Antenna element, antenna device, and electronic apparatus

Abstract

To provide an antenna element composed of a plurality of conductors and having an opening, and to provide an antenna device and an electronic apparatus.SOLUTION: The antenna device 1 includes a plate-shaped first conductive 1a, and a plate-shaped second conductive 1a having a portion overlapping the first conductive 1a in a plan view of a principal surface of the first conductive 1b. The opening 3 is formed in the first conductive side 1a or the second conductive side 1b, or is formed by a combination of the first conductive side 1a and the second conductive side 1b. The first conductive 1a and the second conductive 1b are capacitively coupled at an overlapping portion 3a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an antenna element, an antenna device, and an electronic device. [Background technology]

[0002] In recent years, electronic devices have adopted a structure in which an antenna is built into the device rather than attached to the outside, from the viewpoint of design. Furthermore, by incorporating an antenna into an electronic device, damage to the antenna due to dropping or the like can be prevented. A slot antenna is known as an antenna built into an electronic device (Patent Document 1: U.S. Patent Application Publication No. 2019 / 0221943). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2019 / 0221943 Summary of the Invention [Problem to be solved by the invention]

[0004] However, because a slot antenna functions as an antenna element when a current flows around the slot opening, it may not function as an antenna element if the current flowing around the opening is interrupted. This makes it difficult to configure a slot antenna by dividing it into multiple conductors, which limits the design freedom when incorporating a slot antenna into an electronic device.

[0005] Therefore, an object of the present disclosure is to provide an antenna element, an antenna device, and an electronic device that are configured with a plurality of conductors and have an opening. [Means for solving the problem]

[0006] An antenna element according to one embodiment of the present disclosure includes a plate-shaped first conductor and a plate-shaped second conductor having an overlapping portion with the first conductor when the main surface of the first conductor is viewed in plan. An opening is formed in the first conductor or the second conductor, or by combining the first conductor and the second conductor. The first conductor and the second conductor are capacitively coupled at the overlapping portion.

[0007] An antenna device according to an embodiment of the present disclosure includes the antenna element described above and an excitation electrode electrically connected to a feeder circuit, the excitation electrode electrically connected to a first conductor via a capacitance, and the second conductor electrically connected to a ground electrode of the feeder circuit. [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, an opening is formed in the first conductor or the second conductor, or by combining the first conductor and the second conductor, and the first conductor and the second conductor are capacitively coupled at the overlapping portion of the first conductor and the second conductor, thereby increasing the degree of design freedom when the device is constructed from multiple conductors and incorporated into an electronic device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an antenna device according to a first embodiment. [Figure 2] 1 is a cross-sectional view of an antenna device according to a first embodiment. [Figure 3] FIG. 2 is a schematic diagram of an antenna element according to the first embodiment. [Figure 4] FIG. 10 is a diagram showing the current distribution in an antenna element having an opening. [Figure 5] 10 is a schematic diagram for explaining the lateral division of an antenna element having an opening. FIG. [Figure 6] 4 is a graph showing radiation characteristics of the antenna element according to the first embodiment. [Figure 7] FIG. 10 is a schematic diagram of an antenna element according to a modified example of the first embodiment. [Figure 8] FIG. 10 is a schematic diagram of an antenna element according to a second embodiment. [Figure 9] 10 is a graph showing frequency characteristics of the reflection coefficient of the antenna element according to the second embodiment. [Figure 10] 10 is a schematic diagram for explaining vertical division of an antenna element having an opening. FIG. [Figure 11] FIG. 10 is a schematic diagram of an antenna element according to a modified example of the second embodiment. [Figure 12] FIG. 10 is a schematic diagram of an antenna element according to a first modification. [Figure 13] FIG. 10 is an equivalent circuit diagram of an antenna device according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an antenna element, an antenna device, and an electronic device according to embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] (Embodiment 1) First, an antenna device constituting a slot antenna will be described. FIG. 1 is a schematic diagram of an antenna device 100 according to a first embodiment. FIG. 2 is a cross-sectional view of the antenna device 100 according to the first embodiment. FIG. 2(a) is a cross-sectional view taken along the IA-IA plane shown in FIG. 1, and FIG. 2(b) is a cross-sectional view taken along the IB-IB plane shown in FIG. 1. As shown in FIG. 2(a), the antenna device 100 includes an antenna element 1 and an excitation electrode 2. The antenna device 100 is capable of communication in bands including the 2.4 GHz band and the 5 GHz to 7 GHz band, for example, and is built into electronic devices such as notebook computers, mobile phones, smartphones, and tablets. The electronic devices include at least the antenna device 100 and a power supply circuit 30.

[0012] The antenna element 1 includes a plate-shaped first conductor 1a and a plate-shaped second conductor 1b. The first conductor 1a and the second conductor 1b have an overlapping portion 3a where a part of the first conductor 1a and a part of the second conductor 1b overlap on the XZ plane, and the first conductor 1a and the second conductor 1b are capacitively coupled at the overlapping portion 3a. Specifically, the first conductor 1a and the second conductor 1b form an opening 3 (slot) in the center of the XZ plane, and the overlapping portion 3a is located outside the opening 3 in the X direction.

[0013] As shown in FIG. 2(a), an excitation electrode 2 (also referred to as an excitation conductor, feed line, or simply a microstrip line) is disposed at the position where the opening 3 is formed. The excitation electrode 2 is electrically connected to the first conductor 1a via a capacitance and is also electrically connected to the power feed circuit 30. Furthermore, the second conductor 1b is electrically connected to a GND electrode (ground electrode) of the power feed circuit 30. The power feed circuit 30 is disposed near the antenna element 1 and is electrically connected to the excitation electrode 2 and the second conductor 1b via a coaxial cable (not shown).

[0014] As described above, the antenna device 100 is a slot antenna in which the excitation electrode 2 functions as a capacitive feed element relative to the opening 3. In the antenna device 100, which is a slot antenna, the length of the long side of the opening 3 (slot length) is approximately half the resonant wavelength (λ / 2). Therefore, when the antenna device 100 is used in the 2 to 3 GHz band, the length S1 of the long side (first side) of the opening 3 is approximately 40 mm to 70 mm. Meanwhile, the length S2 (slot width) of the short side (second side) of the opening 3 is approximately 1 to 5 mm. The opening 3 has a rectangular shape in which the second side (short side) is shorter than the first side (long side). Here, the first conductor 1a and the second conductor 1b are, for example, metal plates such as copper foil, copper plate, or aluminum plate.

[0015] As shown in FIG. 2(b), the overlapping portion 3a between the first conductor 1a and the second conductor 1b is arranged with a gap S3 between the first conductor 1a and the second conductor 1b, and the first conductor 1a and the second conductor 1b are not electrically connected. The gap S3 is set to, for example, 0.1 mm. The capacitance of the overlapping portion 3a is increased by increasing the length S4 in the Z direction of the overlapping portion 3a between the first conductor 1a and the second conductor 1b. For example, the length S4 in the Z direction of the overlapping portion 3a is 3 mm.

[0016] In the antenna element 1 shown in FIG. 1, the first conductor 1a has an L-shaped cross section with an XY plane portion and an XZ plane portion, and the second conductor 1b has a box-like shape with an XY plane portion, an XZ plane portion, and a YZ plane portion. However, the antenna element 1 may be configured only with the first conductor 1a and second conductor 1b portions in the XZ plane shown in FIG. 1. FIG. 3 is a schematic diagram of the antenna element 1 according to the first embodiment. The antenna element 1 shown in FIG. 3 schematically illustrates only the first conductor 1a and second conductor 1b portions in the XZ plane shown in FIG. 1. The antenna element 1 is arranged such that the U-shaped first conductor 1a faces downward and overlaps the rectangular second conductor 1b.

[0017] In the antenna element 1, the U-shaped curved portion of the first conductor 1a and one side of the second conductor 1b form the boundary of the opening 3. In this way, the antenna element 1 forms the opening 3 by combining the first conductor 1a and the second conductor 1b, and functions as a slot antenna by current flowing around the opening 3. Figure 4 shows the current distribution in the antenna element having the opening 3. The current distribution in the antenna element shown in Figure 4 is the result of a current distribution simulation performed on the first conductor 1a with the opening 3 formed. As shown in Figure 4, it can be seen that current flows around the opening 3 in the antenna element 1. Note that in Figure 4, the current distribution is represented by the shade of hatching, with darker hatching indicating a larger current amount. Therefore, if the first conductor 1a is divided closer to the opening 3, the current flowing around the opening 3 is divided. In Figure 4, the first conductor 1a below the opening 3 is divided, so the current flowing below the opening 3 is divided.

[0018] FIG. 5 is a schematic diagram illustrating the horizontal division of the antenna element 1 having the opening 3 (the X direction in FIG. 1, a direction parallel to the long side of the opening 3). In the first conductor 1a having the opening 3, as shown in FIG. 5, the distance K1 is defined as the distance from the position C1 of the bottom edge of the opening 3 to the position C2 where the first conductor 1a is cut horizontally. Current distribution simulations have shown that if the distance K1 is in the range of 0 mm to 30 mm, the radiation characteristics decrease by 0.5 dB or more. Therefore, in the antenna element 1 according to this embodiment, as shown in FIGS. 1 and 3, the first conductor 1a and the second conductor 1b are combined to compensate for the divided current. However, the first conductor 1a and the second conductor 1b are not simply joined, but are combined to form an overlapping portion 3a. The overlapping portion 3a capacitively couples the first conductor 1a and the second conductor 1b, and the current flowing around the opening 3 can flow from the first conductor 1a to the second conductor 1b via this capacitive coupling. In this way, the radiation characteristics of the antenna element 1 are improved by allowing the current flowing around the opening 3 to flow between the first conductor 1a and the second conductor 1b via capacitive coupling.

[0019] Specifically, in the antenna element 1 shown in Fig. 1, the length S1 of the long side of the opening 3 is set to 40 mm, the length S2 of the short side is set to 1 mm, and the length S4 of the overlapping portion 3a in the Z direction is set to 3 mm, and the radiation characteristics of the antenna element 1 are simulated. Fig. 6 is a graph showing the radiation characteristics of the antenna element 1 according to the first embodiment. In Fig. 6, the horizontal axis represents frequency (unit: GHz) and the vertical axis represents radiation characteristics (unit: dB). Graph A (solid line) shows the radiation characteristics of the antenna element 1 shown in Fig. 1, and graph B (dashed line) shows the radiation characteristics of an antenna element having an undivided opening for comparison. As can be seen from Fig. 6, graph A has radiation characteristics that are substantially the same as those of graph B in the range of approximately 2.4 GHz to approximately 7.5 GHz.

[0020] Furthermore, graph C (dash-dotted line) shows the radiation characteristics of an antenna element in which the first conductor 1a and the second conductor 1b are joined with a gap of 0.1 mm to form the opening 3. The antenna element of graph C does not have the overlapping portion 3a like the antenna element 1 shown in FIG. 1. Therefore, as shown in graph C, the antenna element without the overlapping portion 3a has deteriorated radiation characteristics in the range of approximately 2.5 GHz to approximately 3.2 GHz. As shown in graph A, it can be seen that the antenna element 1 with the overlapping portion 3a has improved radiation characteristics in the range of approximately 2.5 GHz to approximately 3.2 GHz.

[0021] As described above, even if the first conductor 1a and the second conductor 1b are combined to form the opening 3, if there is no overlapping portion 3a, the required radiation characteristics cannot be obtained. Therefore, the required radiation characteristics can be obtained by capacitively coupling the first conductor 1a and the second conductor 1b at the overlapping portion 3a, as in the antenna element 1 according to this embodiment, and a slot antenna can be formed using the first conductor 1a and the second conductor 1b. When a slot antenna is formed using a single conductor, the shape and size of the conductor are determined according to the shape and size of the opening, which limits the design freedom of the antenna element when incorporating it into an electronic device. However, if a slot antenna can be formed using the first conductor 1a and the second conductor 1b, as in the antenna element 1 according to this embodiment, the design freedom increases when incorporating it into an electronic device.

[0022] When an antenna element 1 (slot antenna) is configured by combining a first conductor 1a and a second conductor 1b, the configuration is not limited to the combination of the first conductor 1a and the second conductor 1b shown in FIGS. 1 and 3. FIG. 7 is a schematic diagram of an antenna element according to a modification of the first embodiment. In the antenna element 1A shown in FIG. 7(a), a U-shaped first conductor 1a and a U-shaped second conductor 1b are combined in the vertical direction in the figure, and an opening 3 is formed at the curved portions of each conductor to configure a slot antenna. In the antenna element 1A, the capacitance of the overlapping portion 3a can be adjusted by the length d1.

[0023] In antenna element 1B shown in FIG. 7(b), a slot antenna is formed by combining a first conductor 1a having an opening 3 with a rectangular second conductor 1b. The first conductor 1a is divided at the lower portion in the figure. The second conductor 1b is arranged to overlap the divided portion of the first conductor 1a. In antenna element 1B, the capacitance of the overlapping portion 3a can be adjusted by changing the length d2.

[0024] In antenna element 1C shown in FIG. 7(c), a slot antenna is formed by combining a rectangular first conductor 1a with a second conductor 1b having an opening 3. The upper portion of second conductor 1b in the figure is divided. First conductor 1a is arranged overlapping the divided portion of second conductor 1b. In antenna element 1C, the capacitance of overlapping portion 3a can be adjusted by changing length d3.

[0025] In the antenna elements 1, 1A to 1C shown in Figures 1, 3, and 7, the first conductor 1a and the second conductor 1b are overlapped so that the first conductor 1a is located at the front in the figures, but the overlapping order of the first conductor 1a and the second conductor 1b is not limited to this. For example, the first conductor 1a and the second conductor 1b may be overlapped so that the second conductor 1b is located at the front in the figures. Furthermore, in the antenna element 1 shown in Figure 3 and the antenna element 1A shown in Figure 7(a), the overlapping order of the first conductor 1a and the second conductor 1b may be different in the overlapping portions 3a on the left and right sides in the figures.

[0026] In the antenna element 1 shown in FIG. 3 and the antenna element 1A shown in FIG. 7(a), at least one side of the first conductor 1a and the second conductor 1b forms the boundary of the opening 3. On the other hand, in the antenna element 1B shown in FIG. 7(b) and the antenna element 1C shown in FIG. 7(c), the boundary of the opening 3 is formed only by the side of the first conductor 1a or the second conductor 1b. However, in the antenna element 1B shown in FIG. 7(b), when one side of the second conductor 1b is positioned above the bottom side of the opening 3 of the first conductor 1a in the drawing, one side of the second conductor 1b forms the boundary of the opening 3. Furthermore, in the antenna element 1C shown in FIG. 7(c), when one side of the first conductor 1a is positioned below the top side of the opening 3 of the second conductor 1b in the drawing, one side of the first conductor 1a forms the boundary of the opening 3.

[0027] In the antenna element 1 shown in Fig. 3 and the antenna element 1A shown in Fig. 7(a), the boundary of the overlapping portion 3a between the first conductor 1a and the second conductor 1b is located on the short side (second side) of the opening 3. On the other hand, in the antenna element 1B shown in Fig. 7(b) and the antenna element 1C shown in Fig. 7(c), the boundary of the overlapping portion 3a between the first conductor 1a and the second conductor 1b is not located on the short side (second side) of the opening 3. However, in the antenna element 1B shown in Fig. 7(b), when one side of the second conductor 1b is positioned higher than the lower side of the opening 3 of the first conductor 1a in the drawing, the boundary of the overlapping portion 3a between the first conductor 1a and the second conductor 1b is located on the short side (second side) of the opening 3. Furthermore, in the antenna element 1C shown in Figure 7(c), when one side of the first conductor 1a is positioned lower than the upper side of the opening 3 of the second conductor 1b in the figure, the boundary of the overlapping portion 3a between the first conductor 1a and the second conductor 1b is located on the side of the short side (second side) of the opening 3.

[0028] (Embodiment 2) In the antenna element 1 according to the first embodiment, a configuration has been described in which the first conductor 1a is divided in the X direction (horizontal direction) shown in Fig. 1, and the first conductor 1a and the second conductor 1b are overlapped so that an overlapping portion 3a is formed at the divided portion. However, the direction in which the conductor is divided is not limited to the X direction (horizontal direction), and the conductor may be divided in the Z direction (vertical direction). Fig. 8 is a schematic diagram of an antenna element 1D according to the second embodiment. In the antenna element 1D shown in Fig. 8, the same components as those of the antenna element 1 shown in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0029] The antenna element 1D includes a plate-shaped first conductor 1c and a plate-shaped second conductor 1d. The first conductor 1c and the second conductor 1d have an overlapping portion 3a where a part of the first conductor 1c and a part of the second conductor 1d overlap on the XZ plane, and the first conductor 1c and the second conductor 1d are capacitively coupled at the overlapping portion 3a. Specifically, the first conductor 1c and the second conductor 1d are separated at the center of the XZ plane, and an opening 3 (slot) is formed by combining the first conductor 1c and the second conductor 1d via the overlapping portion 3a.

[0030] Although not shown, an excitation electrode may be disposed at the position where the opening 3 is formed. The excitation electrode is electrically connected to, for example, the upper side of the first conductor 1c via a capacitance and is also electrically connected to the feed circuit 30. Furthermore, the lower side of the first conductor 1c is electrically connected to a GND electrode (ground electrode) of the feed circuit 30. In this way, the antenna device 100 including the antenna element 1D is a slot antenna in which the excitation electrode functions as a capacitive feed element with respect to the opening 3.

[0031] As shown in FIG. 8, the overlapping portion 3a between the first conductor 1c and the second conductor 1d is arranged with a gap S3 between the first conductor 1c and the second conductor 1d, and the first conductor 1c and the second conductor 1d are not electrically connected. The gap S3 is set to, for example, 0.1 mm. The capacitance of the overlapping portion 3a is increased by increasing the length S4 in the X direction of the overlapping portion 3a between the first conductor 1c and the second conductor 1d. For example, the length S4 in the X direction of the overlapping portion 3a is 3 mm.

[0032] Next, in the antenna element 1D shown in FIG. 8, the length S1 of the long side of the opening 3 is 40 mm, the length S2 of the short side is 1 mm, the width S5 of the first conductor 1c or the second conductor 1d on the upper side of the opening 3 in the figure is 2 mm, and the width S6 of the first conductor 1c or the second conductor 1d on the lower side of the opening 3 in the figure is 4.5 mm. A simulation was performed to determine the frequency characteristics of the reflection coefficient of the antenna element 1D. FIG. 9 is a graph showing the frequency characteristics of the reflection coefficient of the antenna element 1D according to the second embodiment. In FIG. 9, the horizontal axis represents frequency and the vertical axis represents reflection coefficient. Here, reflection coefficient D is the reflection coefficient when viewing the antenna element 1D from the feed circuit. At reflection coefficient D, resonance of the antenna element 1D occurs in a band including approximately 2.5 GHz, and further resonance occurs at approximately 6.4 GHz and approximately 7.1 GHz.

[0033] FIG. 10 is a schematic diagram illustrating the vertical division of an antenna element 1D having an opening 3 (the Z direction in FIG. 8 , a direction parallel to the short side of the opening 3). In the second conductor 1d having the opening 3, as shown in FIG. 10 , the distance from position C3 on the left side of the opening 3 to position C4 where the second conductor 1d is cut in the vertical direction is defined as distance K2. Current distribution simulations have shown that if distance K2 is in the range of 0 mm to 1.0 mm, the radiation characteristics decrease by 0.5 dB or more. Therefore, in the antenna element 1D according to this embodiment, as shown in FIG. 8 , the first conductor 1c and the second conductor 1d are combined to compensate for the divided current. However, the first conductor 1c and the second conductor 1d are not simply joined, but are combined to form an overlapping portion 3a. The overlapping portion 3a capacitively couples the first conductor 1c and the second conductor 1d, allowing the current flowing around the opening 3 to flow from the first conductor 1c to the second conductor 1d via this capacitive coupling. In this way, the antenna element 1D improves the radiation characteristics of the antenna element 1D by allowing the current flowing around the opening 3 to flow between the first conductor 1c and the second conductor 1d via capacitive coupling.

[0034] When an antenna element 1D (slot antenna) is configured by combining a first conductor 1c and a second conductor 1d, the configuration is not limited to the combination of the first conductor 1c and the second conductor 1d shown in FIG. 8. FIG. 11 is a schematic diagram of an antenna element according to a modification of the second embodiment. In the antenna element 1E shown in FIG. 11(a), a U-shaped first conductor 1c and a U-shaped second conductor 1d are combined in the horizontal direction in the figure, and an opening 3 is formed at the curved portions of each conductor to configure a slot antenna. In the antenna element 1E, the capacitance of the overlapping portion 3a can be adjusted by the length d4.

[0035] In antenna element 1F shown in FIG. 11(b), a slot antenna is formed by combining a first conductor 1c having an opening 3 with a rectangular second conductor 1d. The first conductor 1c is divided at the right side in the figure. The second conductor 1d is arranged to overlap the divided portion of the first conductor 1c. In antenna element 1F, the capacitance of the overlapping portion 3a can be adjusted by changing the length d5.

[0036] In antenna element 1G shown in FIG. 11(c), a slot antenna is formed by combining a rectangular first conductor 1c with a second conductor 1d having an opening 3. The second conductor 1d is divided at the left side in the figure. The first conductor 1c is arranged to overlap the divided portion of the second conductor 1d. In antenna element 1G, the capacitance of the overlapping portion 3a can be adjusted by changing the length d6.

[0037] In antenna elements 1D to 1G shown in Fig. 8 and Fig. 11, the first conductor 1c and the second conductor 1d are overlapped so that the first conductor 1c is disposed in the front in the figures, but the overlapping order of the first conductor 1c and the second conductor 1d is not limited to this. For example, the first conductor 1c and the second conductor 1d may be overlapped so that the second conductor 1d is disposed in the front in the figures. Furthermore, in antenna element 1D shown in Fig. 8 and antenna element 1E shown in Fig. 11(a), the overlapping order of the first conductor 1c and the second conductor 1d may be different in the upper and lower overlapping portions 3a in the figures.

[0038] In antenna element 1D shown in FIG. 8 and antenna element 1E shown in FIG. 11(a), at least one side of first conductor 1c and second conductor 1d forms the boundary of opening 3. On the other hand, in antenna element 1F shown in FIG. 11(b) and antenna element 1G shown in FIG. 11(c), the boundary of opening 3 is formed only by the side of first conductor 1c or second conductor 1d. However, in antenna element 1F shown in FIG. 11(b), when one side of second conductor 1d is positioned to the left of the right side of opening 3 of first conductor 1c in the figure, one side of second conductor 1d forms the boundary of opening 3. Also, in antenna element 1G shown in FIG. 11(c), when one side of first conductor 1c is positioned to the right of the left side of opening 3 of second conductor 1d in the figure, one side of first conductor 1c forms the boundary of opening 3.

[0039] In antenna element 1D shown in Fig. 8 and antenna element 1E shown in Fig. 11(a), the boundary of overlapping portion 3a between first conductor 1c and second conductor 1d is located on the long side (first side) of opening 3. On the other hand, in antenna element 1F shown in Fig. 11(b) and antenna element 1G shown in Fig. 11(c), the boundary of overlapping portion 3a between first conductor 1c and second conductor 1d is not located on the long side (first side) of opening 3. However, in antenna element 1F shown in Fig. 11(b), when one side of second conductor 1d is positioned further left than the right side of opening 3 of first conductor 1c in the drawing, the boundary of overlapping portion 3a between first conductor 1c and second conductor 1d is located on the long side (first side) of opening 3. Furthermore, in the antenna element 1G shown in Figure 11(c), when one side of the first conductor 1c is positioned to the right of the left side of the opening 3 of the second conductor 1d in the figure, the boundary of the overlapping portion 3a between the first conductor 1c and the second conductor 1d is located on the side of the long side (first side) of the opening 3.

[0040] (Variation 1) In the above-described embodiments, the antenna element 1A shown in FIG. 7(a) has an opening 3 formed by combining a U-shaped first conductor 1a and a U-shaped second conductor 1b in the vertical direction in the figure, and the antenna element 1E shown in FIG. 11(a) has an opening 3 formed by combining a U-shaped first conductor 1c and a U-shaped second conductor 1d in the horizontal direction in the figure. In the antenna element according to the modification, an antenna element will be described in which an L-shaped first conductor and an L-shaped second conductor are combined to form the opening 3 at their bent portions. FIG. 12 is a schematic diagram of an antenna element 1H according to the first modification.

[0041] The antenna element 1H shown in Fig. 12 includes an L-shaped first conductor 1e and an L-shaped second conductor 1f. The first conductor 1e and the second conductor 1f have overlapping portions 3a at their respective ends, and are capacitively coupled at the overlapping portions 3a. Furthermore, the L-shaped first conductor 1e and the L-shaped second conductor 1f are combined to form an opening 3 at their mutual bends. The size of the opening 3 can be adjusted by the relative positions of the first conductor 1e and the second conductor 1f.

[0042] (Variation 2) The configuration of an antenna device in which the resonances of two excitation electrodes in a slot antenna using antenna elements 1, 1A to 1H according to the above-described embodiments are coupled using an electromagnetic field coupling element (for example, a transformer). Fig. 13 is an equivalent circuit diagram of an antenna device 200 according to Modification 2. In the antenna device 200 shown in Fig. 13, an excitation electrode 21 of a slot antenna connected to a feed circuit 30 is coupled to an excitation electrode 22 of a slot antenna not fed by the feed circuit 30 using an electromagnetic field coupling element 10.

[0043] 13, the excitation electrode 21 and the opening 3 form a slot antenna (first antenna). Although not shown, the opening 3 is formed by the antenna elements 1, 1A to 1H. The excitation electrode 21 is electrically connected to the first external electrode 11 of the electromagnetic coupling element 10, and the power feed circuit 30 is electrically connected to the second external electrode 12 of the electromagnetic coupling element 10. In other words, the coil L1 of the electromagnetic coupling element 10 is connected in series to the excitation electrode 21 and the power feed circuit 30.

[0044] Meanwhile, in the equivalent circuit diagram of the antenna device 200, the excitation electrode 22 and the opening 3 form a slot antenna (second antenna). The excitation electrode 22 is electrically connected to the third external electrode 13 of the electromagnetic field coupling element 10, and the fourth external electrode 14 of the electromagnetic field coupling element 10 is connected (grounded) to GND. In other words, the electromagnetic field coupling element 10 is connected in series to the excitation electrode 22 and GND. A capacitance element 60 is provided between the excitation electrode 22 and the third external electrode 13.

[0045] Coil L1 and coil L2 are arranged in a position where they are magnetically coupled within the electromagnetic coupling element 10, generating a mutual inductance M. The electromagnetic coupling element 10 is a chip coil component formed by laminating a plurality of ceramic green sheets. Of course, the antenna device 200 is not limited to a configuration in which the excitation electrodes 21 and 22 are connected to the electromagnetic coupling element 10, which is a chip coil component, and may have any configuration as long as the coils L1 and L2 are arranged in a position where they are magnetically coupled.

[0046] 13 shows a power supply circuit 30 that supplies power to the excitation electrode 21. The electronic device includes at least the power supply circuit 30 and an antenna device 200.

[0047] [Aspect] (1) The antenna element according to the present disclosure comprises: a plate-shaped first conductor; a plate-shaped second conductor having an overlapping portion with the first conductor when the main surface of the first conductor is viewed in plan view, The opening is formed in the first conductor or the second conductor, or in combination with the first conductor and the second conductor; The first conductor and the second conductor are capacitively coupled at the overlapping portion between them.

[0048] As a result, the antenna element of the present disclosure is formed in the first conductor or the second conductor, or an opening is formed by combining the first conductor and the second conductor, and the first conductor and the second conductor are capacitively coupled at the overlapping portion of the first conductor and the second conductor, so that it is composed of multiple conductors and has high design freedom when incorporated into an electronic device.

[0049] (2) The antenna element according to (1), At least one side of the first conductor and the second conductor forms a boundary of the opening.

[0050] (3) The antenna element according to (1) or (2), At least one of the first conductor and the second conductor is U-shaped, with a curved portion of the U-shape forming a boundary of the opening.

[0051] (4) The antenna element according to (1) or (2), The first conductor and the second conductor are L-shaped, and bent portions of the L-shape combine to form a boundary of the opening.

[0052] (5) The antenna element according to any one of (1) to (4), The opening has a rectangular shape with a second side shorter than the first side, and the boundary of the overlapping portion between the first conductor and the second conductor is located on the second side.

[0053] (6) The antenna element according to (1) or (2), The opening is rectangular with a second side shorter than the first side, and the first conductor or second conductor in which the opening is formed is divided in a direction parallel to the first side of the opening, at a position 0 mm to 30 mm from one of the first sides.

[0054] (7) The antenna element according to (1) or (2), The opening is rectangular with the second side shorter than the first side, and the first conductor or the second conductor in which the opening is formed is divided in a direction parallel to the second side of the opening, and is divided at a position 0 mm to 1.0 mm from one of the second sides.

[0055] (8) The antenna element according to any one of (1) to (7), A current flowing around the opening flows between the first conductor and the second conductor via capacitive coupling.

[0056] (9) The antenna device according to the present disclosure includes: The antenna element according to any one of (1) to (8), an excitation electrode electrically connected to the power supply circuit; the excitation electrode is electrically connected to the first conductor via a capacitance; The second conductor is electrically connected to the ground electrode of the power supply circuit.

[0057] (10) The antenna device according to the present disclosure includes: The antenna element according to any one of (1) to (8), a first excitation electrode and a second excitation electrode disposed at positions corresponding to the opening; a first coil having one end electrically connected to the first excitation electrode and the other end connected to a power supply circuit; a second coil, one end of which is electrically connected to the second excitation electrode; The first coil and the second coil are disposed in a position where they are magnetically coupled.

[0058] (11) The electronic device according to the present disclosure is A power supply circuit; The antenna device according to (9) or (10) is provided.

[0059] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0060] 1, 1A to 1H antenna elements, 1a, 1c, 1e first conductor, 1b, 1d, 1f second conductor, 2, 21, 22 excitation electrodes, 3 opening, 3a overlapping portion, 10 electromagnetic field coupling element, 11 first external electrode, 12 second external electrode, 13 third external electrode, 14 fourth external electrode, 30 power supply circuit, 60 capacitance element, 100, 200 antenna device.

Claims

1. a plate-shaped first conductor; a plate-shaped second conductor having an overlapping portion with the first conductor when a main surface of the first conductor is viewed in plan view, an opening is formed in the first conductor or the second conductor, or by a combination of the first conductor and the second conductor; The antenna element, wherein the first conductor and the second conductor are capacitively coupled at an overlapping portion of the first conductor and the second conductor.

2. The antenna element of claim 1 , wherein at least one side of the first conductor and the second conductor forms a boundary of the opening.

3. 2. The antenna element of claim 1, wherein at least one of the first conductor and the second conductor is U-shaped, a curved portion of the U-shape forming a boundary of the opening.

4. The antenna element of claim 1 , wherein the first conductor and the second conductor are L-shaped, and bent portions of the L-shape combine to form a boundary of the opening.

5. 2. The antenna element according to claim 1, wherein the opening has a rectangular shape with a second side shorter than a first side, and a boundary of an overlapping portion between the first conductor and the second conductor is located on the second side.

6. The antenna element according to claim 1, wherein the opening is rectangular in shape with a second side shorter than a first side, and the first conductor or the second conductor in which the opening is formed is divided in a direction parallel to the first side of the opening and is divided at a position 0 mm to 30 mm from one of the first sides.

7. The antenna element according to claim 1, wherein the opening is rectangular in shape with a second side shorter than a first side, and the first conductor or the second conductor in which the opening is formed is divided in a direction parallel to the second side of the opening, and is divided at a position 0 mm to 1.0 mm from one side of the second side.

8. The antenna element of claim 1 , wherein a current flowing around the opening flows between the first conductor and the second conductor via capacitive coupling.

9. The antenna element according to any one of claims 1 to 8; an excitation electrode electrically connected to the power supply circuit; the excitation electrode is electrically connected to the first conductor via a capacitance; The second conductor is electrically connected to a ground electrode of the feed circuit.

10. The antenna element according to any one of claims 1 to 8; a first excitation electrode and a second excitation electrode disposed at positions corresponding to the opening; a first coil having one end electrically connected to the first excitation electrode and the other end connected to a power supply circuit; a second coil, one end of which is electrically connected to the second excitation electrode; The antenna device, wherein the first coil and the second coil are disposed in a position where they are magnetically coupled.

11. the power supply circuit; An electronic device comprising the antenna device according to claim 9 .

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