Antenna device

Abstract

The antenna device includes: a power supply element having a power supply point for providing a signal in a first frequency band and a signal in a second frequency band lower than the first frequency band; a high-frequency band element connected to the power supply element and resonating with the signal in the first frequency band; a low-frequency band element connected to the power supply element and resonating with the signal in the second frequency band; an auxiliary element capacitively coupled to the low-frequency band element at an open end of the low-frequency band element; a grounded grounding member; and a switch for switching the grounding member and the auxiliary element between a conductive state and a non-conductive state.

Description

Technical Field

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

[0002] Antennas that support multiple frequency bands are known in the past (see, for example, Patent Document 1). The antenna device disclosed in Patent Document 1 includes a powered element and a passive element, and the resonant frequency of the passive element is switched depending on whether the passive element is grounded. Therefore, the antenna device disclosed in Patent Document 1 aims to transmit and receive radio waves in multiple frequency bands without increasing the size of the antenna element.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-67052 Summary of the Invention

[0006] The present disclosure provides an antenna device that can support multiple frequency bands, that is, an antenna device that can achieve both miniaturization and broadband.

[0007] An antenna device according to one embodiment of the present invention comprises: a feed element having a feed point for providing a signal in a first frequency band and a signal in a second frequency band lower than the first frequency band; a high-frequency band element connected to the feed element and resonating with the signal in the first frequency band; a low-frequency band element connected to the feed element and resonating with the signal in the second frequency band; an auxiliary element capacitively coupled with the low-frequency band element at an open end of the low-frequency band element; a grounded grounding member; and a switch for switching a conductive state and a non-conductive state between the grounding member and the auxiliary element.

[0008] According to the present disclosure, it is possible to provide an antenna device that can support multiple frequency bands and that can achieve miniaturization and widening of the bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram showing the overall structure of the antenna device according to the first embodiment.

[0010] Figure 2 This is a graph showing the relationship between the antenna efficiency and the frequency of the antenna device according to the first embodiment.

[0011] Figure 3 It is a schematic diagram showing the overall structure of the antenna device according to the second embodiment.

[0012] Figure 4 This is a schematic diagram showing the overall configuration of an antenna device according to a modified example of the second embodiment.

[0013] Figure 5 This is a schematic diagram showing the overall structure of the antenna device according to the third embodiment.

[0014] Figure 6 It is a schematic perspective view showing the overall structure of the antenna device according to the fourth embodiment.

[0015] Figure 7 This is a schematic diagram showing an example of application of the antenna device according to the fourth embodiment to a tablet-type terminal.

[0016] Figure 8 This is a schematic diagram showing an example of application of the antenna device according to the fourth embodiment to a notebook computer. DETAILED DESCRIPTION

[0017] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0018] The numerical values, shapes, materials, structural elements, configuration positions of structural elements, connection methods, steps, and the order of steps shown in the following embodiments are examples and do not limit the subject matter of the present disclosure.

[0019] In addition, each figure is a schematic diagram and does not necessarily illustrate the strict diagram. In addition, in each figure, the same structural member is given the same symbol.

[0020] (Implementation Method 1)

[0021] The antenna device according to the first embodiment will be described.

[0022] [1-1. Overall structure]

[0023] First, use Figure 1 , the overall structure of the antenna device involved in embodiment 1 is described. Figure 1 This is a schematic diagram showing the overall structure of an antenna device 10 according to this embodiment. Antenna device 10 transmits and receives signals in a first frequency band and a second frequency band. Here, the second frequency band is a frequency band lower than the first frequency band. The first and second frequency bands are not particularly limited. In this embodiment, the first frequency band is a frequency band between 1 GHz and 6 GHz, and the second frequency band is a frequency band between 0.5 GHz and less than 1.0 GHz.

[0024] like Figure 1 As shown, the antenna device 10 includes an antenna element 20 , an auxiliary element 40 , a switch 50 , and a ground member 70 .

[0025] The antenna element 20 is a conductive element that transmits and receives signals in the first frequency band and the second frequency band. The antenna element 20 includes a feed element 23, a high-frequency band element 21, and a low-frequency band element 22. In this embodiment, the feed element 23, the high-frequency band element 21, and the low-frequency band element 22 are connected at a connection portion 25. Furthermore, the high-frequency band element 21 and the low-frequency band element 22 extend from the connection portion 25 in opposite directions. The high-frequency band element 21 and the low-frequency band element 22 are arranged on the same straight line so that their longitudinal directions are aligned.

[0026] The antenna combining feed element 23 with high-band element 21 functions as a monopole antenna corresponding to the first frequency band. In other words, the electrical length of the antenna combining feed element 23 with high-band element 21 is approximately one-quarter the wavelength λ1 corresponding to a frequency f1 included in the first frequency band. Furthermore, the antenna combining feed element 23 with low-band element 22 functions as a monopole antenna corresponding to a second frequency band lower than the first. In other words, the electrical length of the antenna combining feed element 23 with low-band element 22 is approximately one-quarter the wavelength λ2 corresponding to a frequency f2 included in the second frequency band. Because the wavelength λ2 corresponding to the second frequency band is longer than the wavelength λ1 corresponding to the first frequency band, the electrical length of low-band element 22 is longer than that of high-band element 21.

[0027] The antenna element 20 is formed using a conductive material. The antenna element 20 is formed using, for example, a metal such as Cu, Al, Au, or an alloy containing multiple metals. In addition, the shape of the antenna element 20 is not particularly limited. The antenna element 20 may also have, for example, a rod-shaped, plate-shaped, sheet-shaped, or other shapes. In addition, the antenna element 20 may also be formed by a conductive film patterned on an insulating substrate. In addition, the manufacturing method of the antenna element 20 is not particularly limited, and it may be formed using a metal plate, or may be formed by plating, vapor deposition, LDS (Laser Direct Structuring), or the like.

[0028] Feed element 23 is a conductive element having a feed point 60 to which signals in the first frequency band and the second frequency band are supplied. Feed element 23 is the portion of antenna element 20 where both signals in the first frequency band and the second frequency band resonate. Feed point 60 is located at one end of feed element 23, and connector 25 is located at the other end. Signals are supplied to feed point 60 via, for example, a coaxial cable or a feed pin. When using a coaxial cable, the inner conductor of the coaxial cable is connected to feed point 60, and the outer conductor of the coaxial cable is connected to ground member 70. Impedance adjustment can also be performed by connecting a lumped constant circuit to feed point 60.

[0029] High-band element 21 is a conductive element connected to feed element 23 and resonates with signals in the first frequency band. High-band element 21 is the portion of antenna element 20 that primarily resonates with signals in the first frequency band. High-band element 21 has an elongated shape, with one end connected to connector 25 and the other end being an open end 21e.

[0030] Low-band element 22 is a conductive element connected to feed element 23 and resonates with signals in the second frequency band. Low-band element 22 is the portion of antenna element 20 that primarily resonates with signals in the second frequency band. Low-band element 22 has an elongated shape, one end of which is connected to connector 25 and the other end is an open end 22e.

[0031] The auxiliary element 40 is a conductive element that is capacitively coupled to the open end 22e of the low-frequency band element 22 and is adjacent to the low-frequency band element 22. One end of the auxiliary element 40 is connected to the input terminal 51 of the switch 50. The coupling capacitance between the auxiliary element 40 and the low-frequency band element 22 can be adjusted to a desired value by adjusting the spacing between the auxiliary element 40 and the adjacent low-frequency band element 22 and the wiring length (in other words, the length of the portion adjacent to the low-frequency band element 22). The spacing between the auxiliary element 40 and the low-frequency band element 22 is less than 1 / 100 of the wavelength corresponding to a frequency f2 included in the second frequency band. In this embodiment, the spacing between the auxiliary element 40 and the low-frequency band element 22 is approximately 0.5 mm. In addition, the electrical length of the auxiliary element 40 is less than 1 / 8 of the wavelength corresponding to a frequency f2 included in the second frequency band. The auxiliary element 40 is formed using a conductive material. For example, the auxiliary element 40 is formed using a metal such as Cu, Al, Au, or an alloy containing multiple metals.

[0032] Grounding member 70 is a grounded conductive member. Grounding member 70 functions as a ground for antenna element 20. Grounding member 70 is connected to output terminal 52 of switch 50. Grounding member 70 is formed using a conductive material. For example, grounding member 70 can be formed using a metal such as Mg, Cu, Al, or Au, or an alloy containing multiple metals.

[0033] The switch 50 is an element that switches between the conduction and non-conduction between the grounding member 70 and the auxiliary element 40. The switch 50 switches between the conduction and non-conduction between the input terminal 51 and the output terminal 52. The input terminal 51 is connected to the auxiliary element 40, and the output terminal 52 is connected to the grounding member 70. The switch 50 is not particularly limited as long as it is an element that switches between the conduction and non-conduction between the grounding member 70 and the auxiliary element 40. For example, an SPDT (Single-Pole Double-Throw) switch can be used as the switch 50. In this case, as Figure 1As shown, the switch 50 has one input terminal 51 and two output terminals 52 and 53. Output terminal 52 is connected to the ground member 70, while output terminal 53 is open. In other words, when the input terminal 51 and output terminal 52 of the switch 50 are connected, the auxiliary element 40 and the ground member 70 are in a conductive state, and when the input terminal 51 and output terminal 53 are connected, the auxiliary element 40 and the ground member 70 are in a non-conductive state.

[0034] Furthermore, output terminals 52 and 53 can also be configured to be conductive or non-conductive with ground member 70 via a desired impedance, similar to conductive or non-conductive, respectively. For example, the impedance can be formed using lumped constant elements such as inductance (L) and capacitance (C) suitable for adjusting a frequency f3 included in the second frequency band. Switch 50 can also be configured with three or more terminals (SP3T, SP4T, etc.). For example, switch 50 can have three or more switching paths, and the switching paths in which switch 50 is conductive can also include two or more switching paths with different impedances. Furthermore, switch 50 can have three or more switching paths, and the switching paths in which switch 50 is non-conductive can also include two or more switching paths with different impedances. For example, switch 50 provides a control signal for switching between a frequency f2 and a frequency f3 included in the second frequency band of the antenna, based on the communication band (frequency) used in wireless communications.

[0035] [1-2. Action and effect]

[0036] Next, use Figure 2 , the functions and effects of the antenna device 10 according to this embodiment will be described. Figure 2 : is a graph showing the relationship between the antenna efficiency (Antenna Efficiency) and the frequency (Frequency) of the antenna device 10 according to this embodiment. Figure 2 The solid line, dotted line, and dashed line curves in the graph represent the antenna efficiencies at the resonant frequencies f1, f2, and f3, respectively.

[0037] As described above, antenna device 10 includes a monopole antenna corresponding to the first frequency band, including feed element 23 of antenna element 20 and high-band element 21. In other words, the electrical length of the monopole antenna, including feed element 23 and high-band element 21, is approximately one-quarter the wavelength λ1 corresponding to a single frequency f1 included in the first frequency band.

[0038] Furthermore, when switch 50 is in the non-conductive state, a monopole antenna corresponding to the second frequency band is formed, comprising feed element 23 and low-band element 22. In other words, the electrical length of the monopole antenna comprising feed element 23 and low-band element 22 is approximately one-quarter the wavelength λ2 corresponding to a frequency f2 included in the second frequency band. On the other hand, when switch 50 is in the conductive state, a loop antenna corresponding to the second frequency band is formed, comprising feed element 23, low-band element 22, auxiliary element 40, and ground member 70. In this case, the electrical length of the loop antenna comprising feed element 23, low-band element 22, auxiliary element 40, switch 50, and ground member 70 is approximately one-half the wavelength λ3 corresponding to a frequency f3 included in the second frequency band. Furthermore, by adjusting the capacitive coupling of auxiliary element 40 and the impedance of switch 50, the electrical length of the loop antenna can be adjusted without changing the antenna dimensions.

[0039] In this way, the antenna device 10 functions as a multi-band antenna that transmits and receives signals in the first frequency band and signals in the second frequency band. Figure 2 As shown, the resonant frequency in the second frequency band of the antenna device 10 is widened by making the resonant frequency f2 of the monopole antenna corresponding to the second frequency band including the feed element 23 and the low-frequency band element 22 different from the resonant frequency f3 of the loop antenna corresponding to the second frequency band including the feed element 23, the low-frequency band element 22, the auxiliary element 40 and the ground member 70.

[0040] Furthermore, in this embodiment, auxiliary element 40 is not a passive element capable of resonating as an antenna by itself, as described in Patent Document 1. Instead, it is an element that is capacitively coupled adjacent to low-band element 22. Therefore, the electrical length of auxiliary element 40 can be less than 1 / 8 of the wavelength corresponding to a frequency included in the second frequency band. Therefore, in this embodiment, since auxiliary element 40 can be miniaturized, it can be further miniaturized than when using a passive element, as in the antenna device described in Patent Document 1.

[0041] Furthermore, when parasitic elements are used, the frequency band that can be widened is limited to the narrow frequency band that can be resonated by the parasitic elements. On the other hand, in this embodiment, since a loop antenna is formed that includes components such as the ground member 70 that have a high degree of freedom in shape and size, it is possible to achieve a wider bandwidth than when parasitic elements are used.

[0042] Furthermore, the auxiliary element 40 is capacitively coupled to the low-band element 22 at the open end 22e of the low-band element 22. In other words, the auxiliary element 40 is capacitively coupled to the portion of the low-band element 22 that is farthest from the high-band element 21. Therefore, the influence of the auxiliary element 40 on the high-band element 21 can be suppressed. In other words, the influence on the characteristics of the high-band element 21 caused by the switching of the conductive state of the switch 50 can be suppressed. Specifically, the Figure 2 The antenna efficiency of antenna device 10 at resonant frequency f1 shown in FIG. 1 varies due to the switching of switch 50. Furthermore, in this embodiment, the distance between auxiliary element 40 and low-band element 22 is less than 1 / 100 of the wavelength corresponding to a frequency included in the second frequency band. This ensures reliable capacitive coupling between auxiliary element 40 and low-band element 22. Furthermore, since the distance between auxiliary element 40 and low-band element 22 can be shortened, further miniaturization of antenna device 10 is possible.

[0043] (Implementation Method 2)

[0044] The antenna device according to Embodiment 2 will be described. The antenna device according to this embodiment differs from antenna device 10 according to Embodiment 1 in that the antenna element forms a so-called inverted-F antenna. The following description of the antenna device according to this embodiment will focus on the differences from antenna device 10 according to Embodiment 1.

[0045] [2-1. Overall structure and effects]

[0046] use Figure 3 The overall structure and effects of the antenna device according to this embodiment will be described. Figure 3 Schematic diagram showing the overall structure of the antenna device 110 according to this embodiment. Figure 3 As shown, antenna device 110 according to this embodiment includes antenna element 20 , auxiliary element 40 , switch 50 , and ground member 70 , similarly to antenna device 10 according to Embodiment 1. Antenna device 110 according to this embodiment further includes short-circuit element 130 .

[0047] Short-circuit element 130 is a conductive element that connects ground member 70 to feed element 23. Antenna element 20 and short-circuit element 130 form an inverted-F antenna. By forming an inverted-F antenna, the resonant frequency band of antenna device 110 in the second frequency band can be widened.

[0048] [2-2. Modifications]

[0049] exist Figure 3In the antenna device 110 shown in FIG. 1 , the short-circuit element 130 connects the ground member 70 to the feed element 23. However, the short-circuit element 130 does not necessarily need to be connected to the feed element 23. Figure 4 A modified example of the antenna device including the short-circuit element will be described. Figure 4 It is a schematic diagram showing the overall configuration of an antenna device 110 a according to a modification of the present embodiment.

[0050] like Figure 4 As shown, the antenna device 110a according to this variation, like antenna device 110, includes: an antenna element 20, an auxiliary element 40, a switch 50, a grounding member 70, and a short-circuit element 130a. The short-circuit element 130a according to this variation connects the grounding member 70 to the low-band element 22. Furthermore, the short-circuit element 130a is connected to the low-band element 22 at a position closer to the open end 22e than the center in the longitudinal direction of the low-band element 22. Thus, the feed element 23, the low-band element 22, and the short-circuit element 130a form a folded-back antenna. This further broadens the resonant frequency band in the second frequency band of the antenna device 110a.

[0051] (Implementation 3)

[0052] The antenna device according to Embodiment 3 will be described. The antenna device according to this embodiment differs from antenna device 10 according to Embodiment 1 in the structure of the ground member. The following description will focus on the differences between the antenna device according to this embodiment and antenna device 10 according to Embodiment 1.

[0053] use Figure 5 Next, the overall structure of the antenna device according to this embodiment will be described. Figure 5 Schematic diagram showing the overall structure of the antenna device 210 according to this embodiment. Figure 5 As shown, the antenna device 210 according to this embodiment includes the antenna element 20 , the auxiliary element 40 , the switch 50 , and the ground member 270 , similarly to the antenna device 10 according to the first embodiment.

[0054] The grounding member 270 of this embodiment includes a coupling portion 271 separated from the open end 22e of the low-band element 22 in the longitudinal direction of the low-band element 22. The coupling portion 271 and the open end 22e of the low-band element 22 are arranged opposite each other in the longitudinal direction of the low-band element 22. An auxiliary element 40 is disposed between the open end 22e of the low-band element 22 and the coupling portion 271. The auxiliary element 40 is adjacent to the coupling portion 271 and capacitively coupled to the coupling portion 271. In other words, the auxiliary element 40 is capacitively coupled to both the low-band element 22 and the coupling portion 271. The spacing between the auxiliary element 40 and the coupling portion 271 can also be less than 1 / 100 of the wavelength corresponding to a frequency f1 included in the first frequency band. This ensures reliable capacitive coupling between the auxiliary element 40 and the coupling portion 271. Thus, by capacitively coupling the auxiliary element 40 and the coupling portion 271, the higher harmonic components of the low-band element 22 are transmitted via the auxiliary element 40 to the coupling portion 271, which is part of the grounding member. In other words, the harmonic components can be suppressed from circulating back to the switch 50 connected to the auxiliary element 40. Therefore, the influence of switching the conductive state of the switch 50 on the characteristics of the frequency f1 included in the first frequency band can be greatly suppressed.

[0055] Furthermore, when capacitively coupling the auxiliary element 40 and the coupling portion 271, the distance between the auxiliary element 40 and the coupling portion 271 can be shortened, thereby further miniaturizing the antenna device 210. In this embodiment, the distance between the auxiliary element 40 and the coupling portion 271 is approximately 0.5 mm.

[0056] (Implementation 4)

[0057] The antenna device according to Embodiment 4 is described. The antenna device according to this embodiment differs from antenna device 210 according to Embodiment 3 in that the antenna element is formed on an insulating substrate. The following description of the antenna device according to this embodiment focuses on the differences from antenna device 210 according to Embodiment 3.

[0058] [4-1. Overall structure and effects]

[0059] First, use Figure 6 The overall structure and effects of the antenna device according to this embodiment will be described. Figure 6 : is a schematic perspective view showing the overall structure of the antenna device 310 involved in this embodiment. Figure 6As shown, antenna device 310 according to this embodiment, like antenna device 210 according to Embodiment 3, includes an antenna element 320, an auxiliary element 340, a switch 350, and a ground member 370. Antenna device 310 according to this embodiment further includes a short-circuit element 330, ground elements 314 and 316, and an insulating substrate 312.

[0060] The grounding member 370 of this embodiment has a rectangular parallelepiped shape. For example, a metal housing of a portable terminal or the like can be used as the grounding member. The grounding member 370 has a recess 372 and a coupling portion 371 that includes at least a portion of the inner surface of the recess 372.

[0061] Insulating substrate 312 is an insulating substrate on which switch 350 is mounted. Antenna element 320 and auxiliary element 340 are formed on insulating substrate 312. In this embodiment, grounding elements 314 and 316 and short-circuit element 330 are also formed on insulating substrate 312. For example, a printed circuit board can be used as insulating substrate 312. Thus, by including insulating substrate 312 in antenna device 310, patterning the conductive film allows antenna element 320 and other components to be easily formed into any desired shape on insulating substrate 312.

[0062] In this embodiment, the insulating substrate 312 is a flexible substrate. This allows the insulating substrate 312 to be deformed to match the shape of the grounding member 370 and other components. The insulating substrate 312 includes a first portion 312a having a width W1 in the thickness direction of the grounding member 370, and a second portion 312b having a height H1 that is bent substantially perpendicularly to the first portion 312a. The width W1 of the first portion 312a and the height H1 of the second portion 312b of the insulating substrate 312 are approximately the same. The length L1 of the insulating substrate 312 (the dimension perpendicular to the width W1 and the height H1) is approximately five times the width W1 and the height H1.

[0063] The insulating substrate 312 is fixed to the ground member 370. The insulating substrate 312 is disposed in the recess 372 of the ground member 370. This prevents the insulating substrate 312 from protruding from the ground member 370, allowing the ground member 370 to surround the insulating substrate 312 and at least a portion of each element disposed thereon. Thus, by providing a robust structure for the ground member 370, a robust antenna device 310 can be realized. Furthermore, by disposing the insulating substrate 312 in the recess 372, the portion of the recess 372 facing the auxiliary element 340 can be utilized as the coupling portion 371.

[0064] The insulating substrate 312 may be fixed using, for example, conductive screws or the like that electrically connect the ground member 370 and the ground elements 314 and 316 formed on the insulating substrate 312 .

[0065] The antenna element 320 in this embodiment is a conductive film formed on an insulating substrate 312. It includes a feed element 323, a high-band element 321, and a low-band element 322. In this embodiment, the feed element 323 is located on the second portion 312b of the insulating substrate 312, while the high-band element 321 and the low-band element 322 are located on the first portion 312a of the insulating substrate 312. Thus, the antenna elements 320 do not need to be located on the same plane, and may be located on multiple, non-parallel planes.

[0066] Feeding element 323 has a feeding point 360. Feeding element 323 is a rectangular conductive film. By providing a width perpendicular to the signal's resonance direction, feeding element 323 can broaden the resonant frequency band. Feeding point 360 is connected to the inner conductor of a coaxial cable 362 that transmits signals in the first and second frequency bands.

[0067] High-band element 321 is a conductive film having a rectangular shape with a width of approximately W1. By providing a width perpendicular to the signal's resonance direction, high-band element 321 can broaden the resonant frequency band within the first frequency band. One end of high-band element 321 is connected to connector 325, and the other end is an open end 321e.

[0068] Low-band element 322 is a rectangular conductive film with a width of approximately W1. It is located on first portion 312a of insulating substrate 312. By providing a width perpendicular to the signal's resonant direction, low-band element 322 can achieve a wider resonant frequency band. One end of low-band element 322 is connected to connector 325, and the other end is an open end 322e.

[0069] The auxiliary element 340 is a conductive film formed on the insulating substrate 312. The auxiliary element 340 is capacitively coupled to at least a portion of the open end 322e of the low-band element 322. In this embodiment, Figure 6As shown, the auxiliary element 340 includes a portion disposed on the first portion 312a of the insulating substrate 312 and a portion disposed on the second portion 312b. The portion of the auxiliary element 340 disposed on the first portion 312a is capacitively coupled to the open end 322e of the low-band element 322 across a gap G1. Furthermore, the portion of the auxiliary element 340 disposed on the second portion 312b is capacitively coupled to the edge of the open end 322e connected to the low-band element 322 across a gap G3. This allows the auxiliary element 340 to be capacitively coupled not only to the open end 322e of the low-band element 322 but also to the edge of the open end 322e, thereby enabling more reliable capacitive coupling.

[0070] The auxiliary element 340 is capacitively coupled to the coupling portion 371 of the ground member 370 via the gap G2. In this embodiment, the gap between the auxiliary element 340 and the coupling portion 371 of the ground member 370 is approximately 0.5 mm.

[0071] The grounding element 314 is a conductive element formed from a conductive film disposed on the insulating substrate 312 and connected to the grounding member 370. The grounding element 314 is disposed on the second portion 312b of the insulating substrate 312, opposite the power feed point 360 of the power feed element 323, and is connected to the outer conductor of the coaxial cable 362. The method of connecting the grounding element 314 to the grounding member 370 is not particularly limited. For example, the grounding element 314 can be connected to the grounding member 370 using a conductive screw, etc. Alternatively, the screw can secure the insulating substrate 312 to the grounding member 370. Alternatively, the grounding element 314 can be connected to the grounding member 370 using a conductive tape, etc.

[0072] The grounding element 316 is formed from a conductive film disposed on the insulating substrate 312. It is connected to the switch 350 and to the grounding member 370, thereby being grounded. The grounding element 316 is disposed on the second portion 312b of the insulating substrate 312, at a position opposing the auxiliary element 340. In this embodiment, the area occupied by the grounding element 316 on the insulating substrate 312 is larger than the area occupied by the auxiliary element 340 on the insulating substrate 312. This allows the potential of the grounding element 316 to be stably maintained. Therefore, by connecting the grounding element 316 and the auxiliary element 340 using the switch 350, the potential of the auxiliary element 340 can be stably maintained at the ground potential. The connection method between the grounding element 316 and the grounding member 370 is similar to the connection method between the grounding element 314 and the grounding member 370 and is not particularly limited.

[0073] The switch 350 switches between conductive and non-conductive states between the grounding member 370 and the auxiliary element 340. In this embodiment, the switch 350 is mounted on the insulating substrate 312 and connected to the grounding member 370 via the grounding element 316. The switch 350 is directly connected to the grounding element 316 and the auxiliary element 340. This minimizes the electrical length between the auxiliary element 340 and the grounding element 316. Therefore, when the switch 350 is in the conductive state, the potential of the auxiliary element 340 can be stably maintained at the ground potential.

[0074] In this embodiment, switch 350 is controlled by a control signal. The control signal for controlling switch 350 is input from outside insulating substrate 312. This allows the control circuitry that outputs the control signal to be located outside insulating substrate 312. For example, the control signal may be output from a communication module that generates signals of the first frequency band and the second frequency band for input to power supply point 360. For example, the communication module may output a control signal corresponding to the frequency band in use to switch 350. Furthermore, the communication module may be located on grounding member 370.

[0075] Switch 350 can also be covered with resin. For example, switch 350 can be covered with insulating substrate 312 and potting resin, with the potting resin and insulating substrate 312 being sealed liquid-tightly. This makes switch 350 waterproof. In particular, when grounding member 370 forms the chassis of the waterproof terminal, switch 350 is located outside the waterproof terminal and may be submerged in water. Even in this case, by covering switch 350 with resin, switch 350 can be made waterproof.

[0076] The short-circuit element 330 connects the ground member 370 and the low-band element 322 . In this embodiment, the short-circuit element 330 is disposed on the second portion 312 b of the insulating substrate 312 and is connected to the ground member 370 via the ground element 314 .

[0077] [4-2. Application Examples]

[0078] Next, use Figure 7 as well as Figure 8 An application example of the antenna device 310 according to this embodiment will be described. Figure 7 as well as Figure 8 These are schematic diagrams showing application examples of the antenna device 310 according to the present embodiment to a tablet terminal 300 and a notebook computer 301 .

[0079] like Figure 7 as well as Figure 8As shown, the antenna device 310 according to this embodiment can be applied to a tablet terminal 300 , a notebook computer 301 , and the like.

[0080] like Figure 7 As shown in FIG. 3 , the antenna device 310 is disposed inside the tablet terminal 300. The placement of the antenna device 310 in the tablet terminal 300 is not particularly limited, but may be as follows: Figure 7 As shown, it is arranged in the frame portion of the tablet terminal.

[0081] like Figure 8 As shown, the antenna device 310 is arranged inside the notebook computer 301. The arrangement of the antenna device 310 in the notebook computer 301 is not particularly limited, but may be as follows. Figure 8 As shown, it is arranged in the frame portion of the display of the notebook computer 301.

[0082] As the ground member 370 of the antenna device 310 , for example, a metal chassis of the tablet terminal 300 or the notebook computer 301 can be used.

[0083] (Modifications, etc.)

[0084] The present disclosure has been described above based on the above embodiments, but the present disclosure is not limited to the above embodiments. Various modifications that can be made to the above embodiments by those skilled in the art without departing from the spirit of the present disclosure are also within the scope of the present disclosure.

[0085] For example, a portion of the high-band element of the antenna device according to each of the above embodiments may have a meandering structure that suppresses propagation of signals in the second frequency band.

[0086] The shape of the antenna element included in the antenna device according to the above embodiments is not limited to the shapes exemplified in the above embodiments. The feed element, high-band element, and low-band element of the antenna element may each have an elliptical shape or may be curved.

[0087] Furthermore, embodiments in which the structural elements and functions in each embodiment are arbitrarily combined and implemented without departing from the gist of the present disclosure are also included in the present disclosure.

[0088] For example, the antenna device 210 according to the third embodiment may further include the short-circuit element 130 or the short-circuit element 130a according to the second embodiment, and the antenna device 310 according to the fourth embodiment may include the short-circuit element 130 according to the second embodiment instead of the short-circuit element 330. Furthermore, the antenna device 310 according to the fourth embodiment may not include the short-circuit element 330.

[0089] Industrial applicability

[0090] The multi-band antenna of the present disclosure can be utilized as a part of an array antenna for a wireless module used in, for example, an audio device or the like.

[0091] -Explanation of symbols-

[0092] 10, 110, 110a, 210, 310 antenna devices

[0093] 20, 320 antenna elements

[0094] 21, 321 high-frequency band components

[0095] 21e, 22e, 321e, 322e open end

[0096] 22, 322 low-band components

[0097] 23, 323 power supply components

[0098] 25, 325 connection

[0099] 40, 340 auxiliary components

[0100] 50, 350 switch

[0101] 51 Input terminals

[0102] 52, 53 output terminals

[0103] 60, 360 power supply points

[0104] 70, 270, 370 grounding components

[0105] 130, 130a, 330 short-circuit elements

[0106] 271, 371 coupling part

[0107] 300 tablet terminal

[0108] 301 Laptop

[0109] 312 Insulation Substrate

[0110] 312a Part 1

[0111] 312b Part 2

[0112] 314, 316 grounding elements

[0113] 362 coaxial cable

[0114] 372 Recess.

Claims

1. An antenna device comprising: a power supply element having a power supply point for supplying a signal of a first frequency band and a signal of a second frequency band lower than the first frequency band; a high frequency band component connected to the power supply component, and resonating with a signal of the first frequency band; a low-frequency band element connected to the power supply element, and resonating with a signal of the second frequency band; an auxiliary element, at an open end of the low-band element, capacitively coupled to the low-band element; Grounded components that are grounded; and a switch for switching the conductive state and the non-conductive state between the grounding member and the auxiliary element; The ground member includes a coupling portion that is spaced apart from the open end of the low-band element in the longitudinal direction of the low-band element and is arranged to face the open end of the low-band element. The auxiliary element is arranged between the open end of the low-band element and the coupling portion, The auxiliary element is adjacent to the coupling portion and performs capacitive coupling.

2. The antenna device according to claim 1, wherein When the switch is in the non-conductive state, a monopole antenna including the feed element and the low-band element is formed. When the switch is in the on state, a loop antenna including the feed element, the low-frequency band element, the auxiliary element, and the ground member is formed.

3. The antenna device according to claim 1 or 2, wherein: The switch has more than three switching paths, The switching path in which the switch is in the on-state includes two or more switching paths having different impedances.

4. The antenna device according to claim 1 or 2, wherein: The electrical length of the auxiliary element is smaller than 1 / 8 of a wavelength corresponding to a frequency included in the second frequency band.

5. The antenna device according to claim 1 or 2, wherein: The auxiliary element is spaced apart from the low-frequency band element by less than 1 / 100 of a wavelength corresponding to one frequency included in the second frequency band.

6. The antenna device according to claim 1 or 2, wherein: The distance between the auxiliary element and the coupling portion is smaller than 1 / 100 of a wavelength corresponding to one frequency included in the first frequency band.

7. The antenna device according to claim 1 or 2, wherein: The antenna device further includes a short-circuit element connecting the ground member to the feed element or the low-band element.

8. The antenna device according to claim 1 or 2, wherein: The antenna device further comprises: an insulating substrate on which the switch is mounted; The power supply element, the high-band element, the low-band element, and the auxiliary element are conductive films formed on the insulating substrate. The insulating substrate is fixed to the ground member.

9. The antenna device according to claim 8, wherein: The antenna device further includes: a ground element formed of a conductive film disposed on the insulating substrate; The grounding element is connected to the switch and to the grounding member.

10. The antenna device according to claim 8, wherein The grounding member has a recessed portion, The insulating substrate is arranged in the recessed portion.

11. The antenna device according to claim 8, wherein The switch is covered with resin.

12. The antenna device according to claim 8, wherein A control signal for controlling the switch is input from outside the insulating substrate.

13. The antenna device according to claim 8, wherein The insulating substrate is a flexible substrate.

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