Antenna device

Abstract

To provide an antenna device that enables miniaturization and improvement of isolation between antenna elements.SOLUTION: An antenna device 1 includes a first antenna element 21 having a planar radiation electrode 3, a second antenna element 22 having a slit 4 formed in the radiation electrode 3, a first ground electrode 71 aligned with the radiation electrode 3 when viewed in the thickness direction of the radiation electrode 3, a first power supply electrode 5 located between the radiation electrode 3 and the first ground electrode 71 when viewed in the thickness direction of the radiation electrode 3 and supplying power to the first antenna element 21, and a second power supply electrode 6 partially overlapping with the radiation electrode 3 or located adjacent to the radiation electrode 3 when viewed in the thickness direction of the radiation electrode 3 and supplying power to the second antenna element 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an antenna device. [Background technology]

[0002] Patent Document 1 discloses an antenna device. The antenna device disclosed in Patent Document 1 includes a conductive substrate, a first antenna element having a feed portion on the conductive substrate, extending from the feed portion along an edge of a rectangular parallelepiped having a bottom surface in the same plane as the conductive substrate and extending at least along an edge defining the top surface of the rectangular parallelepiped, and a second antenna element having a feed portion on the conductive substrate, extending from the feed portion to at least one of the bottom surface of the rectangular parallelepiped excluding the outer edge and the interior region of the rectangular parallelepiped. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-109190 Summary of the Invention [Problem to be solved by the invention]

[0004] In the antenna device disclosed in Patent Document 1, a first antenna element and a second antenna element are provided separately. In order to ensure isolation between the first antenna element and the second antenna element, the first antenna element and the second antenna element are arranged three-dimensionally and separately using a rectangular parallelepiped.

[0005] In the antenna device disclosed in Patent Document 1, it is necessary to provide a rectangular parallelepiped to isolate the first antenna element from the second antenna element, making it difficult to reduce the size of the antenna device.

[0006] The present disclosure provides an antenna device that allows for miniaturization and improved isolation between antenna elements. [Means for solving the problem]

[0007] An antenna device according to one aspect of the present disclosure includes a first antenna element having a planar radiation electrode, a second antenna element having a slit formed in the radiation electrode, a ground electrode aligned with the radiation electrode when viewed in the thickness direction of the radiation electrode, a first feeding electrode located between the radiation electrode and the ground electrode when viewed in the thickness direction of the radiation electrode and feeding power to the first antenna element, and a second feeding electrode partially overlapping with the radiation electrode or located adjacent to the radiation electrode when viewed in the thickness direction of the radiation electrode and feeding power to the second antenna element.

[0008] An antenna device according to another aspect of the present disclosure includes a radiating element having a planar radiating electrode and a slit formed in the radiating electrode, a ground electrode adjacent to the radiating electrode when viewed in the thickness direction of the radiating electrode, a first feeding electrode that causes the radiating element to function as a first antenna element that generates a change in the electric field using the radiating electrode, and a second feeding electrode that causes the radiating element to function as a second antenna element that generates a change in the magnetic field using the slit. [Effects of the Invention]

[0009] Aspects of the present disclosure allow for miniaturization and improved isolation between antenna elements. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view of a configuration example of an antenna device according to a first embodiment; [Figure 2] A bottom view of the antenna device of Figure 1 [Figure 3] Cross section of line AA in Figure 1 [Figure 4] Graph of frequency characteristics of the first antenna element of the antenna device of FIG. 1 [Figure 5] Graph of frequency characteristics of the second antenna element of the antenna device of FIG. 1 [Figure 6] FIG. 10 is a plan view of a configuration example of an antenna device according to a second embodiment; [Figure 7] 7 is a bottom view of the antenna device of FIG. [Figure 8] Cross section of line BB in Figure 6 [Figure 9] 10 is a graph showing the results of measuring the isolation of the antenna devices according to the first and second embodiments. [Figure 10] FIG. 10 is a plan view of a configuration example of an antenna device according to a third embodiment; [Figure 11] 11 is a bottom view of the antenna device of FIG. [Figure 12] FIG. 10 is a plan view of a configuration example of an antenna device according to a fourth embodiment; [Figure 13] FIG. 13 is a plan view of a configuration example of an antenna device according to a fifth embodiment; [Figure 14] FIG. 13 is a plan view of a configuration example of an antenna device according to a sixth embodiment; [Figure 15] FIG. 13 is a plan view of a configuration example of an antenna device according to a seventh embodiment; [Figure 16] 16 is a bottom view of the antenna device of FIG. 15. [Figure 17] FIG. 13 is a plan view of a configuration example of an antenna device according to an eighth embodiment; [Figure 18] 18 is a bottom view of the antenna device of FIG. 17. [Figure 19] FIG. 18 is a schematic circuit diagram of a configuration example of a first matching circuit of the antenna device of FIG. 17; [Figure 20] FIG. 18 is a schematic circuit diagram of a configuration example of a second matching circuit of the antenna device of FIG. 17; DETAILED DESCRIPTION OF THE INVENTION

[0011] [1. Embodiment] Hereinafter, embodiments of the present disclosure will be described, occasionally with reference to the drawings. However, the following embodiments are merely examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content (e.g., the shape, dimensions, and arrangement of each component). Positional relationships, such as up, down, left, and right, are based on the positional relationships shown in the drawings, unless otherwise specified. Each figure described in the following embodiments is a schematic diagram, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each element are not limited to the ratios shown in the drawings.

[0012] In the following description, when it is necessary to distinguish between multiple components, prefixes such as "first" and "second" are added to the names of the components. However, when the components can be distinguished from each other by the symbols attached to them, the prefixes such as "first" and "second" may be omitted in consideration of readability of the text.

[0013] 1.1 First Embodiment [1.1.1 Configuration] Fig. 1 is a plan view of a configuration example of an antenna device 1 according to a first embodiment. Fig. 2 is a bottom view of the antenna device 1. Fig. 3 is a cross-sectional view taken along line AA in Fig. 1.

[0014] The antenna device 1 is mounted on a device for communication in a predetermined frequency band. As shown in Figures 1, 2, and 3, the antenna device 1 includes a radiating element 2, a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, and a substrate 8.

[0015] 1 has a thickness direction Z, a first direction X perpendicular to the thickness direction Z, and a second direction Y perpendicular to both the thickness direction Z and the first direction X. In this embodiment, the substrate 8 has a rectangular plate shape. For example, the first direction X is the width direction of the substrate 8, and the second direction Y is the length direction of the substrate 8.

[0016] The substrate 8 includes a dielectric layer 80. The dielectric layer 80 has a first main surface 801 and a second main surface 802 opposite to the first main surface 801. The first main surface 801 and the second main surface 802 are, for example, both surfaces of the dielectric layer 80 in the thickness direction.

[0017] The substrate 8 is, for example, a dielectric substrate. Examples of the dielectric substrate include a low-temperature co-fired ceramic (LTCC) multilayer substrate, a multilayer resin substrate formed by laminating multiple resin layers made of resin such as epoxy or polyimide, a multilayer resin substrate formed by laminating multiple resin layers made of liquid crystal polymer (LCP) having a lower dielectric constant, a multilayer resin substrate formed by laminating multiple resin layers made of fluorine-based resin, and a ceramic multilayer substrate other than LTCC.

[0018] As shown in FIG. 1, the radiating element 2, the first feeding electrode 5, and the first ground electrode 71 are located on a first main surface 801 of the dielectric layer 80.

[0019] The radiating element 2, the first feeding electrode 5, and the first ground electrode 71 are aligned on the first main surface 801 of the dielectric layer 80 in the longitudinal direction Y of the substrate 8.

[0020] The first ground electrode 71 is used as a ground for the radiating element 2. The first ground electrode 71 is a conductor pattern that covers the first main surface 801 of the dielectric layer 80 of the substrate 8 so that a first predetermined region 801a where the first ground electrode 71 is not arranged is present on the first main surface 801. In FIG. 1, the first ground electrode 71 is located on the second end side in the length direction Y of the substrate 8 (the lower end side in FIG. 1) so that the first predetermined region 801a is located on the first end side in the length direction Y of the substrate 8 (the upper end side in FIG. 1).

[0021] The radiating element 2 is used as an antenna. As will be described in detail later, the radiating element 2 acts as a first antenna element 21 and a second antenna element 22. The radiating element 2 is a conductor pattern formed in a first predetermined region 801a on a first main surface 810 of the dielectric layer 80.

[0022] As shown in FIG. 1, the radiating element 2 includes a radiating electrode 3 and a slit 4.

[0023] The radiating electrode 3 has a planar shape. The radiating electrode 3 in FIG. 1 has a substantially rectangular shape when viewed in the thickness direction of the radiating electrode 3. In this embodiment, the thickness direction of the radiating electrode 3 corresponds to the thickness direction Z of the substrate 8. As shown in FIG. 1, the radiating electrode 3 is line-symmetric when viewed in the thickness direction of the radiating electrode 3. The symmetry axis S1 of the radiating electrode 3 corresponds to the length direction Y of the substrate 8.

[0024] The radiation electrode 3 constitutes a first antenna element 21. The first antenna element 21 is an electric field antenna that generates a change in an electric field by the radiation electrode 3. The first antenna element 21 is, for example, a grounded λ / 4 monopole antenna. The shape of the radiation electrode 3 is determined according to a first frequency band used for communication by the first antenna element 21. As an example, the first frequency band is a UWB (Ultra Wide Band) frequency band (for example, 7.25 GHz to 10.25 GHz).

[0025] The slits 4 are formed in the radiating electrode 3. As shown in FIG. 1 , the first end 4a and the second end 4b of the slit 4 are closed ends that are not connected to the outer periphery 3a of the radiating electrode 3. The slits 4 are line-symmetric when viewed in the thickness direction of the radiating electrode 3. The symmetry axis S2 of the slits 4 corresponds to the length direction Y of the substrate 8. Therefore, when viewed in the thickness direction of the radiating electrode 3, the radiating electrode 3 and the first ground electrode 71 are aligned along the symmetry axis S2 of the slits 4. In particular, in this embodiment, the symmetry axis S2 of the slits 4 coincides with the symmetry axis S1 of the radiating electrode 3. Therefore, when viewed in the thickness direction of the radiating electrode 3, the radiating electrode 3 is line-symmetric with respect to the symmetry axis S2 of the slits 4. Therefore, the symmetry axis S2 of the slits 4 passes through the center of the radiating electrode 3 when viewed in the thickness direction of the radiating electrode 3.

[0026] The slit 4 in FIG. 1 is substantially U-shaped. The slit 4 in FIG. 1 includes a straight portion 41 and first and second extending portions 42 and 43. The straight portion 41 extends in a direction intersecting the direction in which the radiating electrode 3 and the first ground electrode 71 are aligned when viewed from the thickness direction of the radiating electrode 3. In this embodiment, the straight portion 41 extends in the width direction X of the substrate 8. As shown in FIG. 1, the straight portion 41 is located at the end of the radiating electrode 3 on the first ground electrode 71 side (the lower end in FIG. 1). The first and second extending portions 42 and 43 extend from both ends of the straight portion 41 toward the end of the radiating electrode 3 opposite the first ground electrode 71 side (the upper end in FIG. 1). In this embodiment, the first and second extending portions 42 and 43 extend in the length direction Y of the substrate 8. Therefore, the first and second extending portions 42 and 43 form a right angle with respect to the straight portion 41. In the slit 4 of FIG. 1, the first end 4a is the tip of the first extending portion 42, and the second end 4b is the tip of the second extending portion 43.

[0027] The slit 4 constitutes the second antenna element 22. More specifically, the slit 4 and the peripheral portion of the slit 4 in the radiation electrode 3 constitute the second antenna element 22. The second antenna element 22 is a magnetic field antenna that generates a change in a magnetic field by the slit 4. The second antenna element 22 is, for example, a slot antenna. A slot antenna is an antenna configured by a slot formed in a conductor. In this embodiment, the slot refers to a small hole with both ends closed. In a slot antenna, the shape of the slit 4 is determined according to the second frequency band used for communication by the second antenna element 22. For example, the length of the slit 4 can be set to 1 / 2 of the wavelength corresponding to the second frequency band used for communication by the second antenna element 22. As an example, the second frequency band is the Bluetooth (registered trademark) frequency band (e.g., approximately 2.4 GHz).

[0028] The first feeding electrode 5 is used to feed power to the first antenna element 21. In particular, the first feeding electrode 5 causes the radiating element 2 to function as the first antenna element 21 that generates a change in the electric field through the radiating electrode 3.

[0029] The first feeding electrode 5 in FIG. 1 is a conductor pattern formed in a first predetermined region 801a on a first main surface 801 of the dielectric layer 80. As shown in FIG. 1, the first feeding electrode 5 is located between the radiating electrode 3 and the first ground electrode 71 when viewed in the thickness direction of the radiating electrode 3. In this embodiment, the first feeding electrode 5 is located on the symmetry axis S1 of the radiating electrode 3. In this embodiment, the first feeding electrode 5 is a first connection portion to which a feed line for feeding power to the first antenna element 21 is connected. The first feeding electrode 5 enables direct power feeding from the feed line connected to the first feeding electrode 5 to the first antenna element 21. The first feeding electrode 5 can constitute a feeding point of the first antenna element 21.

[0030] As shown in FIG. 2, the second feeding electrode 6 and the second ground electrode 72 are located on the second main surface 802 of the dielectric layer 80.

[0031] The second ground electrode 72 is used as a ground for the radiating element 2. The second ground electrode 72 is a conductor pattern that covers the second main surface 802 of the dielectric layer 80 of the substrate 8 so that a second predetermined region 802a where the second ground electrode 72 is not arranged is present on the second main surface 802. In FIG. 2, the second ground electrode 72 is located on the second end side in the length direction Y of the substrate 8 (the lower end side in FIG. 2) so that the second predetermined region 802a is located on the first end side in the length direction Y of the substrate 8 (the upper end side in FIG. 2). In this embodiment, the shape of the second ground electrode 72 matches the shape of the first ground electrode 71 in the thickness direction Z of the substrate 8. Therefore, the shape of the second predetermined region 802a matches the shape of the first predetermined region 801a in the thickness direction Z of the substrate 8.

[0032] The second feeding electrode 6 is used to feed power to the second antenna element 22. In particular, the second feeding electrode 6 causes the radiating element 2 to function as the second antenna element 22 that generates a change in the magnetic field through the slit 4.

[0033] 2 is a conductor pattern formed in a second predetermined region 802a on the second main surface 802 of the dielectric layer 80. As shown in Fig. 1, the second feed electrode 6 is located on the symmetry axis S2 of the slit 4. The second feed electrode 6 is located at the end of the radiating electrode 3 on the first ground electrode 71 side (the lower end in Fig. 1) when viewed in the thickness direction of the dielectric layer 80.

[0034] The second power supply electrode 6 in FIG. 2 includes a wiring portion 61 and an electrode portion 62.

[0035] The wiring portion 61 is a portion to which a power feed line for feeding power to the second antenna element 22 is connected. The wiring portion 61 is located at a position overlapping the first power feed electrode 5 when viewed in the thickness direction of the radiation electrode 3.

[0036] The electrode portion 62 couples the wiring portion 61 and the second antenna element 22. In this embodiment, the electrode portion 62 is directly connected to the wiring portion 61 and capacitively coupled to the second antenna element 22. In this embodiment, the electrode portion 62 is planar. The electrode portion 62 in FIG. 2 is substantially rectangular when viewed in the thickness direction of the radiation electrode 3. As shown in FIG. 1, the electrode portion 62 is located so as to overlap with the radiation electrode 3 and straddle the slit 4 when viewed in the thickness direction of the radiation electrode 3. In this manner, the second feeding electrode 6 is located so that a portion (the electrode portion 62) of the second feeding electrode 6 overlaps with the radiation electrode 3 when viewed in the thickness direction of the radiation electrode 3. Particularly in this embodiment, when viewed in the thickness direction of the dielectric layer 80, the electrode portion 62 overlaps both sides of the linear portion 41 of the slit 4 of the radiation electrode 3. This allows the electrode portion 62 to be capacitively coupled to the radiation electrode 3 via the dielectric layer 80, enabling indirect power feeding to the second antenna element 22 from a feeder line connected to the wiring portion 61. In the electrode portion 62 of the second feeding electrode 6, a portion that overlaps with the radiation electrode 3 in the thickness direction of the radiation electrode 3 can form a feeding point of the second antenna element 22.

[0037] As shown in FIG. 1 , the straight portion 41 of the slit 4 is located at the end of the radiation electrode 3 on the first ground electrode 71 side (the lower end in FIG. 1 ), and the first and second extending portions 42 and 43 extend toward the end of the radiation electrode 3 opposite the first ground electrode 71 side (the upper end in FIG. 1 ). The second feeding electrode 6 is located at the end of the radiation electrode 3 on the first ground electrode 71 side (the lower end in FIG. 1 ) when viewed in the thickness direction of the dielectric layer 80. Therefore, in the direction of the symmetry axis S2 of the slit 4, the straight portion 41, which is the center of the slit 4, is closer to the first ground electrode 71, the second ground electrode 72, and the second feeding electrode 6 than the first end 4a and the second end 4b of the slit 4. Here, it is preferable that the connection point between the feeder line for feeding power to the second antenna element 22 and the second feeding electrode 6 be near the ground electrodes (the first ground electrode 71 and the second ground electrode 72). It is preferable that the second antenna element 22 be fed at the center of the slit 4. 1, the distance between the center of the slit 4 and the connection point between the feed line and the second feed electrode 6 can be shortened. This shortens the wiring path for feeding power from the second feed electrode 6 to the second antenna element 22. This reduces the capacitive coupling between the second feed electrode 6 and other parts.

[0038] The antenna device 1 described above includes a first antenna element 21 having a planar radiation electrode 3 and a second antenna element 22 having a slit 4 formed in the radiation electrode 3. Wireless signals can be transmitted using the first antenna element 21 by supplying power from the first feeding electrode 5. Wireless signals can be transmitted using the second antenna element 22 by supplying power from the second feeding electrode 6. The antenna device 1 includes two antenna elements, the first antenna element 21 and the second antenna element 22, realized by the radiation electrode 3 having the slit 4 formed therein. In other words, the antenna device 1 uses the planar radiation electrode 3 and the radiation element 2 having the slit 4 formed in the radiation electrode 3 to function as the first antenna element 21 and the second antenna element 22. This reduces the space required to mount the first antenna element 21 and the second antenna element 22. This allows the antenna device 1 to be miniaturized. The first antenna element 21 utilizes the radiation electrode 3, and therefore functions as an electric field antenna in which the electric field is stronger than the magnetic field near the radiation electrode 3. The second antenna element 22 utilizes the slit 4, and therefore functions as a magnetic field antenna in which the magnetic field is stronger than the electric field near the slit 4. The first antenna element 21 and the second antenna element 22 have different operation modes as antennas, ensuring isolation. Therefore, the antenna device 1 enables improvement of isolation.

[0039] 1.1.2 Evaluation As described above, the antenna device 1 causes the single radiating element 2 including the radiating electrode 3 and the slit 4 to function as two types of antenna elements: the first antenna element 21 and the second antenna element 22. Figures 4 and 5 show the results of an evaluation of whether the radiating element 2 functions as the first antenna element 21 and the second antenna element 22 in the antenna device 1. In this evaluation, the radiating element 2 is designed so that the first antenna element 21 functions as an antenna for UWB wireless communication, and the second antenna element 22 functions as an antenna for Bluetooth wireless communication.

[0040] Fig. 4 is a graph of the frequency characteristics of the first antenna element 21. The frequency characteristics were evaluated using S parameters. As is clear from Fig. 4, it was confirmed that the first antenna element 21 has low return loss over a wide frequency band higher than 6 GHz that can be used in UWB wireless communication.

[0041] Fig. 5 is a graph showing the frequency characteristics of the second antenna element 22. The frequency characteristics were evaluated using S parameters. As is clear from Fig. 5, it was confirmed that the second antenna element 22 had low return loss in the frequency band around 2.4 GHz, which corresponds to Bluetooth wireless communication.

[0042] [1.1.3 Effects, etc.] The antenna device 1 described above includes a first antenna element 21 having a planar radiation electrode 3, a second antenna element 22 having a slit 4 formed in the radiation electrode 3, a first ground electrode aligned with the radiation electrode 3 as viewed in the thickness direction of the radiation electrode 3, a first feeding electrode 5 located between the radiation electrode 3 and the first ground electrode 71 as viewed in the thickness direction of the radiation electrode 3 and for feeding power to the first antenna element 21, and a second feeding electrode 6 located partially overlapping with the radiation electrode 3 as viewed in the thickness direction of the radiation electrode 3 and for feeding power to the second antenna element 22. This configuration enables miniaturization and improved isolation between the first antenna element 21 and the second antenna element 22.

[0043] The antenna device 1 includes a substrate 8 including a dielectric layer 80. The dielectric layer 80 has a first main surface 801 and a second main surface 802 opposite to the first main surface 801. The radiation electrode 3 and the first feeding electrode 5 are located on the first main surface 801. The second feeding electrode 6 is located on the second main surface 802. The first feeding electrode 5 and the radiation electrode 3 are directly connected. The second feeding electrode 6 and the radiation electrode 3 are capacitively coupled. This configuration enables improved isolation in the frequency band corresponding to the second antenna element 22.

[0044] In the antenna device 1, the first end 4a and the second end 4b of the slit 4 are closed ends that are not connected to the outer periphery 3a of the radiation electrode 3. This configuration enables miniaturization and improved isolation between the first antenna element 21 and the second antenna element 22.

[0045] In the antenna device 1, the slits 4 are line-symmetric when viewed from the thickness direction of the radiation electrode 3. When viewed from the thickness direction of the radiation electrode 3, the radiation electrode 3 and the first ground electrode 71 are aligned along the symmetry axis S2 of the slits 4. When viewed from the thickness direction of the radiation electrode 3, the symmetry axis S2 of the slits 4 passes through the center of the radiation electrode 3. This configuration makes it easier for the current flowing around the slits 4 in the radiation electrode 3 to be distributed line-symmetrically, thereby enabling stabilization of the antenna characteristics of the second antenna element 22.

[0046] In the antenna device 1, the second feeding electrode 6 is located on the symmetry axis S2 of the slit 4. This configuration makes it easier for the current flowing around the slit 4 in the radiation electrode 3 to be distributed line-symmetrically, thereby enabling stabilization of the antenna characteristics of the second antenna element 22.

[0047] In the antenna device 1, the radiation electrode 3 is axisymmetric with respect to the axis of symmetry S2 of the slit 4 when viewed in the thickness direction of the radiation electrode 3. This configuration makes it easier for current to be distributed axisymmetrically in the radiation electrode 3, thereby enabling stabilization of the antenna characteristics of the first antenna element 21.

[0048] In the antenna device 1, the first feeding electrode 5 is located on the symmetry axis S1 of the radiation electrode 3. This configuration makes it easier for the current to be distributed line-symmetrically in the radiation electrode 3, thereby stabilizing the antenna characteristics of the first antenna element.

[0049] In the antenna device 1, in the direction of the symmetry axis S2 of the slit 4, the center of the slit 4 is closer to the first ground electrode 71 than the first end 4a and the second end 4b of the slit 4. This configuration can shorten the wiring path for feeding power to the second antenna element 22 from the second feeding electrode 6. As a result, capacitive coupling between the second feeding electrode 6 and other parts can be reduced.

[0050] In the antenna device 1, the slit 4 includes a straight portion 41 extending in a direction intersecting the direction in which the radiation electrode 3 and the first ground electrode 71 are aligned when viewed from the thickness direction of the radiation electrode 3. This configuration enables stabilization of the antenna characteristics of the second antenna element 22.

[0051] The antenna device 1 described above comprises a radiating element 2 having a planar radiating electrode 3 and a slit 4 formed in the radiating electrode 3, a first ground electrode 71 adjacent to the radiating electrode 3 when viewed in the thickness direction of the radiating electrode 3, a first feeding electrode 5 that causes the radiating element 2 to function as a first antenna element 21 that generates a change in the electric field through the radiating electrode 3, and a second feeding electrode 6 that causes the radiating element 2 to function as a second antenna element 22 that generates a change in the magnetic field through the slit 4. This configuration enables miniaturization and improved isolation between the first antenna element 21 and the second antenna element 22.

[0052] 1.2 Second Embodiment [1.2.1 Configuration] Fig. 6 is a plan view of a configuration example of an antenna device 1A according to a second embodiment, Fig. 7 is a bottom view of the antenna device 1A, and Fig. 8 is a cross-sectional view taken along line BB in Fig. 6.

[0053] As shown in FIGS. 6, 7, and 8, the antenna device 1A includes a radiating element 2, a first feeding electrode 5, a second feeding electrode 6A, a first ground electrode 71, a second ground electrode 72, and a substrate 8.

[0054] The second feeding electrode 6A is used to feed power to the second antenna element 22. In particular, the second feeding electrode 6A causes the radiating element 2 to function as the second antenna element 22 that generates a change in the magnetic field through the slit 4.

[0055] 7 is formed in a second predetermined region 802a on a second main surface 802 of the dielectric layer 80. As shown in Fig. 6, the second feed electrode 6A is located on the symmetry axis S2 of the slit 4. The second feed electrode 6A is located at the end of the radiating electrode 3 on the first ground electrode 71 side (the lower end in Fig. 6) when viewed in the thickness direction of the dielectric layer 80.

[0056] The second power supply electrode 6A in FIG. 7 includes a wiring portion 61 and an electrode portion 62A.

[0057] The wiring portion 61 is a portion to which a power feed line for feeding power to the second antenna element 22 is connected. The wiring portion 61 is located at a position overlapping the first power feed electrode 5 when viewed in the thickness direction of the radiation electrode 3.

[0058] The electrode portion 62A couples the wiring portion 61 and the second antenna element 22. In this embodiment, the electrode portion 62A electrically connects the wiring portion 61 and the second antenna element 22.

[0059] The electrode portion 62A includes a first portion 621 and a second portion 622. The first portion 621 is a conductor pattern formed in a second predetermined region 802a on the second main surface 802 of the dielectric layer 80. The first portion 621 has a substantially rectangular shape when viewed in the thickness direction of the radiating electrode 3. As shown in FIG. 6 , the first portion 621 is positioned to overlap the radiating electrode 3 so as to straddle the slit 4 when viewed in the thickness direction of the radiating electrode 3. In particular, in this embodiment, the first portion 621 overlaps both sides of the linear portion 41 of the slit 4 in the radiating electrode 3. The second portion 622 connects the first portion 621 and the radiating electrode 3. As shown in FIG. 8 , the second portion 622 is a through-hole wiring formed in the dielectric layer 80. This allows the first portion 621 to be electrically coupled to the radiating electrode 3 via the second portion 622, enabling direct power supply to the second antenna element 22 from a power supply line connected to the wiring portion 61. The second portion 622 of the electrode portion 62A of the second feeding electrode 6A can form the feeding point of the second antenna element 22.

[0060] 1.2.2 Evaluation In this embodiment, the second feeding electrode 6A is directly connected to the second antenna element 22. On the other hand, in the first embodiment, the second feeding electrode 6A is indirectly connected to the second antenna element 22 by capacitive coupling. We evaluated how such a difference in feeding method affects the isolation between the first antenna element 21 and the second antenna element 22. In this evaluation, the radiating element 2 is designed so that the first antenna element 21 functions as an antenna for UWB wireless communication, and the second antenna element 22 functions as an antenna for Bluetooth wireless communication.

[0061] Fig. 9 is a graph showing the results of measuring the isolation of the antenna devices 1 and 1A according to the first and second embodiments. In Fig. 9, F1 shows the results of measuring the isolation of the antenna device 1 according to the first embodiment, and F2 shows the results of measuring the isolation of the antenna device 1A according to the second embodiment. In Fig. 9, the isolation is improved as the isolation value moves downward.

[0062] 9, it can be seen that in both antenna devices 1 and 1A, the isolation between the first antenna element 21 and the second antenna element 22 is good in a wide frequency band higher than 6 GHz that can be used in UWB wireless communication. In particular, in frequency bands above 6 GHz, the isolation of antenna device 1A is improved more than that of antenna device 1.

[0063] 9, it can be seen that in both antenna devices 1 and 1A, the isolation between the first antenna element 21 and the second antenna element 22 is good in the frequency band around 2.4 GHz corresponding to Bluetooth wireless communication. In particular, in the frequency band around 2.4 GHz, the isolation of antenna device 1 is improved more than that of antenna device 1A.

[0064] 9, when the second feeding electrode 6A is directly connected to the second antenna element 22, as in the antenna device 1A of the second embodiment, isolation is further improved in a wide frequency band higher than 6 GHz that can be used for UWB wireless communication, that is, in the frequency band corresponding to the first antenna element 21. When the second feeding electrode 6A is indirectly connected to the second antenna element 22 by capacitive coupling, as in the antenna device 1 of the first embodiment, isolation is further improved in a frequency band around 2.4 GHz that can be used for Bluetooth wireless communication, that is, in the frequency band corresponding to the second antenna element 22.

[0065] [1.2.3 Effects, etc.] The antenna device 1A described above further includes a substrate 8 including a dielectric layer 80. The dielectric layer 80 has a first main surface 801 and a second main surface 802 opposite to the first main surface 801. The radiation electrode 3 and the first feeding electrode 5 are located on the first main surface 801. The second feeding electrode 6A is located on the second main surface 802. The first feeding electrode 5 is directly connected to the radiation electrode 3. The second feeding electrode 6A is directly connected to the radiation electrode 3. In particular, the second feeding electrode 6A has a wiring portion 61 to which a feeder line for feeding power to the second antenna element 22 is connected, and an electrode portion 62A that electrically connects the wiring portion 61 and the second antenna element 22. This configuration enables improvement of isolation in the frequency band corresponding to the first antenna element 21.

[0066] 1.3 Third Embodiment 1.3.1 Configuration Fig. 10 is a plan view of an example of the configuration of an antenna device 1B according to the third embodiment, and Fig. 11 is a bottom view of the example of the configuration of the antenna device 1B in Fig. 10.

[0067] As shown in FIGS. 10 and 11, the antenna device 1B includes a radiating element 2B, a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, and a substrate 8.

[0068] As shown in FIG. 10 , the radiating element 2B, the first feeding electrode 5, and the first ground electrode 71 are located on the first main surface 801 of the dielectric layer 80. The radiating element 2B, the first feeding electrode 5, and the first ground electrode 71 are aligned in a first direction that is perpendicular to the thickness direction Z of the substrate 8. In this embodiment, the first direction is the Y direction of the substrate 8. The radiating element 2B, the first feeding electrode 5, and the first ground electrode 71 are located at the center of the substrate 8 in a second direction that is perpendicular to the thickness direction Z of the substrate 8 and the first direction. In this embodiment, the second direction is the X direction of the substrate 8.

[0069] The radiating element 2B functions as the first antenna element 21B and the second antenna element 22B. The radiating element 2B is a conductor pattern formed in a first predetermined region 801a on the first main surface 810 of the dielectric layer 80.

[0070] As shown in FIG. 10, the radiation element 2B includes a radiation electrode 3B and a slit 4B.

[0071] The radiating electrode 3B is planar. In this embodiment, the thickness direction of the radiating electrode 3B corresponds to the thickness direction Z of the substrate 8. As shown in Fig. 10, the radiating electrode 3B is line-symmetric when viewed from the thickness direction of the radiating electrode 3B. The symmetry axis S1 of the radiating electrode 3B corresponds to the length direction Y of the substrate 8.

[0072] 10 has a shape in which the dimensions in the thickness direction of the radiating electrode 3B and in a second direction (width direction X) perpendicular to the first direction increase with increasing distance from the first ground electrode 71 in the first direction (length direction Y). In FIG. 10, the radiating electrode 3B has an inverted trapezoidal shape when viewed in the thickness direction.

[0073] The shape of the radiation electrode 3B is determined according to the first frequency band used for communication by the first antenna element 21B. The radiation electrode 3B has a shape such that the dimension in the thickness direction of the radiation electrode 3B and in a second direction (width direction X) perpendicular to the first direction increases with increasing distance from the first ground electrode 71 in the first direction (length direction Y). Therefore, the lengths of both sides 3b1 and 3b2 of the radiation electrode 3B in the second direction can be set to an electrical path length according to the first frequency band used for communication by the first antenna element 21B. In the case of the radiation electrode 3 of the antenna device 1 of FIG. 1, the dimension of the radiation electrode 3 in the X direction is substantially constant, so the dimension of the radiation electrode 3 in the length direction Y can be set to an electrical path length according to the first frequency band used for communication by the first antenna element 21B. Therefore, even if the dimension of the radiation electrode 3B in FIG. 10 in the length direction Y is smaller than that of the radiation electrode 3 of FIG. 1, it can be set to the same electrical path length as the radiation electrode 3 of FIG. 1. 10 can be made smaller in the longitudinal direction Y than the radiation electrode 3 in Fig. 1. This allows the first predetermined region 801a to be made smaller, which in turn allows the substrate 8 to be made smaller. The smaller substrate 8 allows the antenna device 1B to be made smaller.

[0074] The slit 4B is formed in the radiating electrode 3B. As shown in FIG. 10 , the first end 4a and the second end 4b of the slit 4B are closed ends that are not connected to the outer periphery 3a of the radiating electrode 3B. The slit 4B is line-symmetric when viewed in the thickness direction of the radiating electrode 3B. The symmetry axis S2 of the slit 4B corresponds to the longitudinal direction Y of the substrate 8. Therefore, when viewed in the thickness direction of the radiating electrode 3B, the radiating electrode 3B and the first ground electrode 71 are aligned along the symmetry axis S2 of the slit 4B. Particularly in this embodiment, the symmetry axis S2 of the slit 4B coincides with the symmetry axis S1 of the radiating electrode 3B. Therefore, the radiating electrode 3B is line-symmetric with respect to the symmetry axis S2 of the slit 4B when viewed in the thickness direction of the radiating electrode 3B. Therefore, the symmetry axis S2 of the slit 4B passes through the center of the radiating electrode 3B when viewed in the thickness direction of the radiating electrode 3B.

[0075] The slit 4B in FIG. 10 is substantially V-shaped. The slit 4B in FIG. 10 includes a straight portion 41 and first and second extending portions 42 and 43. The straight portion 41 extends in a direction intersecting the direction in which the radiating electrode 3B and the first ground electrode 71 are aligned when viewed from the thickness direction of the radiating electrode 3B. In this embodiment, the straight portion 41 extends in the width direction X of the substrate 8. As shown in FIG. 10, the straight portion 41 is located at the end of the radiating electrode 3B on the first ground electrode 71 side (the lower end in FIG. 10). The first and second extending portions 42 and 43 extend from both ends of the straight portion 41 toward the end of the radiating electrode 3B on the opposite side from the first ground electrode 71 side (the upper end in FIG. 10). In this embodiment, the first and second extending portions 42, 43 extend in a direction intersecting the longitudinal direction Y of the substrate 8 so that the distance between the first and second extending portions 42, 43 increases as the extending portions move away from the straight portion 41 in the first direction (longitudinal direction Y). Therefore, the angles of the first and second extending portions 42, 43 with respect to the straight portion 41 are obtuse angles. The angles of the first and second extending portions 42, 43 with respect to the straight portion 41 may be, for example, greater than 90 degrees and equal to or less than 150 degrees. In the slit 4B of FIG. 10 , the first end 4a is the tip of the first extending portion 42, and the second end 4b is the tip of the second extending portion 43.

[0076] The shape of the slit 4B is determined according to the second frequency band used for communication by the second antenna element 22B. For example, the length of the slit 4B can be set to 1 / 2 the wavelength corresponding to the second frequency band used for communication by the second antenna element 22B. In the slit 4B, the angle between the first and second extension portions 42, 43 and the straight line portion 41 is an obtuse angle. This can reduce the dimension of the radiation electrode 3B in the longitudinal direction Y required to form the slit 4B compared to when the angle between the first and second extension portions 42, 43 and the straight line portion 41 is a right angle, as in the slit 4 of FIG. 1. Compared to when the angle between the first and second extension portions 42, 43 and the straight line portion 41 is a right angle, when the angle between the first and second extension portions 42, 43 and the straight line portion 41 is an obtuse angle, as in the slit 4B, current concentration near the corner between the straight line portion 41 and the first and second extension portions 42, 43 can be reduced, thereby stabilizing the antenna characteristics of the second antenna element 22B. Even if the length of the straight portion 41 of the slit 4B in Figure 10 is equal to the length of the straight portion 41 of the slit 4 in Figure 1, the first and second extension portions 42, 43 are generally further apart in the slit 4B in Figure 10 than in the slit 4 in Figure 1, so interference between the currents flowing near the first and second extension portions 42, 43 can be reduced.

[0077] [1.3.2 Effects, etc.] In the antenna device 1B described above, the radiation electrode 3B and the first ground electrode 71 are aligned in a first direction (length direction Y) when viewed from the thickness direction of the radiation electrode 3B. The radiation electrode 3B has a shape such that the dimension in a second direction (width direction X) perpendicular to the first direction when viewed from the thickness direction of the radiation electrode 3B increases as the radiation electrode 3B moves away from the first ground electrode 71 in the first direction. This configuration allows the dimension of the radiation electrode 3B in the first direction to be reduced, enabling miniaturization.

[0078] In the antenna device 1B, the slit 4B further includes first and second extending portions 42, 43 extending from both ends of the straight portion 41. The first and second extending portions 42, 43 are formed at obtuse angles with respect to the straight portion 41. This configuration enables stabilization of the antenna characteristics of the second antenna element 22.

[0079] 1.4 Fourth embodiment 1.4.1 Configuration 12 is a plan view of a configuration example of an antenna device 1C according to the fourth embodiment. The antenna device 1C of FIG. 12 includes a radiating element 2C that is different from the radiating element 2 of the antenna device 1 according to the first embodiment. Like the antenna device 1, the antenna device 1C of FIG. 12 includes a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, and a substrate 8. Although the second ground electrode 72 is not shown in FIG. 12, a bottom view of the antenna device 1C according to the present embodiment is the same as the bottom view of the antenna device 1 shown in FIG. 2.

[0080] The radiating element 2C functions as the first antenna element 21C and the second antenna element 22C. The radiating element 2C is a conductor pattern formed in a first predetermined region 801a on the first main surface 810 of the dielectric layer 80.

[0081] The radiating element 2C in FIG. 12 includes a radiating electrode 3C and a slit 4C.

[0082] The radiating electrode 3C has a planar shape. The radiating electrode 3C in FIG. 12 has a substantially rectangular shape when viewed in the thickness direction of the radiating electrode 3C. In this embodiment, the thickness direction of the radiating electrode 3C corresponds to the thickness direction Z of the substrate 8. As shown in FIG. 12, the radiating electrode 3C is axisymmetric when viewed in the thickness direction of the radiating electrode 3C. The symmetry axis S1 of the radiating electrode 3C corresponds to the length direction Y of the substrate 8. The radiating electrode 3C constitutes the first antenna element 21C. The shape of the radiating electrode 3C is determined depending on the first frequency band used for communication by the first antenna element 21C.

[0083] The slit 4C is formed in the radiating electrode 3C. As shown in FIG. 12, the first end 4a and the second end 4b of the slit 4C are closed ends that are not connected to the outer periphery 3a of the radiating electrode 3C. The slit 4C is line-symmetric when viewed in the thickness direction of the radiating electrode 3C. The symmetry axis S2 of the slit 4C corresponds to the longitudinal direction Y of the substrate 8. Therefore, when viewed in the thickness direction of the radiating electrode 3C, the radiating electrode 3C and the first ground electrode 71 are aligned along the symmetry axis S2 of the slit 4C. Particularly in this embodiment, the symmetry axis S2 of the slit 4C coincides with the symmetry axis S1 of the radiating electrode 3C. Therefore, the radiating electrode 3C is line-symmetric with respect to the symmetry axis S2 of the slit 4C when viewed in the thickness direction of the radiating electrode 3C. Therefore, the symmetry axis S2 of the slit 4C passes through the center of the radiating electrode 3C when viewed in the thickness direction of the radiating electrode 3C.

[0084] The slit 4C in FIG. 12 includes a straight portion 41 and first and second extending portions 42C and 43C. The straight portion 41 extends in a direction intersecting the direction in which the radiating electrode 3C and the first ground electrode 71 are aligned, as viewed from the thickness direction of the radiating electrode 3C. In this embodiment, the straight portion 41 extends in the width direction X of the substrate 8. As shown in FIG. 12, the straight portion 41 is located at the end of the radiating electrode 3C on the first ground electrode 71 side (the lower end in FIG. 12). The first and second extending portions 42C and 43C extend from both ends of the straight portion 41 toward the end of the radiating electrode 3C on the opposite side from the first ground electrode 71 side (the upper end in FIG. 12). In this embodiment, the first and second extending portions 42C and 43C have a meandering shape. More specifically, the first and second extending portions 42C, 43C are shaped to extend in the length direction Y of the substrate 8 while bending in the width direction X of the substrate 8. In the slit 4C in FIG. 12, the first end 4a is the tip of the first extending portion 42, and the second end 4b is the tip of the second extending portion 43.

[0085] The shape of the slit 4C is determined according to the second frequency band used for communication by the second antenna element 22C. For example, the length of the slit 4C can be set to 1 / 2 the wavelength corresponding to the second frequency band used for communication by the second antenna element 22C. In the slit 4C, the first and second extending portions 42C, 43C have a meandering shape. Therefore, compared to the slit 4 in FIG. 1 where the first and second extending portions 42, 43 are linear, the length of the slit 4C can be set over a wider range without changing the dimension of the radiation electrode 3C in the length direction Y required to form the slit 4C. This allows for greater freedom in designing the second antenna element 22C.

[0086] [1.4.2 Effects, etc.] In the antenna device 1C described above, the slit 4C includes meander-shaped portions (first and second extending portions 42C, 43C). This configuration makes it easy to adjust the length of the slit 4C, thereby improving the degree of freedom in designing the second antenna element 22C.

[0087] 1.5 Fifth embodiment 1.5.1 Configuration 13 is a plan view of a configuration example of an antenna device 1D according to the fifth embodiment. The antenna device 1D of FIG. 13 includes a radiating element 2D that is different from the radiating element 2 of the antenna device 1 according to the first embodiment. Like the antenna device 1, the antenna device 1D of FIG. 13 includes a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, and a substrate 8. Although the second ground electrode 72 is not shown in FIG. 13, a bottom view of the antenna device 1D in this embodiment is the same as the bottom view of the antenna device 1 shown in FIG. 2.

[0088] The radiating element 2D functions as the first antenna element 21D and the second antenna element 22D. The radiating element 2D is a conductor pattern formed in a first predetermined region 801a on the first main surface 810 of the dielectric layer 80.

[0089] A radiating element 2D in FIG. 13 includes a radiating electrode 3D and a slit 4D.

[0090] The radiating electrode 3D has a planar shape. The radiating electrode 3D in FIG. 13 has a substantially rectangular shape when viewed in the thickness direction of the radiating electrode 3D. In this embodiment, the thickness direction of the radiating electrode 3D corresponds to the thickness direction Z of the substrate 8. As shown in FIG. 13, the radiating electrode 3D is axisymmetric when viewed in the thickness direction of the radiating electrode 3D. The symmetry axis S1 of the radiating electrode 3D corresponds to the length direction Y of the substrate 8. The radiating electrode 3D constitutes the first antenna element 21D. The shape of the radiating electrode 3D is determined depending on the first frequency band used for communication by the first antenna element 21D.

[0091] The slit 4D is formed in the radiation electrode 3D. As shown in Fig. 13, a first end 4a and a second end 4b of the slit 4D are closed ends that are not connected to the outer periphery 3a of the radiation electrode 3D.

[0092] The slit 4D in FIG. 13 includes a straight portion 41 and an extending portion 44. The straight portion 41 extends in a direction intersecting the direction in which the radiating electrode 3D and the first ground electrode 71 are arranged, as viewed from the thickness direction of the radiating electrode 3D. In this embodiment, the straight portion 41 extends in the width direction X of the substrate 8. As shown in FIG. 13, the straight portion 41 is located at the end of the radiating electrode 3D on the first ground electrode 71 side (the lower end in FIG. 13). The extending portion 44 extends from one end of the straight portion 41. The extending portion 44 has a spiral shape. More specifically, the extending portion 44 has a spiral shape extending toward the center of the radiating electrode 3D. In the slit 4D in FIG. 13, the first end 4a is the tip of the extending portion 44, and the second end 4b is the end of the straight portion 41 opposite the extending portion 44.

[0093] The shape of the slit 4D is determined according to the second frequency band used for communication by the second antenna element 22D. For example, the length of the slit 4D can be set to 1 / 2 the wavelength corresponding to the second frequency band used for communication by the second antenna element 22D. Because the slit 4D has a spiral shape, the length of the slit 4D can be set over a wider range without changing the dimension of the radiation electrode 3D in the length direction Y, which is necessary to form the slit 4D, compared to when the first and second extension portions 42, 43 are linear, as in the slit 4 of FIG. 1. This allows for greater freedom in designing the second antenna element 22D.

[0094] [1.5.2 Effects, etc.] In the antenna device 1D described above, the slit 4D includes a spiral-shaped portion (extension 44). This configuration makes it easy to adjust the length of the slit 4D, thereby improving the degree of freedom in designing the second antenna element 22D.

[0095] 1.6 Sixth embodiment 1.6.1 Configuration 14 is a plan view of a configuration example of an antenna device 1E according to a sixth embodiment. The antenna device 1E of FIG. 14 includes a radiating element 2E that is different from the radiating element 2 of the antenna device 1 according to the first embodiment. Like the antenna device 1, the antenna device 1E of FIG. 14 includes a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, and a substrate 8. Although the second ground electrode 72 is not shown in FIG. 14, a bottom view of the antenna device 1E in this embodiment is similar to the bottom view of the antenna device 1 shown in FIG. 2.

[0096] The radiating element 2E is used as an antenna. The radiating element 2E functions as a first antenna element 21E and a second antenna element 22E. The radiating element 2E is a conductor pattern formed in a first predetermined region 801a on a first main surface 810 of the dielectric layer 80.

[0097] As shown in FIG. 14, a radiation element 2E includes a radiation electrode 3E and a slit 4E.

[0098] The radiating electrode 3E has a planar shape. The radiating electrode 3E in FIG. 14 has a substantially rectangular shape when viewed in the thickness direction of the radiating electrode 3E. In this embodiment, the thickness direction of the radiating electrode 3E corresponds to the thickness direction Z of the substrate 8. As shown in FIG. 14, the radiating electrode 3E is axisymmetric when viewed in the thickness direction of the radiating electrode 3E. The symmetry axis S1 of the radiating electrode 3E corresponds to the length direction Y of the substrate 8. The radiating electrode 3E constitutes the first antenna element 21E. The shape of the radiating electrode 3E is determined depending on the first frequency band used for communication by the first antenna element 21E.

[0099] The slit 4E is formed in the radiating electrode 3E. As shown in Fig. 14, a first end 4a of the slit 4 is a closed end that is not connected to the outer periphery 3a of the radiating electrode 3. On the other hand, as shown in Fig. 14, a second end 4b of the slit 4 is an open end that is connected to the outer periphery 3a of the radiating electrode 3.

[0100] The slit 4E in FIG. 14 is substantially L-shaped. The slit 4E in FIG. 14 includes a straight portion 41 and an extending portion 45. The straight portion 41 extends in a direction intersecting the direction in which the radiating electrode 3E and the first ground electrode 71 are aligned, as viewed from the thickness direction of the radiating electrode 3E. In this embodiment, the straight portion 41 extends in the width direction X of the substrate 8. As shown in FIG. 14, the straight portion 41 is located at the end of the radiating electrode 3E on the first ground electrode 71 side (the lower end in FIG. 14). The extending portion 45 extends from one end of the straight portion 41 toward the end of the radiating electrode 3E opposite to the first ground electrode 71 side (the upper end in FIG. 14). In this embodiment, the extending portion 45 extends in the length direction Y of the substrate 8. Therefore, the extending portion 45 forms a right angle with respect to the straight portion 41. In the slit 4E of FIG. 14, the first end 4a is the tip of the extending portion 45, and the second end 4b is the end of the straight portion 41 opposite to the extending portion 44.

[0101] The slit 4E constitutes the second antenna element 22E. More specifically, the slit 4E and the peripheral portion of the slit 4E in the radiation electrode 3E constitute the second antenna element 22E. The second antenna element 22E is a magnetic field antenna that generates a change in the magnetic field by the slit 4E. The second antenna element 22E is, for example, a notch antenna. A notch antenna is an antenna formed by a notch formed in a conductor. In this embodiment, the notch refers to a small hole with one end closed and the other end open. The shape of the slit 4E is determined according to the second frequency band used for communication by the second antenna element 22E. For example, in a notch antenna, the length of the slit 4E can be set to ¼ of the wavelength corresponding to the second frequency band used for communication by the second antenna element 22E. As an example, the second frequency band is the Bluetooth (registered trademark) frequency band (e.g., approximately 2.4 GHz). Therefore, the length of the slit 4E required to set the frequency characteristics of the second antenna element 22E can be made shorter than when the first end 4a and the second end 4b of the slit 4E are closed ends, thereby improving the design freedom of the second antenna element 22E.

[0102] The second antenna element 22E is fed by a second feeding electrode 6. The second feeding electrode 6 of the antenna device 1E has the same configuration as the second feeding electrode 6 of the antenna device 1. The second feeding electrode 6 is located on the second main surface 802 so as to be capacitively coupled to the second antenna element 22E via the dielectric layer 80. As a result, the second feeding electrode 6 is capacitively coupled to the radiation electrode 3E via the dielectric layer 80, enabling indirect feeding of power to the second antenna element 22E.

[0103] [1.6.2 Effects, etc.] In the antenna device 1E described above, the first end 4a of the slit 4E is a closed end that is not connected to the outer periphery 3a of the radiation electrode 3E. The second end 4b of the slit 4E is an open end that is connected to the outer periphery 3a of the radiation electrode 3E. This configuration makes it possible to shorten the length of the slit 4E required to set the frequency characteristics of the second antenna element 22E compared to when the first end 4a and the second end 4b of the slit 4E are closed, thereby improving the degree of freedom in designing the second antenna element 22E.

[0104] The antenna device 1E further includes a substrate 8 including a dielectric layer 80. The dielectric layer 80 has a first main surface 801 and a second main surface 802 opposite to the first main surface 801. The radiation electrode 3E and the first feeding electrode 5 are located on the first main surface 801. The second feeding electrode 6 is located on the second main surface 802 so as to be capacitively coupled to the second antenna element 22E via the dielectric layer 80. This configuration enables improved isolation in the frequency band corresponding to the second antenna element 22E.

[0105] 1.7 Seventh embodiment 1.7.1 Configuration Fig. 15 is a plan view of a configuration example of an antenna device 1F according to the seventh embodiment. Fig. 16 is a bottom view of the antenna device 1F of Fig. 15.

[0106] As shown in FIGS. 15 and 16, the antenna device 1F includes a radiating element 2E, a first feeding electrode 5, a second feeding electrode 6F, a first ground electrode 71, a second ground electrode 72, and a substrate 8.

[0107] 15, the radiating element 2E, the first feeding electrode 5, the second feeding electrode 6F, and the first ground electrode 71 are located on a first main surface 801 of the dielectric layer 80. As shown in FIG. 16, the second ground electrode 72 is located on a second main surface 802 of the dielectric layer 80.

[0108] The second feeding electrode 6F is located adjacent to the radiation electrode 3E when viewed in the thickness direction of the radiation electrode 3E. The second feeding electrode 6F is used to feed power to the second antenna element 22E. In particular, the second feeding electrode 6F causes the radiation element 2E to function as the second antenna element 22E that generates a change in the magnetic field through the slit 4E.

[0109] The second feeding electrode 6F in FIG. 15 is a conductor pattern formed in a first predetermined region 801a on the first main surface 801 of the dielectric layer 80. As shown in FIG. 15, the second feeding electrode 6F is located on the radiation electrode 3E between the edge 3c of the second end 4b of the slit 4E and the first ground electrode 71 when viewed in the thickness direction of the radiation electrode 3E. In this embodiment, the second feeding electrode 6F is a second connection portion to which a feed line for feeding power to the second antenna element 22E is connected. The second feeding electrode 6F enables direct power feeding from the feed line connected to the second feeding electrode 6F to the second antenna element 22E. The second feeding electrode 6F can form a feeding point for the second antenna element 22E.

[0110] [1.7.2 Effects, etc.] In the antenna device 1F described above, the first end 4a of the slit 4E is a closed end that is not connected to the outer periphery 3a of the radiation electrode 3E. The second end 4b of the slit 4E is an open end that is connected to the outer periphery 3a of the radiation electrode 3E. This configuration makes it possible to shorten the length of the slit 4E required to set the frequency characteristics of the second antenna element 22E compared to when the first end 4a and the second end 4b of the slit 4E are open ends, thereby improving the degree of freedom in designing the second antenna element 22E.

[0111] The antenna device 1F further includes a substrate 8 including a dielectric layer 80. The dielectric layer 80 has a first main surface 801 and a second main surface 802 opposite to the first main surface 801. The radiation electrode 3E, the first feeding electrode 5, and the second feeding electrode 6E are located on the first main surface 801. The second feeding electrode 6F is located on the radiation electrode 3E between the edge 3c of the second end 4b of the slit 4E and the first ground electrode 71, when viewed in the thickness direction of the radiation electrode 3E. This configuration eliminates the need to form the second feeding electrode 6F on the second main surface 802. This configuration enables improved isolation in the frequency band corresponding to the first antenna element 21E.

[0112] 1.8 Eighth embodiment 1.8.1 Configuration Fig. 17 is a plan view of a configuration example of an antenna device 1G according to an eighth embodiment. Fig. 18 is a bottom view of the antenna device 1G of Fig. 17.

[0113] As shown in Figures 17 and 18, the antenna device 1G includes a radiating element 2, a first feeding electrode 5, a second feeding electrode 6, a first ground electrode 71, a second ground electrode 72, a substrate 8, a first matching circuit 91, and a second matching circuit 92.

[0114] As shown in FIG. 17, the radiating element 2, the first feeding electrode 5, the first ground electrode 71, and the first matching circuit 91 are located on a first main surface 801 of the dielectric layer 80.

[0115] The first matching circuit 91 is connected to the first feeding electrode 5. In this embodiment, the first matching circuit 91 is connected to the middle of the first feeding electrode 5. This means that the first matching circuit 91 forms part of the electrical path of the first feeding electrode 5. The first matching circuit 91 is provided to match the impedance between the feeding line connected to the first feeding electrode 5 and the first antenna element 21. The first matching circuit 91 makes it possible to reduce reflection of signals in a frequency band required for communication with the first antenna element 21.

[0116] FIG. 19 is a schematic circuit diagram of an example configuration of a first matching circuit 91 of the antenna device 1G. The first matching circuit 91 of FIG. 19 includes a capacitor C1 and an inductor L1. The capacitor C1 is connected to the first feeding electrode 5. In FIG. 19, the capacitor C1 is inserted between a first end 51 of the first feeding electrode 5 to which the feed line is connected and a second end 52 of the first feeding electrode 5 to which the first antenna element 21 is connected. The inductor L1 is connected between the first feeding electrode 5 and the ground, particularly between a portion of the first feeding electrode 5 between the first end 51 and the capacitor C1 and the ground. The first ground electrode 71 may be used as the ground.

[0117] 19 can function as a high-pass filter. The first matching circuit 91 is configured to pass signals in a frequency band necessary for communication through the first antenna element 21 and to block signals in a frequency band unnecessary for communication through the first antenna element 21. As an example, the first frequency band used for communication through the first antenna element 21 is a UWB (Ultra Wide Band) frequency band (e.g., 7.25 GHz to 10.25 GHz), and the second frequency band used for communication through the second antenna element 22 is a Bluetooth frequency band (e.g., approximately 2.4 GHz). In this example, the first matching circuit 91 can be configured to pass signals in the first frequency band and to block signals in the second frequency band.

[0118] As shown in FIG. 18, the second feeding electrode 6, the second ground electrode 72, and the second matching circuit 92 are located on the second main surface 802 of the dielectric layer 80.

[0119] The second matching circuit 92 is connected to the wiring portion 61 of the second feed electrode 6. In this embodiment, the second matching circuit 92 is connected to the middle of the wiring portion 61 of the second feed electrode 6. This means that the second matching circuit 92 forms part of the electrical path of the wiring portion 61 of the second feed electrode 6. The second matching circuit 92 is provided to match the impedance between the feed line connected to the wiring portion 61 and the second antenna element 22. The second matching circuit 92 makes it possible to reduce reflection of signals in a frequency band required for communication by the second antenna element 22.

[0120] FIG. 20 is a schematic circuit diagram of a configuration example of the second matching circuit 92 of the antenna device 1G. The second matching circuit 92 in FIG. 20 includes an inductor L2 and a capacitor C2. The capacitor C3 in FIG. 20 is an equivalent circuit of the capacitively coupled electrode portion 62 and the radiation electrode 3. The inductor L2 is connected to the wiring portion 61 of the second power supply electrode 6. In FIG. 20, the inductor L2 is inserted between a first end 611 of the wiring portion 61 to which the power supply line is connected and a second end 612 of the wiring portion 61 to which the electrode portion 62 (capacitor C3) is connected. The capacitor C2 is connected between the wiring portion 61 and ground, particularly between a portion between the first end 611 of the wiring portion 61 and the inductor L2 and ground. The second ground electrode 72 may be used as the ground.

[0121] 20 can function as a low-pass filter. The second matching circuit 92 is configured to pass signals in a frequency band necessary for communication through the second antenna element 22 and to block signals in a frequency band unnecessary for communication through the second antenna element 22. As an example, the first frequency band used for communication through the first antenna element 21 is a UWB (Ultra Wide Band) frequency band (e.g., 7.25 GHz to 10.25 GHz), and the second frequency band used for communication through the second antenna element 22 is a Bluetooth frequency band (e.g., approximately 2.4 GHz). In this example, the second matching circuit 92 can be configured to pass signals in the second frequency band and to block signals in the first frequency band.

[0122] [1.8.2 Effects, etc.] The antenna device 1G described above includes a first matching circuit 91 connected to the first feeding electrode 5. This configuration makes it possible to reduce reflection of signals in the frequency band required for communication in the first antenna element 21.

[0123] In the antenna device 1G, the first matching circuit 91 includes at least one capacitor C1 connected to the first feeding electrode 5, and at least one inductor L1 connected between the first feeding electrode 5 and ground. This configuration makes it possible to block signals in a frequency band unnecessary for communication in the first antenna element 21.

[0124] The antenna device 1G includes a second matching circuit 92. The second feeding electrode 6 includes an electrode portion 62 that is capacitively coupled with the radiation electrode 3, and a wiring portion 61 to which a feeding line for feeding power to the second antenna element 22 is connected. The second matching circuit 92 is connected to the wiring portion 61. This configuration makes it possible to reduce reflection of signals in the frequency band required for communication by the second antenna element 22.

[0125] In the antenna device 1G, the second matching circuit 92 includes at least one inductor L2 connected to the wiring portion 61, and at least one capacitor C2 connected between the wiring portion 61 and the ground. This configuration makes it possible to block signals in a frequency band unnecessary for communication through the second antenna element 22.

[0126] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0127] In one modification, the shapes and dimensions of the radiating elements 2, 2B to 2E, in particular the shapes and dimensions of the radiating electrodes 3, 3B to 3E and the shapes and dimensions of the slits 4, 4B to 4E may be changed as appropriate. As an example, the radiating electrode 3 may not be line-symmetric, and the slits 4 may not be line-symmetric either. The arrangement of the slits 4 relative to the radiating electrode 3 may also be changed as appropriate. The combinations of the radiating electrodes 3, 3B to 3E and the slits 4, 4B to 4E are not limited to the configuration examples of the first to eighth embodiments. For example, a radiating electrode of any embodiment may be combined with a slit of another embodiment. As an example, the slit 4C of embodiment 4 may be formed in the radiating electrode 3B of embodiment 3.

[0128] In one modified example, the first frequency band is not necessarily limited to a frequency band for UWB wireless communication. The second frequency band is not necessarily limited to a frequency band for Bluetooth. The first and second frequency bands may be, for example, frequency bands for Wi-Fi wireless communication. Examples of frequency bands for Wi-Fi wireless communication include a frequency band around 2.4 GHz (e.g., 2.4 GHz to 2.5 GHz) and a frequency band around 5 GHz (e.g., 5.15 GHz to 5.8 GHz). The first and second frequency bands may be selected from well-known frequency bands such as the mid-band of the 2G (second generation mobile communication) standard, the low-band of the 4G (fourth generation mobile communication) standard, and the low-band of the 5G (fifth generation mobile communication) standard. The 2G standard is, for example, the GSM (Global System for Mobile Communications) standard. The 4G standard is, for example, the 3GPP (registered trademark) LTE (Long Term Evolution) standard. The 5G standard is, for example, 5G NR (New Radio). The first and second frequency bands may be selected from frequency bands used in various communication standards such as wireless LAN, specified low-power radio, and short-distance wireless communication.

[0129] In one modification, the first power supply electrode 5 is not limited to the configuration examples of the first to eighth embodiments, and may be modified as appropriate.

[0130] In one modification, the second power supply electrodes 6, 6A, 6F are not limited to the examples of the first to eighth embodiments and may be modified as appropriate. The second power supply electrode 6A of the second embodiment may also be applied to the third, fourth, fifth, sixth, eighth, etc.

[0131] In one modification, the configurations of the first ground electrode 71 and the second ground electrode 72 are not necessarily limited to those of the first to eighth embodiments. The first ground electrode 71 and the second ground electrode 72 do not necessarily have to be formed on the first main surface 801 and the second main surface 802 of the dielectric layer 80, respectively. If the substrate 8 is a multilayer substrate, the first ground electrode 71 and the second ground electrode 72 may be provided as an intermediate layer of the substrate 8. Instead of the first ground electrode 71 and the second ground electrode 72, a single ground electrode shared by the first antenna element 21 and the second antenna element 22 may be provided. The shapes of the first ground electrode 71 and the second ground electrode 72 are not limited to rectangular and may be changed as appropriate.

[0132] In one modified example, the configuration of the substrate 8 is not necessarily limited to the configurations of the first to eighth embodiments. For example, the shape of the substrate is not limited to a rectangular plate. The substrate may have a well-known configuration, such as a double-sided copper-clad laminate or a multilayer substrate. As an example, in the first embodiment, the substrate 8 may include multiple dielectric layers 80, and the first feed electrode 5 and the second feed electrode 6 may be located on different dielectric layers 80.

[0133] In one modified example, the first matching circuit 91 is not limited to the configuration example shown in FIG. 19 and may have any desired filter performance. As an example, in the first matching circuit 91, the inductor L1 may be connected between the first power supply electrode 5 and ground, particularly between a portion between the second end 52 of the first power supply electrode 5 and the capacitor C1, and ground. In addition to the inductor L1, the first matching circuit 91 may include an inductor connected between the first power supply electrode 5, particularly between a portion between the second end 52 of the first power supply electrode 5 and the capacitor C1, and ground. In addition to the capacitor C1, the first matching circuit 91 may include a capacitor connected between the first end 51 of the first power supply electrode 5 and the connection point between the capacitor C1 and the inductor L1. In this way, the first matching circuit 91 may include at least one capacitor connected between the first power supply electrode 5 and ground and at least one inductor connected between the first power supply electrode 5 and ground. The first matching circuit 91 does not necessarily have to be connected to the middle of the first power supply electrode 5, and an end of the first matching circuit 91 may be directly connected to the first power supply electrode 5. The first matching circuit 91 is not essential.

[0134] In one modified example, the second matching circuit 92 is not limited to the configuration example shown in FIG. 20 and may have any desired filter performance. As an example, in the second matching circuit 92, the capacitor C2 may be connected between the wiring portion 61 of the second power supply electrode 6 and ground, particularly between a portion between the second end 612 of the wiring portion 61 and the inductor L2, and ground. In addition to the capacitor C2, the second matching circuit 92 may include a capacitor connected between the wiring portion 61 and ground, particularly between a portion between the second end 612 of the wiring portion 61 and the inductor L2, and ground. In addition to the inductor L2, the second matching circuit 92 may include an inductor connected between the first end 611 of the wiring portion 61 of the second power supply electrode 6 and the connection point between the capacitor C2 and the inductor L2. In this way, the second matching circuit 92 may include at least one capacitor connected midway along the wiring portion 61 of the second power supply electrode 6 and at least one inductor connected between the wiring portion 61 and ground. The second matching circuit 92 does not necessarily have to be connected midway through the wiring portion 61 of the second power supply electrode 6, and an end of the second matching circuit 92 may be directly connected to the second power supply electrode 6. The second matching circuit 92 is not essential.

[0135] [3. Aspects] As is clear from the above-described embodiments and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiments. Note that, in consideration of readability of the text, the reference numerals in parentheses may be omitted from the second and subsequent times.

[0136] The first aspect is an antenna device (1; 1A to 1G) including a first antenna element (21; 21B to 21E) having a planar radiation electrode (3; 3B to 3E), a second antenna element (22; 22B to 22E) having a slit (4; 4B to 4E) formed in the radiation electrode (3; 3B to 3E), a ground electrode (first ground electrode 71) aligned with the radiation electrode (3; 3B to 3E) when viewed from the thickness direction of the radiation electrode (3; 3B to 3E), and a second antenna element (22; 22B to 22E) having a slit (4; 4B to 4E) formed in the radiation electrode (3; 3B to 3E). and a second feeding portion (6; 6A; 6F) that partially overlaps with the radiation electrode (3; 3B to 3E) or is located adjacent to the radiation electrode (3; 3B to 3E) when viewed from the thickness direction of the radiation electrode (3; 3B to 3E) and that feeds power to the second antenna element (22; 22B to 22E). This aspect enables miniaturization and improved isolation between the antenna elements (first antenna element and second antenna element).

[0137] A second aspect is an antenna device (1; 1B to 1E; 1G) based on the first aspect. In the second aspect, the antenna device (1; 1B to 1E; 1G) comprises a substrate (8) including a dielectric layer (80). The dielectric layer (80) has a first main surface (801) and a second main surface (802) opposite to the first main surface (801). The radiation electrodes (3; 3B; 3C; 3D; 3E) and the first feeding electrode (5) are located on the first main surface (801). The second feeding electrode (6) is located on the second main surface (802). The first feeding electrode (5) and the radiation electrode (3) are directly connected. The second feeding electrode (6) and the radiation electrode (3) are capacitively coupled. This aspect enables improved isolation in the frequency band corresponding to the second antenna element.

[0138] A third aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on the first or second aspect. In the third aspect, the first end (4a) and the second end (4b) of the slit (4; 4B; 4C; 4D) are closed ends that are not connected to the outer periphery (3a) of the radiation electrode (3; 3B; 3C; 3D). This aspect enables miniaturization and improved isolation between the antenna elements (first antenna element and second antenna element).

[0139] A fourth aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on the third aspect. In the fourth aspect, the slits (4; 4B; 4C; 4D) are axisymmetric when viewed from the thickness direction of the radiation electrode (3; 3B; 3C; 3D). When viewed from the thickness direction of the radiation electrode (3; 3B; 3C; 3D), the radiation electrodes (3; 3B; 3C; 3D) and the ground electrode (first ground electrode 71) are aligned along the symmetry axis (S2) of the slits (4; 4B; 4C; 4D). When viewed from the thickness direction of the radiation electrode (3; 3B; 3C; 3D), the symmetry axis (S2) of the slits (4; 4B; 4C; 4D) passes through the center of the radiation electrode (3; 3B; 3C; 3D). This configuration makes it easier for the current flowing around the slit in the radiation electrode to be distributed line-symmetrically, thereby enabling stabilization of the antenna characteristics of the second antenna element.

[0140] The fifth aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on the fourth aspect. In the fifth aspect, the second feeding electrode (6) is located on the symmetry axis (S2) of the slits (4; 4B; 4C; 4D). This aspect makes it easier for the current flowing around the slits in the radiation electrode to be distributed line-symmetrically, thereby stabilizing the antenna characteristics of the second antenna element.

[0141] A sixth aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on the fourth or fifth aspect. In the sixth aspect, the radiation electrodes (3; 3B; 3C; 3D) are axisymmetric with respect to the symmetry axis (S2) of the slits (4; 4B; 4C; 4D) when viewed from the thickness direction of the radiation electrodes (3; 3B; 3C; 3D). This aspect makes it easier for current to be distributed axisymmetrically in the radiation electrodes, thereby enabling stabilization of the antenna characteristics of the first antenna element.

[0142] The seventh aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on the sixth aspect. In the seventh aspect, the first feeding electrode (5) is located on the axis of symmetry (S1) of the radiation electrode (3; 3B; 3C; 3D). This aspect makes it easier for current to be distributed line-symmetrically in the radiation electrode, thereby stabilizing the antenna characteristics of the first antenna element.

[0143] The eighth aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1G) based on any one of the fourth to seventh aspects. In the eighth aspect, in the direction of the symmetry axis (S2) of the slits (4; 4B; 4C; 4D), the centers of the slits (4; 4B; 4C; 4D) are closer to the ground electrode (first ground electrode 71) than the first ends (4a) and second ends (4b) of the slits (4; 4B; 4C; 4D). This aspect can shorten the wiring path for feeding power to the second antenna element by the second feeding electrode. Therefore, capacitive coupling between the second feeding electrode and other parts can be reduced.

[0144] A ninth aspect is an antenna device (1E; 1F) based on the first or second aspect. In the ninth aspect, a first end (4a) of the slit (4E) is a closed end that is not connected to the outer periphery (3a) of the radiation electrode (3E). A second end of the slit (4E) is an open end that is connected to the outer periphery (3a) of the radiation electrode (3E). This aspect makes it possible to shorten the length of the slit required to set the frequency characteristics of the second antenna element compared to when the first and second ends of the slit are closed, thereby improving the degree of freedom in designing the second antenna element.

[0145] A tenth aspect is an antenna device (1B) based on any one of the first to ninth aspects. In the tenth aspect, the radiation electrode (3B) and the ground electrode (first ground electrode 71) are aligned in a first direction as viewed from the thickness direction of the radiation electrode (3B). The radiation electrode (3B) has a shape such that the dimension in a second direction orthogonal to the first direction as viewed from the thickness direction of the radiation electrode (3B) increases as the radiation electrode (3B) becomes farther away from the ground electrode (first ground electrode 71) in the first direction. This aspect allows the dimension of the radiation electrode in the first direction to be reduced, enabling miniaturization.

[0146] An eleventh aspect is an antenna device (1C) based on any one of the first to tenth aspects. In the eleventh aspect, the slit (4C) includes meander-shaped portions (42C, 43C). This aspect makes it easy to adjust the length of the slit, thereby improving the degree of freedom in designing the second antenna element.

[0147] A twelfth aspect is an antenna device (1G) based on any one of the first to eleventh aspects. In the twelfth aspect, the antenna device (1G) includes a first matching circuit (91) connected to the first feeding electrode (5). This aspect makes it possible to reduce reflection of signals in a frequency band required for communication at the first antenna element.

[0148] A thirteenth aspect is an antenna device (1G) based on the twelfth aspect. In the thirteenth aspect, the first matching circuit (91) includes at least one capacitor (C1) connected midway through the first feeding electrode (5), and at least one inductor (L1) connected between the first feeding electrode (5) and ground. This aspect makes it possible to block signals in a frequency band unnecessary for communication at the first antenna element.

[0149] A fourteenth aspect is an antenna device (1G) based on any one of the first to thirteenth aspects. In the fourteenth aspect, the antenna device (1G) includes a second matching circuit (92). The second feeding electrode (6) includes an electrode portion (62) that is capacitively coupled with the radiation electrode (3) and a wiring portion (61) to which a feeding line for feeding power to the second antenna element (22) is connected. The second matching circuit (92) is connected to the wiring portion (61). This aspect makes it possible to reduce reflection of signals in a frequency band required for communication by the second antenna element.

[0150] A fifteenth aspect is an antenna device (1G) based on the fourteenth aspect. In the fifteenth aspect, the second matching circuit (92) includes at least one inductor (L2) connected midway along the wiring portion (61) and at least one capacitor (C2) connected between the wiring portion (61) and ground. This aspect makes it possible to block signals in a frequency band unnecessary for communication at the second antenna element.

[0151] A sixteenth aspect is an antenna device (1; 1A; 1B; 1C; 1D; 1E; 1F; 1G) based on any one of the first to fifteenth aspects. In the sixteenth aspect, the slits (4; 4B; 4C; 4D; 4E) include linear portions (41) extending in a direction intersecting the direction in which the radiation electrodes (3; 3B; 3C; 3D; 3E) and the ground electrode (first ground electrode 71) are aligned, as viewed from the thickness direction of the radiation electrodes (3; 3B; 3C; 3D; 3E). This aspect enables stabilization of the antenna characteristics of the second antenna element.

[0152] A seventeenth aspect is an antenna device (1B) based on the sixteenth aspect. In the seventeenth aspect, the slit (4B) further includes first and second extending portions (42, 43) extending from both ends of the linear portion (41). The angles of the first and second extending portions (42, 43) with respect to the linear portion (41) are obtuse angles. This aspect enables stabilization of the antenna characteristics of the second antenna element.

[0153] The eighteenth aspect is an antenna device (1; 1A to 1G) comprising: a radiating element (2; 2B to 2E) having a planar radiating electrode (3; 3B to 3E) and a slit (4; 4B to 4E) formed in the radiating electrode (3; 3B to 3E); a ground electrode (first ground electrode 71) adjacent to the radiating electrode (3; 3B to 3E) when viewed in the thickness direction of the radiating electrode (3; 3B to 3E); a first feeding electrode (5) that causes the radiating element (2; 2B to 2E) to function as a first antenna element (21; 21B to 21E) that generates a change in the electric field through the radiating electrode (3; 3B to 3E); and a second feeding electrode (6; 6A; 6F) that causes the radiating element (2; 2B to 2E) to function as a second antenna element (22; 22B to 22E) that generates a change in the magnetic field through the slit (4; 4B to 4E). This aspect allows for miniaturization and improved isolation between the antenna elements.

[0154] The second to seventeenth aspects are optional and not essential, and the second to seventeenth aspects can be modified appropriately and applied to the eighteenth aspect as well. [Industrial Applicability]

[0155] The present disclosure is applicable to an antenna device, and more specifically, to an antenna device including a plurality of antenna elements. [Explanation of symbols]

[0156] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G Antenna equipment 2, 2B, 2C, 2D, 2E Radiating elements 21, 21B, 21C, 21D, 21E First antenna element 22, 22B, 22C, 22D, 22E Second antenna element 3,3B,3C,3D,3E Emitting electrode 3a outer circumference 4, 4B, 4C, 4D, 4E Slit 4a 1st end 4b 2nd end 41 Straight section 42 1st extension part 42C First extension (meander-shaped part) 43 Second extension part 43C Second extension (meander-shaped part) 5. First power supply electrode C1 capacitor L1 inductor 6, 6A, 6F Second power supply electrode 61 Wiring section 62 Electrode section C2 capacitor L2 inductor 71 First ground electrode (ground electrode) 72 Second ground electrode 8 PCB 80 dielectric layer 801 1st main surface 802 2nd main surface 91 1st matching circuit 92 Second matching circuit S1 symmetry axis S2 symmetry axis

Claims

1. a first antenna element having a planar radiation electrode; a second antenna element having a slit formed in the radiation electrode; a ground electrode arranged next to the radiation electrode when viewed in a thickness direction of the radiation electrode; a first feeding electrode located between the radiation electrode and the ground electrode when viewed in the thickness direction of the radiation electrode, for feeding power to the first antenna element; a second feeding electrode that is positioned adjacent to the radiation electrode or partially overlaps the radiation electrode when viewed in the thickness direction of the radiation electrode, and that feeds power to the second antenna element; Antenna device.

2. a substrate including a dielectric layer; the dielectric layer has a first major surface and a second major surface opposite the first major surface; the radiation electrode and the first feeding electrode are located on the first main surface, the second power supply electrode is located on the second main surface; the first feeding electrode and the radiation electrode are directly connected, the second feeding electrode and the radiation electrode are capacitively coupled; The antenna device according to claim 1 .

3. the first end and the second end of the slit are closed ends that are not connected to the outer periphery of the radiation electrode; The antenna device according to claim 1 .

4. the slit is line-symmetric when viewed from the thickness direction of the radiation electrode, When viewed from the thickness direction of the radiation electrode, the radiation electrode and the ground electrode are aligned in the direction of the symmetrical axis of the slit, the symmetrical axis of the slit passes through the center of the radiation electrode when viewed in the thickness direction of the radiation electrode; The antenna device according to claim 3 .

5. the second feeding electrode is located on the axis of symmetry of the slit; 5. The antenna device according to claim 4.

6. the radiation electrode is linearly symmetrical with respect to the axis of symmetry of the slit when viewed in the thickness direction of the radiation electrode; 5. The antenna device according to claim 4.

7. the first feeding electrode is located on the axis of symmetry of the radiation electrode; 7. The antenna device according to claim 6.

8. In the direction of the symmetry axis of the slit, a center of the slit is closer to the ground electrode than the first end and the second end of the slit.

5. The antenna device according to claim 4.

9. a first end of the slit is a closed end that is not connected to an outer periphery of the radiation electrode, a second end of the slit is an open end connected to the outer periphery of the radiation electrode; The antenna device according to claim 1 .

10. the radiation electrode and the ground electrode are aligned in a first direction when viewed from the thickness direction of the radiation electrode, the radiation electrode has a shape such that a dimension in a second direction perpendicular to the first direction increases as the radiation electrode becomes farther from the ground electrode in the first direction, as viewed from the thickness direction of the radiation electrode. The antenna device according to any one of claims 1 to 9.

11. The slit includes a meander-shaped portion. The antenna device according to any one of claims 1 to 9.

12. a first matching circuit connected to the first feeding electrode; The antenna device according to any one of claims 1 to 9.

13. The first matching circuit includes at least one capacitor connected to the first power supply electrode and at least one inductor connected between the first power supply electrode and ground.

13. The antenna device according to claim 12.

14. a second matching circuit; the second feeding electrode includes an electrode portion that is capacitively coupled to the radiation electrode and a wiring portion to which a feeding line for feeding power to the second antenna element is connected, the second matching circuit is connected to the wiring portion, The antenna device according to any one of claims 1 to 9.

15. the second matching circuit includes at least one inductor connected to a midpoint of the wiring portion, and at least one capacitor connected between the wiring portion and ground.

15. The antenna device according to claim 14.

16. the slit includes a linear portion extending in a direction intersecting a direction in which the radiation electrode and the ground electrode are arranged side by side as viewed from the thickness direction of the radiation electrode. The antenna device according to any one of claims 1 to 9.

17. the slit further includes first and second extension portions extending from both ends of the linear portion, The angles of the first and second extension portions with respect to the linear portion are obtuse angles.

17. The antenna device according to claim 16.

18. a radiation element having a planar radiation electrode and a slit formed in the radiation electrode; a ground electrode adjacent to the radiation electrode when viewed in a thickness direction of the radiation electrode; a first feeding electrode that causes the radiating element to function as a first antenna element that generates a change in an electric field by the radiating electrode; a second feeding electrode that causes the radiating element to function as a second antenna element that generates a change in a magnetic field by the slit; Equipped with Antenna device.

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