JP2006332834A - Radio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To connect an antenna to a feeding point on a substrate easily without damaging a shield effect in a portion to a circuit on the substrate when mounting the built-in antenna of a radio device to a case. <P>SOLUTION: On the substrate 12, a shield cover 13 is mounted so that the portion of the circuit is covered where the mutual interference with the antenna 11 should be avoided. The shield cover 13 is formed while having a U-shaped recess from the periphery toward the center, and is mounted onto the substrate 12 while the shield cover surrounds the feeding point 14 provided on the substrate 12 inside the recess. A terminal 15, where one portion of the antenna 11 is formed in nearly a crank shape by bending its end toward the periphery of the shield cover 13, is connected to the feeding point 14 on the substrate 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless device, and more particularly to a wireless device having an antenna built in a housing.

  As an antenna of a wireless device typified by a mobile phone, an antenna having a shape protruding outside the housing, such as a whip antenna, has been conventionally used. However, in recent years, there is a tendency to use a housing built-in type antenna which is advantageous for carrying and operating a wireless device. In addition to wireless communication, for example, wireless devices of a type incorporating an antenna for GPS reception or television broadcast reception are increasing.

  On the other hand, a substrate on which circuit elements that realize various functions are mounted is incorporated in the housing of the wireless device. In order to prevent mutual interference between the housing built-in type antenna and the circuit on the substrate, electromagnetic shielding is performed by a method such as arranging a grounded conductor plate (shield plate) between them. It is effective. However, since the feeding point of the antenna is also provided on the substrate, there is a problem that the feeding point located on both sides of the shield plate and the antenna must be electrically connected.

One solution to the above problem is to provide a shield plate having a through hole between the substrate and the built-in antenna, and electrically connect the feeding point on the substrate and the antenna through the through hole. Is known (for example, see Patent Document 1).
Japanese Patent No. 3374604 (first and third pages, FIG. 1)

  In many cases, the electrical line connecting the feeding point on the substrate and the built-in antenna is formed to have a certain degree of rigidity as a terminal of the built-in antenna. In such a case, in the conventional technique disclosed in Patent Document 1 described above, the terminal and the through hole must be carefully aligned when the built-in antenna is attached to the housing. Otherwise, there is a problem that the terminal may be caught by the shield plate and deformed. Further, there is a problem that the shielding effect is reduced by the amount of the through hole.

  The present invention has been made to solve the above problems, and provides a wireless device that has no fear of terminal deformation when the built-in antenna is attached to a housing and can enhance the shielding effect as compared with the conventional one. With the goal.

  In order to achieve the above object, a wireless device of the present invention includes a housing, an antenna built in the housing, a built-in housing, and a feeding point for the antenna on one surface. The substrate is disposed between the antenna and the antenna and has a recess from a peripheral edge toward the center, and the recess faces the position of the feeding point. And a shield cover attached to a surface of the substrate on which the feeding point is provided.

  According to the present invention, it is possible to easily connect the antenna to the feeding point by covering and shielding the area excluding the feeding point, which is a portion on the substrate where it is desired to avoid mutual interference with the antenna, and according to the prior art. The shielding effect can be enhanced more than the case.

  Embodiments of the present invention will be described below with reference to the drawings.

  Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram illustrating the appearance and main configuration of a wireless device according to a first embodiment of the present invention, where the left side is a front external view and the right side is a diagram illustrating the main configuration as viewed from the right side. 1 in the figure is the wireless device. The housing 10 of the wireless device 1 includes an antenna 11 and a substrate 12, and a shield cover 13 is attached to a surface of the substrate 12 facing the antenna 11 so as to cover a part thereof. In FIG. 1, the wireless device 1 is configured with one casing 10, but is not limited thereto, and may be configured by connecting two or more casings. Further, description of other configurations of the wireless device 1 shown in the front view is omitted.

  FIG. 2 is a diagram illustrating the positional relationship between the main components of the wireless device 1. The antenna 11, the substrate 12, and the shield cover 13 are the same as those described in FIG. 2 represents an embodiment of the antenna according to the applicant's patent application (Japanese Patent Laid-Open No. 2004-201049), but the type of the antenna is not limited to this. A feeding point 14 is provided on the surface of the substrate 12 facing the antenna 11. The shield cover 13 is configured to cover a range that does not include the power supply point 14 on the same surface so as to sandwich the position where the power supply point 14 is provided inside the U-shape, and is attached to the surface. In other words, the shield cover 13 is formed with a recess from the peripheral edge corresponding to the lower side in the figure toward the center. The shield cover 13 is attached to the surface of the substrate 12 facing the antenna 11 so that the concave portion faces the position of the feeding point 14, and is electrically grounded.

  The antenna 11 has a terminal 15 that is formed such that a part of the antenna 11 is bent in a substantially crank shape with the tip thereof toward the peripheral edge of the shield cover 13. The terminal 15 is configured to be connected to the feeding point 14 when the antenna 11 is built in and attached to the housing 10. The terminal 15 has a signal line side and a return line side when the antenna 11 is of a type that is fed with balanced power, and a signal line when the antenna 11 is of a type that is fed with unbalanced power. 2 are shown without distinguishing them for convenience (the same applies to FIGS. 3 to 5 described later).

  At the time of this attachment, the concave portion formed in the U shape of the shield cover 13 can secure a sufficient clearance with respect to the terminal 15. Therefore, unlike the case where the connection is made through the through hole of the shield plate as in the prior art, there is less possibility that the terminal 15 hits the shield cover 13 and is deformed. Further, since the tip of the terminal 15 bent in a substantially crank shape is directed to the peripheral edge of the shield cover 13, the housing 10 can be easily placed so that the antenna 11 does not hit the shield cover 13 from below in FIG. Can be incorporated into.

  The shield cover 13 can completely cover a portion of the circuit mounted on the surface of the substrate 12 facing the antenna 11 where it is desired to avoid mutual interference with the antenna 11. Therefore, the effect of the electromagnetic shield is not impaired because the through hole is made in the shield plate as in the prior art.

  In FIG. 2, the shield cover 13 is configured so as to sandwich the position where the feeding point 14 is provided inside the U-shaped recess. However, the present invention is not limited thereto, and the position of the feeding point 14 is, for example, the position of the V-shaped recess. It may be configured to be sandwiched inside. FIG. 3 is a diagram illustrating the positional relationship between the main components of the wireless device 1 in the case of the V-shape as in FIG. The shield cover 13A in the figure is a shield cover configured so that the position of the feeding point 14 can be sandwiched inside the V-shaped recess. All other reference numerals are the same as those in FIG. Various modifications other than the U-shape and V-shape are possible. Various modifications can be made to the shape and configuration of the antenna 11.

  According to the first embodiment of the present invention, the built-in antenna can be easily attached and connected without impairing the shielding effect.

  Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a diagram illustrating a positional relationship between main components of the wireless device according to the second embodiment. The configuration shown in FIG. 4 is a substrate 12A in which a region where a conductor pattern (including a ground pattern) is not placed is provided on a part of the periphery of the substrate 12 in the configuration of the wireless device 1 in FIG. Reference numerals 16 and 17 in the figure are regions where no conductor pattern (including a ground pattern) is placed. Other configurations are the same as those shown in FIG.

  In a state where the antenna 11 configured in an H shape as shown in FIG. 4 is built in the wireless device, portions corresponding to the two vertical lines on the left and right of the letter “H” are close to the regions 16 and 17. When the antenna 11 is of an unbalanced power supply type and a ground pattern is provided in the regions 16 and 17, a return current opposite to the antenna current flows in the regions 16 and 17, and the antenna 11 It causes the radiation efficiency to decrease.

  In addition, even when the antenna 11 is of a type in which power is balanced and a ground pattern is provided in the regions 16 and 17, capacitive coupling is provided between the conductor portion of the antenna 11 and the regions 16 and 17. This may change the line impedance, possibly degrading the matching at the feeding point 14.

  Therefore, in the second embodiment, the conductor pattern (including the ground pattern) is not placed in the regions 16 and 17 to prevent the deterioration of the characteristics of the antenna 11.

  The antenna 11 in FIG. 4 represents an embodiment of the antenna according to the applicant's patent application (Japanese Patent Laid-Open No. 2004-201049) as in the first embodiment, but is not limited thereto. Even when a built-in antenna having a different shape and configuration is used, the invention according to the second embodiment can be applied.

  According to the second embodiment of the present invention, the additional effect of preventing the deterioration of the characteristics of the built-in antenna can be obtained by the arrangement of the conductor pattern on the substrate.

  Hereinafter, Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating the positional relationship between the main components of the wireless device according to the third embodiment. The configuration shown in FIG. 5 is in addition to the same substrate 12A shown in FIG. 4 and an antenna 11A obtained by modifying the antenna 11 shown in FIG. An antenna holder 20 described later is newly provided.

  The antenna 11A is obtained by bending a part of the portion corresponding to the two left and right vertical lines of the letter “H” of the antenna 11 in FIG. 4 into a meander shape. 18B, 19A and 19B. In addition, the dashed-dotted line which hits the inside of these edge part 18A, 18B, 19A and 19B represents the reference line for bending in a meander shape. The reason for forming the meander shape is to obtain a required resonance frequency when the antenna is built in a space with a small wavelength ratio. Note that a terminal corresponding to the terminal 15 in FIG.

  The antenna 11A is formed so that the end portions 18A, 18B, 19A, and 19B do not enter the inside of the above-described bending reference line. This is because if the end portions 18A and 18B or 19A and 19B having the highest electric field strength are bent in a direction approaching each other, the radiation efficiency is impaired by interference between the strong electric fields.

  In the third embodiment, the antenna holder 20 formed of a dielectric material is used in order to achieve mechanical stability when the antenna 11A is built in the wireless device. A portion 21A of the antenna holder 20 that is close to the end 18A of the antenna 11A is formed so as to be cut out. Similarly, the portions 22B, 22A, 22B close to the end portions 18B, 19A, 19B are formed so as to be cut out. As described above, the vicinity of the end portions 18A, 18B, 19A, and 19B of the antenna 11A has the highest radiated electric field strength, and when a dielectric is brought close thereto, Joule heat determined by the dielectric loss tangent is generated and the radiation efficiency of the antenna 11A is increased. Damage. In order to prevent this, the antenna holder 20 has portions 21A, 22B, 22A, and 22B formed in a cutout shape.

  The inner portion 23 of the antenna holder 20 is extracted so as not to prevent the connection between the terminal 15A and the feeding point 14. This portion 23 can secure a sufficient clearance with respect to the terminal 15A. The antenna holder 20 is attached from above the shield cover 13 so that the extracted portion 23 faces the concave portion of the shield cover 13. In this way, the terminal 15A can be connected to the feeding point 14.

  The antenna 11A in FIG. 5 represents one embodiment of the antenna according to the applicant's patent application (Japanese Patent Application Laid-Open No. 2004-201049) as in the first embodiment. Even when a built-in antenna having such a shape and configuration is used, the invention according to Embodiment 3 can be applied.

  According to the third embodiment of the present invention, an additional effect is obtained in that a decrease in radiation efficiency when an antenna is built in a space having a small wavelength ratio while maintaining mechanical stability can be suppressed.

1 is a diagram illustrating an appearance and a main configuration of a wireless device according to a first embodiment of the present invention. 1 is a first diagram illustrating a positional relationship between main components of a wireless device according to Embodiment 1. FIG. FIG. 3 is a second diagram illustrating a positional relationship between main components of the wireless device according to the first embodiment. The figure showing the positional relationship of the main structures of the radio | wireless apparatus which concerns on Example 2 of this invention. The figure showing the positional relationship of the main structures of the radio | wireless apparatus which concerns on Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless apparatus 10 Case 11, 11A Antenna 12, 12A Board | substrate 13, 13A Shield cover 14 Feeding point 15, 15A Terminal 16, 17 Area | region 18A, 18B, 19A, 19B which does not place the conductor pattern on board 12A End of antenna 11A Part 20 Antenna holders 21A, 21B, 22A, 22B A part 23 formed so as to cut out the antenna holder 20 A part extracted inside the antenna holder 20

Claims (2)

A housing,
An antenna built in the housing;
A substrate that is built in the housing and provided with a feeding point of the antenna on one surface;
The power feeding of the substrate is disposed between the antenna and the substrate, and is formed with a concave portion from a peripheral portion toward a central portion, and the concave portion is opposed to the position of the feeding point. A radio apparatus comprising: a shield cover attached to a surface provided with dots. The antenna is formed so that a part of the antenna facing the concave portion is bent in a substantially crank shape in a direction from a central portion to a peripheral portion of the shield cover so as to be connectable to the feeding point. Item 2. The wireless device according to Item 1.

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