Antenna device and electronic device

Abstract

This antenna device comprises: an antenna module that is for communicating at a prescribed communication frequency; a substrate that has conductivity, has a first surface, and has a first recess which is formed in the first surface and which can accommodate the antenna module; a dielectric radome that has a second surface which faces the first surface of the substrate and that has a second recess which faces the first recess and which is formed in the second surface; and a waterproofing structure that is arranged between the first surface of the substrate and the second surface of the radome and that is for waterproofing the antenna module. The antenna module includes one or a plurality of antenna elements and an antenna surface on which the one or a plurality of antenna elements are formed. The antenna module is accommodated in the first recess such that the antenna surface projects from the first surface into the second recess.

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a roadside radio device as an antenna device. Patent Document 1 describes that the housing is composed of a base having a radio device main body accommodating recess and an antenna accommodating recess back to back, with the surface of the antenna accommodating recess made a radio wave reflecting surface, a base cover that covers the radio device main body accommodating recess of the base and forms, together with the base, the radio device main body accommodating section that accommodates the radio device main body, and an antenna cover that covers the antenna accommodating recess of the base and forms, together with the base, the antenna accommodating section that accommodates the antenna board, and that the radio device main body is accommodated in the radio device main body accommodating section, and the antenna board is accommodated in the antenna accommodating section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-44734 Summary of the Invention

[0004] However, the antenna device described in Patent Document 1 does not provide sufficient improvement in antenna performance.

[0005] The present disclosure provides an antenna device and electronic device that can achieve improved waterproof performance and antenna performance.

[0006] An antenna device according to one aspect of the present disclosure includes an antenna module for communicating at a predetermined communication frequency, a conductive base having a first surface capable of accommodating the antenna module and a first recess formed in the first surface, a dielectric radome having a second surface facing the first surface of the base and a second recess formed in the second surface facing the first recess, and a waterproof structure disposed between the first surface of the base and the second surface of the radome for waterproofing the antenna module. The antenna module includes one or more antenna elements and an antenna surface on which the one or more antenna elements are formed. The antenna module is accommodated in the first recess such that the antenna surface protrudes from the first surface into the second recess.

[0007] An electronic device according to an aspect of the present disclosure includes the antenna device described above, a communication circuit connected to the antenna device, and a metal housing that houses the communication circuit. The base is a part of the metal housing. A first surface of the base is an outer surface of the metal housing.

[0008] According to the aspects of the present disclosure, waterproof performance and antenna performance can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating an example of the configuration of an electronic device including an antenna device according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the electronic device of FIG. 1. [Figure 3] Side view of the electronic device in Figure 1 [Figure 4] Cross section of line XX in Figure 3 [Figure 5] Enlarged view of part of Figure 4 [Figure 6] Cross section of line YY in Figure 3 [Figure 7] FIG. 2 is a plan view of the antenna device of the electronic device of FIG. 1; [Figure 8] A plan view of the antenna device of Figure 7, omitting the radome. [Figure 9] FIG. 9 is a plan view of the antenna device of FIG. 8, omitting the waterproof structure. [Figure 10] Bottom view of the radome of the antenna device of Figure 7 [Figure 11] FIG. 8 is a perspective view of an elastic member of the antenna device of FIG. 7. [Figure 12] (a) Electric field distribution diagram of the first configuration example of the antenna device, (b) Electric field distribution diagram of the second configuration example of the antenna device [Figure 13] 1A is a plan view of a third configuration example of an antenna device, FIG. 1B is a plan view of a fourth configuration example of an antenna device, and FIG. 1C is a plan view of a fifth configuration example of an antenna device. [Figure 14] Graphs of cumulative distribution functions for antenna device configuration examples 3 to 6 [Figure 15] Graph of angular dependence of antenna gain for antenna device configuration examples 7 and 8 [Figure 16] Graph of angular dependence of antenna gain for antenna device configuration examples 9 and 10 DETAILED DESCRIPTION OF THE INVENTION

[0010] [1. Embodiment] [1.1 Overview] Fig. 1 is a block diagram of an example configuration of an electronic device 1 according to the present embodiment. The electronic device 1 in Fig. 1 is a tablet terminal. The electronic device 1 includes an antenna device 10, a communication circuit 11, an input / output device 12, a storage device 13, and an arithmetic circuit 14.

[0011] Fig. 2 is a perspective view of electronic device 1. Electronic device 1 includes a housing 15 that houses antenna device 10, communication circuit 11, input / output device 12, storage device 13, and arithmetic circuit 14. Fig. 3 is a side view of electronic device 1. As shown in Figs. 2 and 3, antenna device 10 is housed in housing 15 so as to be partially exposed from the side surface of housing 15.

[0012] Fig. 4 is a cross-sectional view taken along line XX in Fig. 3. Fig. 5 is a partially enlarged view of Fig. 4. Fig. 6 is a cross-sectional view taken along line YY in Fig. 3.

[0013] As shown in FIGS. 4 to 6 , the antenna device 10 includes an antenna module 2 for communicating at a predetermined communication frequency, a conductive base 3, a dielectric radome 4, and a waterproof structure 5. The base 3 has a first surface 30, and a first recess 31 capable of accommodating the antenna module 2 is formed on the first surface 30. That is, the first recess 31 accommodates the antenna module 2 and is formed on the first surface 30 of the base 3. The radome 4 has a second surface 40 facing the first surface 30 of the base 3, and a second recess 41 facing the first recess 31 is formed on the second surface 40. That is, the second recess 41 faces the first recess 31 and is formed on the second surface 40 of the radome 4. The waterproof structure 5 is a structure for waterproofing the gap between the first surface 30 of the base 3 and the second surface 40 of the radome 4. That is, the waterproof structure 5 is disposed between the first surface 30 of the base 3 and the second surface 40 of the radome 4, and is configured to waterproof the antenna module 2. The antenna module 2 is accommodated in the first recess 31 so that the antenna surface 20, on which one or more antenna elements 2a are formed, protrudes from the first surface 30 into the second recess 41. In other words, the antenna module 2 is accommodated in the first recess 31 so that the antenna surface 20 protrudes from the first surface 30 into the second recess 41.

[0014] In the antenna device 10, the first recess 31 on the first surface 30 of the base 3 and the second recess 41 on the second surface 40 of the radome 4 form a storage space for the antenna module 2. The storage space for the antenna module 2 is waterproofed by the waterproof structure 5. The waterproof performance of the waterproof structure 5 can be easily improved by increasing the waterproof area between the first surface 30 of the base 3 and the second surface 40 of the radome 4. Furthermore, the antenna module 2 is stored in the first recess 31 so that the antenna surface 20 on which the antenna element 2a is formed protrudes from the first surface 30 into the second recess 41. This allows radio waves radiated from the antenna element 2a on the antenna surface 20 and traveling in the opposite direction from the antenna surface 20 to be reflected by the first surface 30 of the base 3 toward the antenna surface 20. This improves the utilization efficiency of the radio waves radiated from the antenna module 2. Therefore, the antenna device 10 described above achieves improved waterproof performance and antenna performance. In particular, the antenna device described in Patent Document 1 aims to provide environmental resistance, but its antenna performance was not sufficiently improved. In particular, Patent Document 1 does not improve antenna characteristics such as antenna gain and radiation directivity when the antenna is placed inside the main body housing. In contrast, as described above, antenna device 10 of the present embodiment can improve waterproof performance and antenna performance.

[0015] [1.2 Details] The antenna device 10 and the electronic device 1 including the antenna device 10 will be further described below.

[0016] [1.2.1 Electronic equipment] 1, the electronic device 1 includes an antenna device 10, a communication circuit 11, an input / output device 12, a storage device 13, and an arithmetic circuit 14. As shown in Fig. 2, the electronic device 1 includes a housing 15 that houses the antenna device 10, the communication circuit 11, the input / output device 12, the storage device 13, and the arithmetic circuit 14.

[0017] The antenna device 10 is used for wireless communication between the electronic device 1 and an external device. The antenna device 10 will be described in detail later in "[1.2.2 Antenna Device]".

[0018] The communication circuit 11 is connected to the antenna device 10. The communication circuit 11 is communicatively connected to an external device or system via the antenna device 10. The communication circuit 11 has one or more communication interfaces. The communication circuit 11 complies with a predetermined communication protocol. The predetermined communication protocol can be selected from various well-known wireless communication standards.

[0019] The input / output device 12 functions as an input device for inputting information from a user and as an output device for outputting information to a user. That is, the input / output device 12 is used to input information to the electronic device 1 and output information from the electronic device 1. The input / output device 12 includes one or more human-machine interfaces. Examples of human-machine interfaces include input devices such as a keyboard, a pointing device (such as a mouse or a trackball), and a touchpad, output devices such as a display and a speaker, and input / output devices such as a touch panel. In FIG. 2, the input / output device 12 includes a touch panel display 121. The touch panel display 121 is housed in the housing 15 so that its operation surface and display surface are exposed from the housing 15.

[0020] The storage device 13 is used to store information used by the arithmetic circuit 14 and information generated by the arithmetic circuit 14. The storage device 13 includes one or more storages (non-transitory storage media). The storage may be, for example, a hard disk drive, an optical drive, or a solid-state drive (SSD).

[0021] The arithmetic circuit 14 is a circuit that controls the operation of the electronic device 1. The arithmetic circuit 14 is connected to the communication circuit 11 and the input / output device 12, and is accessible to the storage device 13. The arithmetic circuit 14 can be realized, for example, by a computer system including one or more processors (microprocessors) and one or more memories. The one or more processors execute a program (stored in one or more memories or the storage device 13) to realize a predetermined function. Here, the program is pre-recorded in the storage device 13, but it may also be provided via a telecommunications line such as the Internet, or recorded on a non-transitory recording medium such as a memory card.

[0022] The housing 15 is composed of a metal housing 16 and an outer casing 17. The metal housing 16 has a flat rectangular parallelepiped shape. The metal housing 16 houses the communication circuit 11, the input / output device 12, the storage device 13, and the arithmetic circuit 14. The outer casing 17 has a flat rectangular parallelepiped shape like the metal housing 16. The outer casing 17 houses the metal housing 16 inside. In the housing 15, as shown in FIG. 4, the antenna device 10 is housed between the metal housing 16 and the outer casing 17. In FIG. 4, the antenna device 10 is located between the side of the metal housing 16 and the side of the outer casing 17 so as to be positioned on the side of the housing 15. As shown in FIGS. 3 and 4, the outer casing 17 has an opening 171 that exposes the antenna device 10 to allow radio waves from or to the antenna device 10 to pass through. The outer casing 17 is made of metal or resin.

[0023] [1.2.2 Antenna equipment] Next, a detailed description will be given of the antenna device 10. As shown in Figures 2 and 3, the antenna device 10 is housed in the housing 15 so that it is partially exposed from the side surface of the housing 15.

[0024] As shown in FIG. 4, the antenna device 10 includes an antenna module 2, a base 3, a radome 4, a waterproof structure 5, a connecting member 6, and an elastic member 7.

[0025] In the following description, further reference will be made to Figs. 7 to 11. Fig. 7 is a plan view of the antenna device 10. Fig. 8 is a plan view of the antenna device 10 with the radome 4 omitted. Fig. 9 is a plan view of the antenna device 10 with the waterproof structure 5 omitted. Fig. 10 is a bottom view of the radome 4 of the antenna device 10. Fig. 11 is a perspective view of the elastic member 7 of the antenna device 10.

[0026] The antenna module 2 is used for communication at a predetermined communication frequency. The antenna module 2 is used for transmitting and receiving radio waves at the predetermined communication frequency. In this embodiment, the predetermined communication frequency is included in the frequency band of 26 to 300 GHz. The predetermined communication frequency is, for example, a frequency in the 28 GHz band or the 40 GHz band. Therefore, the antenna module 2 is an antenna module for the quasi-millimeter wave band to the millimeter wave band.

[0027] The antenna module 2 shown in FIGS. 4 to 9 is rectangular and plate-shaped. The antenna module 2 has a thickness direction (the vertical direction in FIGS. 4 to 6), a length direction (the horizontal direction in FIGS. 7 to 9), and a width direction (the vertical direction in FIGS. 7 to 9). As shown in FIG. 6, the antenna module 2 has an antenna surface 20 and a ground surface 21 on each of its two sides in the thickness direction. As shown in FIGS. 7 to 9, a plurality of antenna elements 2a-1 to 2a-4 (hereinafter collectively referred to as 2a) are formed on the antenna surface 20. The antenna element 2a is, for example, an electrode formed on the antenna surface 20 and resonating at a predetermined communication frequency. In this embodiment, the plurality of antenna elements 2a are arranged in a straight line. This allows the antenna module 2 to be used as a phased array antenna. The antenna elements 2a-1 to 2a-4 are arranged on the antenna surface 20 along the length direction of the antenna module 2. In this embodiment, the length direction of the antenna module 2 is the direction in which the antenna elements 2a (antenna elements 2a-1 to 2a-4) are arranged on the antenna surface 20. The width direction of the antenna module 2 is a direction perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2a are arranged on the antenna surface 20 (the length direction of the antenna module 2). A ground pattern is formed on the ground surface. The ground pattern functions as a reflector.

[0028] The base 3 houses the antenna module 2. As shown in FIGS. 4 to 6, the base 3 has a first surface 30. The base 3 is conductive. The base 3 is formed of a conductive material such as a metal material. In this embodiment, as shown in FIG. 4, the base 3 is a part of the metal housing 16. Specifically, the base 3 is formed using a side portion of the metal housing 16. The first surface 30 of the base 3 is the outer surface of the metal housing 16. The outer surface of the metal housing 16 is the surface of the metal housing 16 facing the outer casing 17, and is the surface opposite to the communication circuit 11 and the like housed in the metal housing 16. In the base 3, a first recess 31 capable of housing the antenna module 2 is formed on the first surface 30. As shown in FIG. 9, the first recess 31 is substantially rectangular in plan view. The first recess 31 is composed of a bottom 32 on which the antenna module 2 is placed and an inner surface 33 that surrounds the antenna module 2. The bottom 32 and inner surface 33 of the first recess 31 act as reflectors that reflect the radio waves emitted from the antenna module 2 toward the front of the antenna module 2 (toward the antenna surface 20), thereby improving the utilization efficiency of the radio waves emitted from the antenna module 2.

[0029] The antenna module 2 is in a specified position within the first recess 31. The specified position is a position where, in at least a portion of the inner surface 33 of the first recess 31, the distance d2 between the inner surface 33 and the antenna module 2 is greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. In FIG. 9, the distance d2 is greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to the predetermined communication frequency at a portion of the first end and second end in the width direction of the antenna module 2 (the upper end and lower end in FIG. 9) and at the first end in the length direction (the right end in FIG. 9). As will be described in more detail in "[1.4 Evaluation]" below, by having the antenna module 2 in the specified position, the gain in the front direction of the antenna module 2 (the direction of the antenna surface 20) can be improved.

[0030] As shown in Fig. 9, the base 3 has a plurality of positioning protrusions 34-1 to 34-5 (hereinafter collectively referred to as 34) that abut against the antenna module 2 to position the antenna module 2 at a specified position. This facilitates alignment of the antenna module 2 with the base 3, thereby facilitating the assembly work of the antenna device 10. The plurality of positioning protrusions 34 protrude from the inner surface 33 of the first recess 31. This simplifies the structure of the base 3. In this embodiment, the amount of protrusion of the positioning protrusions 34 from the inner surface 33 is set to be greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to a predetermined communication frequency.

[0031] More specifically, the positioning protrusions 34-1 and 34-2 protrude from a portion of the inner surface 33 of the first recess 31 facing a first widthwise end (upper end in FIG. 9 ) of the antenna module 2, thereby setting the distance d2 between the antenna module 2 and the portion of the inner surface 33 facing the first widthwise end of the antenna module 2 greater than 0 and not more than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. The positioning protrusions 34-3 and 34-4 protrude from a portion of the inner surface 33 of the first recess 31 facing a second widthwise end (lower end in FIG. 9 ) of the antenna module 2, thereby setting the distance d2 between the antenna module 2 and the portion of the inner surface 33 facing the second widthwise end of the antenna module 2 greater than 0 and not more than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. The distance d2 may be not more than 1 / 18 of the wavelength corresponding to the predetermined communication frequency, or not more than 1 / 27 of the wavelength corresponding to the predetermined communication frequency. For example, if the predetermined communication frequency is a 28 GHz band frequency, the distance d2 may be approximately 0.4 mm, which is 1 / 27 of the wavelength corresponding to the predetermined communication frequency. For example, if the predetermined communication frequency is a 40 GHz band frequency, the distance d2 may be approximately 0.4 mm, which is 1 / 18 of the wavelength corresponding to the predetermined communication frequency. The positioning protrusions 34-1, 34-2, 34-3, and 34-4 position the antenna module 2 in the width direction of the antenna module 2. The positioning protrusion 34-5 protrudes from a portion of the inner surface 33 of the first recess 31 facing the first longitudinal end of the antenna module 2 (the right end in FIG. 9 ). This sets the distance d2 between the portion of the inner surface 33 facing the first longitudinal end of the antenna module 2 and the antenna module 2 to be greater than 0 and not more than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. In FIG. 9 , the corner of the second longitudinal end (the left end in FIG. 9 ) of the antenna module 2 abuts the inner surface 33 of the first recess 31. This allows the antenna module 2 to be positioned in the longitudinal direction of the antenna module 2.

[0032] As shown in FIG. 9 , the base 3 has a positioning portion 35. In this embodiment, the base 3 has two positioning portions 35. The positioning portions 35 position the radome 4 at a predetermined position. As shown in FIG. 5 , the predetermined position is a position where the center C4 of the radome 4 coincides with the center C2 of the antenna module 2 in directions (the left-right direction in FIG. 5 , the width direction of the antenna module 2) perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2 a are arranged on the antenna surface 20. In other words, when the radome 4 is attached to the base 3, the center C4 of the radome 4 is located at the center C2 of the antenna module 2 in the width direction. Having the radome 4 at such a predetermined position reduces the effect of the radome 4 on the antenna radiation characteristics of the antenna module 2. Furthermore, the positioning portions 35 facilitate the alignment of the radome 4 and the antenna module 2, which facilitates the assembly of the antenna device 10. In this embodiment, the positioning portion 35 positions the radome 4 at a predetermined position by being coupled to a positioning portion 44 (see FIG. 10 ) of the radome 4, which will be described later. 9, the positioning portion 35 is a recess that receives the positioning portion 44 of the radome 4. The positioning portion 35 is formed around the first recess 31 on the first surface 30 of the base 3.

[0033] As shown in FIG. 9 , the base 3 has an opening 36. As shown in FIGS. 4 and 5 , the opening 36 penetrates the bottom 32 of the first recess 31. As described above, the base 3 is part of the metal housing 16, and the opening 36 connects the inside and outside of the metal housing 16. The opening 36 makes it possible to connect the antenna module 2 located outside the metal housing 16 to the communication circuit 11 located inside the metal housing 16. As shown in FIG. 9 , the opening 36 does not overlap with the antenna module 2 in the thickness direction of the antenna module 2. As described above, the bottom 32 of the first recess 31 serves as a reflector that reflects radio waves emitted from the antenna module 2 toward the front direction of the antenna module 2 (the direction of the antenna surface 20). Therefore, by ensuring that the opening 36 does not overlap with the antenna module 2 in the thickness direction of the antenna module 2, it is possible to connect the antenna module 2 to another electric circuit (communication circuit 11) while reducing the effect of the opening 36 on the radiation characteristics of the antenna module 2.

[0034] 9, the opening 36 has a substantially rectangular shape in a plan view. The length and width directions of the opening 36 correspond to the length and width directions of the antenna module 2. The opening 36 is adjacent to the antenna module 2 in a direction (the width direction of the antenna module 2) that is perpendicular to the thickness direction of the antenna module 2 and to the direction in which the antenna elements 2a are arranged on the antenna surface 20 (the length direction of the antenna module 2). This configuration makes it possible to shorten the length of the wiring required to connect the antenna module 2 to another electric circuit (communication circuit 11).

[0035] The dimensions of the opening 36 will be further described. In this embodiment, the dimension D1 of the opening 36 in the direction in which the antenna elements 2a are arranged on the antenna surface 20 (the length direction of the antenna module 2) is less than half the dimension of the antenna module 2. As will be described in detail in "[1.4 Evaluation]" below, this configuration enables connection of the antenna module 2 to another electrical circuit (communication circuit 11) while reducing the impact of the opening 36 on the radiation characteristics of the antenna module 2. In this embodiment, the dimension D2 of the opening 36 in the direction perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2a are arranged on the antenna surface 20 (the width direction of the antenna module 2) is less than one-third of the wavelength corresponding to a predetermined communication frequency. This enables connection of the antenna module 2 to another electrical circuit (communication circuit 11) while reducing the impact of the opening 36 on the radiation characteristics of the antenna module 2.

[0036] 6 , the antenna module 2 is housed in the first recess 31 in the first surface 30 of the base 3, and the elastic member 7 is disposed between the antenna module 2 and the bottom 32 of the first recess 31 in the base 3. The depth of the first recess 31 is smaller than the thickness of the antenna module 2 and the thickness of the elastic member 7. Therefore, the antenna module 2 is housed in the first recess 31 so that the antenna surface 20 protrudes from the first surface 30.

[0037] The radome 4 protects the antenna module 2. The radome 4 is made of a dielectric material such as a resin material so as to transmit radio waves to or from the antenna module 2. As shown in FIGS. 4 to 6, the radome 4 has a second surface 40 facing the first surface 30 of the base 3. The radome 4 has a second recess 41 formed on the second surface 40 facing the first recess 31. The second recess 41, together with the first recess 31, forms a space for accommodating the antenna module 2. As shown in FIGS. 7 and 10, the radome 4 has a rectangular plate shape in a plan view. The surface of the radome 4 facing the base 3 in the thickness direction is the second surface 40. As shown in FIG. 10, the radome 4 includes a first portion 4a corresponding to the bottom of the second recess 41 and a second portion 4b corresponding to the side wall portion of the second recess 41 and the flange portion protruding outward from the side wall portion. The thickness t1 of the first portion 4a is uniform, and both surfaces of the first portion 4a in the thickness direction are flat. Therefore, the bottom surface 411 of the second recess 41 is also a flat surface. The first portion 4a is symmetrical with respect to a line that runs along the length direction of the radome 4 and passes through the center of the radome 4 in the width direction. The second portion 4b has a uniform thickness, and both surfaces of the second portion 4b in the thickness direction are flat surfaces.

[0038] In this embodiment, as shown in FIG. 5 , the antenna module 2 is accommodated in the first recess 31 so that the antenna surface 20 protrudes from the first surface 30. When the radome 4 is attached to the base 3, the antenna surface 20 of the antenna module 2 is located within the second recess 41 of the radome 4. The bottom surface 411 of the second recess 41 is flat. As a result, the bottom surface 411 of the second recess 41 of the radome 4 includes a facing region 412 that faces the antenna surface 20 in parallel. The distance d1 between the facing region 412 and the antenna surface 20 is within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. For example, when the predetermined communication frequency is a frequency in the 28 GHz band, the distance d1 is within a range of approximately 0.2 mm to 0.35 mm. For example, when the predetermined communication frequency is a frequency in the 40 GHz band, the distance d1 is within a range of approximately 0.15 mm to 0.25 mm. It has been confirmed through tests that the antenna gain drops significantly when the distance d1 exceeds 1 / 30 of the wavelength corresponding to the predetermined communication frequency. Therefore, by setting the distance d1 between the facing region 412 and the antenna surface 20 within the range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency, it is possible to suppress the drop in antenna gain due to the reflection of radio waves at the radome 4.

[0039] As shown in FIG. 10 , the radome 4 has spacers 42-1 to 42-6 (hereinafter collectively referred to as 42) to set the distance d1 within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. As shown in FIG. 5 , the spacer 42 is located between the facing region 412 and the antenna surface 20, and sets the distance d1 between the facing region 412 and the antenna surface 20 within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. In this embodiment, the spacer 42 is formed on the bottom surface 411 of the second recess 41. The spacer 42 is formed integrally and continuously with the first portion 4a and the second portion 4b, and is also made of a dielectric material. The height of the spacer 42 is set so that when the antenna surface 20 abuts on the spacer 42, the distance d1 is within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. This facilitates the task of setting the distance d1 within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency.

[0040] As shown in FIG. 10, the spacer 42 is arranged so as not to face the antenna element 2a of the antenna module 2 (in the thickness direction of the antenna module 2). Furthermore, a distance d3 between the spacer 42 and the antenna element 2a in a plane parallel to the antenna surface 20 (shown in FIG. 10 as the distance between the spacer 42-5 and the antenna element 2a-3) is set to be equal to or greater than 1 / 5 of the wavelength corresponding to the predetermined communication frequency. More specifically, the distance between the spacer 42-5 and each of the antenna elements 2a-1 to 2a-4 is set to be equal to or greater than 1 / 5 of the wavelength corresponding to the predetermined communication frequency. The distance d3 may be equal to or less than 1 / 8 of the wavelength corresponding to the predetermined communication frequency. In this embodiment, the spacers 42-1 to 42-6 are arranged around the bottom surface 411 of the second recess 41. The distance d3 between each of the spacers 42-1 to 42-6 and the nearest antenna element 2a among the antenna elements 2a-1 to 2a-4 in a plane parallel to the antenna surface 20 is within a range of 1 / 5 to 1 / 8 of the wavelength corresponding to the predetermined communication frequency. For example, when the predetermined communication frequency is a frequency in the 28 GHz band, the distance d3 is within a range of approximately 1.3 mm to 2.1 mm. For example, when the predetermined communication frequency is a frequency in the 40 GHz band, the distance d3 is within a range of approximately 0.9 mm to 1.5 mm. In this embodiment, the spacers 42 are dielectric. Therefore, by setting the distance d3 to 1 / 5 or more of the wavelength corresponding to the predetermined communication frequency, it is possible to reduce the influence of the spacers 42 on antenna characteristics such as antenna gain and radiation directivity while maintaining the distance d1 within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency.

[0041] As shown in FIG. 10 , the radome 4 has a positioning portion 44. In this embodiment, the radome 4 has two positioning portions 44. The positioning portions 44, together with the positioning portion 35 of the base 3, are used to position the radome 4 at the predetermined position. In FIG. 10 , the positioning portion 44 is a protrusion that fits into the positioning portion 35 of the base 3. The positioning portion 44 is formed on the edge of the second portion 4b of the radome 4. As shown in FIG. 5 , the predetermined position is a position where the center C4 of the radome 4 and the center C2 of the antenna module 2 coincide with each other in directions (the left-right direction in FIG. 5 , the width direction of the antenna module 2) that are perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2a are arranged on the antenna surface 20. As described above, in the radome 4, the first portion 4a is symmetrical with respect to a line that passes through the center of the width direction of the radome 4 along the length direction of the radome 4. Therefore, by positioning the radome 4 at a predetermined position, the first portion 4a is symmetrical with respect to a line L1 passing through the centers of the antenna elements 2a (antenna elements 2a-1 to 2a-4) aligned in one direction on the antenna surface 20. The first portion 4a is the portion of the radome 4 that covers the antenna module 2. Therefore, the portion of the radome 4 that covers the antenna module 2 (the first portion 4a) is symmetrical with respect to the line L1 passing through the centers of the antenna elements 2a aligned in one direction on the antenna surface 20. In other words, the radome 4 has a concave structure that is approximately symmetrical with respect to the short side direction of the antenna module 2. This configuration reduces the possibility that the radome 4 will disturb the radiation characteristics of the antenna module 2, causing the radiation to be strengthened or weakened in an unintended direction. As a result, the antenna gain in the front direction of the antenna module 2 (toward the antenna surface 20) can be improved.

[0042] As described above, the thickness t1 of the first portion 4a of the radome 4 is uniform, and both surfaces of the first portion 4a in the thickness direction are flat. The thickness t1 of the first portion 4a is in the range of 1 / 10 to 1 / 8 of the wavelength corresponding to the predetermined communication frequency. That is, since the first portion 4a of the radome 4 is the portion facing the antenna surface 20, the thickness t1 of the facing portion is in the range of 1 / 10 to 1 / 8 of the wavelength corresponding to the predetermined communication frequency. For example, when the predetermined communication frequency is a frequency in the 28 GHz band, the thickness t1 is in the range of approximately 1.1 mm to 1.3 mm. For example, when the predetermined communication frequency is a frequency in the 40 GHz band, the thickness t1 is in the range of approximately 0.8 mm to 0.9 mm. This configuration reduces the possibility that the radome 4 will disturb the radiation characteristics of the antenna module 2, causing increased or decreased radiation in unintended directions. As a result, the antenna gain in the front direction of the antenna module 2 (toward the antenna surface 20) is improved.

[0043] The waterproof structure 5 is a structure for waterproofing the gap between the first surface 30 of the base 3 and the second surface 40 of the radome 4. In this embodiment, the waterproof structure 5 is located between the periphery of the first recess 31 on the first surface 30 of the base 3 and the periphery of the second recess 41 on the second surface 40 of the radome 4. In particular, the waterproof structure 5 is a joining member that fills the gap between the first surface 30 of the base 3 and the second surface 40 of the radome 4 to join the radome 4 to the base 3. The joining member is, for example, a waterproof cushioned double-sided tape. As shown in FIG. 8 , the waterproof structure 5 is in the shape of a rectangular frame having an opening 50. Alternatively, the waterproof structure 5 may be a waterproof elastic member. The waterproof structure 5 may be configured to fill the gap between the first surface 30 of the base 3 and the second surface 40 of the radome 4, and the radome 4 may be fastened with screws or the like to sandwich the waterproof structure 5 between the radome 4 and the base 3. The waterproof structure 5 is disposed on the first surface 30 of the base 3 so that the antenna module 2 in the first recess 31 is exposed from the opening 50.

[0044] The connecting member 6 is used to connect the antenna module 2 to the communication circuit 11. As shown in FIG. 4 , the connecting member 6 includes a first piece 61 and a second piece 62. The first piece 61 is connected to the antenna module 2 and extends from the antenna module 2 toward the opening 36 of the first recess 31 of the base 3. The second piece 62 extends from the tip of the first piece 61 through the opening 36. The second piece 62 is connected to the communication circuit 11 in the metal housing 16. The second piece 62 is sized to pass through the opening 36. In this embodiment, after connecting the connecting member 6 to the antenna module 2, the antenna module 2 and the connecting member 6 can be housed in the first recess 31 by passing the second piece 62 through the opening 36. This facilitates the assembly of the antenna device 10. In this case, to prevent the antenna module 2 and the connecting member 6 from unintentionally coming off, it is recommended to fix the first piece 61 of the connecting member 6 to the antenna module 2 with a fixing tape 8, as shown in FIG. 6 . The connecting member 6 has a wiring pattern extending from the first piece 61 to the second piece 62. The wiring pattern connects the antenna module 2 connected to the first piece 61 and the communication circuit 11 connected to the second piece 62 to each other. Use of the connecting member 6 eliminates the need to connect the antenna module 2 and the communication circuit 11 with a connecting wire or the like passing through the opening 36. This facilitates connection between the antenna module 2 and the communication circuit 11. In this embodiment, the connecting member 6 includes a connector 63. The connector 63 is provided on the first piece 61 and facilitates connection between the antenna module 2 and the first piece 61. In this embodiment, the first piece 61 and the second piece 62 are formed by bending a flexible substrate. This makes it easy to install the connecting member 6. As described above, in the connecting member 6, the wiring pattern is configured to follow the shortest route to minimize line loss. Furthermore, by making the second piece 62 smaller than the opening 36, the flexible substrate is bent at a substantially right angle from the connector end of the antenna module 2 and drawn into the metal housing 16. Furthermore, by providing a conductive reinforcing plate on the surface of the flexible cable, the conductivity when the surfaces come into contact can be improved.

[0045] The elastic member 7 is used to position the antenna module 2 relative to the radome 4 in the thickness direction of the antenna module 2. As shown in FIGS. 4 to 6 , the elastic member 7 is disposed between the antenna module 2 and the bottom 32 of the first recess 31 of the base 3. More specifically, the elastic member 7 is disposed between the antenna module 2 and the bottom 32 of the first recess 31 of the base 3 in a compressed state in the thickness direction of the antenna module 2. The elastic member 7 has enough elasticity to withstand the weight of the antenna module 2 and press the antenna module 2 against the radome 4. With this configuration, the elastic member 7 uniformly presses the antenna module 2 against the radome 4. Therefore, even if shape errors or thermal expansion and contraction occur in the antenna module 2, the base 3, the radome 4, the waterproof structure 5, the connecting member 6, etc., the antenna module 2 can be positioned at a fixed position relative to the radome 4. This reduces variations in the performance of the antenna device 10 due to variations in the distance between the antenna module 2 and the radome 4, thereby improving yield.

[0046] As shown in FIG. 11, the elastic member 7 includes a main body 71 and a conductive layer 72.

[0047] The main body 71 has elasticity. The main body 71 shown in FIG. 11 has a flat rectangular parallelepiped shape. The thickness, length, and width directions of the main body 71 correspond to the thickness, length, and width directions of the antenna module 2, respectively. The surfaces of the main body 71 include a first surface 71a and a second surface 71b in the thickness direction of the main body 71, a third surface 71c and a fourth surface 71d in the length direction of the main body 71, and a fifth surface 71e and a sixth surface 71f in the width direction of the main body 71. The first surface 71a of the main body 71 is the surface of the main body 71 that faces the antenna module 2. The second surface 71b of the main body 71 is the surface of the main body 71 opposite to the antenna module 2. The third surface 71c and the fourth surface 71d of the main body 71 are both surfaces of the antenna surface 20 in the direction in which the antenna elements 2a are arranged. The fifth surface 71e and the sixth surface 71f of the main body 71 are both surfaces perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2a are arranged on the antenna surface 20. Materials for the main body 71 include cushioning materials and heat-dissipating rubber materials. Cushioning materials include polyurethane foam, polyethylene foam, ethylene propylene rubber, etc. Heat-dissipating rubber materials include silicone, acrylic, etc. In this embodiment, the main body 71 is formed from heat-dissipating rubber material. Therefore, the main body 71 has thermal conductivity.

[0048] The conductive layer 72 connects the ground surface 21 of the antenna module 2 to the base 3. The conductive layer 72 can be said to connect the ground surface 21 of the antenna module 2 to the base 3 at high frequencies. This makes it possible to use the base 3 as the ground for the antenna module 2. This reduces the influence of sensitivity suppression due to unwanted radiation from the antenna module 2. In this embodiment, the conductive layer 72 is formed of a metal material and has thermal conductivity. A metal material with relatively high thermal conductivity is preferable as the metal material for the conductive layer 72. The conductive layer 72 is formed on the surface of the main body 71. More specifically, as shown in FIG. 11 , the conductive layer 72 includes a first portion 72a, a second portion 72b, and third portions 72c and 72d. The first portion 72a covers the first surface 71a of the main body 71. The first portion 72a is located on the first surface 71a of the main body 71 facing the antenna module 2 and is connected to the antenna module 2. The second portion 72b covers the second surface 71b of the main body 71. The second portion 72b is located on the second surface 71b of the main body 71 opposite the antenna module 2 and is connected to the base 3. The third portions 72c and 72d cover the third surface 71c and the fourth surface 71d of the main body 71, respectively. The third portions 72c and 72d connect the first portion 72a and the second portion 72b. The third portions 72c and 72d are located on both surfaces (the third surface 71c and the fourth surface 71d) of the main body 71 in the direction in which the antenna elements 2a are arranged on the antenna surface 20 (the left-right direction in FIG. 11) and connect the first portion 72a and the second portion 72b. As such, there are no portions covering the fifth surface 71e and the sixth surface 71f of the main body 71. The conductive layer 72 is formed, for example, by wrapping a conductive sheet around the main body 71 with the width direction of the main body 71 as the central axis. This will be described in more detail in "[1.4 Evaluation]" below, but by doing so, the effect of providing the conductive layer 72 on the radiation characteristics of the antenna module 2 can be reduced.

[0049] In this embodiment, the main body 71 and the conductive layer 72 have thermal conductivity, and therefore the elastic member 7 as a whole has thermal conductivity. With this configuration, heat generated in the antenna module 2 can be transferred to the base 3 via the elastic member 7, thereby improving the heat dissipation performance of the antenna device 10.

[0050] Such an elastic member 7 can reduce the influence of sensitivity suppression due to unwanted radiation from the antenna module 2, reduce the influence on the radiation characteristics of the antenna module 2 due to the provision of the conductive layer 72, and further improve the heat dissipation properties of the antenna device 10.

[0051] [1.3 Assembly] Next, an example of a method for assembling the antenna device 10 will be briefly described.

[0052] First, the connecting member 6 is connected to the antenna module 2. Specifically, the antenna module 2 is connected to the connector 63 of the connecting member 6, and the first piece 61 of the connecting member 6 is fixed to the antenna module 2 with the fixing tape 8.

[0053] Next, the elastic member 7 is placed on the bottom 32 of the first recess 31 of the base 3.

[0054] Next, as shown in Fig. 9, the antenna module 2 and the connecting member 6 are accommodated in the first recess 31 with the second piece 62 of the connecting member 6 passing through the opening 36. This positions the elastic member 7 between the antenna module 2 and the bottom 32 of the first recess 31 of the base 3. The antenna module 2 is positioned at a predetermined position by the positioning protrusion 34 of the base 3. As described above, the predetermined position is a position where, in at least a part of the inner surface 33 of the first recess 31, the distance d2 between the inner surface 33 and the antenna module 2 is greater than 0 and is equal to or less than 1 / 10 of the wavelength corresponding to a predetermined communication frequency, as shown in Fig. 9.

[0055] Next, as shown in FIG. 8, the waterproof structure 5 is disposed around the first recess 31 of the base body 3.

[0056] Next, as shown in Fig. 7, the radome 4 is attached to the base 3. In this embodiment, the waterproof structure 5 is a double-sided tape, and therefore the radome 4 is fixed to the base 3 by the waterproof structure 5. When attaching the radome 4 to the base 3, the positioning portion 44 of the radome 4 is joined to the positioning portion 35 of the base 3, so that the radome 4 is positioned at a predetermined position. As described above, as shown in Fig. 5, the predetermined position is a position where the center C4 of the radome 4 and the center C2 of the antenna module 2 coincide with each other in the directions (the left-right direction in Fig. 5, the width direction of the antenna module 2) that are perpendicular to the thickness direction of the antenna module 2 and the direction in which the antenna elements 2a are arranged on the antenna surface 20.

[0057] This provides the antenna device 10. In the antenna device 10, the elastic member 7 is disposed between the antenna module 2 and the bottom 32 of the first recess 31 of the base 3 in a state compressed in the thickness direction of the antenna module 2. As a result, the antenna surface 20 of the antenna module 2 protrudes from the first recess 31 and is pressed against the opposing region 412 of the bottom surface 411 of the second recess 41 of the radome 4 by the elastic member 7. Since the radome 4 includes the spacer 42, the distance d1 between the antenna surface 20 and the opposing region 412 is maintained within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to a predetermined communication frequency.

[0058] According to the antenna device 10 described above, when the antenna module 2 is disposed between the radome 4 and the base 3, it is possible to suppress deterioration of antenna characteristics due to variations in positioning during assembly and reduce the influence of sensitivity suppression due to unwanted radiation from the antenna element 2a of the antenna module 2. In addition, the antenna module 2 has excellent heat dissipation properties and can achieve stable operation. In particular, in this embodiment, the base 3 is part of the metal housing 16 of the electronic device 1, and the first surface 30 of the base 3 on which the first recess 31 is formed is the outer surface, not the inner surface, of the metal housing 16. Therefore, it is possible to arrange the antenna module 2 in a limited space, suppress variations in positioning during assembly, and minimize deterioration of antenna characteristics, thereby achieving both miniaturization and antenna performance.

[0059] [1.4 Evaluation] The results of an evaluation of the advantages of the configuration of the antenna device 10 are shown below.

[0060] [1.4.1 Conductive layer of elastic member] The conductive layer 72 of the elastic member 7 was evaluated using configuration examples 1 and 2 of the antenna device 10. Configuration examples 1 and 2 of the antenna device 10 differ in the configuration of the conductive layer 72 of the elastic member 7. In configuration example 1, as described above, the conductive layer 72 is formed by wrapping a conductive sheet around the main body 71 with the width direction of the main body 71 as the central axis. As a result, the first portion 72a and the second portion 72b of the conductive layer 72 are connected by third portions 72c and 72d that cover the third surface 71c and the fourth surface 71d of the main body 71, respectively. The conductive layer 72 does not cover the fifth surface 71e and the sixth surface 71f of the main body 71. In configuration example 2, the conductive layer 72 is formed by wrapping a conductive sheet around the main body 71 with the length direction of the main body 71 as the central axis. In this case, the first portion 72a and the second portion 72b of the conductive layer 72 are connected by a third portion that covers the fifth surface 71e and the sixth surface 71f of the main body 71. The conductive layer 72 does not cover the third surface 71c and the fourth surface 71d of the main body 71.

[0061] 12, (a) is an electric field distribution diagram of the antenna device 10 in Configuration Example 1, and (b) is an electric field distribution diagram of the antenna device 10 in Configuration Example 2. As is clear from FIG. 12, in the vicinity of the opening of the first recess 31 and in the gap between the inner surface 33 of the first recess 31 and the antenna module 2, indicated by P1, the electric field is strongly distributed in Configuration Example 2, whereas the electric field peaks are dispersed in Configuration Example 1. In the portion between the antenna module 2 and the bottom 32 of the first recess 31 of the base 3, indicated by P2, the electric field is distributed in Configuration Example 1. Furthermore, in the portion in front of the antenna surface 20 of the antenna module 2, indicated by P3, the influence of reflection from the radome 4 is large in Configuration Example 2, whereas the influence of reflection from the radome 4 is reduced in Configuration Example 1. In Configuration Example 1, unlike Configuration Example 2, the electric field on the base 3 side of the antenna module 2 is not blocked by the conductive layer 72 of the elastic member 7, thereby reducing the influence on the radiation characteristics of the antenna module 2.

[0062] 1.4.2 Openings in the base The opening 36 of the base 3 was evaluated using configuration examples 3 to 6 of the antenna device 10. Configuration examples 3 to 6 of the antenna device 10 differ in the configuration of the opening 36 of the first recess 31 of the base 3. In FIG. 13, (a) is a plan view of configuration example 3 of the antenna device 10, (b) is a plan view of configuration example 4 of the antenna device 10, and (c) is a plan view of configuration example 5 of the antenna device 10. In configuration example 3, the dimension D1 of the opening 36 in the direction in which the antenna elements 2a are lined up on the antenna surface 20 (the length direction of the antenna module 2) is ½ of the dimension L of the antenna module 2. In configuration example 4, the dimension D1 of the opening 36 in the direction in which the antenna elements 2a are lined up on the antenna surface 20 (the length direction of the antenna module 2) is ⅔ of the dimension L of the antenna module 2. In configuration example 5, the dimension D1 of the opening 36 in the direction in which the antenna elements 2a are lined up on the antenna surface 20 (the length direction of the antenna module 2) is equal to the dimension L of the antenna module 2. In the sixth configuration example, the base body 3 does not have the opening 36 .

[0063] FIG. 14 is a graph of the cumulative distribution function for configuration examples 3 to 6 of the antenna device 10. In FIG. 14, graphs G13 to G16 correspond to configuration examples 3 to 6, respectively. As is clear from FIG. 14, graph G16 is located at the far right. In other words, the radiation characteristics of the antenna module 2 are better without the opening 36. However, since graph G13 is roughly the same as graph G16, if the dimension D1 of the opening 36 is half the dimension L of the antenna module 2, as in configuration example 3, the presence of the opening 36 has little effect on the radiation characteristics of the antenna module 2. On the other hand, in the region where the antenna gain is low, graphs G14 and G15 corresponding to configuration examples 4 and 5 are shifted to the left compared to graph G16. This means that the probability that the antenna gain will be below a predetermined value is higher than in graph G16. From the above, it can be seen that by setting the dimension D1 of the opening 36 to half the dimension L of the antenna module 2, the effect of the opening 36 on the radiation characteristics of the antenna module 2 can be reduced, while enabling connection of the antenna module 2 to another electrical circuit (communication circuit 11).

[0064] [1.4.3 Base positioning protrusions] The opening 36 of the base 3 was evaluated using configuration examples 7 and 8 of the antenna device 10. Configuration examples 7 and 8 of the antenna device 10 differ in the configuration of the positioning protrusion 34 of the base 3. In configuration example 7, the protrusion amount of the positioning protrusion 34 from the inner surface 33 is set to be greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. As a result, the distance d2 between the inner surface 33 of the first recess 31 and the antenna module 2 is greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to the predetermined communication frequency in at least a portion of the inner surface 33 of the first recess 31. For example, the distance d2 can be set to 1 / 18 or 1 / 27 of the wavelength corresponding to the predetermined communication frequency. In configuration example 8, the protrusion amount of the positioning protrusion 34 from the inner surface 33 is set to be greater than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. As a result, the distance d2 between the inner surface 33 of the first recess 31 and the antenna module 2 is greater than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. For example, the distance d2 can be set to 1 / 5 or 1 / 4 of the wavelength corresponding to the predetermined communication frequency.

[0065] FIG. 15 is a graph showing the angular dependence of the antenna gain for Configuration Examples 7 and 8 of the antenna device 10. In FIG. 15, graphs G21 and G22 correspond to Configuration Examples 7 and 8, respectively. In FIG. 15, the direction of angle 0 corresponds to the front direction of the antenna module 2 (the direction of the antenna surface 20). As can be seen from FIG. 15, graph G21 corresponding to Configuration Example 7 tends to have a larger gain in the front direction of the antenna module 2 than graph G22 corresponding to Configuration Example 8. For antennas that use millimeter waves, the maximum gain is an important indicator in terms of characteristics, so it can be said that the antenna characteristics of Configuration Example 7 are better than those of Configuration Example 8. In other words, the antenna characteristics can be improved by positioning the antenna module 2 closer to the inner surface 33 of the first recess 31 of the base 3.

[0066] 1.4.4 Conductivity of the substrate The properties of the base 3 were evaluated using configuration examples 9 and 10 of the antenna device 10. Configuration examples 9 and 10 of the antenna device 10 differ in the material of the base 3. In configuration example 9, the base 3 is made of metal and is conductive. In configuration example 10, the base 3 is a dielectric material such as a resin material and is not conductive.

[0067] FIG. 16 is a graph showing the angular dependence of antenna gain for Configuration Examples 9 and 10 of the antenna device 10. In FIG. 16, graphs G31 and G32 correspond to Configuration Examples 9 and 10, respectively. In FIG. 16, the direction of angle 0 corresponds to the front direction of the antenna module 2 (the direction of the antenna surface 20). As can be seen from FIG. 16, graph G31 corresponding to Configuration Example 9 tends to have a larger gain in the front direction of the antenna module 2 and a smaller gain in the rear direction of the antenna module 2 (the direction of the ground surface 21) than graph G32 corresponding to Configuration Example 10. This is thought to be because the base 3 is made of metal, which causes radio waves from the antenna module 2 to be reflected around the first recess 31 of the base 3. For millimeter-wave antennas, the maximum gain is an important indicator of performance, so it can be said that the antenna characteristics of Configuration Example 9 are better than those of Configuration Example 10. In other words, a conductive base 3 of the antenna module 2 can improve antenna characteristics.

[0068] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0069] The electronic device 1 is not limited to a tablet terminal as in the above embodiment. The electronic device 1 may be a device having a communication function such as a terminal device and a server. Examples of the terminal device include a personal computer (desktop computer, laptop computer), a mobile terminal (smartphone, wearable terminal, etc.), etc.

[0070] In one modification, the antenna module 2 is not limited to a phased array antenna. The antenna module 2 may be a multi-band antenna capable of communication in different frequency bands. The shape and number of the antenna elements 2a are not particularly limited. That is, the antenna module 2 may include only one antenna element 2a. The predetermined communication frequency is not limited to the frequency band of 26 to 300 GHz, and may be selected from a desired frequency band.

[0071] In one modified example, the base 3 does not necessarily have to be a part of the metal housing 16, and may be a member independent of the metal housing 16. The shape of the first recess 31 is not limited to the shape in the above embodiment, and may be set appropriately depending on the shape of the antenna module 2.

[0072] In one modified example, the positioning protrusions 34 may protrude from the bottom 32 of the first recess 31 instead of from the inner surface 33 of the first recess 31. The shape and number of the positioning protrusions 34 are not particularly limited as long as they can position the antenna module 2 at the specified position by coming into contact with the antenna module 2.

[0073] In one modified example, the positioning portion 35 is not limited to a recess, but may be a protrusion, or a combination of a protrusion and a recess. The shape of the positioning portion 44 of the radome 4 and whether or not the positioning portion 44 is provided are determined depending on the shape of the positioning portion 35 of the base 3. The positioning portion 35 is not essential.

[0074] In one modified example, the opening 36 may be formed so that at least a portion, rather than all, of it does not overlap with the antenna module 2 in the thickness direction of the antenna module 2. The opening 36 may be adjacent to the antenna module 2 in the direction in which the antenna elements 2a are arranged on the antenna surface 20. The dimensions of the opening 36 are preferably the dimensions given in the above embodiment, but are not particularly limited. The opening 36 is not essential.

[0075] In one modified example, the shape of the radome 4 is not limited to the shape in the above embodiment, and may be set appropriately depending on the shape of the antenna module 2.

[0076] In one modified example, the spacer 42 may protrude from the inner surface of the second recess 41 rather than from the bottom surface 411 of the second recess 41. The shape and number of the spacer 42 are not particularly limited as long as the spacer 42 can set the distance d1 within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to a predetermined communication frequency by contacting the antenna module 2.

[0077] In one modified example, the positioning portion 44 is not limited to a protrusion, but may be a recess, or a combination of a protrusion and a recess. The positioning portion 44 is not essential.

[0078] In one modified example, the waterproof structure 5 is not limited to double-sided tape, and may be any structure that can waterproof the space between the first surface 30 of the base 3 and the second surface 40 of the radome 4. The waterproof structure 5 may be, for example, an adhesive, or a well-known waterproof member such as a seal or packing. The waterproof structure 5 may be a resin or metal member that covers the second portion 4b of the radome 4 so as to press the second surface 40 of the radome 4 against the first surface 30 of the base 3. The waterproof structure 5 may also be a fastening member such as a screw.

[0079] In one modified example, the connection member 6 is not limited to a configuration in which the first piece 61 and the second piece 62 are formed from a flexible substrate. For example, the first piece 61 and the second piece 62 may be separate substrates. The connector 63 is not required in the connection member 6. The second piece 62 does not need to be directly connected to the communication circuit 11, and may be connected using an electric wire such as a coaxial cable. The connection member 6 is not required.

[0080] In one modification, the conductive layer 72 in the elastic member 7 may have only one of the third portions 72c and 72d. That is, the conductive layer 72 may have the third portions 72c and 72d that are located on at least one of the two surfaces (the third surface 71c and the fourth surface 71d) of the main body 71 in the direction in which the antenna elements 2a are arranged on the antenna surface 20 and connect the first portion 72a and the second portion 72b. The conductive layer 72 may include a portion that covers at least one of the fifth surface 71e and the sixth surface 71f of the main body 71. In the elastic member 7, at least one of the main body 71 and the conductive layer 72 may be thermally conductive. As long as the antenna module 2 has sufficient heat dissipation capability, the elastic member 7 does not necessarily have to be thermally conductive. The elastic member 7 is not essential.

[0081] [3. Aspects] As is clear from the above-described embodiment and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clarify the correspondence with the embodiment.

[0082] A first aspect of the present invention is an antenna device (10) comprising: an antenna module (2) for communicating at a predetermined communication frequency; a conductive base (3) having a first surface (30) in which a first recess (31) capable of accommodating the antenna module (2) is formed; a dielectric radome (4) having a second surface (40) facing the first surface (30) of the base (3) and having a second recess (41) formed in the second surface (40) facing the first recess (31); and a waterproof structure (5) for waterproofing between the first surface (30) of the base (3) and the second surface (40) of the radome (4). The antenna module (2) is accommodated in the first recess (31) such that an antenna surface (20) on which an antenna element (2a) is formed protrudes from the first surface (30) into the second recess (41). This aspect improves waterproofing and antenna performance.

[0083] A second aspect is an antenna device (10) based on the first aspect. In the second aspect, the bottom surface (411) of the second recess (41) includes a facing region (412) that faces the antenna surface (20) in parallel. A distance (d1) between the facing region (412) and the antenna surface (20) is within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. According to this aspect, it is possible to suppress a decrease in antenna gain due to reflection of radio waves at the radome (4).

[0084] A third aspect is the antenna device (10) based on the second aspect, in which the radome (4) has a spacer (42) between the facing region (412) and the antenna surface (20) that maintains the distance (d1) between the facing region (412) and the antenna surface (20) within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency. This aspect facilitates the task of setting the distance (d1) between the facing region (412) and the antenna surface (20) within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency.

[0085] A fourth aspect is the antenna device (10) based on the third aspect, in which the spacer (42) does not face the antenna element (2 a). A distance (d3) between the spacer (42) and the antenna element (2 a) in a plane parallel to the antenna surface (20) is equal to or greater than 1 / 5 of the wavelength corresponding to the predetermined communication frequency. This aspect makes it possible to reduce the effect of providing the spacer (42) on the antenna characteristics.

[0086] A fifth aspect is an antenna device (10) based on any one of the first to fourth aspects. In the fifth aspect, a portion (4a) of the radome (4) that covers the antenna module (2) is symmetrical with respect to a line (L1) that passes through the centers of the antenna elements (2a) that are aligned in one direction on the antenna surface (20). According to this aspect, it is possible to improve the gain in the front direction of the antenna module (2) (toward the antenna surface (20)).

[0087] A sixth aspect is an antenna device (10) based on any one of the first to fifth aspects. In the sixth aspect, the radome (4) includes a facing portion (4a) facing the antenna surface (20). The thickness of the facing portion (4a) is in the range of 1 / 10 to 1 / 8 of the wavelength corresponding to the predetermined communication frequency. According to this aspect, the gain in the front direction of the antenna module (2) (toward the antenna surface (20)) can be improved.

[0088] A seventh aspect is an antenna device (10) based on any one of the first to sixth aspects, wherein the antenna module (2) is at a predetermined position within the first recess (31). The predetermined position is a position where, in at least a part of the inner surface (33) of the first recess (31), the distance between the inner surface (33) and the antenna module (2) is greater than 0 and equal to or less than 1 / 10 of the wavelength corresponding to the predetermined communication frequency. According to this aspect, it is possible to improve the gain in the front direction of the antenna module (2) (toward the antenna surface (20)).

[0089] An eighth aspect is an antenna device (10) based on the seventh aspect, in which the base (3) has a positioning protrusion (34) that positions the antenna module (2) at the specified position by contacting the antenna module (2). According to this aspect, it is easy to align the antenna module (2) with the base (3), which facilitates the assembly work of the antenna device (10).

[0090] A ninth aspect is the antenna device 10 based on the eighth aspect, in which the positioning projection 34 projects from the inner surface 33 of the first recess 31. According to this aspect, the structure of the base 3 can be simplified.

[0091] A tenth aspect is an antenna device (10) based on any one of the first to ninth aspects. In the tenth aspect, the base (3) has a positioning portion (35) that positions the radome (4) at a predetermined position where the center (C4) of the radome (4) and the center (C2) of the antenna module (2) coincide in directions perpendicular to the thickness direction of the antenna module (2) and the direction in which the antenna elements (2 a) are arranged on the antenna surface (20). According to this aspect, the influence of the radome (4) on the antenna radiation characteristics of the antenna module (2) can be reduced. According to this aspect, the alignment of the radome (4) and the antenna module (2) is facilitated, thereby facilitating the assembly work of the antenna device (10).

[0092] An eleventh aspect is an antenna device (10) based on any one of the first to tenth aspects. In the eleventh aspect, the base (3) has an opening (36) penetrating the bottom (32) of the first recess (31). The opening (36) does not overlap the antenna module (2) in the thickness direction of the antenna module (2). According to this aspect, it is possible to connect the antenna module (2) to another electric circuit (communication circuit (11)) while reducing the effect of providing the opening (36) on the radiation characteristics of the antenna module (2).

[0093] A twelfth aspect is an antenna device 10 based on the eleventh aspect, in which the opening 36 is adjacent to the antenna module 2 in a direction perpendicular to the thickness direction of the antenna module 2 and to the direction in which the antenna elements 2 a are arranged on the antenna surface 20. According to this aspect, the length of the wiring required to connect the antenna module 2 to another electric circuit (communication circuit 11) can be shortened.

[0094] A thirteenth aspect is the antenna device (10) based on the eleventh or twelfth aspect, in which the dimension (D1) of the opening (36) is equal to or less than half the dimension of the antenna module in the direction in which the antenna elements (2 a) are arranged on the antenna surface (20). According to this aspect, it is possible to connect the antenna module (2) to another electric circuit (communication circuit (11)) while reducing the effect of providing the opening (36) on the radiation characteristics of the antenna module (2).

[0095] A fourteenth aspect is an antenna device (10) based on any one of the eleventh to thirteenth aspects. In the fourteenth aspect, the dimensions of the opening (36) are equal to or less than one-third of the wavelength corresponding to the predetermined communication frequency in the thickness direction of the antenna module (2) and in directions perpendicular to the direction in which the antenna elements (2 a) are arranged on the antenna surface (20). According to this aspect, it is possible to connect the antenna module (2) to another electric circuit (communication circuit (11)) while reducing the effect of providing the opening (36) on the radiation characteristics of the antenna module (2).

[0096] A fifteenth aspect is an antenna device (10) based on any one of the eleventh to fourteenth aspects. In the fifteenth aspect, the antenna device (10) further includes a connection member (6) for connecting the antenna module (2) to a communication circuit (11). The connection member (6) includes a first piece (61) connected to the antenna module (2) and extending from the antenna module (2) toward the opening (36), and a second piece (62) extending from a tip of the first piece (61) through the opening (36) and connected to the communication circuit (11). According to this aspect, the antenna module (2) and the communication circuit (11) can be easily connected.

[0097] A sixteenth aspect is the antenna device (10) based on the fifteenth aspect. In the sixteenth aspect, the first piece (61) and the second piece (62) are formed by bending a flexible substrate. According to this aspect, the connecting member (6) can be easily provided.

[0098] A seventeenth aspect is an antenna device (10) based on any one of the first to sixteenth aspects. In the seventeenth aspect, the antenna device (10) further includes an elastic member (7) disposed between the antenna module (2) and the bottom (32) of the first recess (31) of the base (3) in a compressed state in the thickness direction of the antenna module (2). According to this configuration, it is possible to reduce variations in performance of the antenna device (10) due to variations in the distance between the antenna module (2) and the radome (4), thereby improving yield.

[0099] An 18th aspect is an antenna device (10) based on the 17th aspect. In the 18th aspect, the elastic member (7) includes an elastic main body (71) and a conductive layer (72) formed on the surface of the main body (71) and connecting the ground surface (21) of the antenna module (2) to the base (3). With this configuration, the base (3) can be used as the ground of the antenna module (2), thereby reducing the influence of sensitivity suppression due to unwanted radiation from the antenna module (2).

[0100] A nineteenth aspect is an antenna device (10) based on the eighteenth aspect. In the nineteenth aspect, the conductive layer (72) includes a first portion (72a) on a surface (first surface 71a) of the main body (71) facing the antenna module (2) and connected to the antenna module (2), a second portion on a surface (second surface 71b) of the main body (71) opposite the antenna module (2) and connected to the base (3), and a third portion (72c, 72d) on at least one of both surfaces (third surface 71c and fourth surface 71d) of the main body (71) in the direction in which the antenna elements (2a) are arranged on the antenna surface (20), connecting the first portion (72a) and the second portion (72b). This configuration reduces the effect of providing the conductive layer (72) on the radiation characteristics of the antenna module (2).

[0101] A twentieth aspect is the antenna device (10) based on the eighteenth or nineteenth aspect. In the twentieth aspect, the elastic member (7) has thermal conductivity. According to this aspect, heat generated in the antenna module (2) can be transferred to the base (3) via the elastic member (7), thereby improving the heat dissipation performance of the antenna device (10).

[0102] A twenty-first aspect is an antenna device (10) based on any one of the first to twentieth aspects. In the twenty-first aspect, the predetermined communication frequency is included in a frequency band of 26 to 300 GHz. According to this aspect, the communication speed by the antenna device (10) can be improved.

[0103] A 22nd aspect is an electronic device (1), comprising an antenna device (10) based on any one of the first to 21st aspects, a communication circuit (11) connected to the antenna device (10), and a metal housing (16) that houses the communication circuit (11). The base (3) is a part of the metal housing (16). A first surface (30) of the base (3) is the outer surface of the metal housing (16). According to this aspect, waterproof performance and antenna performance can be improved. [Industrial Applicability]

[0104] The present disclosure relates to an antenna device and an electronic device, and more particularly to an antenna device in which a waterproof antenna module is required, and an electronic device having a metal housing. [Explanation of symbols]

[0105] 1 Electronic equipment 10 Antenna device 11 Communication Circuits 12 Input / Output Devices 121 Touch Panel Display 13 Storage device 14 Arithmetic circuit 15 Case 16 Metal housing 17 Outer Wall 171 Aperture 2 Antenna Module 2a, 2a-1 to 2a-4 Antenna elements 20 Antenna surface 21 Ground plane 3 Base 30 Page 1 31 First recess 32 Bottom 33 Inner surface 34, 34-1 to 34-5 Positioning protrusions 35 Positioning part 36 Aperture 4 Radome 4a 1st part 4b 2nd part 40 Side 2 41 Second recess 411 bottom 412 Opposing area 42, 42-1 to 42-6 spacers 44 Positioning part 5 Waterproof structure 50 aperture 6 Connecting members 61 1st piece 62 2nd piece 63 Connector 7 Elastic member 71 Main Unit 71a 1st page 71b 2nd page 71c 3rd page 71d 4th page 71e 5th page 71f Page 6 72 Conductive layer 72a Part 1 72b Part 2 72c,72d 3rd part 8 Fixing Tape d1 Distance (distance between the facing area and the antenna surface) d2 Distance (distance between the inner surface and the antenna module) d3 Distance (distance between the spacer and the antenna element) L1 line (line passing through the center of the antenna element) t1 Thickness of the first part C2 center C4 Center D1,D2 inch method P1, P2, P3 parts

Claims

1. an antenna module for communicating at a predetermined communication frequency; a conductive base having a first surface, capable of accommodating the antenna module, and having a first recess formed in the first surface; a dielectric radome having a second surface opposite to the first surface of the substrate, the second recess facing the first recess and formed in the second surface; a waterproof structure disposed between the first surface of the base and the second surface of the radome for waterproofing the antenna module; Equipped with The antenna module includes: one or more antenna elements; an antenna surface on which the one or more antenna elements are formed, the antenna module is accommodated in the first recess such that the antenna surface protrudes from the first surface of the base into the second recess; Antenna device.

2. a bottom surface of the second recessed portion includes an opposing region that faces the antenna surface in parallel; the distance between the facing region and the antenna surface is within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency; The antenna device according to claim 1 .

3. the radome is located between the facing region and the antenna surface, a spacer that maintains the distance between the facing region and the antenna surface within a range of 1 / 50 to 1 / 30 of the wavelength corresponding to the predetermined communication frequency; The antenna device according to claim 2 .

4. the spacer does not face the one or more antenna elements, a distance between the spacer and each of the one or more antenna elements in a plane parallel to the antenna plane is equal to or greater than 1 / 5 of a wavelength corresponding to the predetermined communication frequency; The antenna device according to claim 3 .

5. a portion of the radome covering the antenna module is symmetrical with respect to a line passing through the centers of the plurality of antenna elements arranged in one direction on the antenna surface; The antenna device according to any one of claims 1 to 4.

6. the radome includes a facing portion facing the antenna surface, a thickness of the facing portion is in the range of 1 / 10 to 1 / 8 of a wavelength corresponding to the predetermined communication frequency; The antenna device according to any one of claims 1 to 5.

7. the antenna module is in a predetermined position within the first recess; the predetermined position is a position where a distance between at least a part of the inner surface of the first recess and the antenna module is greater than 0 and is equal to or less than 1 / 10 of a wavelength corresponding to the predetermined communication frequency; The antenna device according to any one of claims 1 to 6.

8. the base has a positioning protrusion that abuts against the antenna module to position the antenna module at the specified position; 8. The antenna device according to claim 7.

9. The positioning protrusion protrudes from an inner surface of the first recess.

9. The antenna device according to claim 8.

10. the base has a positioning portion that positions the radome at a predetermined position where a center of the radome coincides with a center of the antenna module in directions perpendicular to a thickness direction of the antenna module and a direction in which the plurality of antenna elements are arranged on the antenna surface. The antenna device according to any one of claims 1 to 9.

11. the base has an opening penetrating a bottom of the first recess, At least a portion of the opening does not overlap with the antenna module in a thickness direction of the antenna module. The antenna device according to any one of claims 1 to 10.

12. the opening is adjacent to the antenna module in directions perpendicular to a thickness direction of the antenna module and a direction perpendicular to a direction in which the plurality of antenna elements are arranged on the antenna surface. The antenna device according to claim 11.

13. a first dimension of the opening, which is a dimension of the opening in a direction in which the plurality of antenna elements are arranged on the antenna plane, is equal to or smaller than half a dimension of the antenna module; 13. The antenna device according to claim 11 or 12.

14. a second dimension of the opening, which is a dimension of the opening in a direction perpendicular to a thickness direction of the antenna module and a direction perpendicular to a direction in which the plurality of antenna elements are arranged on the antenna surface, is equal to or less than 1 / 3 of a wavelength corresponding to the predetermined communication frequency; The antenna device according to any one of claims 11 to 13.

15. a connecting member for connecting the antenna module to a communication circuit; The connecting member is a first piece connected to the antenna module and extending from the antenna module toward the opening; a second piece extending from the tip of the first piece through the opening and connected to the communication circuit, The antenna device according to any one of claims 11 to 14.

16. the first piece and the second piece are formed by bending a flexible substrate; 16. The antenna device according to claim 15.

17. further comprising an elastic member disposed between the antenna module and a bottom of the first recess of the base body in a compressed state in the thickness direction of the antenna module; An antenna device according to any one of claims 1 to 16.

18. The elastic member is a resilient body; a conductive layer formed on the surface of the body and connecting the ground plane of the antenna module to the base; Including, 18. The antenna device according to claim 17.

19. The body includes: a first surface of the body facing the antenna module; a second surface of the body opposite the antenna module; a third surface and a fourth surface of the main body that are arranged in a direction in which the plurality of antenna elements are arranged on the antenna surface; Including, The conductive layer is a first portion on a first surface of the body and connected to the antenna module; a second portion on a second surface of the body and connected to the base; a third portion located on at least one of a third surface and a fourth surface of the main body and connecting the first portion and the second portion; Including, 19. The antenna device according to claim 18.

20. The elastic member has thermal conductivity.

20. An antenna device according to claim 18 or 19.

21. the waterproof structure is a joining member that joins the second surface of the radome to the first surface of the base; The antenna device according to claim 1 .

22. The predetermined communication frequency is included in the frequency band of 26 to 300 GHz. An antenna device according to any one of claims 1 to 21.

23. An antenna device according to any one of claims 1 to 22; a communication circuit connected to the antenna device; a metal housing that houses the communication circuit; Equipped with the base is a part of the metal housing, the first surface of the base is the outer surface of the metal housing; electronic equipment.

Images