlap with each other.

[0215] In the second example of positional relationship, Figure 17 In the side view shown in C, the patch antenna 30 and the resonant portion 61 do not overlap each other. Figure 17 In the plan view shown in D, the patch antenna 30 and the resonant portion 61 overlap each other. Figure 17 The dotted line indicated by C is an auxiliary line for indicating that the patch antenna 30 and the resonating portion 61 overlap with each other.

[0216] In either the plan view or the side view as in the first and second examples of the positional relationship, even when the patch antenna 30 and the resonant portion 61 do not overlap each other, the directivity of the patch antenna 30 can be more easily controlled.

[0217] ==Summary==

[0218] The vehicle-mounted antenna device 10 of this embodiment has been described above. Figure 1 As shown, the vehicle-mounted antenna device 10 includes a patch antenna 30 (first antenna) that responds to radio waves in the 2.3 GHz frequency band (first frequency band), for example, for SDARS, and an antenna 32 (second antenna) that responds to radio waves in a frequency band different from the first frequency band, such as the 522 kHz to 1710 kHz frequency band for AM broadcasting and the 76 MHz to 108 MHz frequency band for FM broadcasting (second frequency band). Furthermore, at least a portion (e.g., the metal body 60A) of the vibrator (e.g., the capacitor loading element 60) that constitutes the second antenna resonates in the first frequency band. The vehicle-mounted antenna device 10 of this embodiment makes it easy to control the directivity of the planar antenna (e.g., the patch antenna 30).

[0219] In addition, the vehicle-mounted antenna devices 80A to 80C of this embodiment have been described. Figure 11and Figure 12 As shown, vehicle-mounted antenna devices 80A-80C include a patch antenna 30 (first antenna) that responds to radio waves in the 2.3 GHz frequency band (first frequency band) used for SDARS, for example, and antennas 33A-33C (second antenna) that respond to radio waves in a frequency band different from the first frequency band, such as that used for telematics (second frequency band). Furthermore, at least a portion of the vibrator (e.g., vibrators 90A-90C) that constitute the second antenna resonates in the first frequency band. The vehicle-mounted antenna devices 80A-80C of this embodiment make it easy to control the directivity of the planar antenna (e.g., patch antenna 30).

[0220] In addition, for example Figure 3 、 Figure 8 、 Figure 9 and Figure 10 As shown, at least a portion (eg, metal body 60A) of the vibrator (eg, capacitance loading element 60) has a resonant portion 61 having an electrical length that resonates in the first frequency band. This facilitates control of the directivity of the planar antenna (eg, patch antenna 30).

[0221] Furthermore, the electrical length of the resonance portion 61 is half the wavelength of the first frequency band. This makes it possible to easily control the directivity of the planar antenna (for example, the patch antenna 30).

[0222] In addition, for example Figure 3 、 Figure 8 、 Figure 9 and Figure 10 As shown, the resonating portion 61 has at least one fold 64. This allows the resonating portion 61 to have an electrical length sufficient to resonate in the first frequency band.

[0223] In addition, for example Figure 3 、 Figure 8 、 Figure 9 and Figure 10 As shown, the resonating portion 61 is formed with a gap (slit 62 or slot 63) extending in at least one of the horizontal direction and the vertical direction. This allows the resonating portion 61 to have an electrical length sufficient to resonate in the first frequency band.

[0224] In addition, for example Figure 3 、 Figure 8 B. Figure 9 A and Figure 10 As shown in A, the resonating portion 61 is formed by repeatedly forming folds in the horizontal direction. This allows the resonating portion 61 to have an electrical length sufficient to resonate in the first frequency band.

[0225] In addition, for example Figure 1 and Figure 6As shown, in plan view and side view, the patch antenna 30 (first antenna) and the resonant portion 61 do not overlap each other. This makes it easier to control the directivity of the planar antenna (eg, the patch antenna 30).

[0226] In addition, for example Figure 17 As shown, in a plan view or a side view, the patch antenna 30 (first antenna) and the resonant portion 61 do not overlap each other. This makes it easier to control the directivity of the planar antenna (eg, the patch antenna 30).

[0227] In addition, for example Figure 1 and Figure 6 As shown, the patch antenna 30 (first antenna) is separated from the resonant portion 61 by a predetermined distance in the horizontal or vertical direction. This makes it easier to control the directivity of the planar antenna (eg, the patch antenna 30).

[0228] In addition, the predetermined distance is equal to or greater than a quarter of the wavelength of the first frequency band. This makes it easier to control the directivity of the planar antenna (eg, the patch antenna 30).

[0229] In addition, the second frequency band is lower than the first frequency band. This makes it possible to easily control the directivity of the planar antenna (for example, the patch antenna 30).

[0230] In this embodiment, "vehicle-mounted" means capable of being carried on a vehicle. Therefore, the antenna device is not limited to being mounted on a vehicle and also encompasses situations where the antenna device is brought inside a vehicle and used within the vehicle. Furthermore, the antenna device of this embodiment is intended for use on a vehicle with wheels, but is not limited thereto. For example, the antenna device may also be used on flying objects such as drones, probes, and mobile objects without wheels, such as construction machinery, agricultural machinery, and ships.

[0231] The above embodiments are for easy understanding of the present invention and are not intended to limit the present invention. In addition, the present invention can be changed or improved without departing from the gist of the present invention, and the present invention naturally includes its equivalents.

Claims

1. A composite antenna device capable of receiving signals in multiple frequency bands, characterized in that: The composite antenna device comprises: Antenna base; a first antenna having a radiating element, which is placed on the antenna base and is capable of receiving signals in a first frequency band; and a second antenna capable of receiving signals in a second frequency band lower than the first frequency band; The second antenna has a capacitance loading element that is arranged with a gap in the height direction relative to the antenna base. The capacitor loading element includes at least one notch, which does not overlap with the radiating element of the first antenna when viewed from above, so that the radiating element is arranged near the radiating element in a manner that is located on an extension line of the long side direction of the capacitor loading element, and is set in a manner that intersects with the long side direction to control the directivity of the first antenna.

2. The composite antenna device according to claim 1, wherein: The capacitance loading element is in a mountain shape including a ridge portion extending along the longitudinal direction and two side portions extending from the ridge portion. The notch is composed of two first slits and a second slit, the two first slits extending parallel to the middle of the other side portion from the lower end of one side portion through the ridge portion, and the second slit extending parallel to the middle of one side portion from the lower end of the other side portion through the ridge portion, and being located between the two first ridge portions.

3. The composite antenna device according to claim 1 or 2, characterized in that: The notch of the second antenna is disposed at a predetermined distance from an end portion in the longitudinal direction of the capacitance loading element, thereby improving the characteristics of the first antenna.

4. The composite antenna device according to claim 1 or 2, characterized in that: The first antenna is composed of a GNSS antenna.

5. The composite antenna device according to claim 1 or 2, characterized in that: The first antenna supports a plurality of frequency bands.

6. The composite antenna device according to claim 1 or 2, characterized in that: The second antenna further includes a coil having one end connected to the capacitance loading element, and the first antenna functions as an AM / FM antenna.

Images