Antenna device

Abstract

An antenna device includes a substrate, a coil antenna, and a resonance circuit. The substrate has a planar conductor portion. An opening portion and a slit are formed in the conductor portion. The slit is connected to the opening. The coil antenna is mounted on the substrate so as to at least partially overlap the opening portion when viewed in a vertical direction orthogonal to the substrate. The coil antenna has a coil and a magnetic core. The magnetic core partially constitutes a magnetic circuit of the coil. The magnetic core is located in a region other than a specific region directly below the coil. The magnetic core has at least a central core. The central core is at least partially located inside the coil.

Description

Technical Field

[0001] The present invention relates to an antenna device having a substrate and a coil antenna. Background Art

[0002] like Fig.31 As shown in FIG. 1 , such an antenna device 900 is disclosed in Patent Document 1. The antenna device 900 can be used for communications such as NFC (Near field communication) and RFID (radio frequency identifier). The antenna device 900 includes a substrate 910, a first coil antenna (coil antenna) 930, and a second coil antenna (coil antenna) 940. Fig.32 As shown, a planar conductor (conductor portion) 922 is formed on the first main surface 920 of the substrate 910. The conductor portion 922 is formed with a first opening (opening portion) 9222, a second opening (opening portion) 9224, a first slit (slit) 9223, and a second slit (slit) 9225. The slit 9223 is connected to the opening portion 9222. The slit 9225 is connected to the opening portion 9224. Fig.31 and Fig.32 The coil antenna 930 is mounted on the substrate 910 in a manner that partially overlaps with the opening 9222 when viewed along the direction perpendicular to the substrate 910, that is, the Z direction. The coil antenna 940 is mounted on the substrate 910 in a manner that partially overlaps with the opening 9224 when viewed along the direction perpendicular to the substrate 910, that is, the Z direction. The coil antennas 930 and 940 each have a coil (not shown) and a laminate (not shown). Specifically, the coil has a winding axis in the direction perpendicular to the first main surface 920, that is, the Z direction, and the laminate is formed by laminating insulating substrate layers such as magnetic ferrite.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent document 1: Japanese Patent No. 6566184. Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In an antenna device such as antenna device 900 of Patent Document 1, further improvement of antenna characteristics is required.

[0008] Therefore, an object of the present invention is to provide an antenna device that achieves further improvement in antenna characteristics.

[0009] Solutions for solving problems

[0010] In a coil antenna in which the coil is completely embedded in the magnetic core, a closed magnetic circuit is formed by the magnetic core. The inventors of the present invention have noticed that in the case of an antenna device such as antenna device 900 formed by such a coil antenna, the magnetic flux generated by the coil passes through the closed magnetic circuit formed by the magnetic core, so the coupling between the current loop flowing through the outer periphery of the slit of the substrate and the coil antenna becomes weak. Therefore, the inventors of the present invention have proposed a structure in which the magnetic core is at least not located directly below the coil of the coil antenna, so that the antenna device has an open magnetic circuit through which the magnetic flux generated by the coil of the coil antenna passes. The inventors of the present invention have found that this new structure can enhance the coupling between the current loop flowing through the outer periphery of the slit of the substrate and the coil antenna. The present invention was completed based on this discovery.

[0011] In one aspect of the present invention, an antenna device is provided as a first antenna device.

[0012] The antenna device includes a substrate, a coil antenna, and a resonant circuit.

[0013] The substrate has a planar conductor portion.

[0014] An opening and a slit are formed in the conductor portion,

[0015] The conductor portion has a first path surrounding the opening portion and the slit.

[0016] The first path forms part of the resonant circuit,

[0017] The slit is connected to the opening,

[0018] The coil antenna is mounted on the substrate so as to at least partially overlap the opening when viewed in a vertical direction perpendicular to the substrate.

[0019] The coil antenna comprises a coil and a magnetic core.

[0020] The coil has a winding axis extending in the up-down direction.

[0021] The magnetic core partially constitutes the magnetic circuit of the coil,

[0022] The magnetic core is located in an area other than a specific area directly below the coil,

[0023] The magnetic core has at least a central core.

[0024] The core is at least partially located inside the coil.

[0025] Effects of the Invention

[0026] The antenna device of the present invention is configured as follows: the coil antenna is mounted on the substrate in such a manner that the coil antenna at least partially overlaps the opening portion when viewed in the up-down direction perpendicular to the substrate; the magnetic core is located in an area other than a specific area directly below the coil; the magnetic core has at least a center core; and the center core is at least partially located inside the coil. Thus, in the antenna device of the present invention, the coupling between the current loop flowing through the outer periphery of the slit of the substrate and the coil antenna is strengthened. That is, in the antenna device of the present invention, further improvement of the antenna characteristics is achieved.

[0027] By discussing the following description of the best mode while referring to the accompanying drawings, the objectives of the present invention can be accurately understood and its structure can be more completely understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a perspective view showing the antenna device according to the first embodiment of the present invention.

[0029] Figure 2 To express Figure 1 A top view of an antenna device.

[0030] Figure 3 It is represented along the AA line Figure 2 A cross-sectional view of a portion of an antenna device of FIG. 1 . The resin molded portion, the terminal, and the pad are omitted in the figure.

[0031] Figure 4 To express Figure 1 A three-dimensional diagram of a coil antenna included in the antenna device.

[0032] Figure 5 To express Figure 4 Side view of the coil antenna.

[0033] Figure 6 To express Figure 4 Top view of the coil antenna.

[0034] Figure 7 To express Figure 4 Front view of the coil antenna.

[0035] Figure 8 To express in Figure 4 A three-dimensional view of a coil antenna with the resin molded portion removed.

[0036] Fig. 9 To express Figure 8 Side view of the coil antenna.

[0037] Fig.10 To express Figure 8 Top view of the coil antenna.

[0038] Fig.11 To express Figure 8 Front view of the coil antenna.

[0039] Fig.12 To express Figure 2 A top view of a substrate included in the antenna device.

[0040] Fig.13 To express Figure 4 A stereoscopic view of a first variation of the coil antenna.

[0041] Fig.14 To express Fig.13 Side view of the coil antenna.

[0042] Fig.15 To express Fig.13 Top view of the coil antenna.

[0043] Fig.16 To express Fig.13 Front view of the coil antenna.

[0044] Fig.17 To express in Fig.13 A three-dimensional view of a coil antenna with the resin molded portion removed.

[0045] Fig.18 To express Fig.17 Side view of the coil antenna.

[0046] Fig.19 To express Fig.17 Top view of the coil antenna.

[0047] Fig. 20 is represented along line BB Fig.19 A cross-sectional view of a coil antenna.

[0048] Fig.21 To express Fig.17 Front view of the coil antenna.

[0049] Fig. 22 To express Figure 4 A stereoscopic view of a second variation of the coil antenna.

[0050] Fig.23 To express Fig. 22 Side view of the coil antenna.

[0051] Fig.24 To express Fig. 22 Top view of the coil antenna.

[0052] Fig.25 It is represented along the CC line Fig.24A cross-sectional view of a coil antenna of FIG. 1 is shown in FIG. 1 . The resin molded portion is omitted in the figure.

[0053] Fig.26 To express Fig. 22 Front view of the coil antenna.

[0054] Fig. 27 It is a plan view showing an antenna device according to a second embodiment of the present invention.

[0055] Fig.28 It is a plan view showing an antenna device according to a third embodiment of the present invention.

[0056] Fig.29 It is a plan view showing an antenna device according to a fourth embodiment of the present invention.

[0057] Fig.30 It is a plan view showing an antenna device according to a fifth embodiment of the present invention.

[0058] Fig.31 1 is a plan view showing the antenna device of Patent Document 1.

[0059] Fig.32 To express Fig.31 A top view of a substrate included in the antenna device. DETAILED DESCRIPTION

[0060] The present invention can be implemented in various ways and in various forms. As an example of the present invention, a specific embodiment shown in the accompanying drawings is described in detail below. The accompanying drawings and embodiments do not limit the present invention to the specific embodiments disclosed herein, and all modifications, equivalents, and alternatives within the scope of the attached claims are included in the object of the present invention.

[0061] (First Embodiment)

[0062] like Figure 1 As shown, the antenna device 10 according to the first embodiment of the present invention includes a substrate 500 , a coil antenna 100 , and a resonant circuit.

[0063] like Fig.12 As shown in FIG. 1 , the substrate 500 of the present embodiment has a planar conductor portion 510. More specifically, the conductor portion 510 is a ground conductor. Specifically, the substrate 500 is a substrate in which a conductive layer as the conductor portion 510 is stacked on an insulating substrate such as a glass epoxy substrate.

[0064] like Fig.12 As shown, an opening 512 and a slit 514 are formed in the conductor part 510. The conductor part 510 has a first path surrounding the opening 512 and the slit 514. The first path constitutes a part of the resonance circuit.

[0065] Reference Fig.12 , the opening 512 of this embodiment is a portion that does not have a conductive pattern on the substrate 500. The opening 512 has a substantially circular outer edge when the substrate 500 is viewed from above in the up-down direction. In addition, the present invention is not limited thereto, and the opening 512 may also have an outer edge in a shape other than a substantially circular shape. In this embodiment, the up-down direction is the Z direction. In addition, the upper direction is the +Z direction, and the lower direction is the -Z direction.

[0066] like Fig.12 As shown, the slit 514 of this embodiment is a portion that does not have a conductive pattern on the substrate 500, similarly to the opening 512. The slit 514 is connected to the opening 512. The slit 514 extends from the opening 512. In this embodiment, the number of slits 514 extending from the opening 512 is one. In addition, the present invention is not limited to this, and a plurality of slits 514 may extend from the opening 512. The slit 514 is not connected to the outside of the conductor part 510 in a plane orthogonal to the up-down direction. The slit 514 has a predetermined portion PP. The slit 514 has a first portion 5142 and a second portion 5144.

[0067] like Fig.12 As shown, the width of the slit 514 is smaller than the diameter of the opening 512. In addition, the present invention is not limited thereto, and the width of the slit 514 may be the same as the diameter of the opening 512, or the width of the slit 514 may be larger than the diameter of the opening 512. In addition, when the width of the slit 514 is increased, the current loop formed around the slit 514 becomes larger, so the communication distance of the antenna device 10 increases.

[0068] like Fig.12 As shown, the first portion 5142 extends from the opening 512 to the right in the left-right direction. In this embodiment, the left-right direction is the Y direction. Here, the right is the +Y direction and the left is the -Y direction.

[0069] like Fig.12 As shown, the second portion 5144 extends from the first portion 5142 in a direction intersecting the first portion 5142. The second portion 5144 extends from the right end of the first portion 5142 to the rear in the front-rear direction. In this embodiment, the front-rear direction is the X direction. Here, the front is the +X direction and the rear is the -X direction. The second portion 5144 is the prescribed portion PP.

[0070] like Fig.12 As shown, the slit 514 also has a third portion 5146 .

[0071] like Fig.12As shown, the third portion 5146 extends from the second portion 5144 in a direction intersecting the second portion 5144. The third portion 5146 extends from the rear end of the second portion 5144 to the left in the left-right direction.

[0072] like Fig.12 As shown, substrate 500 has an edge 520 .

[0073] like Fig.12 As shown, the edge 520 defines the outer edge of the substrate 500. That is, the edge 520 defines the outer edge of the substrate 500 in a direction perpendicular to the up-down direction. After extending from the opening 512 toward the edge 520, the slit 514 is bent and extends along the edge 520, and further bent to extend away from the edge 520. The slit 514 does not reach the edge 520. The first portion 5142 extends from the opening 512 toward the edge 520. The prescribed portion PP extends along the edge 520 near the edge 520. Thus, a large area on the substrate 500 where electronic components can be arranged can be ensured, and the length of the slit 514 can be increased, so that the current loop formed around the slit 514 can be increased to obtain the communication distance of the antenna device 10.

[0074] As described above, the slit 514 extends from the opening 512 toward the edge 520, then bends and extends along the edge 520, and further bends and extends away from the edge 520. In addition, as described above, the slit 514 does not reach the edge 520, and the slit 514 does not communicate with the outside of the conductor part 510 in the plane perpendicular to the up-down direction. In addition, the present invention is not limited to this, and the slit 514 may extend toward the edge 520 or may reach the edge 520. That is, the slit 514 may also communicate with the outside of the conductor part 510 in the plane perpendicular to the up-down direction.

[0075] Reference Figure 2 and Fig.12 The coil antenna 100 is mounted on the substrate 500 so as to at least partially overlap the opening 512 when viewed in the up-down direction perpendicular to the substrate 500. The coil antenna 100 is surface mounted on the substrate 500. That is, the coil antenna 100 is a surface mounted antenna.

[0076] like Figure 3 As shown, the coil antenna 100 has a coil 200 and a magnetic core 300 .

[0077] like Figure 3As shown, the coil 200 of this embodiment has a winding axis AX extending in the up-down direction. The coil 200 is formed by winding a flat coated electric wire by an oblong winding method. In addition, the present invention is not limited to this, and the coil 200 may also be formed by winding a coated round wire, and the material, cross-sectional shape, and winding method of the conductor are not limited to this embodiment. The coil 200 is circular when observed along the up-down direction. In addition, the present invention is not limited to this, and the coil 200 may also have a shape other than a circular shape. The coil 200 has an upper end 210 and a lower end 220 in the up-down direction. The coil 200 has an inner periphery 240 and an outer periphery 230.

[0078] Reference Figure 3 and Fig.12 , when the cross-sectional area of ​​the inner periphery 240 of the coil 200 is S1 and the area of ​​the opening 512 is S2, 1≤S2 / S1≤2 is satisfied. Thus, the coupling coefficient between the coil antenna 100 and the slit 514 can be maximized, and the coil antenna 100 is more easily coupled to the magnetic field of the current (current loop) around the opening 512 and the slit 514 in the conductor 510.

[0079] Reference Figure 3 , the magnetic core 300 of the present embodiment is a cast core. More specifically, the magnetic core 300 is a composite magnet in which soft magnetic alloy powders formed of iron-based alloys, ferrites, etc. are dispersed and arranged inside a solidified adhesive. That is, the magnetic core 300 is formed by solidifying a slurry containing soft magnetic alloy powders and an adhesive, etc. In addition, the magnetic core 300 is not limited to this and can be manufactured by any manufacturing method. The magnetic core 300 partially constitutes the magnetic circuit of the coil 200. The magnetic core 300 is located in an area other than a specific area SR directly below the coil 200. That is, the magnetic core 300 does not have a portion directly below the coil 200. In addition, the specific area SR is an area hidden under the coil 200 when the coil 200 monomer is observed from above. The specific area SR is located below the lower end 220 of the coil 200 in the up and down direction. The specific area SR is located outside the inner circumference 240 of the coil 200 in the radial direction orthogonal to the winding axis AX. The specific region SR is located inside the outer periphery 230 of the coil 200 in the radial direction orthogonal to the winding axis AX. The magnetic core 300 has at least a center core 310 .

[0080] Reference Figure 3 The core 310 of this embodiment has a cylindrical shape extending in the vertical direction. The core 310 is at least partially located inside the coil 200. The central axis of the cylindrical shape of the core 310 is consistent with the winding axis AX of the coil 200. The size of the cross section of the core 310 perpendicular to the vertical direction is smaller than the diameter of the opening 512. The projection of the core 310 on the substrate 50 in the vertical direction is located inside the opening 512.

[0081] As described above, the coil antenna 100 is mounted on the substrate 500 in such a manner that the coil antenna 100 at least partially overlaps the opening 512 when viewed in the vertical direction perpendicular to the substrate 500, the magnetic core 300 is located in a region other than the specific region SR directly below the coil 200, and the magnetic core 300 has at least the center core 310, and the center core 310 is at least partially located inside the coil 200. As a result, in the antenna device 10 of the present embodiment, a part of the magnetic flux of the coil 200 is directed toward the opening 512 of the substrate 500, and the coil antenna 100 is easily magnetically coupled with the current (current loop) surrounding the opening 512 and the slit 514 in the conductor portion 510. That is, in the antenna device 10 of the present embodiment, the coupling between the current loop flowing through the outer periphery of the slit 514 of the substrate 500 and the coil antenna 100 is strengthened, and the antenna characteristics are further improved.

[0082] like Figure 3 As shown in FIG. 1 , the core 310 extends further downward than the lower end 220 of the coil 200 in the vertical direction. As a result, in the antenna device 10 of the present embodiment, a portion of the magnetic flux of the coil 200 is further directed toward the opening 512 of the substrate 500, and the coil antenna 100 is easily coupled to the magnetic field of the current (current loop) around the opening 512 and the slit 514 in the conductor portion 510. That is, in the antenna device 10 of the present embodiment, the current flowing through the slit 514 (see FIG. 1 ) of the substrate 500 is Fig.12 )'s peripheral current loop is further coupled with the coil antenna 100, thereby further improving the antenna characteristics.

[0083] like Figure 3 As shown, the core 310 extends upward from the upper end 210 of the coil 200 in the vertical direction.

[0084] like Figure 3 As shown, the magnetic core 300 also has an upper portion 320 .

[0085] like Figure 3 As shown, the upper portion 320 extends from the core 310 toward the outer periphery 230 of the coil 200. In the radial direction orthogonal to the central axis of the cylindrical shape of the core 310, the outer end of the upper portion 320 is located outside the outer periphery 230 of the coil 200. The upper portion 320 overlaps the coil 200 when viewed from the top and bottom. Thus, the magnetic flux of the coil 200 that passes through the core 310 and flows to the upper side of the magnetic core 300 can be effectively flowed toward the outer periphery 230 of the coil 200.

[0086] like Figure 7 As shown, the coil antenna 100 further has two terminals 400 .

[0087] Reference Figure 8The terminals 400 of this embodiment are respectively mounted at the ends of the coil 200. In addition, the present invention is not limited thereto, and the terminal 400 may also be formed by extending the end of the coil 200. The terminal 400 defines the lower end of the coil antenna 100. The terminal 400 is connected to a communication circuit (not shown) via a pad (not shown) of the substrate 500.

[0088] like Figure 4 As shown, the coil antenna 100 has a resin molded portion 700 .

[0089] Reference Figure 5 and Fig. 9 , the resin molded part 700 covers the coil 200. Figure 3 , Figure 5 and Figure 7 , the specific region SR is filled with the resin mold part 700 . That is, the resin mold part 700 is located directly below the coil 200 .

[0090] like Figure 2 As shown, the antenna device 10 further includes a capacitor 600 which forms a part of the resonant circuit.

[0091] Reference Fig.12 , the capacitor 600 forms a current loop path together with the first path around the opening 512 and the slit 514 in the conductor part 510. That is, the capacitor 600 forms a resonant circuit together with the first path around the opening 512 and the slit 514 in the conductor part 510. The resonant frequency of the resonant circuit is the communication frequency band of the antenna device 10. The capacitor 600 is mounted on the area between the edge 520 and the slit 514 on the substrate 500. In more detail, the capacitor 600 is mounted on the area between the edge 520 and the second portion 5144 on the substrate 500. In addition, the capacitor 600 is not limited to being arranged at the above-mentioned position, and the capacitor 600 can be arranged at any position of the conductor part 510 as long as it forms a current loop path with the first path around the opening 512 and the slit 514 in the conductor part 510.

[0092] The structure of the coil antenna 100 is not limited to the above-described structure, and for example, the following modifications are possible.

[0093] (First Modification)

[0094] Reference Fig.13 and Fig. 20 The coil antenna 100A according to the first modification of the present invention includes a coil 200 and a magnetic core 300A. The coil 200 of this modification is the same as the coil 200 of the above-mentioned embodiment, and detailed description thereof will be omitted.

[0095] Reference Fig. 20, the magnetic core 300A of this variation is a cast core like the magnetic core 300 described above. The magnetic core 300A partially constitutes the magnetic circuit of the coil 200. The magnetic core 300A is located in an area other than a specific area SR directly below the coil 200. In addition, the specific area SR is an area hidden under the coil 200 when the coil 200 is viewed from above. The specific area SR is located below the lower end 220 of the coil 200 in the up and down direction. The specific area SR is located outside the inner circumference 240 of the coil 200 in a radial direction orthogonal to the winding axis AX. The specific area SR is located inside the outer circumference 230 of the coil 200 in a radial direction orthogonal to the winding axis AX. The magnetic core 300A has a center core 310.

[0096] Reference Fig.17 and Fig. 20 The core 310 of this modification example has a cylindrical shape extending in the up-down direction. The core 310 is partially located inside the coil 200 .

[0097] like Fig. 20 As shown, the core 310 extends to a lower position than the lower end 220 of the coil 200 in the vertical direction. The core 310 extends to a higher position than the upper end 210 of the coil 200 in the vertical direction.

[0098] Reference Fig.10 and Fig. 20 , the magnetic core 300A is different from the magnetic core 300 and does not have the upper portion 320 .

[0099] like Fig.13 As shown, the coil antenna 100A has a resin molded portion 700A.

[0100] Reference Fig.14 and Fig.18 The resin molded portion 700A covers the coil 200. Fig. 20 , the specific region SR is filled with the resin molded portion 700A. That is, the resin molded portion 700A is located directly below the coil 200. Fig.15 , the upper end of the core 310 is not covered by the resin mold part 700A.

[0101] Also in an antenna device (not shown) in which the coil antenna 100A according to this modification is mounted on a substrate 500 , the same effects as those of the above-described embodiment can be obtained.

[0102] (Second Modification)

[0103] Reference Fig. 22 and Fig.25 The coil antenna 100B of the second modification of the present invention includes a coil 200 and a magnetic core 300B. The coil 200 of this modification is the same as the coil 200 of the above-mentioned embodiment, and detailed description thereof will be omitted.

[0104] Reference Fig.25 , the magnetic core 300B of this variation is a cast core like the magnetic core 300 described above. The magnetic core 300B partially constitutes the magnetic circuit of the coil 200. The magnetic core 300B is located in an area other than a specific area SR directly below the coil 200. In addition, the specific area SR is an area hidden under the coil 200 when the coil 200 is viewed from above. The specific area SR is located below the lower end 220 of the coil 200 in the up and down direction. The specific area SR is located outside the inner circumference 240 of the coil 200 in a radial direction orthogonal to the winding axis AX. The specific area SR is located inside the outer circumference 230 of the coil 200 in a radial direction orthogonal to the winding axis AX. The magnetic core 300B has at least a center core 310.

[0105] Reference Fig.25 The core 310 of this modification example has a cylindrical shape extending in the up-down direction. The core 310 is at least partially located inside the coil 200 .

[0106] like Fig.25 As shown, the core 310 extends to a lower position than the lower end 220 of the coil 200 in the vertical direction. The core 310 extends to a higher position than the upper end 210 of the coil 200 in the vertical direction.

[0107] like Fig.25 As shown in FIG. 1 , the magnetic core 300B further includes an upper portion 320B. The upper portion 320B of this modification is the same as the upper portion 320 of the above-described embodiment, and detailed description thereof will be omitted.

[0108] like Fig.25 As shown, the magnetic core 300B also has a side portion 340 .

[0109] like Fig.25 As shown, the side portion 340 of this modified example is located outside the coil 200 in a plane orthogonal to the up-down direction. The side portion 340 extends from the upper portion 320B to the lower side in the up-down direction. As a result, the magnetic flux of the coil 200 passing through the upper portion 320B can effectively flow toward the lower side of the coil 200. The side portion 340 covers the entire periphery 230 of the coil 200. In addition, the present invention is not limited to this, and the side portion 340 can also be configured to cover only a portion of the periphery 230 of the coil 200.

[0110] Reference Fig.25 The coil antenna 100B has a resin molded portion (not shown).

[0111] Reference Fig.25 The resin molded part of this modification covers the coil 200 . The specific region SR is filled with the resin molded part. That is, the resin molded part is located directly below the coil 200 .

[0112] Also in an antenna device (not shown) in which the coil antenna 100B according to this modification is mounted on a substrate 500 , the same effects as those of the above-described embodiment can be obtained.

[0113] (Second Embodiment)

[0114] like Fig. 27 As shown, the antenna device 10C of the second embodiment of the present invention includes a substrate 500C, a coil antenna 100, and a resonant circuit. The coil antenna 100 of this embodiment has the same structure as the coil antenna 100 of the first embodiment, and detailed description thereof is omitted. In addition, hereinafter, the orientation and direction of this embodiment are expressed in the same manner as in the first embodiment.

[0115] like Fig. 27 As shown in FIG. 1 , the substrate 500C of the present embodiment has a planar conductor portion 510C. More specifically, the conductor portion 510C is a ground conductor. Specifically, the substrate 500C is a substrate in which a conductive layer serving as the conductor portion 510C is stacked on an insulating substrate such as a glass epoxy substrate.

[0116] like Fig. 27 As shown in FIG. 1 , an opening 512 and a slit 514C are formed in the conductor part 510C. The opening 512 of this embodiment has the same structure as the opening 512 of the first embodiment, and detailed description thereof is omitted. The conductor part 510C has a first path surrounding the opening 512 and the slit 514C. The first path constitutes a part of the resonant circuit.

[0117] like Fig. 27 As shown, the slit 514C of this embodiment is a portion that does not have a conductive pattern on the substrate 500C, similarly to the opening 512. The slit 514C is connected to the opening 512. The slit 514C extends from the opening 512. The slit 514C is not connected to the outside of the conductor part 510C in a plane perpendicular to the up-down direction. The slit 514C has a predetermined portion PP. The slit 514C has a first portion 5142 and a second portion 5144.

[0118] like Fig. 27 As shown, the width of the slit 514C is smaller than the diameter of the opening 512. In addition, the present invention is not limited thereto, and the width of the slit 514C may be the same as the diameter of the opening 512, or the width of the slit 514C may be larger than the diameter of the opening 512. In addition, when the width of the slit 514C is increased, the current loop formed around the slit 514C becomes larger, so the communication distance of the antenna device 10C increases.

[0119] like Fig. 27 As shown, the first portion 5142 extends from the opening 512 to the right in the left-right direction.

[0120] like Fig. 27 As shown, the second portion 5144 extends from the first portion 5142 in a direction intersecting the first portion 5142. The second portion 5144 extends rearward in the front-rear direction from the right end of the first portion 5142. The second portion 5144 is a predetermined portion PP.

[0121] Reference Figure 2 and Fig. 27 , the slit 514C is different from the slit 514 of the first embodiment and does not have the third portion 5146 .

[0122] like Fig. 27 As shown, substrate 500C has an edge 520 .

[0123] like Fig. 27 As shown, the edge 520 of the present embodiment defines the outer edge of the substrate 500C. That is, the edge 520 defines the outer edge of the substrate 500C in a direction perpendicular to the up-down direction. The first portion 5142 extends from the opening 512 toward the edge 520. The prescribed portion PP extends along the edge 520 near the edge 520. Thus, a large area where electronic components can be arranged can be ensured on the substrate 500C, and the length of the slit 514C can be increased, so that the current loop formed around the slit 514C can be increased to obtain the communication distance of the antenna device 10C.

[0124] like Fig. 27 As shown, the antenna device 10C further includes a capacitor 600 constituting a part of the resonance circuit.

[0125] Reference Fig. 27 The capacitor 600 and the first path around the opening 512 and the slit 514C in the conductor part 510C together form a current loop path. That is, the capacitor 600 and the first path around the opening 512 and the slit 514C in the conductor part 510C together form a resonant circuit. The resonant frequency of the resonant circuit is the communication frequency band of the antenna device 10C. Fig. 27 As shown, the capacitor 600 is mounted on the region between the edge 520 and the slit 514C on the substrate 500C. More specifically, the capacitor 600 is mounted on the region between the edge 520 and the second portion 5144 on the substrate 500C. In addition, the capacitor 600 is not limited to being arranged at the above-mentioned position, and the capacitor 600 may be arranged at any position of the conductor portion 510C as long as it forms a current loop path with the first path surrounding the opening 512 in the conductor portion 510C and the slit 514C.

[0126] (Third Embodiment)

[0127] like Fig.28As shown, the antenna device 10D of the third embodiment of the present invention includes a substrate 500D, a coil antenna 100, and a resonant circuit. The coil antenna 100 of this embodiment has the same structure as the coil antenna 100 of the first embodiment, and detailed description thereof is omitted. In addition, hereinafter, the orientation and direction of this embodiment are expressed in the same manner as in the first embodiment.

[0128] like Fig.28 As shown in FIG. 1 , the substrate 500D of the present embodiment has a planar conductor portion 510D. More specifically, the conductor portion 510D is a ground conductor. Specifically, the substrate 500D is a substrate having an electrical conductor layer as the conductor portion 510D stacked on an insulating substrate such as a glass epoxy substrate.

[0129] like Fig.28 As shown, the conductor portion 510D is formed with an opening 512 and a slit 514D. The conductor portion 510D has a first path surrounding the opening 512 and the slit 514D. The first path constitutes a part of the resonant circuit. The opening 512 of this embodiment has the same structure as the opening 512 of the first embodiment, and detailed description thereof is omitted.

[0130] like Fig.28 As shown, the slit 514D of this embodiment is a portion that does not have a conductive pattern on the substrate 500D, similarly to the opening 512. The slit 514D is connected to the opening 512. The slit 514D extends from the opening 512. The slit 514D extends in the front-back direction from the opening 512. The slit 514D is not connected to the outside of the conductor part 510D in a plane orthogonal to the up-down direction.

[0131] like Fig.28 As shown, the width of the slit 514D is smaller than the diameter of the opening 512. In addition, the present invention is not limited thereto, and the width of the slit 514D may be the same as the diameter of the opening 512, or the width of the slit 514D may be larger than the diameter of the opening 512. In addition, when the width of the slit 514D is increased, the current loop formed around the slit 514D becomes larger, so the communication distance of the antenna device 10D increases.

[0132] like Fig.28 As shown, an additional opening portion 516 is further formed in the conductor portion 510D.

[0133] like Fig.28As shown, the additional opening portion 516 of the present embodiment is a hole that passes through the substrate 500D. That is, the additional opening portion 516 passes through the substrate 500D in the up-down direction. In addition, the present invention is not limited to this, and the additional opening portion 516 may also be a portion that does not have a conductive pattern on the substrate 500D, similar to the opening portion 512. The additional opening portion 516 is located in front of the opening portion 512 in the front-to-back direction. In a plane orthogonal to the up-down direction, the additional opening portion 516 is larger than the opening portion 512. The conductor portion 510D has a second path surrounding the additional opening portion 516. The second path constitutes a part of the resonant circuit. The slit 514D is connected to both the opening portion 512 and the additional opening portion 516.

[0134] like Fig.28 As shown, an additional slit 518 is formed in the conductor portion 510D.

[0135] like Fig.28 As shown, the additional slit 518 of this embodiment is a portion that does not have a conductive pattern on the substrate 500D, similarly to the opening 512. The additional slit 518 is connected to the opening 512. The additional slit 518 extends from the opening 512. The additional slit 518 extends in the left-right direction. The additional slit 518 is connected to the outside of the conductor part 510D in a plane perpendicular to the up-down direction. The opening 512, the slit 514D, the additional opening 516, and the additional slit 518 are all connected to each other.

[0136] like Fig.28 As shown, the width of the additional slit 518 is smaller than the diameter of the opening 512. In addition, the present invention is not limited thereto, and the width of the additional slit 518 may be the same as the diameter of the opening 512, or the width of the additional slit 518 may be larger than the diameter of the opening 512.

[0137] like Fig.28 As shown, substrate 500D has an edge 520 .

[0138] like Fig.28 As shown, the edge 520 defines the outer edge of the substrate 500D. That is, the edge 520 defines the outer edge of the substrate 500D in a direction perpendicular to the vertical direction. The slit 514D does not reach the edge 520. The additional slit 518 extends toward the edge 520. That is, the additional slit 518 extends from the opening 512 toward the edge 520. The additional slit 518 reaches the edge 520.

[0139] Reference Fig.28The coil antenna 100 is mounted on the substrate 500D so as to at least partially overlap the opening 512 when viewed in the up-down direction orthogonal to the substrate 500D. The coil antenna 100 is mounted on the substrate 500D so as not to overlap the additional opening 516 when viewed in the up-down direction. The coil antenna 100 is surface mounted on the substrate 500D.

[0140] like Fig.28 As shown, the antenna device 10D further includes a capacitor 600D constituting a part of the resonant circuit.

[0141] Reference Fig.28 , the capacitor 600D forms a current loop path together with the path around the opening 512, the additional opening 516, the slit 514D, and the additional slit 518 in the conductor part 510D. That is, the capacitor 600D forms a resonant circuit together with the path around the opening 512, the additional opening 516, the slit 514D, and the additional slit 518 in the conductor part 510D. The resonant frequency of the resonant circuit is the communication frequency band of the antenna device 10D. The capacitor 600D is mounted on the substrate 500D in a manner that crosses the additional slit 518. In addition, the capacitor 600D is not limited to being arranged at the above-mentioned position, and the capacitor 600D can also be arranged at any position of the conductor part 510D as long as it forms a current loop path with the path around the opening 512, the additional opening 516, the slit 514D, and the additional slit 518 in the conductor part 510D.

[0142] (Fourth Embodiment)

[0143] like Fig.29 As shown, the antenna device 10E of the fourth embodiment of the present invention includes a substrate 500E, a coil antenna 100, and a resonant circuit. The coil antenna 100 of this embodiment has the same structure as the coil antenna 100 of the first embodiment, and detailed description is omitted. In addition, the orientation and direction of this embodiment are described in the same way as the first embodiment.

[0144] like Fig.29 As shown in FIG. 1 , the substrate 500E of the present embodiment has a planar conductor portion 510E. More specifically, the conductor portion 510E is a ground conductor. Specifically, the substrate 500E is a substrate in which a conductive layer serving as the conductor portion 510E is stacked on an insulating substrate such as a glass epoxy substrate.

[0145] like Fig.29As shown, the conductor part 510E is formed with an opening 512 and a slit 514E. The conductor part 510E has a first path surrounding the opening 512 and the slit 514E. The first path constitutes a part of the resonant circuit. The opening 512 of this embodiment has the same structure as the opening 512 of the first embodiment, and detailed description is omitted.

[0146] like Fig.29 As shown, the slit 514E of this embodiment is a portion that does not have a conductive pattern on the substrate 500E, similarly to the opening 512. The slit 514E is connected to the opening 512. The slit 514E extends from the opening 512 to the left in the left-right direction and then extends to the rear in the front-rear direction. The slit 514E extends from the opening 512. The slit 514E is not connected to the outside of the conductor part 510E in a plane perpendicular to the up-down direction.

[0147] like Fig.29 As shown, the width of the slit 514E is smaller than the diameter of the opening 512. In addition, the present invention is not limited thereto, and the width of the slit 514E may be the same as the diameter of the opening 512, or the width of the slit 514E may be larger than the diameter of the opening 512. In addition, when the width of the slit 514E is increased, the current loop formed around the slit 514E becomes larger, so the communication distance of the antenna device 10E increases.

[0148] like Fig.29 As shown, an additional opening portion 516 is further formed in the conductor portion 510E.

[0149] like Fig.29 As shown, the additional opening portion 516 of the present embodiment is a hole that passes through the substrate 500E. That is, the additional opening portion 516 passes through the substrate 500E in the up-down direction. In addition, the present invention is not limited to this, and the additional opening portion 516 can also be a portion that does not have a conductive pattern on the substrate 500E, similar to the opening portion 512. The additional opening portion 516 is located behind the opening portion 512 in the front-to-back direction. In a plane orthogonal to the up-down direction, the additional opening portion 516 is larger than the opening portion 512. The conductor portion 510E has a second path surrounding the additional opening portion 516. The second path constitutes a part of the resonant circuit. The slit 514E is connected to both the opening portion 512 and the additional opening portion 516.

[0150] like Fig.29 As shown, an additional slit 518 is formed in the conductor portion 510E.

[0151] like Fig.29As shown, the additional slit 518 of this embodiment is a portion that does not have a conductive pattern on the substrate 500E, similarly to the opening 512. The additional slit 518 is connected to the additional opening 516. The additional slit 518 extends from the additional opening 516. The additional slit 518 extends in the left-right direction. The additional slit 518 is connected to the outside of the conductor part 510E in a plane perpendicular to the up-down direction. The opening 512, the slit 514E, the additional opening 516, and the additional slit 518 are all connected to each other.

[0152] like Fig.29 As shown, substrate 500E has an edge 520 .

[0153] like Fig.29 As shown, the edge 520 defines the outer edge of the substrate 500E. That is, the edge 520 defines the outer edge of the substrate 500E in a direction perpendicular to the up-down direction. The slit 514E does not reach the edge 520. The additional slit 518 extends toward the edge 520. That is, the additional slit 518 extends from the additional opening 516 toward the edge 520. The additional slit 518 reaches the edge 520.

[0154] Reference Fig.29 The coil antenna 100 is mounted on the substrate 500E in such a manner that the coil antenna 100 at least partially overlaps with the opening 512 when viewed in the up-down direction orthogonal to the substrate 500E. The coil antenna 100 is mounted on the substrate 500E in such a manner that the coil antenna 100 does not overlap with the additional opening 516 when viewed in the up-down direction. The coil antenna 100 is surface mounted on the substrate 500E.

[0155] like Fig.29 As shown, the antenna device 10E further includes a capacitor 600E constituting a part of the resonant circuit.

[0156] Reference Fig.29 , the capacitor 600E and the path around the opening 512, the additional opening 516, the slit 514E, and the additional slit 518 in the conductor part 510E together constitute a current loop path. That is, the capacitor 600E and the path around the opening 512, the additional opening 516, the slit 514E, and the additional slit 518 in the conductor part 510E together constitute a resonant circuit. The resonant frequency of the resonant circuit is the communication frequency band of the antenna device 10E. The capacitor 600E is mounted on the substrate 500E in a manner that crosses the additional slit 518. In addition, the capacitor 600E is not limited to being arranged at the above-mentioned position, and the capacitor 600E can also be arranged at any position of the conductor part 510E as long as it forms a current loop path with the path around the opening 512, the additional opening 516, the slit 514E, and the additional slit 518 in the conductor part 510E.

[0157] (Fifth Embodiment)

[0158] like Fig.30 As shown, the antenna device 10F of the fifth embodiment of the present invention includes a substrate 500F, a coil antenna 100, and a resonant circuit. The coil antenna 100 of this embodiment has the same structure as the coil antenna 100 of the first embodiment, and detailed description thereof is omitted. In addition, hereinafter, the orientation and direction of this embodiment are expressed in the same manner as in the first embodiment.

[0159] like Fig.30 As shown in FIG. 1 , the substrate 500F of the present embodiment has a planar conductor portion 510F. More specifically, the conductor portion 510F is a ground conductor. Specifically, the substrate 500F is a substrate in which a conductive layer serving as the conductor portion 510F is stacked on an insulating substrate such as a glass epoxy substrate.

[0160] like Fig.30 As shown, the conductor part 510F is formed with an opening 512 and a slit 514F. The conductor part 510F has a first path surrounding the opening 512 and the slit 514F. The first path constitutes a part of the resonant circuit. The opening 512 of this embodiment has the same structure as the opening 512 of the first embodiment, and detailed description is omitted.

[0161] like Fig.30 As shown in FIG. 1 , the slit 514F of this embodiment is a portion that does not have a conductive pattern on the substrate 500F, similarly to the opening 512 . The slit 514F is connected to the opening 512 . The slit 514F extends from the opening 512 .

[0162] like Fig.30 As shown, the width of the slit 514F is smaller than the diameter of the opening 512. In addition, the present invention is not limited to this, and the width of the slit 514F may be the same as the diameter of the opening 512, or the width of the slit 514F may be larger than the diameter of the opening 512. In addition, when the width of the slit 514F is increased, the current loop formed around the slit 514F becomes larger, so the communication distance of the antenna device 10F increases.

[0163] like Fig.30 As shown, an additional opening portion 516 is further formed in the conductor portion 510F.

[0164] like Fig.30As shown, the additional opening portion 516 of the present embodiment is a hole that passes through the substrate 500F. That is, the additional opening portion 516 passes through the substrate 500F in the up-down direction. In addition, the present invention is not limited to this, and the additional opening portion 516 can also be a portion that does not have a conductive pattern on the substrate 500F like the opening portion 512. The additional opening portion 516 is located behind the opening portion 512 in the front-to-back direction. In a plane orthogonal to the up-down direction, the additional opening portion 516 is larger than the opening portion 512. The conductor portion 510F has a second path surrounding the additional opening portion 516. The second path constitutes a part of the resonant circuit. The slit 514F is connected to both the opening portion 512 and the additional opening portion 516.

[0165] like Fig.30 As shown, an additional slit 518 is formed in the conductor portion 510F.

[0166] like Fig.30 As shown, the additional slit 518 of this embodiment is a portion that does not have a conductive pattern on the substrate 500F, similarly to the opening 512. The additional slit 518 is connected to the slit 514F. The additional slit 518 extends from the slit 514F in the left-right direction. The additional slit 518 is connected to the outside of the conductor part 510F in a plane perpendicular to the up-down direction. In the plane perpendicular to the up-down direction, the slit 514F is connected to the outside of the conductor part 510F via the additional slit 518. The opening 512, the slit 514F, the additional opening 516, and the additional slit 518 are all connected to each other.

[0167] like Fig.30 As shown, the width of the additional slit 518 is the same as the width of the slit 514F. In addition, the present invention is not limited thereto, and the width of the additional slit 518 may be smaller than the width of the slit 514F, or may be larger than the width of the slit 514F.

[0168] like Fig.30 As shown, substrate 500F has an edge 520 .

[0169] like Fig.30 As shown, the edge 520 defines the outer edge of the substrate 500F. That is, the edge 520 defines the outer edge of the substrate 500F in a direction perpendicular to the vertical direction. The additional slit 518 extends toward the edge 520. That is, the additional slit 518 extends from the slit 514F toward the edge 520. The additional slit 518 reaches the edge 520.

[0170] Reference Fig.30The coil antenna 100 is mounted on the substrate 500F so as to at least partially overlap the opening 512 when viewed in the up-down direction perpendicular to the substrate 500F. The coil antenna 100 is mounted on the substrate 500F so as not to overlap the additional opening 516 when viewed in the up-down direction. The coil antenna 100 is surface mounted on the substrate 500F.

[0171] like Fig.30 As shown, the antenna device 10F further includes a capacitor 600F constituting a part of the resonance circuit.

[0172] Reference Fig.30 , the capacitor 600F and the path around the opening 512, the additional opening 516, the slit 514F, and the additional slit 518 in the conductor part 510F together constitute a current loop path. That is, the capacitor 600F and the path around the opening 512, the additional opening 516, the slit 514F, and the additional slit 518 in the conductor part 510F together constitute a resonant circuit. The resonant frequency of the resonant circuit is the communication frequency band of the antenna device 10F. The capacitor 600F is mounted on the substrate 500F in a manner that straddles the additional slit 518. In addition, the capacitor 600F is not limited to being arranged at the above-mentioned position, and the capacitor 600F can also be arranged at any position of the conductor part 510F as long as it forms a current loop path with the path around the opening 512, the additional opening 516, the slit 514F, and the additional slit 518 in the conductor part 510F.

[0173] As mentioned above, although the present invention was specifically described by giving the embodiment, the present invention is not limited to this, and various deformation|transformation and changes are possible.

[0174] In the antenna devices 10 and 10C of the first and second embodiments described above, a portion corresponding to the additional opening 516 of the antenna devices 10D, 10E, and 10F of the third, fourth, and fifth embodiments is not provided, but the present invention is not limited thereto. That is, in the antenna devices 10 and 10C, an additional opening 516 constituting a part of the slit 514 and 514C may be provided.

[0175] The present invention is based on Japanese Patent Application No. 2022-074955 filed with the Japan Patent Office on April 28, 2022, and Japanese Patent Application No. 2022-118580 filed with the Japan Patent Office on July 26, 2022, the contents of which are incorporated herein by reference as a part of this specification.

[0176] Although the best mode for carrying out the present invention has been described, it is obvious to those skilled in the art that the mode for carrying out the present invention can be modified without departing from the spirit of the present invention, and such mode for carrying out the present invention belongs to the scope of the present invention.

[0177] Description of Reference Numerals

[0178] 10, 10C, 10D, 10E, 10F: antenna device;

[0179] 100, 100A, 100B: coil antenna;

[0180] 200: coil;

[0181] 210: upper end;

[0182] 220: lower end;

[0183] 230: Periphery;

[0184] 240: Inner circumference;

[0185] 300, 300A, 300B: magnetic core;

[0186] 310: SMIC;

[0187] 320, 320B: upper part;

[0188] 340: side;

[0189] 400: terminal;

[0190] 500, 500C, 500D, 500E, 500F: base plate;

[0191] 510, 510C, 510D, 510E, 510F: conductor part;

[0192] 512: opening;

[0193] 514, 514C, 514D, 514E, 514F: slits;

[0194] 5142: first part;

[0195] 5144: Second part;

[0196] 5146: The third part;

[0197] 516: additional opening;

[0198] 518: additional slit;

[0199] 520: edge;

[0200] 600, 600D, 600E, 600F: capacitors;

[0201] 700, 700A: resin molding part;

[0202] AX: winding axis;

[0203] PP: prescribed part;

[0204] SR: Specific Region.

Claims

1. An antenna device comprising a substrate, a coil antenna, and a resonant circuit, wherein: The substrate has a planar conductor portion. An opening and a slit are formed in the conductor portion, The conductor portion has a first path surrounding the opening portion and the slit. The first path forms part of the resonant circuit, The slit is connected to the opening, The coil antenna is mounted on the substrate so as to at least partially overlap the opening when viewed in a vertical direction perpendicular to the substrate. The coil antenna comprises a coil and a magnetic core. The coil has a winding axis extending in the up-down direction. The magnetic core partially constitutes the magnetic circuit of the coil, The magnetic core is located in an area other than a specific area directly below the coil, The magnetic core has at least a central core. The core is at least partially located inside the coil.

2. The antenna device according to claim 1, wherein: The substrate has an edge, The slit extends toward the edge.

3. The antenna device according to claim 1, wherein: An additional opening is formed in the conductor portion. The conductor portion has a second path surrounding the additional opening portion, The second path forms part of the resonant circuit, The slit is connected to both the opening and the additional opening, The coil antenna is mounted on the substrate so as not to overlap with the additional opening when viewed in the up-down direction.

4. The antenna device according to claim 3, wherein: The substrate has an edge, An additional slit is also formed in the conductor portion, The additional slit extends toward the edge, The antenna device further comprises a capacitor forming part of the resonant circuit, The capacitor is mounted on the substrate in such a manner as to straddle the additional slit.

5. The antenna device according to claim 4, wherein: The opening, the slit, the additional opening, and the additional slit are all connected to each other.

6. The antenna device according to claim 1, wherein: The coil has a lower end in the up-down direction, The core extends below the lower end in the up-down direction.

7. The antenna device according to claim 1, wherein: The coil has an upper end in the up-down direction, The core extends above the upper end in the up-down direction.

8. The antenna device according to claim 7, wherein: The coil has an outer periphery, The magnetic core also has an upper portion, The upper portion extends from the core toward the periphery, The upper portion overlaps the coil when viewed from the up-down direction.

9. The antenna device according to claim 8, wherein: The magnetic core also has a side portion, The side portion is located outside the coil in a plane perpendicular to the up-down direction, The side portion extends from the upper portion downward in the up-down direction.

10. The antenna device according to claim 1, wherein: The substrate has an edge, The slit has a predetermined position, The predetermined portion extends along the edge in the vicinity of the edge.

11. The antenna device according to claim 10, wherein: The antenna device further comprises a capacitor forming part of the resonant circuit, The capacitor is mounted on the substrate in a region between the edge and the slit.

12. The antenna device according to claim 10, wherein: The slit has a first portion and a second portion, The first portion extends from the opening toward the edge, The second portion extends from the first portion in a direction intersecting the first portion, The second portion is the predetermined portion.

13. The antenna device according to claim 12, wherein: The slit also has a third portion, The third portion extends from the second portion in a direction intersecting the second portion.

14. The antenna device according to claim 1, wherein: The coil has an inner circumference, When the cross-sectional area of ​​the inner circumference of the coil is denoted as S1 and the area of ​​the opening is denoted as S2, 1≤S2 / S1≤2 is satisfied.

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