JP2012195534A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus which improves the quality of wireless communication in a housing.SOLUTION: An electronic apparatus 100 according to an embodiment includes substrates 10, a housing 11, and electric wave absorbers 30. Each substrate 10 has a wireless communication part 20 for conducting wireless communication. The housing 11 houses the substrates 10. Each electric wave absorber 30 is provided in at least a part of a region which overlaps with a communication range of the wireless communication part 20, from among a surface of a reflection material included in the housing 11 and reflecting electric waves, and absorbs the electric waves.

Description

  Embodiments described herein relate generally to an electronic apparatus.

  2. Description of the Related Art Conventionally, a technique for performing wireless communication between substrates in an electronic device in which a plurality of substrates each mounted with an electronic circuit is housed in a housing is known. When wireless communication is performed in the housing, multipath fading occurs due to the reflection of the wireless signal on the inner wall of the housing and the like, which causes a reduction in communication quality. Therefore, a technique is known in which a radio wave absorber that absorbs radio waves is provided on the surface of the inner wall of the housing that has the largest area to reduce multipath fading.

JP 2007-150256 A

  However, in the conventional technology, for example, when a substrate having a communication unit that performs wireless communication is arranged near a surface of the housing whose inner area is not the maximum, the reflection of the wireless signal on the surface The resulting multipath fading cannot be reduced. That is, there is a problem that the quality of wireless communication in the housing cannot be ensured sufficiently.

  The problem to be solved by the present invention is to provide an electronic device capable of improving the quality of wireless communication in a housing.

  The electronic device according to the embodiment includes a substrate, a housing, and a radio wave absorber. The substrate has a wireless communication unit for performing wireless communication. The housing stores the substrate. The radio wave absorber is provided in at least a part of the surface of the reflective material that reflects the radio wave included in the housing and overlaps the communication range of the wireless communication unit, and absorbs the radio wave.

1 is a diagram illustrating an example of a schematic configuration of an electronic device according to a first embodiment. FIG. 6 is a diagram illustrating an example of a schematic configuration of an electronic device according to a second embodiment. FIG. 10 is a diagram illustrating an example of a schematic configuration of an electronic apparatus according to a third embodiment. The figure for demonstrating the structure of the modification 1. FIG. The figure for demonstrating the variation of the modification 1. FIG. The figure for demonstrating the variation of the modification 1. FIG. The figure for demonstrating the structure of the modification 2. FIG. The figure for demonstrating the variation of the modification 2. FIG. The figure for demonstrating the variation of the modification 2. FIG. The figure for demonstrating the structure of the further deformation | transformation of the modification 2. FIG. The figure for demonstrating the variation of the further deformation | transformation of the modification 2. FIG. The figure for demonstrating the variation of the further deformation | transformation of the modification 2. FIG.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a schematic configuration of an electronic device 100 according to the first embodiment. As shown in FIG. 1, the electronic device 100 includes a plurality of substrates 10a to 10d and a housing 11 that houses the plurality of substrates 10a to 10d. Here, in FIG. 1, the first substrate from the left is represented as 10a, the second substrate is represented as 10b, the third substrate is represented as 10c, and the fourth substrate is represented as 10d. When it is not necessary to distinguish each of the substrates 10a to 10d, they are simply referred to as the substrate 10. As shown in FIG. 1, the substrates 10 a to 10 d are arranged in parallel at predetermined intervals. More specifically, each of the substrates 10a to 10d is arranged perpendicular to the side surface in the housing 11 so as to be parallel to each other.

  Each substrate 10 includes a wireless communication unit 20 that performs wireless communication. Here, the wireless communication unit included in the substrate 10a is expressed as 20a, the wireless communication unit included in the substrate 10b is expressed as 20b, the wireless communication unit included in the substrate 10c is expressed as 20c, and the wireless communication unit included in the substrate 10d is expressed as 20d. When it is not necessary to distinguish between the wireless communication units 20a to 20d, they are simply referred to as the wireless communication unit 20. In the present embodiment, the wireless communication unit 20a performs wireless communication only with the wireless communication unit 20b. The wireless communication unit 20b performs wireless communication with each of the wireless communication unit 20a and the wireless communication unit 20c. The wireless communication unit 20c performs wireless communication with each of the wireless communication unit 20b and the wireless communication unit 20d. Furthermore, the radio communication unit 20d performs radio communication only with the radio communication unit 20c. Although not shown in detail, each substrate 10 is mounted (mounted) with an electronic circuit including an active element such as a transistor and a diode and a passive element such as a resistor and a capacitor in addition to the wireless communication unit 20. The

  In the present embodiment, a radio wave absorber that absorbs radio waves is provided in an area of the inner surface of the housing 11 that overlaps the communication range of the wireless communication unit 20. The communication range can be regarded as a substantially spherical area having a radius of the communication distance of the wireless communication unit 20. And a communication distance means the distance (distance which can communicate wirelessly) which the wireless communication part 20 can transmit / receive communication data. The communication distance can be calculated by, for example, transmission power, antenna gain, NF (Noise Figure) of the receiving side radio unit, SNR (Signal to Noise Ratio) necessary for receiving communication data without error. For example, when a standardized wireless communication method is used, the communication distance may be indicated by the communication standard. The starting point of the communication distance in the wireless communication unit 20 can be arbitrarily set. For example, the end of the wireless communication unit 20 can be used as the starting point of the communication distance, or the end of the antenna provided in the wireless communication unit 20 Can be the starting point of the communication distance.

  In the present embodiment, each wireless communication unit 20 does not perform wireless communication with a device outside the housing 11, and therefore the communication distance of each wireless communication unit 20 is arbitrary in the housing 11. Among the straight lines connecting the two points, a value shorter than the maximum length straight line is set. However, the present invention is not limited to this, and each wireless communication unit 20 may perform wireless communication with a device outside the housing 11, and the communication distance of each wireless communication unit 20 is within the housing 11. It may be set to a value equal to or greater than the maximum length of the straight lines connecting any two points.

  Hereinafter, the wireless communication unit 20a will be described with reference to FIG. Since the wireless communication unit 20a performs wireless communication only with the wireless communication unit 20b, the communication distance of the wireless communication unit 20a is longer than the straight line connecting the wireless communication unit 20a and the wireless communication unit 20b, and wirelessly. It is set to a value d shorter than a straight line connecting the communication unit 20a and the wireless communication unit 20c. Therefore, the communication range Wa of the wireless communication unit 20a can be regarded as a substantially spherical region having the communication distance d as a radius.

  As shown in FIG. 1, in this embodiment, the bottom surface 101 in the housing 11 has a region Ta that overlaps the communication range Wa of the wireless communication unit 20a, and a radio wave absorber 30 is provided in the region Ta. . Here, the radio wave absorber 30 is provided over the entire area Ta. However, the present invention is not limited to this, and for example, the radio wave absorber 30 may be provided only in a part of the area Ta. In short, the radio wave absorber 30 only needs to be provided in at least a part of the region Ta.

  The radio wave absorber 30 only needs to absorb radio waves, and its configuration is arbitrary. For example, a magnetic material can be mixed with a resin, or iron powder can be mixed with a synthetic rubber, or a resin such as urethane foam or styrene can be impregnated with carbon. .

  The same applies to the other radio communication units 20b to 20d, and here, the communication distance of each of the other radio communication units 20b to 20d is also set to d. Therefore, each of the communication range Wb of the wireless communication unit 20b, the communication range Wc of the wireless communication unit 20c, and the communication range Wd of the wireless communication unit 20d is regarded as a substantially spherical region having a communication distance d as a radius. Can do. The radio wave absorber 30 is provided in each of the area Tb that overlaps the communication range Wb, the area Tc that overlaps the communication range Wc, and the area Td that overlaps the communication range Wd in the bottom surface 101 in the housing 11. Below, when it is not necessary to distinguish each communication range Wa-Wd, it only describes with W, and when it is not necessary to distinguish each area | region Ta-Td, it only describes with T.

  Here, when multipath fading occurs in the communication range of the wireless communication unit 20, the wireless signal received by the wireless communication unit 20 is distorted. From the viewpoint of improving communication quality, the wireless communication unit 20 It is particularly preferable to reduce multipath fading that occurs in the communication range. As described above, in the present embodiment, the radio wave absorber 30 is provided in at least a part of the region T that overlaps the communication range W of each wireless communication unit 20 in the inner surface (here, the bottom surface 101) of the housing 11. Multipath fading that occurs in the communication range of each wireless communication unit 20 is reduced. Therefore, according to this embodiment, there is an advantageous effect that the quality of wireless communication in the housing 11 can be improved.

(Second Embodiment)
Next, a second embodiment will be described. Below, it demonstrates centering on the part which is different from the above-mentioned 1st Embodiment. Parts common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  In the second embodiment, the radio wave absorber 30 is different from the first embodiment in that the radio wave absorber 30 is provided in an area including the above-described area T in the bottom surface 101 in the housing 11. FIG. 2 is a diagram illustrating an example of a schematic configuration of an electronic device 200 according to the second embodiment. As shown in FIG. 2, the bottom surface 101 of the housing 11 has a rectangular area Sa including the area Ta, a rectangular area Sb including the area Tb, a rectangular area Sc including the area Tc, and a rectangle including the area Td. Region Sd. When it is not necessary to distinguish the areas Sa to Sd, they are simply expressed as areas S. And the electromagnetic wave absorber 30 is provided over each whole area | region Sa-Sd. In addition, in each area S, the radio wave absorber 30 may be provided only in a part of the area S, but the radio wave absorber is provided in at least a part of the area T included in the area S. 30 is required.

  In the present embodiment, by providing the radio wave absorber 30 in each region S, it is possible to reduce not only the communication range of each wireless communication unit 20 but also multipath fading that occurs outside the communication range. Therefore, there is an advantageous effect that the quality of wireless communication in the housing 11 can be further improved. Here, the example in which the shape of the region S is rectangular has been described, but the shape of the region S is not limited to this and is arbitrary. For example, the shape of the region S may be a circle.

(Third embodiment)
Next, a third embodiment will be described. Below, it demonstrates centering on the part which is different from the above-mentioned 1st Embodiment. Parts common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  In the present embodiment, the radio wave absorber 30 includes not only the area T that overlaps the communication range W of the wireless communication unit 20 in the bottom surface 101 in the housing 11 but also the communication range W of the wireless communication unit 20 in the substrate 10. This is different from the first embodiment described above in that it is also provided in a region overlapping with the first embodiment. FIG. 3 is a diagram illustrating an example of a schematic configuration of an electronic apparatus 300 according to the third embodiment. As shown in FIG. 3, the substrate 10a has a region Qab that overlaps the communication range Wb of the wireless communication unit 20b. A radio wave absorber 30 is provided in the region Qab. Further, the substrate 10b has a region Qba that overlaps the communication range Wa of the wireless communication unit 20a and a region Qbc that overlaps the communication range Wc of the wireless communication unit 20c. A radio wave absorber 30 is provided in each of the regions Qba and Qbc.

  The substrate 10c has a region Qcb that overlaps the communication range Wb of the wireless communication unit 20b and a region Qcd that overlaps the communication range Wd of the wireless communication unit 20d. A radio wave absorber 30 is provided in each of regions Qcb and Qcd. Furthermore, the substrate 10d has a region Qdc that overlaps the communication range Wc of the wireless communication unit 20c. A radio wave absorber 30 is provided in the region Qdc.

  Here, multipath fading also occurs due to reflection of radio signals on the substrate 10. In the present embodiment, the radio wave absorber 30 is also provided in a region of the substrate 10 that overlaps the communication range W of each wireless communication unit 20, so that the radio communication unit 20 of each wireless communication unit 20 is compared with the first embodiment described above. Multipath fading that occurs in the communication range W can be further reduced. Therefore, there is an advantageous effect that the quality of wireless communication in the housing 11 can be further improved.

  As mentioned above, although embodiment of this invention was described, this embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof. Hereinafter, modifications will be described. Note that the following modifications can be arbitrarily combined.

(Modification 1)
The communication distance of each wireless communication unit 20 only needs to be shorter than the maximum length of the straight lines connecting any two points in the housing 11, and the communication range W can be arbitrarily changed within the range. is there.
For example, as shown in FIG. 4, the communication distance of each wireless communication unit 20 is set to d2 larger than the above-mentioned d, and the communication range W of each wireless communication unit 20 is not limited to the bottom surface 101 in the housing 11. The side surfaces 102 and 103 may overlap. Below, it demonstrates paying attention to the radio | wireless communication part 20a, referring FIG.

  As shown in FIG. 4, the bottom surface 101 in the housing 11 has a region T2a that overlaps the communication range Wa of the wireless communication unit 20a, and the radio wave absorber 30 is provided in the region T2a. Here, the radio wave absorber 30 is provided over the entire region T2a. However, the present invention is not limited to this. For example, the radio wave absorber 30 may be provided only in a part of the region T2a. In short, the radio wave absorber 30 only needs to be provided in at least a part of the region T2a. The side surface 102 in the housing 11 has a region Xa that overlaps the communication range Wa, and the radio wave absorber 30 is provided in the region Xa. Here, the radio wave absorber 30 is provided over the entire area Xa. However, the present invention is not limited thereto, and the radio wave absorber 30 may be provided only in a part of the area Xa, for example. In short, the radio wave absorber 30 only needs to be provided in at least a part of the region Xa. Furthermore, the side surface 103 in the housing 11 has an area Ya that overlaps the communication range Wa, and the radio wave absorber 30 is provided in the area Ya. Here, the radio wave absorber 30 is provided over the entire area Ya. However, the present invention is not limited to this. For example, the radio wave absorber 30 may be provided only in a part of the area Ya. In short, the radio wave absorber 30 only needs to be provided in at least a part of the region Ya.

  The same applies to the wireless communication units 20b to 20d. As shown in FIG. 4, in the bottom surface 101 in the housing 11, each of a region T2b overlapping the communication range Wb, a region T2c overlapping the communication range Wc, and a region T2d overlapping the communication range Wd 30 is provided. When it is not necessary to distinguish the regions T2a to T2d, they are simply expressed as T2. In addition, the radio wave absorber 30 is also provided in each of the region Xb that overlaps the communication range Wb, the region Xc that overlaps the communication range Wc, and the region Xd that overlaps the communication range Wd among the side surfaces 102 in the housing 11. When it is not necessary to distinguish the regions Xa to Xd, they are simply expressed as X. Furthermore, the radio wave absorber 30 is also provided in each of the region Yb that overlaps the communication range Wb, the region Yc that overlaps the communication range Wc, and the region Yd that overlaps the communication range Wd on the side surface 103 in the housing 11. When it is not necessary to distinguish the areas Ya to Yd, they are simply written as Y.

  Also in the example of FIG. 4, since the radio wave absorber 30 is provided in at least a part of the inner surface of the housing 11 that overlaps the communication range W of each wireless communication unit 20, multipath fading is reduced.

  However, as in the above-described embodiments, if the communication range W is narrow (if the communication distance of the wireless communication unit 20 is short), the area of the inner surface of the housing 11 that overlaps the communication range W is also small, and thus is small. There is an advantage that multipath fading can be reduced by the radio wave absorber 30. The millimeter wave signal has a large amplitude attenuation with an increase in propagation distance, and if used for wireless communication, the communication distance can be shortened. Therefore, in each of the above embodiments, the millimeter wave signal is used. It is preferable to perform wireless communication.

  In the example of FIG. 4, the radio wave absorber 30 may not be provided in a region where the sensitivity of the antenna is low (region deviating from the antenna directivity) among the region T2, the region X, and the region Y. Thereby, there is an advantage that multipath fading can be effectively reduced even with a small number of radio wave absorbers 30.

  Similarly to the above-described second embodiment, the region including the above-described region T <b> 2 in the bottom surface 101 in the housing 11, the region including the above-described region X in the side surface 102, and the above-described region in the side surface 103. The radio wave absorber 30 can be provided in each of the regions including Y. In this case, for example, as shown in FIG. 5, the bottom surface 101 of the housing 11 has a rectangular (rectangular) region S2 including a region T2a, a region T2b, a region T2c, and a region T2d, and the region S2 absorbs radio waves. A body 30 is provided. The side surface 102 of the housing 11 has a rectangular area S3 including an area Xa, an area Xb, an area Xc, and an area Xd, and the radio wave absorber 30 is provided in the area S3. Further, the side surface 103 of the housing 11 has a rectangular area S4 including an area Ya, an area Yb, an area Yc, and an area Yd, and the radio wave absorber 30 is provided in the area S4.

  Furthermore, similarly to the above-described third embodiment, the radio wave absorber 30 can be provided in a region of the substrate 10 that overlaps the communication range W of the wireless communication unit 20. In this case, for example, as shown in FIG. 6, the substrate 10a has a region Q2ab that overlaps the communication range Wb of the wireless communication unit 20b. A radio wave absorber 30 is provided in the region Q2ab. Further, the substrate 10b has a region Q2ba that overlaps the communication range Wa of the wireless communication unit 20a and a region Q2bc that overlaps the communication range Wc of the wireless communication unit 20c. Radio wave absorber 30 is provided in each of regions Q2ba and Q2bc.

  The board 10c has a region Q2cb that overlaps the communication range Wb of the wireless communication unit 20b and a region Q2cd that overlaps the communication range Wd of the wireless communication unit 20d. Radio wave absorber 30 is provided in each of regions Q2cb and Q2cd. Furthermore, the substrate 10d has a region Q2dc that overlaps the communication range Wc of the wireless communication unit 20c. A radio wave absorber 30 is provided in the region Q2dc.

(Modification 2)
In each of the above-described embodiments, the four substrates 10 are accommodated in the housing 11, but the number is not limited thereto, and the number of the substrates 10 accommodated in the housing 11 is arbitrary. For example, the number of substrates 10 accommodated in the housing 11 may be only one, or may be five or more. For example, as illustrated in FIG. 7, a configuration may be adopted in which a substrate 40 that performs wireless communication with each of the substrates 10 a to 10 d is accommodated in the housing 11.

  FIG. 7 is a diagram illustrating an example of a schematic configuration of an electronic apparatus 400 according to a modification. As shown in FIG. 7, the substrate 40 is disposed on the bottom surface 101 of the housing 11, and a plurality of signal transfer units 50 a to 50 d are arranged on the surface of the substrate 40. Here, the first signal transfer unit, counting from the left in FIG. 4, is denoted as 50a, the second signal transfer unit as 50b, the third signal transfer unit as 50c, and the fourth signal transfer unit as 50d. When there is no need to distinguish the signal transfer units 50a to 50d, they are simply referred to as the signal transfer unit 50.

  Wired communication is performed between the signal transfer units 50 via the communication line 60. More specifically, the signal transfer unit 50 a performs wired communication with the signal transfer unit 50 b via the communication line 60. Further, the signal transfer unit 50 b performs wired communication with the signal transfer unit 50 c via the communication line 60. Further, the signal transfer unit 50 c performs wired communication with the signal transfer unit 50 d via the communication line 60. As a result, data transfer between the signal transfer units 50 becomes possible. Further, the signal transfer units 50 may perform wired communication directly with each other. For example, the signal transfer unit 50a may perform wired communication directly with the signal transfer unit 50c or the signal transfer unit 50d via the communication line 60.

  In the example of FIG. 7, the signal transfer unit 50a performs wireless communication only with the wireless communication unit 110a included in the substrate 10a, and the wireless communication unit 110a performs wireless communication only with the signal transfer unit 50a. The signal transfer unit 50b performs wireless communication only with the wireless communication unit 110b included in the substrate 10b, and the wireless communication unit 110b performs wireless communication only with the signal transfer unit 50b. The signal transfer unit 50c performs wireless communication only with the wireless communication unit 110c included in the substrate 10c, and the wireless communication unit 110c performs wireless communication only with the signal transfer unit 50c. The signal transfer unit 50d performs wireless communication only with the wireless communication unit 110d included in the substrate 10d, and the wireless communication unit 110d performs wireless communication only with the signal transfer unit 50d. In addition, when it is not necessary to distinguish each radio | wireless communication part 110a-110d, it only describes with the radio | wireless communication part 110. FIG.

  In the example of FIG. 7, the positional relationship between the substrates 10a to 10d and the substrate 40 is such that at least a part of the wireless communication unit 110a overlaps the signal transfer unit 50a, and at least a part of the wireless communication unit 110b extends to the signal transfer unit 50b. Overlap is set such that at least a part of the wireless communication unit 110c overlaps the signal transfer unit 50c and at least a part of the wireless communication unit 110d overlaps the signal transfer unit 50d.

  Here, Ua is a set (pair) of the wireless communication unit 110a and the signal transfer unit 50a, Ub is a set of the wireless communication unit 110b and the signal transfer unit 50b, Uc is a set of the wireless communication unit 110c and the signal transfer unit 50c, A set of the wireless communication unit 50d and the signal transfer unit 50d is denoted as Ud. When there is no need to distinguish each group, it is simply expressed as a group U.

  Below, it demonstrates paying attention to the group Ua. The communication distance of the wireless communication unit 110a is longer than the straight line connecting the wireless communication unit 110a and the signal transfer unit 50a, and shorter than the maximum length of the straight lines connecting any two points in the housing 11. Set to Further, the communication distance of the signal transfer unit 50a is longer than the straight line connecting the wireless communication unit 110a and the signal transfer unit 50a, and is longer than the maximum length of the straight lines connecting any two points in the housing 11. Set to a short value. Here, the communication distance of the wireless communication unit 110a and the communication distance of the signal transfer unit 50a are both set to d3. Therefore, the size of the communication range W2a of the wireless communication unit 110a is the same as the size of the communication range W3a of the signal transfer unit 50a.

  In the example of FIG. 7, the bottom surface 101 of the housing 11 has a region that overlaps each of the communication range W2a of the wireless communication unit 110a and the communication range W3a of the signal transfer unit 50a. Here, a region of the bottom surface 101 of the housing 11 that overlaps the communication range W2a of the wireless communication unit 110a is included in a region T3a of the bottom surface 101 of the housing 11 that overlaps the communication range W3a of the signal transfer unit 50a. . The radio wave absorber 30 is provided in a region other than the region overlapping the substrate 40 in the region T3a. This reduces multipath fading that occurs in the communication ranges (W2a, W3a) of the wireless communication unit 110a and the signal transfer unit 50a. In addition, since the board | substrate 40 prevents that a radio signal advances to the area | region (namely, back side of the board | substrate 40) which overlaps with the board | substrate 40 among area | region T3a, even if it does not provide the electromagnetic wave absorber 30 in the said area | region, the said area | region Multipath fading that occurs due to the reflection of radio signals at can be reduced.

  The same applies to the other sets Ub to Ud, and the bottom surface 101 of the housing 11 has a region T3b that overlaps the communication range W3b, and a radio wave absorber in a region other than the region that overlaps the substrate 40 in the region T3b. 30 is provided. The bottom surface 101 in the housing 11 has a region T3c that overlaps the communication range W3c, and the radio wave absorber 30 is provided in a region other than the region that overlaps the substrate 40 in the region T3c. Furthermore, the bottom surface 101 in the housing 11 has a region T3d that overlaps the communication range W3d, and the radio wave absorber 30 is provided in a region other than the region that overlaps the substrate 40 in the region T3d. When it is not necessary to distinguish each of the regions T3a to T3d, they are simply expressed as a region T3.

  Further, similarly to the above-described second embodiment, the radio wave absorber 30 can be provided in a region including the above-described region T3 in the bottom surface 101 of the housing 11. In this case, for example, as shown in FIG. 8, the bottom surface 101 of the housing 11 has a rectangular (rectangular) region S5 including a region T3a, a region T3b, a region T3c, and a region T3d, and the substrate 40 in the region S5. The radio wave absorber 30 is provided in an area other than the area overlapping with the radio wave absorber 30. However, the present invention is not limited to this, and the radio wave absorber 30 may be provided in a region overlapping the region S5 on the surface of the substrate 40. Thereby, since reflection of the radio signal on the surface of the substrate 40 is suppressed, multipath fading can be further reduced.

  Furthermore, similarly to the above-described third embodiment, the radio wave absorber 30 can be provided in a region of the substrate 10 that overlaps the communication range W2 of the wireless communication unit 110. In this case, for example, as illustrated in FIG. 9, the substrate 10a has a region Q3ab that overlaps the communication range W2b of the wireless communication unit 110b. A radio wave absorber 30 is provided in the region Q3ab. In addition, the substrate 10b includes a region Q3ba that overlaps the communication range W2a of the wireless communication unit 110a and a region Q3bc that overlaps the communication range W2c of the wireless communication unit 110c. A radio wave absorber 30 is provided in each of regions Q3ba and Q3bc.

  The board 10c has a region Q3cb that overlaps the communication range W2b of the wireless communication unit 110b and a region Q3cd that overlaps the communication range W2d of the wireless communication unit 110d. Radio wave absorber 30 is provided in each of regions Q3cb and Q3cd. Furthermore, the board 10d has a region Q3dc that overlaps the communication range W2c of the wireless communication unit 110c. A radio wave absorber 30 is provided in the region Q3dc.

  Further, in the example of FIG. 9, the radio wave absorber 30 is also provided in a region of the surface of the substrate 40 that overlaps the communication range W2 of the wireless communication unit 110 and the communication range W3 of the signal transfer unit 50. Here, the region of the bottom surface 101 of the housing 11 that overlaps the communication range W2 of the wireless communication unit 110 is included in the region T3 of the bottom surface 101 that overlaps the communication range W3 of the signal transfer unit 50. A region overlapping the communication range W2 of the wireless communication unit 110 in the surface of the substrate 40 arranged on the bottom surface 101 is included in a region overlapping the communication range W3 of the signal transfer unit 50 in the surface of the substrate 40. And the area | region which overlaps with the communication range W3 of the signal transfer part 50 among the surfaces of the board | substrate 40 can be regarded as an area | region which overlaps with area | region T3 among the surfaces of the board | substrate 40. FIG. Therefore, the radio wave absorber 30 is provided in a region overlapping the region T3 on the surface of the substrate 40. Thereby, since reflection of the radio signal on the surface of the substrate 40 is suppressed, multipath fading can be further reduced.

  Although detailed illustration is omitted here, the radio wave absorber 30 can be provided in at least a part of the substrate 10 that overlaps the communication range W3 of the signal transfer unit 50.

(Further modification of Modification 2)
In the above-described modification 2, the signal transfer unit 50a to the signal transfer unit 50d are provided on one substrate 40. However, the present invention is not limited to this, and the signal transfer unit 50a to the signal transfer unit 50d are provided on separate substrates. It may be provided. For example, as shown in FIG. 10, on the bottom surface 101 of the housing 11, a substrate 70a on which the signal transfer unit 50a is mounted, a substrate 70b on which the signal transfer unit 50b is mounted, and a substrate on which the signal transfer unit 50c is mounted. 70c and a substrate 70d on which the signal transfer unit 50d is mounted may be provided. When it is not necessary to distinguish the substrates 70a to 70d, they are simply referred to as the substrate 70. In the example of FIG. 10, the radio wave absorber 30 is provided in a region other than the region overlapping the substrate 70 in the region T3 of the bottom surface 101 of the housing 11. The other contents are the same as the contents of FIG.

  In the example of FIG. 10, similarly to the second embodiment described above, the radio wave absorber 30 can be provided in a region including the region T3 in the bottom surface 101 in the housing 11. In this case, for example, as shown in FIG. 11, the bottom surface 101 of the housing 11 has a rectangular (rectangular) region S6 including a region T3a, a region T3b, a region T3c, and a region T3d, and each substrate in the region S6. The radio wave absorber 30 is provided in a region other than the region overlapping with 70a to 70d. However, the present invention is not limited to this, and the radio wave absorber 30 may be provided in a region overlapping the region S6 on the surface of each of the substrates 70a to 70d. Thereby, since the reflection of the radio signal on the surface of each of the substrates 70a to 70d is suppressed, multipath fading can be further reduced.

  In the example of FIG. 10, similarly to the above-described third embodiment, the radio wave absorber 30 can also be provided in a region of the substrate 10 that overlaps the communication range W2 of the wireless communication unit 110. In this case, for example, as illustrated in FIG. 12, the substrate 10a has a region Q3ab that overlaps the communication range W2b of the wireless communication unit 110b. A radio wave absorber 30 is provided in the region Q3ab. In addition, the substrate 10b includes a region Q3ba that overlaps the communication range W2a of the wireless communication unit 110a and a region Q3bc that overlaps the communication range W2c of the wireless communication unit 110c. A radio wave absorber 30 is provided in each of regions Q3ba and Q3bc.

  The board 10c has a region Q3cb that overlaps the communication range W2b of the wireless communication unit 110b and a region Q3cd that overlaps the communication range W2d of the wireless communication unit 110d. Radio wave absorber 30 is provided in each of regions Q3cb and Q3cd. Furthermore, the board 10d has a region Q3dc that overlaps the communication range W2c of the wireless communication unit 110c. A radio wave absorber 30 is provided in the region Q3dc. The above contents are the same as the contents of FIG.

  Furthermore, in the example of FIG. 12, the radio wave absorber 30 is also provided in a region of the surface of the substrate 70 that overlaps the communication range W2 of the wireless communication unit 110 and the communication range W3 of the signal transfer unit 50. Here, the region of the bottom surface 101 of the housing 11 that overlaps the communication range W2 of the wireless communication unit 110 is included in the region T3 of the bottom surface 101 that overlaps the communication range W3 of the signal transfer unit 50. Of the surface of the substrate 70 disposed on the bottom surface 101, the region overlapping the communication range W <b> 2 of the wireless communication unit 110 is included in the region of the surface of the substrate 70 overlapping the communication range W <b> 3 of the signal transfer unit 50. The region overlapping the communication range W3 of the signal transfer unit 50 on the surface of the substrate 70 can be regarded as the region overlapping the region T3 on the surface of the substrate 70. Therefore, the radio wave absorber 30 is provided in a region overlapping the region T3 on the surface of the substrate 70. Thereby, since reflection of the radio signal on the surface of the substrate 70 is suppressed, multipath fading can be further reduced.

(Modification 3)
In the above, of the inner surface (bottom surface 101, side surface 102, side surface 103, etc.) of the housing 11 and the surface of the substrate (10, 40, 70, etc.), it overlaps the communication range of the wireless communication unit (20, 50, 110). The configuration in which the radio wave absorber 30 is provided in at least a part of the region is illustrated, but is not limited thereto. In short, it is only necessary that the radio wave absorber 30 is provided in at least a part of the surface of the reflective material that reflects the radio wave included in the housing 11 and overlaps the communication range of the wireless communication unit. As an example of the reflective material, in addition to the inner surface (101, 102, 103, etc.) of the casing 11 and the substrate (10, 40, 70, etc.) housed in the casing 11, a power source disposed inside the casing 11 , Cables, metal fittings for mounting the substrate, other electronic components, and the like.

DESCRIPTION OF SYMBOLS 10 Board | substrate 11 Case 20 Wireless communication part 30 Radio wave absorber 40 Board | substrate 50 Signal transfer part 60 Communication line 70 Board | substrate 100 Electronic device 101 Bottom surface 102 Side surface 103 Side surface 110 Wireless communication part 200 Electronic device 300 Electronic device 400 Electronic device Q area | region S area | region T area U set W communication range X area Y area

Claims (6)

A substrate having a wireless communication unit for performing wireless communication;
A housing for storing the substrate;
A radio wave absorber that is provided in at least a part of a region that overlaps a communication range of the wireless communication unit in a surface of a reflective material that reflects radio waves included in the housing, and that absorbs radio waves.
An electronic device characterized by that. The communication distance of the wireless communication unit is shorter than the maximum length of the straight lines connecting any two points in the housing.
The electronic device according to claim 1. The reflective material is an inner surface of the housing;
The electronic device according to claim 1. The radio wave absorber is
Of the inner surface of the housing, provided in a region including a region overlapping the communication range of the wireless communication unit,
The electronic device according to claim 3. The reflective material is another substrate housed in the housing.
The electronic device according to claim 1. The wireless communication unit performs wireless communication using millimeter waves.
The electronic device according to claim 1.

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