Antenna equipment

Abstract

Provided is an antenna device which comprises: a first ground part that is located on the upper side of an inclined part which is inclined relative to a horizontal plane; a first antenna that is disposed on the front surface side of the first ground part and that corresponds to a first frequency band of a ground wave; a second ground part that is located on the upper side of the inclined part and that has a front surface parallel to the horizontal plane; and a second antenna that is disposed on the front surface side of the second ground part and that corresponds to a second frequency band of a satellite wave, wherein the first ground part and the first antenna are positioned lower than the second ground part.

Description

【Technical Field】 【0001】 The present invention relates to an antenna device. 【Background Art】 【0002】 Patent Document 1 describes an antenna disposed on an inclined portion inside a vehicle. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2009-272821 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 By the way, when attempting to arrange a plurality of antennas on an inclined portion, it has been difficult to efficiently arrange each of the plurality of antennas while ensuring desired characteristics within a limited accommodation space. 【0005】 An example of the object of the present invention is to arrange each of a plurality of antennas on an inclined portion while ensuring desired characteristics and efficiently arranging them within a limited accommodation space. Other objects of the present invention will become apparent from the description herein. 【Means for Solving the Problems】 【0006】 One aspect of the present invention includes a first ground portion located above an inclined portion inclined with respect to a horizontal plane, a first antenna disposed on the front surface side of the first ground portion and corresponding to a first frequency band of terrestrial waves, a second ground portion located above the inclined portion and having a front surface parallel to the horizontal plane, and a second antenna disposed on the front surface side of the second ground portion and corresponding to a second frequency band of satellite waves. The first ground portion and the first antenna are located below the second ground portion, and it is an antenna device. 【0007】 According to the above embodiment of the present invention, in the inclined section, each of the multiple antennas can be efficiently arranged within a limited space while ensuring the desired characteristics. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a perspective view of the mobile body M on which the antenna device 100 is located. [Figure 2A] This is an explanatory diagram of the antenna device 100 of this embodiment. [Figure 2B] This is a plan view of the second antenna 21. [Figure 3] This is an explanatory diagram of the comparative example antenna device 100A. [Figure 4] This is an explanatory diagram of the antenna device 100B, the first reference example. [Figure 5] This figure shows the frequency characteristics of the VSWR of the first antenna 11 and the first antenna 11B. [Figure 6] This is an explanatory diagram of the first modified antenna device 100C. [Figure 7] This is an explanatory diagram of the second modified antenna device 100D. [Figure 8] This is an explanatory diagram of the third modified antenna device 100E. [Figure 9] This is an explanatory diagram of the fourth modified antenna device 100F. [Figure 10A] This is an explanatory diagram of the antenna device 100G in the second reference example. [Figure 10B] This is a plan view of antenna device 100G. [Figure 11A] This is an explanatory diagram of the fifth modified antenna device 100H. [Figure 11B] This is an explanatory diagram of the sixth modified antenna device 100I. [Figure 12] This figure shows the frequency characteristics of the average gain of the second antenna 21G in the second reference example. [Figure 13] This figure shows the frequency characteristics of the average gain of the second antenna 21H in the fifth modified example. [Figure 14]It is a diagram showing the frequency characteristics of the average gain of the second antenna 21I in the sixth modification example. [Figure 15A] It is an explanatory diagram of the antenna device 100J of the seventh modification example. [Figure 15B] It is an explanatory diagram of the antenna device 100K of the eighth modification example. [Figure 16] It is a diagram showing the frequency characteristics of the average gain of the third antenna 31J and the third antenna 31K. [Figure 17] It is an explanatory diagram of the antenna device 100L of the ninth modification example. [Figure 18] It is an explanatory diagram of the antenna device 100M of the tenth modification example. 【Embodiments for Carrying out the Invention】 【0009】 From the description in this specification and the accompanying drawings, at least the following matters become clear. 【0010】 Hereinafter, preferred embodiments of the present invention will be described while referring to the drawings. The same or equivalent components, members, etc. shown in each drawing are denoted by the same reference numerals, and repeated explanations will be omitted as appropriate. 【0011】 ==This Embodiment== FIG. 1 is a perspective view of a moving body M on which the antenna device 100 is arranged. FIG. 2A is an explanatory diagram of the antenna device 100 of the present embodiment. FIG. 2B is a plan view of the second antenna 21. 【0012】 <<Definition of Directions, etc.>> First, while referring to FIGS. 1, 2A, and 2B, directions, etc. (X direction, Y direction, and Z direction) in the antenna device 100 are defined. 【0013】 The direction forward as viewed from the driver's seat of the mobile body M (in this embodiment, a vehicle) on which the antenna device 100 is located is defined as the +X direction (forward direction) of the antenna device 100. The direction to the left as viewed from the driver's seat of the mobile body M is defined as the +Y direction (left direction) of the antenna device 100, and the direction upward (zenith direction) as viewed from the driver's seat of the mobile body M is defined as the +Z direction (upward direction) of the antenna device 100. The opposite directions of the +X, +Y, and +Z directions are defined as the -X direction (rear direction), -Y direction (right direction), and -Z direction (downward direction), respectively. Each of the +X, -X, +Y, -Y, +Z, and -Z directions is a direction with a fixed orientation. 【0014】 In addition, the directions described above are not fixed directions, and both the +X direction (forward) and the -X direction (backward) are sometimes simply called the "X direction" or "forward / backward direction." Similarly, both the +Y direction (left) and the -Y direction (right) are sometimes simply called the "Y direction" or "left / right direction." Furthermore, both the +Z direction (up) and the -Z direction (down) are sometimes simply called the "Z direction" or "up / down direction." 【0015】 Furthermore, the XY plane (a plane containing both the axis along the X direction and the axis along the Y direction) is sometimes called the "horizontal plane" because it is perpendicular to the zenith. The direction parallel to the XY plane is sometimes called the "horizontal direction." 【0016】 In Figures 1, 2A, and 2B, the +X direction (forward), +Y direction (left), and +Z direction (upward) are represented by line segments with arrows to facilitate understanding of the direction of the antenna device 100. Note that the intersection of these line segments with arrows does not represent the coordinate origin. Furthermore, the forward / backward direction or left / right direction is sometimes called the "width direction," and the up / down direction is sometimes called the "height direction." 【0017】 The definitions of directions and other terms described above are also common to other embodiments of this specification unless otherwise specified. 【0018】 <<Overview of Antenna Device 100>> Next, the outline of the antenna device 100 of this embodiment will be described again, referring to Figures 1, 2A, and 2B mentioned above. 【0019】 The antenna device 100 is an antenna device positioned on a mobile body M, as shown in Figure 1. Here, "mobile body" refers to a moving vehicle. In this embodiment, the mobile body M is a vehicle. Here, "vehicle" refers to a vehicle having wheels. However, the mobile body M is not limited to a vehicle and may also be construction machinery, agricultural machinery, ships, aircraft, drones, etc., that do not have wheels. In the following description, "mobile body" may sometimes be referred to as "vehicle". 【0020】 The antenna device 100 of this embodiment is located on the instrument panel 2 of the vehicle, for example, as shown in Figure 1. However, the antenna device 100 may also be located on the side mirror 3 or bumper 4 of the vehicle. Furthermore, the location of the antenna device 100 on the vehicle is not limited to the locations described above, and can be changed as appropriate to the spoiler, roof, hood, pillar, etc. 【0021】 Furthermore, the antenna device 100 of this embodiment is positioned on an inclined portion of the instrument panel 2 of the vehicle, as described above. Here, "inclined portion" refers to a part that is inclined with respect to the horizontal plane (XY plane). The antenna device 100 may be positioned anywhere on the vehicle, including the instrument panel 2, as long as it is an inclined portion. 【0022】 Figure 2A shows an example of an antenna device positioned on an inclined section of a vehicle, specifically an antenna device 100 positioned on an inclined section 1. The portion of the inclined section 1 on which the antenna device 100 is positioned is made of a conductive material (conductive part). In other words, the inclined section 1 has a conductive part. However, the portion of the surface on which the antenna device 100 is positioned may be made of an insulating material (for example, resin). In other words, the inclined section 1 does not necessarily have a conductive part. 【0023】 The antenna device 100 includes a case 90, a first ground section 10, a first antenna 11, a first base section 12, a second ground section 20, a second antenna 21, a second base section 22, and a support section 91. In the following description, the first ground section 10, the first antenna 11, and the first base section 12 may be referred to as the "first antenna unit A1". Also, the second ground section 20, the second antenna 21, and the second base section 22 may be referred to as the "second antenna unit A2". 【0024】 <Case 90> The case 90 is a component that constitutes the outer surface of the antenna device 100. In the antenna device 100 of this embodiment, the case 90 is formed of, for example, an insulating resin. However, the case 90 may be formed of a material other than an insulating resin that transmits radio waves. Furthermore, the case 90 may consist of an insulating resin portion and a portion made of another material that transmits radio waves, and the components may be freely combined. 【0025】 In this embodiment, the case 90 is fixed to the inclined portion 1 by screws (not shown). However, the case 90 is not limited to being fixed by screws; it may also be fixed to the inclined portion 1 by snap-fitting, welding, adhesive, etc. The first antenna unit A1 and the second antenna unit A2 of the antenna device 100 are arranged in a housing space formed by the case 90 that constitutes the outer surface of the antenna device 100. Note that the case 90 may be fixed to a location other than the inclined portion 1, and the antenna device 100 does not need to have a case 90. 【0026】 <First Antenna Unit A1> The first ground section 10 is a component that functions as the ground for the first antenna 11. However, the first ground section 10 may also function as a common ground for the first antenna 11 and other antennas (not shown in Figure 2A). In this embodiment, the first ground section 10 is formed as a single metal plate (sheet metal) as shown in Figure 2A and is located on the upper side of the inclined section 1. However, the first ground section 10 may be formed as a plurality of separate metal plates, and these plurality of metal plates may be formed by electrically connecting them. Furthermore, the first ground section 10 is arranged parallel to the upper surface of the inclined section 1 and is electrically connected to the inclined section 1. 【0027】 Furthermore, the first ground section 10 may be formed in a form other than a plate, as long as it functions as the ground for the first antenna 11. Also, the first ground section 10 may be composed of a combination of metal and non-metallic materials, as long as it functions as the ground for the first antenna 11. For example, the first ground section 10 may include a metal plate and a resin insulator. In addition, the first ground section 10 may be formed from a single printed circuit board (PCB) with a conductor pattern formed on it, or it may be formed from multiple boards. 【0028】 The first antenna 11 is an antenna element that corresponds to the terrestrial frequency band. The first antenna 11 may, for example, correspond to the frequency band used for TEL (Telephone Information Technology) used in GSM, UMTS, LTE, 5G, etc., or to the frequency band used for telematics, V2X (Vehicle to Everything: vehicle-to-vehicle communication, vehicle-to-infrastructure communication), Wi-Fi, Bluetooth, etc. The first antenna 11 may also correspond to the frequency band used for AM / FM radio or DAB (Digital Access Control), or to the frequency band used for keyless entry antennas or smart key antennas. The first antenna 11 is a terrestrial frequency band and only needs to correspond to the desired frequency band. 【0029】 In this embodiment, the first antenna 11 is a monopole antenna, as shown in Figure 2A. However, the first antenna 11 may be of other antenna types, such as a dipole antenna, loop antenna, collinear antenna, or bowtie antenna. The first antenna 11 is positioned on the front side of the first ground section 10 via the first base section 12. Here, "front side" refers to the side on which the antenna (in this case, the first antenna 11) is located. 【0030】 The first base 12 is a component on which the feed point and matching circuit of the first antenna 11 are located. The feed point of the first antenna 11 is a region including the feed point of the first antenna 11. The first antenna 11 is connected to a coaxial cable (not shown) via a matching circuit mounted on the first base 12. Other circuit elements and electronic components besides the matching circuit, such as a connection detection circuit, amplifier, and filter, may be mounted on the first base 12. 【0031】 The first base portion 12 is a substrate (circuit board), and conductive patterns (not shown), circuit elements such as the matching circuit described above, and electronic components are mounted on the front side of the first base portion 12. Alternatively, the first base portion 12 may be constructed by forming a conductive pattern on a resin material using MID technology (Molded Interconnect Device). The first base portion 12 is positioned parallel to the first ground portion 10 on the front side of the first ground portion 10. That is, the first base portion 12 is positioned parallel to the upper surface of the inclined portion 1. 【0032】 The contact surface of the first base 12 with the first ground portion 10 may be treated with a conductive surface treatment such as solder rivet, gold plating, or gold flash. This makes it easier to establish electrical conductivity between the first base 12 and the first ground portion 10. 【0033】 <Second antenna unit A2 and support section 91> The second ground section 20 is a component that functions as the ground for the second antenna 21. However, the second ground section 20 may also function as a common ground for the second antenna 21 and other antennas (not shown in Figure 2A). The configuration of an antenna device having a common ground for the second antenna and other antennas will be described in detail in the explanations of the antenna device 100L shown in Figure 17 and the antenna device 100M shown in Figure 18. 【0034】 In this embodiment, the second ground portion 20 is formed as a single metal plate (sheet metal) as shown in Figure 2A and is located above the inclined portion 1. However, the second ground portion 20 may also be formed as a plurality of separate metal plates, which are electrically connected to each other. Furthermore, the second ground portion 20 is supported by a support portion 91 (described later) which is made of an insulator. In other words, the second ground portion 20 is insulated from the inclined portion 1 and is supported by the inclined portion 1. However, the second ground portion 20 may also be supported by the case 90, as will be described later. 【0035】 Furthermore, the second ground section 20 may be formed in a form other than a plate, as long as it functions as the ground for the second antenna 21. Also, the second ground section 20 may be composed of a combination of metal and non-metallic materials, as long as it functions as the ground for the second antenna 21. For example, the second ground section 20 may include a metal plate and a resin insulator. In addition, the second ground section 20 may be formed from a single printed circuit board (PCB) with a conductor pattern formed on it, or from multiple circuit boards. 【0036】 As shown in Figure 2B, the outer shape of the second ground section 20 is a square in plan view when viewed in the -Z direction (downward), with equal length and width. However, the outer shape of the second ground section 20 may be a quadrilateral other than a square, such as a circle, ellipse, polygon, etc. Here, "quadrilateral" refers to a shape consisting of four sides, including, for example, a square, rectangle, trapezoid, parallelogram, rhombus, etc. In the shape of a "quadrilateral," for example, at least some of the corners may be cut diagonally relative to the sides. Also, in the shape of a "quadrilateral," notches (recesses) or protrusions (convex parts) may be formed on some of the sides. 【0037】 The second antenna 21 is an antenna that corresponds to the frequency band of satellite waves. The second antenna 21 is a planar antenna (for example, a patch antenna) and corresponds to radio waves in the frequency band for, for example, the Global Navigation Satellite System (GNSS). The second antenna 21 corresponds to radio waves in the L1 band (1559MHz~1610MHz band). 【0038】 However, the communication standards and frequency bands of the radio waves that the second antenna 21 supports are not limited to GNSS, but may be other communication standards and frequency bands. The second antenna 21 may, for example, support radio waves in the frequency band for Satellite Digital Audio Radio Service (SDARS). Furthermore, the second antenna 21 may support desired circular polarization, or desired linear polarization such as vertical polarization or horizontal polarization. The second antenna 21 is in the satellite wave frequency band and only needs to support radio waves in the desired frequency band. The second antenna 21 is also positioned on the front side of the second ground section 20 via the second base section 22. 【0039】 Furthermore, the second antenna 21 may be a so-called multi-band antenna that can handle radio waves in multiple frequency bands. Specifically, the second antenna 21 may handle radio waves in two frequency bands: the L1 band and the L5 band (1164MHz to 1214MHz band). Also, the frequency bands of radio waves that the second antenna 21 can handle may be a combination of two frequency bands, for example, the L1 band and the L2 band (1212MHz to 1254MHz band), or a combination of three frequency bands, the L1 band, the L2 band and the L5 band. 【0040】 The target frequencies for each of the L1, L2, and L5 bands are, for example, the center frequencies of those frequency bands. Here, the center frequency for the L1 band is 1575.42 MHz, the center frequency for the L2 band is 1227.60 MHz, and the center frequency for the L5 band is 1176.45 MHz. In the second antenna 21, the shape of the radiating element 23, which will be described later, is designed based on the target frequencies. 【0041】 The antenna device 100 may be a so-called patch antenna stacking type antenna device, which stacks multiple second antennas 21 corresponding to radio waves in different frequency bands in order to respond to radio waves in multiple frequency bands. For example, the antenna device 100G shown in Figure 10A, which will be described later, is a patch antenna stacking type antenna device. 【0042】 Furthermore, the frequency bands of the radio waves that the second antenna 21 operates on may include the L6 band (1273MHz~1284MHz band) and the L band (1525MHz~1559MHz band), which are formed by further combining the L1 band, L2 band, and L5 band with the correction satellite signal. Also, the frequency bands of the radio waves that the second antenna 21 operates on are not limited to the specific combination of multiple frequency bands mentioned above, but may be any combination of multiple frequency bands. 【0043】 The second antenna 21 has a radiating element 23 and a dielectric 24, as shown in Figure 2B. 【0044】 The radiating element 23 is a conductive member placed on the dielectric 24. The external shape of the radiating element 23 is a quadrilateral in a plan view when viewed in the -Z direction (downward), as shown in Figure 2B. In this embodiment, the external shape of the radiating element 23 is a square, with equal length and width. However, the external shape of the radiating element 23 may be a rectangle, with different length and width. Furthermore, the external shape of the radiating element 23 is not limited to a quadrilateral, but may be a circle, ellipse, polygon, etc. 【0045】 The radiating element 23 may have at least one of a slot or a notch (slit) formed therein. For example, the frequency band of radio waves that a radiating element 23 with a slot (or slit) corresponds to has two frequency bands: one determined by the external dimensions of the radiating element 23 and another determined by the length of the slot (or slit) formed in the radiating element 23. This allows the second antenna 21 to correspond to radio waves of multiple frequency bands, even if it is not the patch antenna stacked type described above. 【0046】 The radiating element 23 has a feed section 25. The feed section 25 is a conductive part that includes a feed point. The feed point is the part to which a feed line (not shown) supplies power to the radiating element 23. In the second antenna 21 in this embodiment, two feed lines (not shown) are provided to supply power to the radiating element 23; in other words, a two-feed system is adopted. Therefore, in this embodiment, the radiating element 23 has two feed sections 25. 【0047】 However, the feeding method for the second antenna 21 is not limited to a two-feed method. For example, the second antenna 21 may employ a four-feed method. In the second antenna 21 employing a four-feed method, the radiating element 23 will have four feeding points 25. Alternatively, the second antenna 21 may employ a single-feed method. In the second antenna 21 employing a single-feed method, the radiating element 23 will have one feeding point 25. 【0048】 The dielectric 24 is a component formed of a dielectric material such as ceramic. The outer shape of the dielectric 24 is a quadrilateral in a plan view when viewed in the -Z direction (downward), as shown in Figure 2B. In this embodiment, the outer shape of the dielectric 24 is a square, with equal length and width. However, the outer shape of the dielectric 24 may be a rectangle, with different length and width. Furthermore, the outer shape of the dielectric 24 is not limited to a quadrilateral, but may be a circle, ellipse, polygon, etc. A radiating element 23 is arranged on the front side of the dielectric 24. A conductive pattern (not shown) that functions as a ground conductor film (or ground conductor plate) is formed on the back side of the dielectric 24. The dielectric 24 may be a dielectric substrate, or a solid or hollow resin component. 【0049】 The second base portion 22 is a member on which the dielectric 24 is arranged. In this embodiment, the second base portion 22 is fixed to the second ground portion 20 by, for example, a screw (not shown). However, the second base portion 22 may also be supported by a base portion formed by bending a part of the second ground portion 20 so as to protrude upward, and fixed to the base portion by a screw (not shown). 【0050】 Furthermore, in this embodiment, the second base portion 22 is directly positioned on the front surface of the second ground portion 20, as shown in Figure 2A. That is, the second base portion 22 is positioned without any separation from the front surface of the second ground portion 20. However, the second base portion 22 may be positioned at a predetermined distance above the front surface of the second ground portion 20. 【0051】 In this embodiment, the second base portion 22 is a substrate (circuit board), and conductive patterns (not shown) are formed on the front and back surfaces of the second base portion 22. On the front surface of the second base portion 22, conductive patterns are formed that function as the ground conductor plate (ground conductor film) of the second antenna 21 and the ground of a circuit (not shown). On the back surface of the second base portion 22, conductive patterns and circuit patterns are formed to which signal lines of a coaxial cable (not shown) are connected. However, the conductive patterns formed on the second base portion 22 are not limited to these and may differ depending on the type of second antenna 21. Furthermore, the second base portion 22 may be constructed by forming conductive patterns on a resin material using MID technology. 【0052】 The antenna device 100 may further have a shielding case between the back surface of the second base 22 and the front surface of the second ground section 20. The shielding case is a metal member that electrically shields the conductive pattern formed on the back side of the second base 22 and the mounted electronic components. 【0053】 The support portion 91 is a member that supports the second ground portion 20 with respect to the inclined portion 1. In this embodiment, the support portion 91 is a plate-shaped member, as shown in Figure 2A, for example, with the second ground portion 20 positioned on its front side. The support portion 91 is positioned parallel to the horizontal plane (XY plane), and with the second ground portion 20 positioned on its front side, the front surface of the second ground portion 20 is parallel to the horizontal plane. Here, "the front surface of the second ground portion 20 is parallel to the horizontal plane" is not limited to strict parallelism; the front surface of the second ground portion 20 may be inclined at a predetermined angle with respect to the horizontal plane. 【0054】 As shown in Figure 2A, a space for housing the first antenna unit A1 is formed on the back side of the support portion 91 between it and the upper surface of the inclined portion 1. This allows the first antenna unit A1 to be positioned below the second antenna unit A2. In other words, the first ground portion 10 and the first antenna 11 can be positioned below the second ground portion 20. 【0055】 However, if the second ground section 20 is supported so that its front surface is parallel to the horizontal plane, and the first ground section 10 and the first antenna 11 are positioned below the second ground section 20, the support section 91 does not need to be arranged parallel to the horizontal plane, nor does it need to be formed in the shape of a plate. The support section 91 may be formed, for example, as part of the case 90, so that the second ground section 20 is supported by the case 90. Also, as described above, the case 90 is fixed to the inclined section 1. Therefore, the second ground section 20 may be supported by the inclined section 1. Furthermore, if the second ground section 20 is directly fixed to the inclined section 1, the antenna device 100 does not need to have a support section 91. 【0056】 As described above, the shape of the second ground section 20 is square in a plan view when viewed in the -Z direction (downward), as shown in Figure 2B. When the shape of the second ground section 20 is square in this way, the gain and directivity in the zenith direction can be improved by positioning the second antenna 21 at the center of the second ground section 20, as shown in Figure 2B. Specifically, "positioning the second antenna 21 at the center of the second ground section 20" means that the center of the second antenna 21 is located at the center of the second ground section 20. Here, "center" refers to the geometric center of the shape. 【0057】 In the antenna device 100 of this embodiment, the support portion 91 is made of an insulator. If the second ground portion 20 were to be electrically connected to another conductor (in this case, the inclined portion 1), the portion that effectively functions as a ground would extend to the inclined portion 1, which could worsen the gain and directivity of the second antenna 21 in the zenith direction. Therefore, by positioning the second ground portion 20 on the support portion 91 made of an insulator (i.e., the second ground portion 20 is insulated from the inclined portion 1), the gain and directivity of the second antenna 21 in the zenith direction can be improved. 【0058】 <<Characteristics of the first antenna 11 and the second antenna 21 located on the inclined section 1>> In the antenna device 100 of this embodiment, the first antenna 11 of the first antenna unit A1 and the second antenna 21 of the second antenna unit A2 can be arranged in the inclined section 1 to ensure desired characteristics. Below, the characteristics of the upper second antenna 21 and the lower first antenna 11 will be described in detail using comparative examples. 【0059】 <Comparative Example> Figure 3 is an explanatory diagram of the comparative example antenna device 100A. 【0060】 The comparative example antenna device 100A is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. However, the antenna device 100A only has a second ground section 20A corresponding to the second antenna unit A2 of this embodiment, a second antenna 21A, and a second base section 22A, and does not have the configuration corresponding to the first antenna unit A1 of this embodiment. 【0061】 In the comparative example antenna device 100A, the second ground portion 20A is also formed as a single metal plate (sheet metal) similar to this embodiment and is located on the upper side of the inclined portion 1. However, because the second ground portion 20A is directly positioned on the upper surface of the inclined portion 1, the front surface of the second ground portion 20 is parallel to the upper surface of the inclined portion 1. Furthermore, because the second antenna 21A is positioned on the front surface side of the second ground portion 20 via the second base portion 22A, the front surface of the second antenna 21A (i.e., the front surface of the radiating element 23A of the second antenna 21A) is parallel to the upper surface of the inclined portion 1. 【0062】 For antennas corresponding to satellite wave frequency bands, gain in the zenith direction (+Z direction) is important. Antennas corresponding to satellite wave frequency bands can obtain the greatest gain in the zenith direction when the direction perpendicular to the front surface of the radiating element (normal direction of the front surface) points towards the zenith direction (Z direction). However, as in the comparative example antenna device 100A shown in Figure 3, if the second ground section 20A is placed directly on the upper surface of the inclined section 1, the front surface of the radiating element 23A becomes parallel to the inclined section 1. As a result, the direction N perpendicular to the front surface of the radiating element 23A (normal direction of the front surface N) becomes tilted with respect to the zenith direction (+Z direction). Therefore, in the comparative example antenna device 100A, the gain in the zenith direction deteriorates. 【0063】 In contrast, in the antenna device 100 of this embodiment, as shown in Figure 2A, the front surface of the radiating element 23 is parallel to the horizontal plane (XY plane), so that the direction N perpendicular to the front surface of the radiating element 23 (normal direction N of the front surface) points towards the zenith (+Z direction). Therefore, in the antenna device 100 of this embodiment, it is possible to suppress the deterioration of the zenith-direction gain of the second antenna 21. 【0064】 Furthermore, as described above, in the antenna device 100 of this embodiment, by arranging the second ground portion 20 so that the front surface of the radiating element 23 is parallel to the horizontal plane, a space is formed between the second ground portion 20 and the inclined portion 1 below it. The first antenna unit A1 (first ground portion 10, first antenna 11, and first base portion 12) can be arranged in this space. Therefore, the first antenna 11 of the first antenna unit A1 and the second antenna 21 of the second antenna unit A2 can be efficiently arranged within the limited housing space (within the housing space formed by the case 90). In the antenna device 100 of this embodiment, the first antenna 11 of the first antenna unit A1 and the second antenna 21 of the second antenna unit A2 can be arranged in the inclined portion 1 so as to ensure desired characteristics. 【0065】 <Structure to suppress unwanted resonance> Figure 4 is an explanatory diagram of the antenna device 100B of the first reference example. Note that the illustration and explanation of the support portion 91 are omitted in the following description. Furthermore, explanations of configurations similar to those of the antenna device 100 in this embodiment may be omitted. 【0066】 The antenna device 100B of the first reference example is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100B includes a case 90, a first ground section 10B, a first antenna 11B, and a first base section 12B corresponding to the first antenna unit A1, and a second ground section 20, a second antenna 21, and a second base section 22 corresponding to the second antenna unit A2. 【0067】 The first ground section 10B in the first reference example may be in a different configuration from the first ground section 10 in this embodiment. That is, in the antenna device 100B of the first reference example, unlike the antenna device 100 of this embodiment, the first ground section 10B extends parallel to the horizontal plane (XY plane). However, the first ground section 10B is not limited to extending in the horizontal direction, but may extend at a predetermined angle with the inclined section 1. This allows for the formation of space below the first ground section 10B to accommodate other antennas, electronic components, etc. However, in the antenna device 100B, the back surface of the first ground section 10B and the upper surface of the inclined section 1 are separated in the -X direction, and the distance between the back surface of the first ground section 10B and the upper surface of the inclined section 1 increases as you move towards the -X direction (see double arrows in Figure 4). 【0068】 The first ground section 10B is electrically connected to the inclined section 1 which has a conductor, similar to the first ground section 10 in this embodiment. As a result, a parasitic capacitance may occur depending on the distance between the first ground section 10B and the inclined section 1, due to the separation between the back surface of the first ground section 10B and the upper surface of the inclined section 1. This parasitic capacitance, along with the inductance determined by the first ground section 10B, may cause unwanted resonance in the first ground section 10B. In this case, the unwanted resonance generated in the first ground section 10B may affect the relationship between the first antenna 11B and the frequency band of the radio waves it corresponds to. Specifically, the desired frequency characteristics of the VSWR of the first antenna 11B may deteriorate, which may cause a decrease in the gain of the first antenna 11B. 【0069】 Figure 5 shows the frequency characteristics of the VSWR of the first antenna 11 and the first antenna 11B. 【0070】 In Figure 5, the horizontal axis represents frequency, and the vertical axis represents voltage standing wave ratio (VSWR). The results for the first antenna 11 of this embodiment described above are shown by a solid line, and the results for the first antenna 11B of the first reference example are shown by a dashed line. 【0071】 As shown in Figure 5, the VSWR of the first antenna 11 in this embodiment is 3 or less in the frequency band of the radio waves that the first antenna 11 corresponds to, which is a good result. In contrast, the VSWR of the first antenna 11B in the first reference example exceeds 3 around 800 MHz in the frequency band of the radio waves that the first antenna 11B corresponds to. In other words, it can be seen that the desired frequency characteristics of the VSWR of the first antenna 11B have deteriorated. Therefore, it can be seen that the gain of the first antenna 11B is lower compared to the first antenna 11. 【0072】 In the antenna device 100 of this embodiment, the first ground section 10 is formed to suppress unwanted resonance in the frequency band of the radio waves corresponding to the first antenna 11. Specifically, as shown in Figure 2A, the first ground section 10 is arranged parallel to the upper surface of the inclined section 1. 【0073】 As a result, in the antenna device 100 of this embodiment, the distance between the back surface of the first ground section 10 and the upper surface of the inclined section 1 can be reduced, and the potential difference between the first ground section 10 and the inclined section 1 can be reduced compared to the case in the first ground section 10B. This makes it possible to lower the frequency of unwanted resonance due to parasitic capacitance between the first ground section 10 and the inclined section 1 compared to the case in the first ground section 10B, thereby suppressing the influence of the first antenna 11 on the frequency band of the radio waves it corresponds to and preventing a decrease in the gain of the first antenna 11. 【0074】 Furthermore, if unwanted resonances affecting the frequency band of the radio waves that the first antenna corresponds to can be suppressed, the configuration of the first ground section is not limited to the case shown in Figure 2A. 【0075】 Figure 6 is an explanatory diagram of the first modified antenna device 100C. 【0076】 The first modified antenna device 100C is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100C includes a case 90, a first ground section 10C, a first antenna 11C, and a first base section 12C corresponding to the first antenna unit A1, and a second ground section 20, a second antenna 21, and a second base section 22 corresponding to the second antenna unit A2. 【0077】 The first ground portion 10C extends at a predetermined angle with the inclined portion 1, similar to the first ground portion 10B in the first reference example described above. Specifically, the first ground portion 10C extends parallel to the horizontal plane (XY plane). However, unlike the first ground portion 10B in the first reference example, the first ground portion 10C further has a restraining portion 13 on its back side. 【0078】 The suppression section 13 is a component that suppresses unwanted resonance in the frequency band of the radio waves corresponding to the first antenna 11C. The suppression section 13 is a conductive component, and is formed, for example, from a gasket made by wrapping a conductive cloth around a cushion made of a dielectric material, or from a conductive leaf spring. 【0079】 In the first modified antenna device 100C, by having a suppression part 13 on the back side of the first ground part 10C, the distance between the back side of the suppression part 13 of the first ground part 10C and the upper side surface of the inclined part 1 can be reduced. As a result, the potential difference generated between the first ground part 10C and the inclined part 1 can be reduced compared to the case of the first ground part 10B. Consequently, the frequency of unwanted resonance due to parasitic capacitance between the first ground part 10C and the inclined part 1 can be reduced compared to the case of the first ground part 10B, thereby suppressing the influence of the first antenna 11C on the frequency band of the radio waves it corresponds to and preventing a decrease in the gain of the first antenna 11C. 【0080】 Figure 7 is an explanatory diagram of the second modified antenna device 100D. 【0081】 The second modified antenna device 100D is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100D includes a case 90, a first ground section 10D, a first antenna 11D, and a first base section 12D corresponding to the first antenna unit A1, and a second ground section 20, a second antenna 21, and a second base section 22 corresponding to the second antenna unit A2. 【0082】 The first ground portion 10D has a first main body portion 14 and a first extension portion 15. The first main body portion 14 is a portion that extends so as to form a predetermined angle with the inclined portion 1, similar to the first ground portion 10B in the first reference example described above. Specifically, the first main body portion 14 extends parallel to the horizontal plane (XY plane). The first extension portion 15 extends from the first main body portion 14 and is a portion located between the first main body portion 14 and the inclined portion 1. Specifically, the first extension portion 15 extends downward from the end of the first main body portion 14 on the -X direction side. 【0083】 In the second modified antenna device 100D, the end 18 of the first main body 14 on the inclined portion 1 side and the end 19 of the first extension 15 on the inclined portion 1 side are electrically connected to the inclined portion 1. 【0084】 By making the first ground section 10D electrically connected to the inclined section 1 at ends 18 and 19, the occurrence of parasitic capacitance between the first ground section 10D and the inclined section 1 at the end side is suppressed. This suppresses the first antenna 11D from affecting the frequency band of the corresponding radio waves and prevents a decrease in the gain of the first antenna 11D. 【0085】 <<Variations concerning the first antenna>> As described above, in the antenna device 100 of this embodiment, as shown in Figure 2A, a first antenna 11 corresponding to the terrestrial wave frequency band is positioned on the lower side, and a second antenna 21 corresponding to the satellite wave frequency band is positioned on the upper side. Above the first antenna 11, which is positioned on the lower side, is the second ground section 20. 【0086】 In this case, it may be difficult to ensure the element length of the first antenna 11. Also, extending the first antenna 11 may bring it closer to the second ground section 20, causing interference. 【0087】 Therefore, in the third modified antenna device 100E described later, the element length of the first antenna 11E can be increased by changing the shape of the first antenna 11E, and interference with the second ground section 20 can be suppressed. 【0088】 Figure 8 is an explanatory diagram of the third modified antenna device 100E. 【0089】 The third modified antenna device 100E is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100E includes a case 90, a first ground section 10E, a first antenna 11E, and a first base section 12E corresponding to the first antenna unit A1, and a second ground section 20, a second antenna 21, and a second base section 22 corresponding to the second antenna unit A2. 【0090】 In the third modified antenna device 100E, the first antenna 11E has an upright portion 16 and an opposing portion 17. 【0091】 The upright portion 16 is a part of the element of the first antenna 11E that is formed to rise up relative to the front surface of the first ground portion 10E. As shown in Figure 8, the upright portion 16 is formed to rise upward (+Z direction). However, the upright portion 16 is not limited to rising upward, but may also be inclined at a predetermined angle with respect to the upward direction. Above the upright portion 16 is the second ground portion 20 of the second antenna unit A2. 【0092】 The opposing portion 17 is the part of the element of the first antenna 11E that extends from the upper end of the upright portion 16 and faces the back surface of the second ground portion 20. The opposing portion 17 extends parallel to the back surface of the second ground portion 20. In this case, in a plan view from above (+Z direction), the tip of the opposing portion 17 protrudes in the -X direction relative to the second ground portion 20. In other words, in a plan view from above (+Z direction), at least a part of the opposing portion 17 does not overlap with the second ground portion 20. To put it another way, in a plan view from above (+Z direction), at least a part of the element of the first antenna 11E does not overlap with the second ground portion 20. 【0093】 However, the opposing portion 17 may be formed to extend from an end other than the upper end of the upright portion 16. In other words, the opposing portion 17 may be formed to extend from a point in the vertical direction of the upright portion 16. Furthermore, the direction in which the opposing portion 17 extends is not limited to a direction parallel to the back surface of the second ground portion 20, but may also be a direction inclined at a predetermined angle from a direction parallel to the back surface of the second ground portion 20. 【0094】 In the third modified antenna device 100E, the first antenna 11E has an opposing portion 17, which allows for an increase in the element length of the first antenna 11E. Furthermore, interference with the second ground portion 20 can be suppressed. 【0095】 Furthermore, in the third modified antenna device 100E, the area below the opposing portion 17 in which the first ground portion 10E and the first base portion 12E are not located can be increased. That is, the area below the first antenna 11E (here, the opposing portion 17) in which there is no conductor equal to the thickness of the first ground portion 10E and the first base portion 12E can be increased. This makes it possible to secure a larger separation distance in the Z direction from the inclined portion 1 to the first antenna 11E (here, the opposing portion 17), and to make the effective element length of the first antenna 11E longer. Moreover, in the third modified antenna device 100E, interference with the inclined portion 1 can be suppressed by extending the first antenna 11E to the side opposite to the inclined portion 1. 【0096】 The structure that allows for an increased element length of the first antenna while suppressing interference with the second ground section is not limited to the third modified example described above. 【0097】 Figure 9 is an explanatory diagram of the fourth modified antenna device 100F. 【0098】 The fourth modified antenna device 100F is arranged on the inclined section 1, similar to the antenna device 100 in this embodiment. The antenna device 100F includes a case 90, a first ground section 10F, a first antenna 11F, and a first base section 12F corresponding to the first antenna unit A1, and a second ground section 20, a second antenna 21, and a second base section 22 corresponding to the second antenna unit A2. 【0099】 In the fourth modified antenna device 100F, the first antenna 11F is inclined at a predetermined angle with respect to the upward direction (+Z direction). Specifically, the first antenna 11F extends inclined toward the -X direction with respect to the upward direction. In this case, in a plan view from above (+Z direction), the tip of the first antenna 11F protrudes toward the -X direction relative to the second ground portion 20. In other words, in a plan view from above (+Z direction), at least a portion of the elements of the first antenna 11F does not overlap with the second ground portion 20. 【0100】 In the fourth modified antenna device 100F, the first antenna 11F is tilted at a predetermined angle with respect to the upward direction (+Z direction), allowing its upper end to extend without overlapping with the second ground section 20. This allows for a longer element length of the first antenna 11F. Furthermore, interference with the second ground section 20 can be suppressed. Also, similar to the third modified antenna device 100E, the area below the first antenna 11F where the first ground section 10F and the first base section 12F are not located can be increased, allowing for a further increase in the effective element length of the first antenna 11F. 【0101】 <<Variations concerning the second ground area>> In the following, a modified example of the second ground section will be described using a comparative example. Note that in the following description, the case 90, the support section 91, and the first antenna unit A1 are not shown or described. Furthermore, the description of configurations similar to those of the antenna device 100 in this embodiment may be omitted. 【0102】 Figure 10A is an explanatory diagram of the antenna device 100G of the second reference example. Figure 10B is a plan view of the antenna device 100G. 【0103】 The antenna device 100G of the second reference example is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100G has a second ground section 20G, a second antenna 21G, and a second base section 22G, which correspond to the second antenna unit A2. 【0104】 The second ground section 20G, like the second ground section 20 in this embodiment, is a component that functions as the ground for the second antenna 21G corresponding to the satellite wave frequency band. As shown in Figure 10B, the external shape of the second ground section 20G is rectangular in plan view when viewed from above (+Z direction), with different vertical and horizontal lengths. 【0105】 The second antenna 21G, like the second antenna 21 in this embodiment, is an antenna corresponding to the frequency band of satellite waves. In the antenna device 100G, as shown in Figure 10A, a so-called patch antenna stacking type antenna device is employed, in which multiple second antennas 21G corresponding to radio waves in different frequency bands are stacked to accommodate radio waves in multiple frequency bands. In the antenna device 100G, as shown in Figure 10A, two stages of second antennas 21G are stacked. Each of the two stages of second antennas 21G has a radiating element 23 and a dielectric 24. However, the radiating element 23 of the lower stage second antenna 21G is hidden by the upper stage second antenna 21G and is not shown. 【0106】 Incidentally, it is desirable that the second ground section 20G of the second antenna 21G, which corresponds to the satellite wave frequency band, has a size (hereinafter sometimes referred to as "predetermined size") determined from a predetermined wavelength (hereinafter sometimes referred to as "predetermined wavelength") so as to correspond to the wavelength of a predetermined frequency band. Here, the predetermined size is determined by the length from the center of the second antenna 21G placed on the second ground section 20G. If the size of the second ground section 20G becomes smaller than the predetermined size, the gain of the second antenna 21G in the zenith direction may decrease. 【0107】 Specifically, it is desirable that the second ground section 20G has a size that extends at least one-quarter wavelength from the center 29G of the second antenna 21G to the frequency band of the radio waves that the second antenna 21G corresponds to. On the other hand, if the entire antenna device 100G is to be miniaturized, the second ground section 20G must be made smaller. If the external shape of the second ground section 20G is a rectangle with different vertical and horizontal lengths, for example, the gain in the zenith direction can be improved by bringing the length of the longitudinal direction of the second ground section 20G (arrow shown in Figure 10B) closer to one-quarter wavelength. 【0108】 Furthermore, if the outer shape of the second ground section is rectangular, positioning the second antenna at the center of the longitudinal direction of the second ground section can improve the gain and directivity in the zenith direction. 【0109】 However, in the antenna device 100G of the second reference example, as shown in Figure 10B, the second antenna 21G is positioned closer to the +Y direction than the center 28G of the second ground section 20G. Specifically, the center 29G of the second antenna 21G is located on the +Y direction side relative to the center 28G of the second ground section 20G. In this case, the second ground section 20G in the second reference example may reduce the zenith-direction gain and directivity of the second antenna 21G. 【0110】 Therefore, as shown in the fifth modified antenna device 100H described later, the second ground section 20H having a folded structure can improve the zenith-direction gain and directivity of the second antenna 21H. 【0111】 Figure 11A is an explanatory diagram of the fifth modified antenna device 100H. 【0112】 The antenna device 100H of the fifth modified example is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100H has a second ground section 20H, a second antenna 21H, and a second base section 22H, which correspond to the second antenna unit A2. 【0113】 The second ground section 20H, like the second ground section 20 in this embodiment, is a component that functions as the ground for the second antenna 21H corresponding to the satellite wave frequency band. As shown in Figure 11A, the second ground section 20H has a second main body section 26H and a second extension section 27H. 【0114】 The second main body section 26H is the part of the second ground section 20H where the second antenna 21H is located. Similar to the second ground section 20G in the second reference example described above, the second main body section 26H is rectangular in plan view when viewed from above (+Z direction), with different vertical and horizontal lengths. 【0115】 The second extension portion 27H is a part of the second ground portion 20H that extends from the second main body portion 26H and is located between the second main body portion 26H and the inclined portion 1. Specifically, the second extension portion 27H extends downward from the end of the second main body portion 26H on the +Y direction side. Therefore, compared to the second ground portion 20G in the second reference example, the second ground portion 20H in the fifth modified example further has the folded structure of the second extension portion 27H. 【0116】 The second antenna 21H, like the second antenna 21 in this embodiment, is an antenna that corresponds to the frequency band of satellite waves. The antenna device 100H employs a so-called patch antenna stacking type antenna device, which stacks multiple (in this case, two stages) second antennas 21H corresponding to radio waves in different frequency bands, in order to respond to radio waves in multiple frequency bands. 【0117】 Furthermore, the two-stage second antenna 21H is positioned closer to the +Y direction than the center 28H of the second main body 26H. Specifically, the center 29H of each of the two-stage second antennas 21H is located on the +Y direction side relative to the center 28H of the second main body 26H. 【0118】 Furthermore, the folded structure of the second ground section is not limited to the embodiment shown in the fifth modified example described above. 【0119】 Figure 11B is an explanatory diagram of the sixth modified antenna device 100I. 【0120】 The sixth modified antenna device 100I is arranged on the inclined section 1, similar to the antenna device 100 in this embodiment. The antenna device 100I has a second ground section 20I, a second antenna 21I, and a second base section 22I, which correspond to the second antenna unit A2. 【0121】 The second ground section 20I, like the second ground section 20 in this embodiment, is a component that functions as the ground for the second antenna 21I corresponding to the satellite wave frequency band. The second ground section 20I has a second main body section 26I and a second extension section 27I. 【0122】 The second main body portion 26I is the part of the second ground portion 20I where the second antenna 21I is located. Similar to the second ground portion 20H in the fifth modified example described above, the second main body portion 26I is rectangular in plan view when viewed from above (+Z direction), with different vertical and horizontal lengths. 【0123】 The second extension portion 27I is a part of the second ground portion 20I that extends from the second main body portion 26I and is located between the second main body portion 26I and the inclined portion 1. Specifically, the second extension portion 27I extends downward from the end of the second main body portion 26I on the +Y direction side. Unlike the second extension portion 27H of the fifth modified example, the second extension portion 27I has a shape that follows the inclined portion 1. 【0124】 The second antenna 21I, like the second antenna 21 in this embodiment, is an antenna corresponding to the satellite wave frequency band. The antenna device 100I employs a so-called patch antenna stacking type antenna device, which stacks multiple (in this case, two stages) second antennas 21I corresponding to radio waves in different frequency bands, in order to respond to radio waves in multiple frequency bands. 【0125】 Furthermore, the two-stage second antenna 21I is positioned closer to the +Y direction than the center 28I of the second main body 26I. Specifically, the center 29I of each of the two-stage second antennas 21I is located on the +Y direction side relative to the center 28I of the second main body 26I. 【0126】 Figure 12 shows the frequency characteristics of the average gain of the second antenna 21G in the second reference example. Figure 13 shows the frequency characteristics of the average gain of the second antenna 21H in the fifth modified example. Figure 14 shows the frequency characteristics of the average gain of the second antenna 21I in the sixth modified example. 【0127】 In Figures 12 to 14, the horizontal axis represents frequency and the vertical axis represents average gain. Antenna devices 100G to 100I are, as described above, patch antenna stacking type antenna devices, and each corresponds to radio waves in different frequency bands. In Figures 12 to 14, the results for the second antenna corresponding to L1 band radio waves and the second antenna corresponding to L5 band radio waves are shown by dashed and solid lines, respectively. 【0128】 Furthermore, in each of Figures 12 to 14, the average gain values ​​for each angle θ are plotted using markers. Here, angle θ is the angle that the angle at which the average gain is calculated makes with the +Z direction, where θ=0. That is, in each of Figures 12 to 14, the ○ marks (white circles) on the dashed lines and the ● marks (black circles) on the solid lines represent the results for angles θ from 0 to 30 degrees. The △ marks (white triangles) on the dashed lines and the ▲ marks (black triangles) on the solid lines represent the results for angles θ from 35 to 60 degrees. The ◇ marks (white diamonds) on the dashed lines and the ◆ marks (black diamonds) on the solid lines represent the results for angles θ from 65 to 90 degrees. 【0129】 As shown in Figures 12 to 14, the second antenna 21H, which is located in the second ground section 20H and has a folded structure, shows improved average gain, particularly in the L5 band frequency range, compared to the second antenna 21G, which is located in the second ground section 20G and does not have a folded structure. Furthermore, the second antenna 21I, which is located in the second ground section 20I, shows improved average gain, particularly in the L5 band frequency range, compared to the second antenna 21H, which is located in the second ground section 20H. 【0130】 Therefore, by having a folded structure, the longitudinal length of the second ground section can be brought close to one-quarter wavelength within a limited housing space, thereby improving the gain in the zenith direction. 【0131】 <<Other variations>> Figure 15A is an explanatory diagram of the seventh modified antenna device 100J. Note that the case 90 and support portion 91 are not shown or described in the following description. Also, the description of components similar to those of the antenna device 100 in this embodiment may be omitted. 【0132】 The seventh modified antenna device 100J is arranged on an inclined section (not shown), similar to the antenna device 100 of this embodiment. The antenna device 100J includes a first ground section 10J, a first antenna 11J, and a first base section 12J corresponding to the first antenna unit A1, and a second ground section 20J, a second antenna 21J, and a second base section 22J corresponding to the second antenna unit A2. 【0133】 In the antenna device 100 of the embodiment described above, the first antenna 11 of the first antenna unit A1 was positioned on the lower side of the inclined section 1, and the second antenna 21 of the second antenna unit A2 was positioned on the upper side. The seventh modified antenna device 100J may further have other antennas. The antenna device 100J further has a third antenna 31J and a third base 32J on the +Y direction side of the first antenna 11J and the second antenna 21J. 【0134】 In the seventh modified antenna device 100J, the first ground section 10J functions as a common ground for the first antenna 11J and the third antenna 31J. However, the antenna device 100J may further have a ground section that functions as the ground for the third antenna 31J and is electrically connected to the first ground section 10J. 【0135】 The third antenna 31J is an antenna that corresponds to the terrestrial broadcast frequency band. The third antenna 31J corresponds to radio waves in the frequency band used for TEL, such as GSM, UMTS, LTE, and 5G. However, the third antenna 31J may also correspond to radio waves in the frequency band used for telematics, V2X, Wi-Fi, Bluetooth, etc. 【0136】 The third antenna 31J is a planar antenna. Here, a "planar antenna" is an antenna in which the elements are mainly formed from plate-shaped members. The third antenna 31J is a so-called plate-shaped inverted L antenna. However, it is not necessary for all of the antenna elements to be formed from plate-shaped members; the antenna elements may have parts formed from materials other than plate-shaped members. Also, a "planar antenna" has a shape with a predetermined width. 【0137】 The third antenna 31J has a vertical plate portion 33J and a horizontal plate portion 34J. 【0138】 The vertical plate portion 33J is a part of the element of the third antenna 31J that is formed to rise up relative to the front surface of the first ground portion 10J. As shown in Figure 15A, the vertical plate portion 33J is formed to rise upward (+Z direction). However, the vertical plate portion 33J is not limited to rising upward, but may also be inclined at a predetermined angle with respect to the upward direction. 【0139】 The horizontal plate portion 34J is the part of the element of the third antenna 31J that extends horizontally from the upper end of the vertical plate portion 33J. However, the horizontal plate portion 34J may be formed to extend from a point other than the upper end of the vertical plate portion 33J. That is, the horizontal plate portion 34J may be formed to extend from a point in the vertical direction of the vertical plate portion 33J. Furthermore, the direction in which the horizontal plate portion 34J extends is not limited to the horizontal direction, but may also be in a direction inclined at a predetermined angle from the horizontal direction. 【0140】 Figure 15B is an explanatory diagram of the eighth modified antenna device 100K. 【0141】 The eighth modified antenna device 100K is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100K has a first ground section 10K, a first antenna 11K, and a first base section 12K corresponding to the first antenna unit A1, and a second ground section 20K, a second antenna 21K, and a second base section 22K corresponding to the second antenna unit A2. 【0142】 The antenna device 100K, like the antenna device 100J of the seventh modified example described above, further includes a third antenna 31K and a third base 32K. The third antenna 31K has a vertical plate portion 33K, a horizontal plate portion 34K, and an additional portion 35K. 【0143】 The vertical plate section 33K and the horizontal plate section 34K are the same as the vertical plate section 33J and the horizontal plate section 34J in the seventh modified example. The additional section 35K is an additional part of the element connected to the horizontal plate section 34K. The additional section 35K is located on the opposite side (-X direction side) from the inclined section 1 relative to the horizontal plate section 34K. 【0144】 Figure 16 shows the frequency characteristics of the average gain of the third antenna 31J and the third antenna 31K. 【0145】 In each of the figures in Figure 16, the horizontal axis represents frequency and the vertical axis represents average gain. The results for the third antenna 31J in the seventh modification described above are shown by a dashed line, and the results for the third antenna 31K in the eighth modification are also shown by a dashed line. 【0146】 As shown in Figure 16, the average gain of the third antenna 31K is improved by the addition of the extension 35K. This is because the capacitance of the third antenna 31K increases due to the addition of the extension 35K, resulting in broadband characteristics. Furthermore, by positioning the extension 35K on the opposite side (-X direction side) from the inclined section 1 relative to the horizontal plate section 34K, even broader bandwidth characteristics can be obtained. 【0147】 Figure 17 is an explanatory diagram of the ninth modified antenna device 100L. In the following description, the case 90, the support part 91, and the first antenna unit A1 are not shown or described. Also, the description of components similar to those of the antenna device 100 in this embodiment may be omitted. 【0148】 The ninth modified antenna device 100L is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100L includes a second ground section 20L, a second antenna 21L, and a second base section 22L corresponding to the second antenna unit A2, as well as a fourth antenna 41 and a fourth base section 42. 【0149】 The fourth antenna 41 corresponds to, for example, radio waves in the frequency band used for V2X. The fourth base 42 is the component on which the feed point and matching circuit of the fourth antenna 41 are located. In the antenna device 100L of the ninth modified example, the fourth antenna 41 and the fourth base 42 are arranged in the second ground section 20L as a common ground. 【0150】 Figure 18 is an explanatory diagram of the 10th modified antenna device 100M. 【0151】 The antenna device 100M of the 10th modified example is arranged on the inclined section 1, similar to the antenna device 100 of this embodiment. The antenna device 100M includes a second ground section 20M, a second antenna 21M, and a second base section 22M, which correspond to the second antenna unit A2, and a fifth antenna 51. 【0152】 The fifth antenna 51 corresponds to radio waves in the frequency band used for TEL, such as GSM, UMTS, LTE, and 5G. In the antenna device 100M of the 10th modified example, the fifth antenna 51 is located in the second ground section 20M as a common ground. 【0153】 The embodiments and modifications of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted. 【0154】 ==Summary== According to this specification, antenna devices in the following embodiments are provided. 【0155】 (Aspect 1) Embodiment 1 comprises a first ground section 10 located above an inclined section 1 that is inclined with respect to a horizontal plane, a first antenna 11 positioned on the front side of the first ground section 10 and corresponding to a first frequency band of terrestrial waves, a second ground section 20 located above the inclined section 1 with its front surface parallel to the horizontal plane, and a second antenna 21 positioned on the front side of the second ground section 20 and corresponding to a second frequency band of satellite waves, wherein the first ground section 10 and the first antenna 11 are located below the second ground section 20. 【0156】 According to the above-described embodiment, in the inclined section 1, each of the multiple antennas can be arranged efficiently within a limited space while ensuring the desired characteristics. 【0157】 (Aspect 2) In embodiment 2, the inclined portion 1 has a conductive portion, and the first ground portion 10 is formed to suppress unwanted resonance in the first frequency band. 【0158】 According to the above-described embodiment, it is possible to suppress a decrease in the gain of the first antenna 11. 【0159】 (Aspect 3) In embodiment 3, the first ground portion 10 is arranged parallel to the upper surface of the inclined portion 1. 【0160】 According to the above-described embodiment, it is possible to suppress a decrease in the gain of the first antenna 11. 【0161】 (Aspect 4) In embodiment 4, the first ground portion 10C extends at a predetermined angle with the inclined portion 1, and the back side of the first ground portion 10C has a suppression portion 13 for suppressing unwanted resonance in the first frequency band. 【0162】 According to the above embodiment, it is possible to suppress a decrease in the gain of the first antenna 11C. 【0163】 (Aspect 5) In embodiment 5, the first ground portion 10D includes a first main body portion 14 that extends at a predetermined angle with the inclined portion 1, and a first extension portion 15 that extends from the first main body portion 14 and is located between the first main body portion 14 and the inclined portion 1. The end portion 18 of the first main body portion 14 on the inclined portion 1 side and the end portion 19 of the first extension portion 15 on the inclined portion 1 side are electrically connected to the inclined portion 1. 【0164】 According to the above embodiment, it is possible to suppress a decrease in the gain of the first antenna 11D. 【0165】 (Aspect 6) In embodiment 6, in a plan view from above, at least a portion of the elements of the first antenna 11E does not overlap with the second ground portion 20. 【0166】 According to the above-described embodiment, the element length of the first antenna 11E can be increased, and interference with the second ground section 20 can be suppressed. 【0167】 (Aspect 7) In embodiment 7, the inclined portion 1 has a conductive portion and includes a support portion 91 that supports the second ground portion 20 relative to the inclined portion 1, and the support portion 91 is made of an insulator. 【0168】 According to the above-described embodiment, the gain and directivity of the second antenna 21 in the zenith direction can be improved. 【0169】 (Pattern 8) In embodiment 8, the second ground portion 20H has a second main body portion 26H that extends in a direction parallel to the horizontal plane and on which the second antenna 21H is arranged, and a second extension portion 27H that extends from the second main body portion 26H and is located between the second main body portion 26H and the inclined portion 1. 【0170】 According to the above-described embodiment, the gain and directivity of the second antenna 21H in the zenith direction can be improved. 【0171】 (Aspect 9) In embodiment 9, the center 29H of the second antenna 21H is located on a predetermined side relative to the center 28H of the second main body 26H, and the second extension 27H extends from the end of the second main body 26H on the predetermined side. 【0172】 According to the above-described embodiment, the gain and directivity of the second antenna 21H in the zenith direction can be improved. 【0173】 (Aspect 10) In embodiment 10, the antenna device 100 is located on the vehicle. 【0174】 According to the above-described embodiment, in the inclined section 1 of the vehicle, each of the multiple antennas can be efficiently arranged within a limited space while ensuring the desired characteristics. 【0175】 The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. Furthermore, the present invention may be modified or improved without departing from its spirit, and it goes without saying that the present invention includes equivalents thereof. [Explanation of Symbols] 【0176】 1 Slope 10, 10B~10F, 10J, 10K First Ground Section 11, 11B~11F, 11J, 11K First Antenna 13 Suppression part 14. First main body 15 1st extension section 18,19 End 20, 20A, 20G~20M Second Ground Section 21, 21A, 21G~21M Second Antenna 26H,26I 2nd main body 27H,27I 2nd extension section 28G~28I,29G~29I center 91 Support part 100, 100A~100M Antenna Equipment

Claims

[Claim 1] A first ground section located above the inclined section that slopes with respect to the horizontal plane, The first antenna is positioned on the front side of the first ground section and corresponds to the first frequency band of terrestrial broadcasting, A second ground portion is located above the aforementioned inclined portion, and its front surface is parallel to the horizontal plane, The second antenna is positioned on the front side of the second ground section and corresponds to the second frequency band of satellite waves, Equipped with, The first ground portion and the first antenna are located below the lower surface of the second ground portion in a direction perpendicular to the horizontal plane. Antenna device. [Claim 2] The inclined portion has a conductive portion, The first ground section is formed to suppress unwanted resonance in the first frequency band. The antenna device according to claim 1. [Claim 3] The first ground portion is arranged parallel to the upper surface of the inclined portion. The antenna device according to claim 1 or 2. [Claim 4] The first ground portion extends so as to form a predetermined angle with the inclined portion, The back side of the first ground portion has a suppression portion that suppresses unwanted resonance in the first frequency band, The antenna device according to claim 1 or 2. [Claim 5] The aforementioned first ground section is, A first main body portion extending at a predetermined angle with the inclined portion, A first extension portion extending from the first main body portion and located between the first main body portion and the inclined portion, It has, The end of the first main body on the inclined side and the end of the first extension on the inclined side are electrically connected to the inclined portion. The antenna device according to claim 1 or 2. [Claim 6] In a plan view from above, at least a portion of the elements of the first antenna does not overlap with the second ground portion. The antenna device according to claim 1 or 2. [Claim 7] The inclined portion has a conductive portion, The second ground portion is provided with a support portion that supports the inclined portion, The support portion is formed of an insulator. The antenna device according to claim 1. [Claim 8] The aforementioned second ground section is, A second main body portion extending in a direction parallel to the horizontal plane, on which the second antenna is located, A second extension portion extending from the second main body portion and located between the second main body portion and the inclined portion, Having, The antenna device according to claim 1 or 2. [Claim 9] The center of the second antenna is located on a side in a predetermined direction relative to the center of the second main body. The second extension extends from the end of the second main body on the side in the predetermined direction, The antenna device according to claim 8. [Claim 10] The aforementioned antenna device is located on the vehicle. The antenna device according to claim 1 or 2.

Images