Antenna device and electronic device

Abstract

This disclosure provides an antenna device and electronic device capable of miniaturization and achieving the desired radiation efficiency. The antenna device (100) of this disclosure includes: a substrate (20); and a first antenna and a second antenna formed on the substrate (20). A grounding region (20b) includes: a region (20b1) having a length (D2) in the Y direction orthogonal to the X direction; and a region (20b2) having a length (D3) longer than the length (D2). In the case where the substrate (20) is divided in the X direction by an electromagnetic field coupling element (10) into a first side (20c) for the formation of the first antenna element (41) and the second antenna element (42) and a second side (20d) opposite to the first side (20c), the region (20b2) is provided on the second side (20d) of the substrate (20), and a cable (40) connecting the power supply circuit (30) to the first antenna or the second antenna is fixed to the region (20b2).

Description

Technical Field

[0001] This disclosure relates to antenna devices and electronic equipment. Background Technology

[0002] In recent years, electronic devices used for communication have encountered situations where they need to operate in multiple frequency bands. Therefore, such electronic devices include antenna devices that couple two antennas (radiating elements) to broaden the usable frequency band. For example, Patent Document 1 shows an antenna device that couples a powered antenna and a non-powered antenna using an electromagnetic field coupling element.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6614363 Utility Model Content

[0006] Problems to be solved by utility models

[0007] However, in the case of forming an antenna device with two antennas mounted on a substrate, the radiation efficiency may be degraded due to the positional relationship between the two radiating elements and the grounding area. On the other hand, since the antenna device is assembled and used in electronic devices, miniaturization is required according to the specifications of the electronic devices, but there are situations where the configuration of the two radiating elements and the grounding area is constrained by the cables connecting the power supply circuit.

[0008] Therefore, the purpose of this disclosure is to provide antenna devices and electronic devices that can be miniaturized and achieve the required radiation efficiency.

[0009] Solution for solving the problem

[0010] An antenna device according to one embodiment of this disclosure includes: a substrate; and a first antenna and a second antenna formed on the substrate. The first antenna includes: a first radiating element formed extending along a first direction of the substrate; and a first coil connected in series with the first radiating element. The second antenna includes: a second radiating element formed extending along the first direction; and a second coil connected in series with the second radiating element and magnetically coupled to the first coil. The first coil and the second coil constitute an electromagnetic field coupling element. The substrate includes: an antenna region in which the first radiating element and the second radiating element are formed; and a ground region formed along the antenna region in the first direction. The ground region includes: a first region having a length of a second direction orthogonal to the first direction that is a first length; and a second region having a second length longer than the first length. When the substrate is divided in the first direction into a first side for forming the first radiating element and the second radiating element and a second side opposite to the first side, a second region is provided on the second side of the substrate, and the cable for connecting the power supply circuit to the first antenna or the second antenna is fixed in the second region.

[0011] Preferably, a portion of the first radiating element of the first antenna is electrically connected to the grounding region.

[0012] Preferably, the second radiating element is formed on a side further away from the grounding region than the first radiating element.

[0013] Preferably, the second radiating element comprises a first portion extending in the positive direction of the first direction and a second portion extending in the negative direction of the first direction.

[0014] Preferably, the length of the second portion of the second radiating element is shorter than the length of the first portion.

[0015] Preferably, the distance from the first radiating element or the second radiating element to the grounding region in the second direction is longer than the distance from the first radiating element to the second radiating element in the second direction.

[0016] Preferably, the grounding region is formed from one end of the substrate to the other end in the first direction.

[0017] An electronic device according to one aspect of this disclosure includes: the antenna device described above; and a power supply circuit connected to the first antenna or the second antenna via a cable.

[0018] Effects of the utility model

[0019] According to one aspect of this disclosure, in an antenna device, the grounding region includes a second region of a second length that is longer than the first region in a second direction, and a cable is fixed in the second region, thereby enabling miniaturization and achieving the desired radiation efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an electronic device including an antenna device with an embodiment.

[0021] Figure 2 This is a perspective view of the electromagnetic field coupling element in the implementation method.

[0022] Figure 3 This is a top view of the electromagnetic field coupling element in the implementation method.

[0023] Figure 4 This is a side view of the electromagnetic field coupling element in the embodiment.

[0024] Figure 5 This is an equivalent circuit diagram of the antenna device in the implementation method.

[0025] Figure 6 This is a graph showing the frequency characteristics of the radiation efficiency of the antenna device in the embodiment.

[0026] Figure 7 This is a schematic diagram of an electronic device that includes the antenna device of Variation 1.

[0027] Figure 8 This is a schematic diagram of an electronic device that includes the antenna device of Variation 2.

[0028] Figure 9 This is a schematic diagram of an electronic device that includes the antenna device of variant 3.

[0029] Figure 10 This is a schematic diagram of an electronic device that includes the antenna device of Variation 4.

[0030] Figure 11 This is a schematic diagram of an electronic device that includes the antenna device of Variation 5.

[0031] Figure 12 This is a schematic diagram of an electronic device that includes the antenna device of Variation 6. Detailed Implementation

[0032] Hereinafter, the antenna device and electronic device of this embodiment will be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0033] First, let's describe the electronic equipment that includes an antenna device. Figure 1 This is a schematic diagram of an electronic device 200 including the antenna device 100 of the embodiment. (See diagram below.) Figure 1As shown, the electronic device 200 includes an antenna device 100 and a power supply circuit 30 that supplies power to the first antenna element 41 (first radiating element). The electronic device 200 is a laptop, mobile phone, smartphone, or tablet computer, etc., that has an antenna device 100 built-in and is capable of communication in frequency bands including, for example, the 2.4 GHz band and the 5 GHz to 7 GHz band.

[0034] [Structure of the antenna device]

[0035] The antenna device 100 includes a first antenna element 41 (first radiating element) and a second antenna element 42 (second radiating element) extending along the X direction (first direction) of a plate-shaped substrate 20. Here, the substrate 20 is a printed wire board (PWB), for example, a board made of FR4 (Flame Retardant Type 4) substrate with copper foil bonded thereon. Therefore, the first antenna element 41 and the second antenna element 42 are formed by etching after patterning the copper foil on the substrate 20.

[0036] The substrate 20 includes an antenna region 20a for forming the first antenna element 41 and the second antenna element 42, and a ground region 20b formed along the antenna region 20a in the X direction. The ground region 20b represents the area where a copper foil serving as a reference potential is adhered, and it is formed from one end of the substrate 20 to the other in the X direction. Furthermore, the ground region 20b has a step along its length in the Y direction (second direction). In addition, the ground region 20b is electrically connected to the ground electrode of the electronic device 200 using a conductive material such as copper tape (not shown). On the other hand, the antenna region 20a does not have a copper foil serving as a reference potential because the radiation efficiency of the antenna would be degraded due to the copper foil serving as a reference potential, as described later.

[0037] The antenna device 100 has an electromagnetic field coupling element 10 mounted on the substrate 20. As described later, the electromagnetic field coupling element 10 includes a coil L1 (first coil) and a coil L2 (second coil), which are magnetically coupled. One end of the coil L1 is connected to a first external electrode 11, and the other end is connected to a second external electrode 12. Additionally, one end of the coil L2 is connected to a third external electrode 13, and the other end is connected to a fourth external electrode 14.

[0038] like Figure 1As shown, the first antenna element 41 is connected to the first external electrode 11 of the electromagnetic field coupling element 10 and electrically connected to the coil L1 of the electromagnetic field coupling element 10. For the coil L1, the second external electrode 12 is connected to the wiring 43, which is electrically connected to the power supply circuit 30 via the cable 40. Specifically, the antenna elements formed on the substrate 20, the wiring, and the external electrode of the electromagnetic field coupling element 10 are electrically connected using solder and conductive adhesive. Therefore, the first antenna, comprising the first antenna element 41 and the coil L1 of the electromagnetic field coupling element 10, functions as a power supply antenna by being powered by the power supply circuit 30.

[0039] Additionally, the first antenna is electrically connected to the grounding region 20b via wiring 41a of the first antenna element 41, functioning as an inverted-F antenna (IFA). The first antenna is capable of communication, for example, in a frequency band covering approximately 5 GHz.

[0040] like Figure 1 As shown, the second antenna element 42 is connected to the fourth external electrode 14 of the electromagnetic field coupling element 10 and electrically connected to the coil L2 of the electromagnetic field coupling element 10. For the coil L2, the third external electrode 13 is connected to the wiring 44 and electrically connected to the grounding region 20b. Therefore, the second antenna, comprising the second antenna element 42 and the coil L2 of the electromagnetic field coupling element 10, functions as a power-free antenna.

[0041] Furthermore, the second antenna functions as a branched monopole antenna. The second antenna element 42 includes a first portion 42a extending in the positive X direction (direction of the arrow) and a second portion 42b extending in the negative X direction (opposite to the arrow). For the second antenna, the length of the first portion 42a is longer than the length of the second portion 42b; therefore, the first portion 42a can communicate in a frequency band, for example, approximately 2.4 GHz, while the second portion 42b can communicate in a frequency band, for example, approximately 6 GHz.

[0042] like Figure 1As shown, antenna device 100 forms a first antenna and a second antenna on substrate 20 and is mounted on electronic device 200. Therefore, with the miniaturization requirements of electronic device 200, miniaturization of antenna device 100 itself is required. However, in order to achieve wide communication frequency bands, antenna device 100 arranges the second antenna element 42 (without power supply) and the first antenna element 41 (with power supply) close together for electromagnetic field coupling. But if the first antenna element 41 and the second antenna element 42 are not separated from the grounding region 20b to a certain extent, this electromagnetic field coupling may be hindered. Therefore, it is preferable that the distance in the Y direction from the first antenna element 41 or the second antenna element 42 to the grounding region 20b is longer than the distance in the Y direction from the first antenna element 41 to the second antenna element 42.

[0043] On the other hand, it is necessary to shorten the Y-direction length D1 of the antenna region 20a forming the first antenna element 41 and the second antenna element 42 to miniaturize the antenna device 100. In addition, if the first antenna element 41 and the second antenna element 42 are arranged close to the grounding region 20b, the radiation efficiency of the antenna device 100 may be degraded due to the influence of the grounding region 20b on each antenna element.

[0044] Furthermore, the antenna device 100 needs to supply power from the power supply circuit 30 to the first antenna element 41 of the power supply antenna, thus requiring a cable 40 to be connected to the electromagnetic field coupling element 10. The cable 40 is a coaxial cable that electrically connects the inner conductor 40b to the wiring 43. Additionally, if the cable 40 moves, defects such as the connection between the inner conductor 40b and the wiring 43 may occur. Therefore, the cable 40 is fixed to the grounding region 20b using a fixing component 40c such as brazing, and the outer conductor 40a is electrically connected to the grounding region 20b. Furthermore, an insulator 40d is provided between the outer conductor 40a and the inner conductor 40b of the cable 40. However, the cable 40 requires a certain thickness for mechanical strength, and the length D3 (second length) of the grounding region 20b in the Y direction also needs to match the thickness of the cable 40 to ensure a certain length. Therefore, the grounding region becomes a bottleneck for the miniaturization of the antenna device.

[0045] Therefore, the antenna device 100 employs a grounding region 20b with a step along its length in the Y direction. Specifically, as... Figure 1 As shown, the grounding region 20b includes a region 20b1 (first region) with a length D2 (first length) in the Y direction and a region 20b2 (second region) with a length D3 (>D2) in the Y direction. In the grounding region 20b, region 20b1 is disposed in the region formed by the first antenna element 41 and the second antenna element 42, and region 20b2 is disposed in the fixed region of the cable 40.

[0046] That is, when the substrate 20 is divided in the X direction into a first side 20c for forming the first antenna element 41 and the second antenna element 42, and a second side 20d opposite to the first side 20c, with the electromagnetic field coupling element 10 as the boundary, at least the region 20b2 can be provided on the second side 20d. Therefore, the grounding region 20b can shorten the length D2 of the region 20b1, thus ensuring the length D1 of the antenna region 20a in the Y direction and miniaturizing the antenna device 100. For example, if the length D1 of the antenna region 20a in the Y direction is 3 mm and the length D2 of the region 20b1 is 1 mm, the length of the antenna device 100 in the Y direction can be miniaturized to 4 mm. The length D3 of the region 20b2 is 2 mm, thus the cable 40 can be sufficiently fixed in this region 20b2.

[0047] On the other hand, without setting a step in the length of the Y direction, the antenna device with a grounding area having a length of D3 in the Y direction needs to add the length of the antenna area in the Y direction D1 (3mm) and the length of the grounding area D3 (2mm) to obtain the length (5mm) as the length in the Y direction, which makes it difficult to achieve miniaturization.

[0048] [Construction of Electromagnetic Field Coupling Components]

[0049] Next, with reference to the accompanying drawings, the electromagnetic field coupling element of the embodiment will be described. Figure 2 This is a perspective view of the electromagnetic field coupling element 10 according to the embodiment. Figure 3 This is a top view of the electromagnetic field coupling element 10 according to the embodiment. Figure 4 This is a side view of the electromagnetic field coupling element 10 according to the embodiment. Here, in Figures 2-4 In this design, the short side direction of the electromagnetic field coupling element 10 is defined as the X direction, the long side direction as the Y direction, and the height direction as the Z direction. Additionally, the substrate's stacking direction is the Z direction, and the arrow indicates the upper layer direction.

[0050] Electromagnetic field coupling element 10 is an antenna coupling element that couples two antennas (radiating elements); it is a cuboid-shaped chip component. For example... Figure 2 As shown, a first external electrode 11, a second external electrode 12, a third external electrode 13, and a fourth external electrode 14 are formed on the outer surface of the electromagnetic field coupling element 10. Furthermore, the electromagnetic field coupling element 10 has a pair of main surfaces facing each other. Figure 2 The main surface on the lower side is the mounting surface, which is opposite to the circuit board.

[0051] In order to magnetically couple two antennas (radiating elements), the electromagnetic field coupling element 10 contains two coils, namely coil L1 and coil L2, forming a transformer in which coil L1 and coil L2 are magnetically coupled.

[0052] The specific structure of the electromagnetic field coupling element 10 is described below. For example... Figures 2-4 As shown, the electromagnetic field coupling element 10 is composed of an insulator 1 (ceramic blank) made of multiple ceramic layers formed by stacking substrates (ceramic green sheets) that form coil wiring. The insulator 1 has a pair of main surfaces facing each other and a side surface connecting the main surfaces. Multiple first conductor patterns 21, second conductor patterns 22, multiple third conductor patterns 23, and fourth conductor patterns 24 are stacked parallel to the main surfaces of the insulator 1 to form the electromagnetic field coupling element 10 enclosing coils L1 and L2.

[0053] Coil L1 consists of two layers of first conductor patterns 21a and 21b and one layer of second conductor pattern 22, all stacked together, and electrically connected by a conductor 31. Specifically, coil L1 connects the two layers of first conductor patterns 21a and 21b in parallel using conductor 31, and connects the second conductor pattern 22 in series with the two layers of first conductor patterns 21 using conductor 31. Therefore, compared to connecting the first conductor patterns 21a and 22 in series, coil L1 can reduce the inductance. Furthermore, the first conductor pattern 21 can also be two or more conductor patterns.

[0054] Coil L2 consists of two layers of third conductor patterns 23a and 23b and one layer of fourth conductor pattern 24, all electrically connected by a conductor 32. Specifically, coil L2 connects the two layers of third conductor patterns 23a and 23b in parallel using conductor 32, and connects the fourth conductor pattern 24 in series with the two layers of third conductor patterns 23 using conductor 32. Therefore, compared to connecting the third conductor patterns 23a and 24 in series, coil L2 can reduce the inductance. Furthermore, the third conductor pattern 23 can also be two or more conductor patterns.

[0055] Coils L1 and L2 are arranged within insulator 1 such that the opening of coil L1 overlaps with the opening of coil L2 when viewed from the stacking direction of insulator 1. Furthermore, as... Figure 3 As shown, when viewed from the stacking direction of the insulator 1, the openings of coil L1 and coil L2 are offset relative to the center of the electromagnetic field coupling element 10 in the long side direction, and are positioned close to the side of the second external electrode 12 located on the short side of the electromagnetic field coupling element 10. However, Figure 3The configuration of coils L1 and L2 shown is one example, but other configurations are also possible. Specifically, coils L1 and L2 are arranged within the insulator 1 with the second conductor pattern 22 and the fourth conductor pattern 24 facing each other. Since coils L1 and L2 form a structure with one layer of the second conductor pattern 22 and one layer of the fourth conductor pattern 24 facing each other through an insulating layer, the capacitance component is smaller compared to a structure with three conductor patterns facing each other through an insulating layer.

[0056] Furthermore, when coils L1 and L2 are arranged with the second conductor pattern 22 and the fourth conductor pattern 24 facing each other, the coupling coefficient between coils L1 and L2 can be maintained at a higher level compared to the case where two layers of the first conductor pattern 21 and two layers of the third conductor pattern 23 are facing each other. Therefore, when the electromagnetic field coupling element 10 arranges coils L1 and L2 with the second conductor pattern 22 and the fourth conductor pattern 24 facing each other, the mutual inductance M between coils L1 and L2 does not decrease.

[0057] like Figure 2 As shown, on the side of the insulator 1, a first external electrode 11 is provided on one side of the short side, a second external electrode 12 is provided on the other side of the short side, a third external electrode 13 is provided on one side of the long side, and a fourth external electrode 14 is provided on the other side of the long side.

[0058] Multiple first conductor patterns 21 are electrically connected to the first external electrode 11. Alternatively, among the multiple first conductor patterns 21, only the lower first conductor pattern 21b is electrically connected to the first external electrode 11, while the upper first conductor patterns 21a and 21b are electrically connected via a conductive path. The second conductor pattern 22 is electrically connected to the second external electrode 12.

[0059] Multiple third conductor patterns 23 are electrically connected to the third external electrode 13. Alternatively, among the multiple third conductor patterns 23, only the lower third conductor pattern 23b is electrically connected to the third external electrode 13, while the upper third conductor patterns 23a and 23b are electrically connected via a conductive path. The fourth conductor pattern 24 is electrically connected to the fourth external electrode 14.

[0060] [Equivalent circuit of the antenna device]

[0061] For adoption Figures 2-3 The equivalent circuit of the antenna device 100 of the electromagnetic field coupling element 10 shown will be described. Figure 5This is an equivalent circuit diagram of the antenna device 100 according to the embodiment. The antenna device 100 uses an electromagnetic field coupling element 10 to couple a powered antenna, i.e., a first antenna element 41, which is connected to the power supply circuit 30, and a non-powered antenna, i.e., a second antenna element 42, which is not powered by the power supply circuit 30.

[0062] Specifically, the first antenna element 41 is electrically connected to the first external electrode 11 of the electromagnetic field coupling element 10, and the power supply circuit 30 is electrically connected to the second external electrode 12 of the electromagnetic field coupling element 10. That is, the coil L1 of the electromagnetic field coupling element 10 is connected between the first antenna element 41 and the power supply circuit 30.

[0063] In coil L1, as Figure 5 As shown, the coil portion formed by the first conductor pattern 21a is connected in parallel with the coil portion formed by the first conductor pattern 21b, and the coil portion formed by the second conductor pattern 22 is connected in series with these portions. In coil L1, the coil portion formed by the second conductor pattern 22 is connected to the power supply circuit 30.

[0064] On the other hand, the second antenna element 42 is electrically connected to the fourth external electrode 14 of the electromagnetic field coupling element 10, and the third external electrode 13 of the electromagnetic field coupling element 10 is connected to GND (grounded). That is, the coil L2 of the electromagnetic field coupling element 10 is connected between the second antenna element 42 and GND.

[0065] In coil L2, as Figure 5 As shown, the coil portion formed by the third conductor pattern 23a and the coil portion formed by the third conductor pattern 23b are connected in parallel, and the coil portion formed by the fourth conductor pattern 24 is connected in series with these portions. In coil L2, the coil portions formed by the third conductor pattern 23a and the coil portions formed by the third conductor pattern 23b connected in parallel are connected to GND. Compared with the second antenna element 42 side, the current flowing on the GND side is greater, so by setting the coil portions connected in parallel to the GND side, the Q value of coil L2 can be improved. Furthermore, by setting the third external electrode 13 of the electromagnetic field coupling element 10 as the GND electrode (ground electrode), the coil portions connected in parallel can be set to the GND side.

[0066] In antenna device 100, such as Figure 5 As shown, by magnetically coupling coils L1 and L2, a wide frequency band can be made available in the first antenna element 41 and the second antenna element 42. Furthermore, a mutual inductance M is generated between coils L1 and L2.

[0067] also, Figures 2-4The electromagnetic field coupling element 10 shown is an example, but the construction of the electromagnetic field coupling element is not limited to this. As long as it is an electromagnetic field coupling element that magnetically couples coil L1 and coil L2 to form a transformer, it can be any construction.

[0068] [Radiation efficiency of the antenna device]

[0069] Explanation Figure 1 The antenna device 100 shown improves radiation efficiency by employing a grounding region 20b with a step along its length in the Y direction. Specifically, the improvement in radiation efficiency of the antenna device 100 compared to a comparative object is explained. Figure 6 This is a graph showing the frequency characteristics of the radiation efficiency of the antenna device 100 according to the embodiment. Figure 6 In the diagram, the horizontal axis represents frequency, and the vertical axis represents antenna efficiency (radiation efficiency). Figure 6 The solid curve A3 shown represents the frequency response of the radiation efficiency of the antenna device 100. The antenna device 100 has a step along the Y-direction of the grounding region 20b, with the length D2 of region 20b1 set to 1 mm and the length D3 of region 20b2 set to 2 mm.

[0070] On the other hand, the frequency response of the radiation efficiency of the antenna device of comparison object A is represented by the dashed curve A1. The antenna device of comparison object A does not have a step in the Y-direction of the grounding region, and the Y-direction length of the grounding region is 1.5 mm. However, the Y-direction length of the antenna device of comparison object A is set to 4 mm in order to be the same as that of antenna device 100, and the Y-direction length of the antenna region is set to 2.5 mm.

[0071] Furthermore, curve A2, represented by a dashed line, indicates the frequency response of the radiation efficiency of the antenna device of comparison object B. The antenna device of comparison object B does not have a step along the Y-direction of the grounding region, and the Y-direction length of the grounding region is 1.8 mm. However, the Y-direction length of the antenna device of comparison object B is set to 4 mm to be the same as that of antenna device 100, and the Y-direction length of the antenna region is set to 2.2 mm.

[0072] It can be known that: Figure 6 As shown, curve A3 demonstrates higher antenna efficiency across all frequency bands compared to curves A1 and A2 of comparison objects A and B. Therefore, antenna device 100 can achieve the desired radiation efficiency by employing a grounding region 20b with a step along its length in the Y direction.

[0073] [Example of an antenna device]

[0074] Figure 1The antenna device 100 shown is an example, and the structure is not limited to this. Hereinafter, modified examples of the antenna device will be described using the accompanying drawings. Furthermore, regarding the modified examples described below and... Figure 1 The structure of the antenna device 100 shown can be appropriately combined as long as there are no technical obstacles to its integration.

[0075] (Variation Example 1)

[0076] In the antenna device 100, a structure is described in which the first antenna element 41 is electrically connected to the power supply circuit 30, and the second antenna element 42 is used as a power-free antenna. However, it is not limited to this; it is also possible to have the second antenna element electrically connected to the power supply circuit, and the first antenna element used as a power-free antenna.

[0077] Figure 7 This is a schematic diagram of an electronic device 200a including the antenna device 100a of Modified Example 1. Furthermore, in Figure 9 In the antenna device 100a shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0078] For the electromagnetic field coupling element 10a, one end of coil L1 is connected to the first external electrode 11 and the other end is connected to the third external electrode 13. One end of coil L2 is connected to the second external electrode 12 and the other end is connected to the fourth external electrode 14.

[0079] like Figure 7 As shown, the first antenna element 41 is connected to the first external electrode 11 of the electromagnetic field coupling element 10a and electrically connected to the coil L1 of the electromagnetic field coupling element 10a. For the coil L1, the third external electrode 13 is connected to the wiring 44 and electrically connected to the grounding region 20b. Therefore, the first antenna, comprising the first antenna element 41 and the coil L1 of the electromagnetic field coupling element 10a, functions as a power-free antenna.

[0080] like Figure 1 As shown, the second antenna element 42 is connected to the fourth external electrode 14 of the electromagnetic field coupling element 10a and electrically connected to the coil L2 of the electromagnetic field coupling element 10a. For the coil L2, the second external electrode 12 is connected to wiring 43, which is electrically connected to the power supply circuit 30 via cable 40. Therefore, the second antenna, comprising the second antenna element 42 and the coil L2 of the electromagnetic field coupling element 10a, functions as a power supply antenna by being powered by the power supply circuit 30.

[0081] In the antenna device 100a, the second antenna element 42 functions as a powered antenna and the first antenna element 41 functions as a non-powered antenna. However, by using a grounding region 20b with a step along the length in the Y direction, miniaturization can be achieved and the required radiation efficiency can be obtained.

[0082] The second antenna element 42 is formed on a side further away from the grounding region 20b than the first antenna element 41. This is because the frequency band of the second antenna element 42 is lower than that of the first antenna element 41, making it more susceptible to the influence of the grounding region 20b. Furthermore, the frequency band of the first portion 42a of the second antenna element 42 is, for example, about 2.4 GHz, while the frequency band of the first antenna element 41 is, for example, about 5 GHz. If the frequency band of the second antenna element 42 is higher than that of the first antenna element 41, then the second antenna element 42 can also be formed on a side closer to the grounding region 20b than the first antenna element 41. Additionally, the second portion 42b of the second antenna element 42 is formed on the second side 20d, and is therefore located near region 20b2 of the grounding region 20b. However, the length of the second portion 42b is shorter than the length of the first portion 42a, resulting in a frequency band as high as, for example, about 6 GHz, making it less susceptible to the influence of the grounding region 20b compared to the first portion 42a of the second antenna element 42.

[0083] (Variation Example 2)

[0084] In the antenna device 100, it is described that the second antenna element 42 comprises two parts, a first part 42a and a second part 42b, each having a frequency band. However, it is not limited to this and the second antenna element may also be composed of a simple monopole antenna.

[0085] Figure 8 This is a schematic diagram of electronic equipment 200b including antenna device 100b of modified example 2. Furthermore, in Figure 8 In the antenna device 100b shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0086] The second antenna element 42B has a shape that extends only from the portion connected to the fourth external electrode 14 of the electromagnetic field coupling element 10 in the positive X direction. Therefore, the second antenna, which includes the second antenna element 42B and the coil L2 of the electromagnetic field coupling element 10, functions as a simple monopole antenna.

[0087] The antenna device 100b has the shape of only the portion of the second antenna element 42B extending in the positive direction of the X direction, but adopts a grounding region 20b with a step along its length in the Y direction, thus enabling miniaturization and achieving the required radiation efficiency.

[0088] Furthermore, the second antenna, which includes the second antenna element and the electromagnetic field coupling element 10, can be configured not only as a monopole antenna, but also as an inverted F-type antenna or a loop antenna.

[0089] (Variation Example 3)

[0090] In the antenna device 100, it is described that the first antenna element 41 is electrically connected to the grounding region 20b via wiring 41a and functions as an inverted F-type antenna. However, it is not limited to this and the first antenna element may also be composed of a monopole antenna.

[0091] Figure 9 This is a schematic diagram of an electronic device 200c including the antenna device 100c of Modified Example 3. Furthermore, in Figure 9 In the antenna device 100c shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0092] The first antenna element 41C has a shape that extends only from the portion connected to the first external electrode 11 of the electromagnetic field coupling element 10 in the positive X direction. Therefore, the first antenna, which includes the first antenna element 41C and the coil L1 of the electromagnetic field coupling element 10, functions as a monopole antenna.

[0093] The antenna device 100c has the shape of only the portion of the first antenna element 41C extending in the positive direction of the X direction, but adopts a grounding region 20b with a step along the length in the Y direction, thus enabling miniaturization and achieving the required radiation efficiency.

[0094] Furthermore, the first antenna of the coil L1, which includes the first antenna element and the electromagnetic field coupling element 10, can be configured not only as a monopole antenna and an inverted F-type antenna, but also as a loop antenna.

[0095] (Variation Example 4)

[0096] In the antenna device 100, it is described that the grounding region 20b is formed from one end of the substrate 20 to the other end in the X direction. However, it is not limited to this, and a structure in which the grounding region is not formed from one end of the substrate to the other end in the X direction may also be adopted.

[0097] Figure 10 This is a schematic diagram of an electronic device 200d including the antenna device 100d of Modified Example 4. Furthermore, in Figure 10 In the antenna device 100d shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0098] The substrate 20 includes an antenna region 20a for forming the first antenna element 41 and the second antenna element 42, and a ground region 20D formed along the antenna region 20a in the X direction. The ground region 20D is not formed from one end of the substrate 20 to the other in the X direction, as shown below. Figure 10 As shown, the wiring 41a of the first antenna element 41 is formed at the position where it is connected to the wiring 41a of the first antenna element 41, and is not formed in the positive direction of the X direction from that position.

[0099] The grounding region 20D has a step along its length in the Y direction. Specifically, as follows: Figure 10 As shown, the grounding region 20D has a region 20D1 with a length D2 in the Y direction and a region 20D2 with a length D3 (>D2) in the Y direction. Region 20D1 is positioned in the region formed by the first antenna element 41 and the second antenna element 42, and region 20D2 is positioned in the fixed region of the cable 40. Furthermore, the grounding region 20D is electrically connected to the grounding electrode of the electronic device 200d using a conductive material such as copper tape (not shown).

[0100] In the antenna device 100d, the grounding region 20D is not formed from one end of the substrate 20 to the other in the X direction, but a grounding region 20D with a step in the length of the Y direction is adopted, so miniaturization can be achieved and the required radiation efficiency can be obtained.

[0101] (Variation Example 5)

[0102] In the antenna device 100, a region 20b1 with a length D2 in the Y direction and a region 20b2 with a length D3 (> D2) in the Y direction are described. However, it is not limited to this and may also be an antenna device that uses a ground region that includes a region with a length D2 in the Y direction that is 0 (zero).

[0103] Figure 11 This is a schematic diagram of an electronic device 200e including the antenna device 100e of variant 5. Furthermore, in Figure 11 In the antenna device 100e shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0104] The substrate 20 includes an antenna region 20a formed by the first antenna element 41 and the second antenna element 42, and a ground region 20E formed along the antenna region 20a in the X direction.

[0105] For grounding area 20E, such as Figure 11As shown, a region with a length of D3 in the Y direction is formed up to the position where it connects to the wiring 41a of the first antenna element 41, and from this position, a region with a length of 0 (zero) in the Y direction is formed in the positive X direction. That is, the grounding region 20E includes a region with a length of 0 (zero) in the Y direction and a region with a length of D3 in the Y direction, forming a structure with a step along the length in the Y direction. Furthermore, the grounding region 20E is electrically connected to the grounding electrode of the electronic device 200e using a conductive material such as copper tape (not shown).

[0106] In the region along the positive X-direction relative to the location where the wiring 41a of the first antenna element 41 is connected, the length of the grounding region 20E in the Y-direction becomes 0 (zero). Therefore, the first antenna element 41 and the second antenna element 42 in this region are not affected by the grounding region 20E. Thus, miniaturization and the desired radiation efficiency can also be achieved in the antenna device 100e. Furthermore, the cable 40 is fixed in the grounding region 20E with a length D3 in the Y-direction. Here, an example is shown where the grounding region 20E is formed only in the region where the cable 40 is fixed, but other grounding regions can also be formed on the top side of the second antenna element 42.

[0107] (Variation Example 6)

[0108] In the antenna device 100, it is described that the grounding region 20b is electrically connected to the grounding electrode of the electronic device 200 using a conductive material such as copper tape (not shown). However, it is not limited to this, and the structure may also use a conductive material such as copper tape or copper foil to cover the entire grounding region.

[0109] Figure 12 This is a schematic diagram of electronic equipment 200f including antenna device 100f of variant 6. Furthermore, in Figure 12 In the antenna device 100f shown, for the antenna with Figure 1 The antenna device 100 shown has the same structure and is labeled with the same reference numerals, so detailed descriptions will not be repeated.

[0110] For grounding area 20E, such as Figure 12 As shown, a region of length D3 in the Y direction is formed up to the position where it is connected to the wiring 41a of the first antenna element 41, and a region of length 0 (zero) in the Y direction is formed from this position in the positive direction of the X direction.

[0111] Furthermore, a copper foil 60 is provided to cover the entire grounding region 20E. The copper foil 60 is not only provided in the grounding region 20E, but also extends from the substrate 20. However, the copper foil 60 does not cover the antenna region 20a outside the grounding region 20E.

[0112] The copper foil 60 is bonded to the grounding area 20E using a conductive adhesive, solder, or the like. The cable 40 is fixed to the grounding area 20E, which is covered by the copper foil 60. That is, the cable 40 is fixed to the grounding area 20E through the copper foil 60. Furthermore, the cable 40 and the copper foil 60 are bonded using a conductive adhesive, solder, or the like.

[0113] [Way]

[0114] (1) The antenna device disclosed herein is an antenna device comprising: a substrate; and a first antenna and a second antenna formed on the substrate, the first antenna comprising: a first radiating element formed extending along a first direction of the substrate; and a first coil connected in series with the first radiating element; the second antenna comprising: a second radiating element formed extending along the first direction; and a second coil connected in series with the second radiating element and magnetically coupled to the first coil, the first coil and the second coil constituting an electromagnetic field coupling element; the substrate comprising: an antenna region, the first antenna, the second ... A first radiating element and a second radiating element are formed in the antenna region; and a grounding region is formed along the antenna region in a first direction, the grounding region comprising: a first region whose length in a second direction orthogonal to the first direction is a first length; and a second region having a second length longer than the first length. In the case where the substrate is divided in the first direction into a first side for forming the first radiating element and the second radiating element and a second side opposite to the first side, the second region is provided on the second side of the substrate, and the cable connecting the power supply circuit to the first antenna or the second antenna is fixed in the second region.

[0115] (2) In the antenna device described in (1), a portion of the first radiating element of the first antenna is electrically connected to the grounding region.

[0116] (3) In the antenna device described in (1) or (2), the second radiating element is formed on the side further away from the grounding region than the first radiating element.

[0117] (4) In the antenna device described in (3), the second radiating element comprises a first portion extending in the positive direction of the first direction and a second portion extending in the negative direction of the first direction.

[0118] (5) In the antenna device described in (4), the length of the second part of the second radiating element is shorter than the length of the first part.

[0119] (6) In any one of (1) to (5) the antenna device, the distance from the first radiating element or the second radiating element to the grounding region in the second direction is longer than the distance from the first radiating element to the second radiating element in the second direction.

[0120] (7) In any one of (1) to (6) the antenna device, the grounding region is formed from one end of the substrate to the other end in the first direction.

[0121] (8) The antenna device of this disclosure includes: the antenna device of any one of (1) to (7); and a power supply circuit connected to the first antenna or the second antenna via a cable.

[0122] It should be considered that the embodiments disclosed herein are illustrative and not limiting in all respects. The scope of this utility model is indicated by the claims rather than by the foregoing description of the embodiments, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0123] Explanation of reference numerals in the attached figures

[0124] 1. Insulator; 10, 10a. Electromagnetic field coupling element; 11. First external electrode; 12. Second external electrode; 13. Third external electrode; 14. Fourth external electrode; 20. Substrate; 20a. Antenna region; 20b, 20D, 20E. Grounding region; 30. Power supply circuit; 40. Cable; 40a. External conductor; 40b. Internal conductor; 40c. Fixing component; 41, 41C. First antenna element; 42, 42B. Second antenna element; 100, 100a-100f. Antenna device; 200, 200a-200f. Electronic equipment.

Claims

1. An antenna device, characterized in that, The antenna device includes: a substrate; and a first antenna and a second antenna formed on the substrate. The first antenna includes: A first radiating element is formed extending along a first direction of the substrate; and The first coil is connected in series with the first radiating element. The second antenna includes: A second radiating element, which is formed extending along the first direction; and The second coil, which is connected in series with the second radiating element, is coupled to the magnetic field of the first coil. The first coil and the second coil constitute an electromagnetic field coupling element. The substrate includes: an antenna region on which the first radiating element and the second radiating element are formed; and a ground region formed along the antenna region in the first direction. The grounding area includes: The first region, whose length in the second direction orthogonal to the first direction is the first length; and The second region has a second length that is longer than the first length. When the substrate is divided in the first direction into a first side for the formation of the first radiating element and the second radiating element and a second side opposite to the first side, the second region is provided on the second side of the substrate, and the cable connecting the power supply circuit to the first antenna or the second antenna is fixed in the second region.

2. The antenna device according to claim 1, characterized in that, A portion of the first radiating element of the first antenna is electrically connected to the grounding region.

3. The antenna device according to claim 1 or 2, characterized in that, The second radiating element is formed on a side that is farther away from the grounding region than the first radiating element.

4. The antenna device according to claim 3, characterized in that, The second radiating element comprises a first portion extending in the positive direction of the first direction and a second portion extending in the negative direction of the first direction.

5. The antenna device according to claim 4, characterized in that, The length of the second part of the second radiating element is shorter than the length of the first part.

6. The antenna device according to claim 1 or 2, characterized in that, The distance from the first radiating element or the second radiating element to the grounding region in the second direction is longer than the distance from the first radiating element to the second radiating element in the second direction.

7. The antenna device according to claim 1 or 2, characterized in that, The grounding region is formed from one end of the substrate to the other end in the first direction.

8. An electronic device, characterized in that, The electronic device includes: an antenna device according to any one of claims 1 to 7; and the power supply circuit, which is connected to the first antenna or the second antenna via the cable.

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