JP6394277B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device including an array antenna in which a plurality of radiation electrodes are provided on a substrate.

  Patent Document 1 discloses a configuration in which a planar antenna (patch antenna) is provided separately in an opening of a conductor plate. At this time, the planar antenna includes a single radiating element (radiating electrode) provided on the dielectric substrate and a ground.

JP 2007-259373 A

  By the way, in the antenna device described in Patent Document 1, radiation of sound waves from the opening is not taken into consideration, and the periphery of the planar antenna is surrounded by a fixing member made of, for example, a nonmetallic material. For this reason, radio waves from the planar antenna can be radiated from the opening, but sound waves cannot be radiated.

  In addition, the planar antenna described in Patent Document 1 includes a single radiating element and does not include a plurality of radiating elements. For this reason, there exists a problem that the radiation | emission direction of an electromagnetic wave cannot be adjusted actively, for example.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an antenna device capable of emitting radio waves and sound waves from an opening.

  In order to solve the above-described problem, an antenna device according to the invention of claim 1 is opposed to an array antenna in which a plurality of radiation electrodes capable of emitting radio waves of a predetermined wavelength and a ground electrode are provided on a substrate, and the substrate. Formed between the conductor plate and the array antenna, and a plurality of openings provided in the conductor plate at positions corresponding to some of the plurality of radiation electrodes. And a sound wave transmission unit capable of transmitting sound waves, wherein the radiation electrode has a length dimension equal to or less than half of the predetermined wavelength, and the ground electrode has a length dimension equal to or greater than the predetermined wavelength. The interval between the plurality of openings is set to be half or more of the predetermined wavelength.

  In a second aspect of the present invention, the plurality of openings are respectively arranged at positions corresponding to the plurality of radiation electrodes.

  In the invention of claim 3, the conductor plate is provided with a sheet member that covers the opening and has a dustproof and waterproof property.

  In the invention of claim 4, the substrate of the array antenna is formed of a rigid flexible substrate or a flexible substrate.

  According to the first aspect of the present invention, the conductor plate is provided with a plurality of openings, and the openings are arranged at positions corresponding to some of the radiation electrodes. For this reason, the radio wave by a radiation electrode can be radiated | emitted through an opening part. Further, since the sound wave transmission unit is formed between the conductor plate and the array antenna, the sound wave can be transmitted to the opening of the conductor plate through the sound wave transmission unit. For this reason, it is possible to radiate both radio waves and sound waves from the opening of the conductor plate. Furthermore, since the array antenna includes a plurality of radiation electrodes and the conductor plate is provided with a plurality of openings, radio waves can be radiated from the plurality of radiation electrodes through the plurality of openings. For this reason, for example, by adjusting the phase of radio waves from a plurality of radiation electrodes, the radiation direction of radio waves can be actively adjusted.

  According to the invention of claim 2, since the plurality of openings are respectively arranged at positions corresponding to the plurality of radiation electrodes, each opening can be opened with a length dimension corresponding to the radiation electrode. For this reason, the opening can pass radio waves having a predetermined wavelength corresponding to the radiation electrode and block radio waves having a longer wavelength than the predetermined wavelength. As a result, even when a radio wave having a wavelength longer than the predetermined wavelength is radiated by the ground electrode having a length dimension greater than or equal to the predetermined wavelength, it is possible to prevent the radio wave having the long wavelength from being output from the opening.

  According to the invention of claim 3, since the conductive plate is provided with the dust-proof and waterproof sheet member that covers the opening, the sheet member can prevent the entry of dust, water droplets, etc. from the opening, The reliability and durability of the array antenna can be improved. Further, since the sheet member is formed of, for example, a non-conductive material capable of air circulation and vibration, radio waves and sound waves can pass through the sheet member.

  According to the invention of claim 4, since the substrate of the array antenna is formed of a rigid flexible substrate or a flexible substrate, for example, even when the conductor plate is bent or curved, the array antenna is attached along the shape of the conductor plate. be able to.

It is a front view which shows the tablet terminal to which the antenna apparatus by 1st Embodiment is applied. It is a rear view which shows the tablet terminal in FIG. It is a rear view which expands and shows the A section in FIG. It is sectional drawing which looked at the antenna apparatus from the arrow IV-IV direction in FIG. It is sectional drawing which expands and shows the circumference | surroundings of the single radiation electrode in FIG. It is a top view which shows an array antenna alone. It is a bottom view which shows an array antenna alone. It is a rear view of the position similar to FIG. 3 which shows the antenna apparatus by 2nd Embodiment. It is sectional drawing of the position similar to FIG. 4 which shows the antenna apparatus by 3rd Embodiment. It is sectional drawing of the position similar to FIG. 4 which shows the antenna apparatus by 4th Embodiment. It is sectional drawing of the position similar to FIG. 4 which shows the antenna apparatus by a modification.

  Hereinafter, a case where an antenna device according to an embodiment of the present invention is applied to a tablet terminal (tablet computer) will be described in detail with reference to the accompanying drawings.

  1 to 7 show a tablet terminal 1 to which the antenna device 10 according to the first embodiment is applied. For convenience of explanation, an arrow X direction in FIGS. 2 to 4 is a width direction, an arrow Y direction is a length direction, and an arrow Z direction is a thickness direction.

  The tablet terminal 1 includes a housing 2, a display device 6, a built-in speaker 7, and the like. The housing | casing 2 comprises the outer shell of the tablet terminal 1, and is formed in the substantially rectangular parallelepiped box shape. The housing 2 includes a front surface side case 3 that covers the front surface side of the tablet terminal 1 and a back surface side case 4 that covers the back surface side of the tablet terminal 1.

  The front side case 3 is formed in a rectangular flat plate shape, and a display mounting portion 5 having a rectangular opening is formed in the center thereof. For this reason, the front side case 3 is formed in a rectangular frame shape.

  A display device 6 made of, for example, a liquid crystal panel or the like is fitted into the display mounting portion 5 of the front side case 3. The display device 6 displays various information to the operator. In addition, the display device 6 has a touch panel function that enables various input operations by the operator.

  The back side case 4 is formed of, for example, a conductive metal plate and constitutes a conductor plate. The back surface side case 4 is formed in a rectangular box shape having an open front side, and has a flat bottom surface portion 4A and four side surfaces extending along the thickness direction from the outer peripheral edge of the bottom surface portion 4A toward the surface. Part 4B.

  A built-in speaker 7 as a sound wave generator is attached to one side in the length direction of the bottom surface portion 4A (the lower side in FIGS. 1 and 2). The bottom surface portion 4A is formed with a plurality of openings 9A and 9B that are located in the vicinity of the built-in speaker 7 and are capable of outputting the sound wave S from the built-in speaker 7. A mounting substrate 8 is accommodated inside the housing 2, and an array antenna 11 described later is attached to the mounting substrate 8 at a position facing the plurality of openings 9 </ b> A. The built-in speaker 7 and the display device 6 are connected to a processing device (not shown) such as a microcomputer, and perform screen display and output of sound waves S based on signals from the processing device.

  The openings 9A and 9B are, for example, circular openings that penetrate the bottom surface 4A in the thickness direction. The openings 9A and 9B are provided in the vicinity of the built-in speaker 7 on one side in the length direction of the bottom surface 4A (the lower side in FIGS. 1 and 2). For this reason, the openings 9 </ b> A and 9 </ b> B output the sound wave S from the built-in speaker 7 to the outside of the housing 2.

  As shown in FIGS. 3 and 4, the opening 9 </ b> A is provided to face the array antenna 11 and is disposed at a position corresponding to the radiation electrode 15 of the array antenna 11. Specifically, the six openings 9 </ b> A are disposed at positions corresponding to the six radiation electrodes 15, for example. For this reason, the center position of each opening 9A and the center position of each radiation electrode 15 substantially coincide. In addition to the sound wave S, the opening 9 </ b> A outputs a high-frequency signal RF including, for example, a millimeter wave or a submillimeter wave from the radiation electrode 15 to the outside of the housing 2. That is, the opening 9A serves both as radio wave radiation and sound wave radiation.

  Here, the plurality of openings 9 </ b> A have a spacing dimension Lax, Lay (spacing dimension at the center position) adjacent to each other in the X direction and the Y direction that is half the wavelength λ of the high-frequency signal RF output from the array antenna 11 (λ / 2) Arranged so as to be above. The inner diameter of the opening 9A is set to a value larger than the outer dimensions Lex and Ley of the radiation electrode 15, and is set to a value smaller than the outer dimensions Lgx and Lgy of the ground electrode 16. Preferably, the inner diameter of the opening 9A is set to a value larger than, for example, a half wavelength (λ / 2) of the high-frequency signal RF and smaller than one wavelength λ of the high-frequency signal RF.

  The antenna device 10 includes a back side case 4, an array antenna 11, and the like. The array antenna 11 includes a substrate 12, a radiation electrode 15, a ground electrode 16, and the like. The array antenna 11 outputs a high frequency signal RF (radio wave) from the plurality of radiation electrodes 15. Further, the high-frequency signals RF radiated from the plurality of radiation electrodes 15 are appropriately adjusted in phase, amplitude and the like. Thereby, the array antenna 11 can actively adjust the radiation direction of the high-frequency signal RF.

  The substrate 12 is a multilayer substrate formed in a flat plate shape extending in the X direction and the Y direction. The substrate 12 includes, for example, resin layers 13 and 14 as insulating layers, and these two resin layers 13 and 14 are laminated. In addition, although the resin substrate is illustrated as the board | substrate 12, it is not restricted to this, The ceramic multilayer substrate which laminated | stacked the insulating ceramic layer as an insulating layer may be sufficient, and a low-temperature simultaneous baking ceramic multilayer substrate (LTCC multilayer substrate) may be sufficient.

  For example, six radiation electrodes 15 are formed on the exposed surface of the resin layer 13 (the upper surface of the resin layer 13 in FIG. 4). As shown in FIGS. 3, 6 and 7, the six radiation electrodes 15 are arranged in a matrix of 2 rows and 3 columns. For this reason, the three radiation electrodes 15 are arranged at equal intervals in the X direction, and are separated from the remaining three radiation electrodes 15 in the Y direction. At this time, the interval dimension (separation interval) between the centers of the adjacent radiation electrodes 15 is set so that the X direction is Lx and the Y direction is Ly.

  The radiation electrode 15 is formed of, for example, a substantially rectangular conductor pattern. This conductor pattern is formed of, for example, a conductive thin film such as copper or silver. The dimensions Lex and Ley in the X direction and the Y direction of the radiation electrode 15 are, for example, about several mm to several hundred μm, and preferably 1 mm or less. The dimension Lex in the X direction of the radiation electrode 15 is set so that the electrical length becomes, for example, a length dimension equal to or less than a half wavelength (λ / 2) of the wavelength λ of the high-frequency signal RF to be fed. As a result, the radiation electrode 15 can radiate radio waves having a wavelength λ (high-frequency signal RF).

  The ground electrode 16 is formed between the resin layer 13 and the resin layer 14 so as to face the radiation electrode 15 and cover substantially the entire surface of the resin layer 13. The ground electrode 16 is formed of, for example, a conductive thin film such as copper or silver, and is connected to an external ground. The ground electrode 16 has lengths Lgx and Lgy that are equal to or longer than the wavelength λ of the high-frequency signal RF in the X and Y directions.

  As shown in FIG. 5, the ground electrode 16 is provided with a via opening 17 including, for example, a circular opening in order to form the via 18. The opening diameter of the via opening 17 is formed larger than the inner diameter of the via 18. For this reason, the via 18 and the ground electrode 16 are insulated by the clearance between the via 18 and the via opening 17.

  The via 18 is a columnar conductor in which a conductive material such as copper or silver is provided in a through hole having an inner diameter of about several tens to several hundreds of μm. One end side of the via 18 is connected to, for example, an intermediate position in the X direction except for the center of the radiation electrode 15 as a feeding point. As shown in FIGS. 6 and 7, the other end side of the via 18 is connected to the feed line 19.

  The feed line 19 is, for example, a microstrip line, and includes a strip-like strip line 20 provided on the exposed surface of the resin layer 14 (the lower surface of the resin layer 14 in FIG. 4) and the ground electrode 16. The feed line 19 supplies a high frequency signal RF to the radiation electrode 15. For this reason, the feed line 19 constitutes a patch antenna together with the radiation electrode 15 and the ground electrode 16.

  The front end portion of the strip line 20 penetrates through the resin layers 13 and 14 and is electrically connected to the radiation electrode 15 through a via 18 extending in the Z direction. The base end portion of the strip line 20 is disposed on the outer edge side of the substrate 12 and includes bumps 21 for external connection. The array antenna 11 is flip-chip mounted on the mounting substrate 8 by the bumps 21.

  The sound wave transmission unit 22 is formed between the back case 4 and the array antenna 11. That is, the array antenna 11 and the bottom surface portion 4 </ b> A of the back surface side case 4 are separated from each other with a predetermined interval, and the sound wave transmission portion 22 is formed by a space formed between the back surface side case 4 and the array antenna 11. As shown in FIG. 4, the sound wave transmission unit 22 communicates with the built-in speaker 7 and the openings 9A and 9B, and transmits the sound wave S between the built-in speaker 7 and the openings 9A and 9B.

  Next, the operation of the antenna device 10 according to the present embodiment will be described.

  When power is fed from the feed line 19 toward the radiation electrode 15, a current flows through the radiation electrode 15, for example, in the X direction. Thereby, the array antenna 11 radiates a high-frequency signal RF corresponding to the dimension Lex in the X direction of the radiation electrode 15 from the substrate 12 toward the bottom surface portion 4A of the back surface side case 4. At this time, the array antenna 11 can also receive a high-frequency signal RF corresponding to the dimension Lex of the radiation electrode 15 in the X direction.

  However, the bottom surface portion 4 </ b> A of the back side case 4 is provided with a plurality of openings 9 </ b> A, and the plurality of openings 9 </ b> A are arranged at positions corresponding to different radiation electrodes 15. For this reason, the high frequency signal RF by the radiation electrode 15 can be radiated | emitted to the exterior of the housing | casing 2 through the opening part 9A. Further, the high-frequency signal RF propagating in the external space can be incident on the inside of the housing 2 through the opening 9 </ b> A and received by the radiation electrode 15.

  In addition, since the plurality of openings 9A are respectively arranged at positions corresponding to the plurality of radiation electrodes 15, each opening 9A can be opened with an inner diameter dimension corresponding to the radiation electrode 15. For this reason, the opening 9 </ b> A can pass a high-frequency signal RF having a wavelength λ corresponding to the radiation electrode 15, and can block radio waves that are noise having a longer wavelength than the wavelength λ. As a result, even when a radio wave having a wavelength longer than the wavelength λ is radiated by the ground electrode 16 having a length dimension Lgx or Lgy that is equal to or longer than the wavelength λ, the long wavelength radio wave can be blocked by the opening 9A.

  Further, the array antenna 11 can be mounted close to the built-in speaker 7 or integrated with the built-in speaker 7. For this reason, it is possible to reduce the mounting space for the built-in speaker 7 and the array antenna 11 and to reduce the size of the tablet terminal 1 as compared with the case where sound waves and radio waves are emitted separately.

  On the other hand, since the sound wave transmission part 22 is formed between the bottom surface part 4A of the back side case 4 and the array antenna 11, the sound wave S can be transmitted to the openings 9A and 9B of the bottom surface part 4A through the sound wave transmission part 22. . For this reason, it is possible to radiate both the radio wave composed of the high-frequency signal RF and the sound wave S such as voice from the openings 9A and 9B.

  Furthermore, since the array antenna 11 includes a plurality of radiation electrodes 15 and the back case 4 is provided with a plurality of openings 9A, a high-frequency signal RF can be radiated from the plurality of radiation electrodes 15 through the plurality of openings 9A. it can. For this reason, the radiation direction of the high frequency signal RF can be actively adjusted by adjusting the phase of the high frequency signal RF from the plurality of radiation electrodes 15, for example. As a result, the direction of the radiation beam emitted from the array antenna 11 can be scanned in the X direction and the Y direction.

  In the first embodiment, the substrate 12 of the array antenna 11 is formed in a substantially quadrangular shape. However, the substrate 12 is not limited to a quadrangular shape but may have any shape such as various polygons, circles, ellipses, and the like. You may form in. Further, as shown in FIGS. 6 and 7, the substrate 12 may be provided with a notch 23 for positioning with the opening 9A.

  Next, FIG. 8 shows an antenna device 31 according to a second embodiment of the present invention. The feature of the second embodiment is that the opening 32A is formed to a size that faces the plurality of radiation electrodes 15. In the description of the antenna device 31, the same components as those of the antenna device 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The openings 32A and 32B are configured substantially the same as the openings 9A and 9B according to the first embodiment, and are provided in the vicinity of the built-in speaker 7.

  However, the openings 32A and 32B are, for example, elliptical or oval openings. One opening 32A is formed with a size that surrounds the two radiation electrodes 15, for example. Specifically, the opening 32A has a shape that is longer in the X direction than in the Y direction, and is formed in such a size that the two radiation electrodes 15 adjacent in the X direction face each other. However, the dimension in the X direction of the opening portion 32 </ b> A is set to a value smaller than the outer dimension of the ground electrode 16. The opening 32A may have a shape that is longer in the Y direction than in the X direction, and may have a size such that a plurality of (for example, two) radiation electrodes 15 that are adjacent in the Y direction face each other.

  The opening 32A is provided to face the array antenna 11 and is disposed at a position corresponding to the radiation electrode 15 of the array antenna 11. In addition to the sound wave S, the opening 32 </ b> A outputs a high-frequency signal RF including, for example, a millimeter wave or a submillimeter wave from the radiation electrode 15 to the outside of the housing 2. Here, the plurality of openings 32A are arranged so that the distance between adjacent ones in the X direction and the Y direction is equal to or more than half (λ / 2) of the wavelength λ of the high-frequency signal RF output from the array antenna 11. Yes.

  Thus, also in the second embodiment, it is possible to obtain the same effects as those in the first embodiment. Moreover, since the openings 32A and 32B can be enlarged, the efficiency of sound wave radiation and radio wave radiation by the openings 32A and 32B can be increased.

  In the second embodiment, the opening 32A is formed so as to face two radiation electrodes 15. However, the opening 32A is large enough to face three, four, and five radiation electrodes 15. It may be formed. In other words, the size of the opening may not be such that it faces all of the plurality of radiation electrodes 15 and may be smaller than the ground electrode 16.

  Next, FIG. 9 shows an antenna device 41 according to a third embodiment of the present invention. The feature of the third embodiment is that the back side case 4 is provided with a sheet member 42 that covers the openings 9A and 9B and has a dustproof and waterproof property. In the description of the antenna device 41, the same components as those of the antenna device 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The sheet member 42 is formed of, for example, a nonwoven fabric or a waterproof and moisture-permeable material as a material having dustproof and waterproof properties. The sheet member 42 is provided inside or outside the housing 2 in the back side case 4. The sheet member 42 is formed of an insulating material and transmits the high frequency signal RF from the radiation electrode 15. Further, the sheet member 42 is formed in a film shape capable of air flow and vibration, and can transmit air vibration due to the sound wave S.

  Thus, in the third embodiment, it is possible to obtain the same operational effects as in the first embodiment. Further, since the sheet member 42 that covers the openings 9A and 9B is provided in the back side case 4, the sheet member 42 can prevent dust, water droplets, and the like from entering the openings 9A and 9B. Reliability and durability can be improved. On the other hand, since the sheet member 42 is formed of, for example, a non-conductive material capable of air circulation and vibration, the high-frequency signal RF (radio wave) and the sound wave S can pass through the sheet member 42.

  Next, FIG. 10 shows an antenna device 51 according to a fourth embodiment of the present invention. The feature of the fourth embodiment is that the substrate 52 of the array antenna 11 is formed of a rigid flexible substrate or a flexible substrate. In the description of the antenna device 51, the same components as those of the antenna device 10 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The substrate 52 is formed of a multilayer substrate in which resin layers 53 and 54 are laminated. A plurality of radiation electrodes 15 are formed on the exposed surface of the resin layer 53, and the ground electrode 16 is formed between the resin layers 53 and 54. Since the substrate 52 is formed of a rigid flexible substrate or a flexible substrate, the substrate 52 can be deformed.

  Thus, in the fourth embodiment, it is possible to obtain the same effects as those in the first embodiment. Further, since the substrate 52 of the array antenna 11 is formed of a flexible substrate or the like, for example, even when the bottom surface portion 4A1 of the back surface side case 4 is bent or curved, along the bent surface or curved surface of the bottom surface portion 4A1, The substrate 52 can be bent or curved. For this reason, since the array antenna 11 can be attached along the shape of the bottom surface portion 4A1, the degree of freedom in designing the housing 2 of the tablet terminal 1 can be increased, and the design of the housing 2 can be improved. .

  In each of the above embodiments, the array antenna 11 includes a plurality of planar antennas each including the planar radiation electrode 15. However, the present invention is not limited to this, and the array antenna may include a plurality of linear antennas such as dipole antennas. Further, the polarization of the radiation electrode 15 is not limited to that described above, and can be set as appropriate according to specifications and the like.

  In each of the above embodiments, the array antenna 11 includes the six radiation electrodes 15 arranged in a matrix of 2 rows and 3 columns. However, the number and arrangement of the radiation electrodes 15 are the specifications of the array antenna 11. It can set suitably according to etc. For this reason, the radiation electrodes of the array antenna are not limited to a two-dimensional matrix, and may be arranged in a one-dimensional column.

  In each of the embodiments described above, the openings 9A and 32A output the sound wave S such as the sound from the built-in speaker 7, but the sound wave S may be a flow of air such as cooling air, for example.

  In each of the embodiments, the openings 9A and 32A extend in the thickness direction (Z direction) orthogonal to the bottom surface portion 4A of the back surface side case 4. However, the present invention is not limited to this. For example, an antenna device 61 according to a modification shown in FIG. In this case, the radiation direction of the high-frequency signal RF can be inclined from the orthogonal direction of the bottom surface portion 4A along the direction in which the opening 62 extends.

  In each of the embodiments described above, the antenna devices 10, 31, 41, 51 are provided on the bottom surface portion 4 </ b> A of the back surface side case 4, but may be provided on the side surface portion 4 </ b> B of the back surface case 4, for example. In this case, good radio wave radiation in the side surface direction of the housing 2 can be realized.

  In each of the embodiments described above, the antenna devices 10, 31, 41, and 51 have been described by way of example when applied to the tablet terminal 1. However, the antenna devices 10, 31, 41, and 51 may be applied to various mobile devices such as mobile phones, smartphones, and laptop computers. For example, the present invention may be applied to a fixed device having a communication function such as a wireless LAN.

  It is needless to say that each of the embodiments described above is an exemplification, and partial replacement or combination of the configurations shown in the different embodiments is possible.

2 Housing 3 Front side case 4 Back side case (conductor plate)
7 Built-in speaker 9A, 9B, 32A, 32B, 62 Opening 10, 31, 41, 51, 61 Antenna device 11 Array antenna 12, 52 Substrate 15 Radiation electrode 16 Ground electrode 22 Sound wave transmission part 42 Sheet member

Claims (4)

An array antenna in which a plurality of radiation electrodes capable of emitting radio waves of a predetermined wavelength and a ground electrode are provided on a substrate;
A conductor plate disposed opposite to the substrate;
A plurality of openings provided in the conductor plate at positions corresponding to some of the plurality of radiation electrodes;
A sound wave transmission unit formed between the conductor plate and the array antenna and capable of transmitting sound waves;
The radiation electrode has a length dimension of half or less of the predetermined wavelength,
The ground electrode has a length dimension equal to or longer than the predetermined wavelength,
The distance between the plurality of openings is an antenna device set to be half or more of the predetermined wavelength.   The antenna device according to claim 1, wherein the plurality of openings are respectively arranged at positions corresponding to the plurality of radiation electrodes.   The antenna device according to claim 1, wherein the conductive plate is provided with a sheet member that covers the opening and has a dustproof and waterproof property.   4. The antenna device according to claim 1, wherein the array antenna substrate is formed of a rigid flexible substrate or a flexible substrate.

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