JP4436197B2 - Portable radio - Google Patents

Description

  The present invention relates to a portable wireless device including a battery unit, which can obtain high antenna performance regardless of a connection position between the battery unit and a circuit board.

  The portable wireless device includes a battery unit for operating a wireless circuit and a logic circuit in a housing. The battery part is disposed in parallel and close to the circuit board, and is connected to the ground of the circuit board via a connection terminal on the circuit board. Therefore, the antenna current flowing through the ground of the circuit board interferes with the antenna current flowing through the battery through the connection with the ground, and there is a problem that the antenna performance deteriorates.

  As a structure corresponding to such a subject, the structure of patent document 1 is mention | raise | lifted. According to Patent Document 1, by connecting an antenna element to a battery unit to form a loop antenna, the influence of the battery unit on the antenna can be removed and the antenna performance can be improved.

JP 05-067910 A

  However, in the above example, there is a problem that the arrangement position of the battery and the antenna configuration are limited, and the degree of freedom in designing the portable wireless device is reduced.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a portable wireless device capable of ensuring high antenna performance regardless of the connection position between the battery unit and the circuit board.

  A portable wireless device of the present invention includes a housing, a circuit board housed in the housing, a battery unit housed in the housing, and an antenna attached to the housing and electrically connected to the circuit board. Have. In addition, the power supply terminal of the battery unit is connected to the circuit board, and the power supply connection unit that supplies current from the battery unit to the circuit board, and the ground connection that connects the ground of the battery unit and the circuit board ground at high frequency at least under radio frequency And the ground connection portion is disposed at a position closer to the antenna than the feeding connection portion.

  It is preferable that the ground connection portion is configured to be disposed at a position closest to the antenna while being adjacent to the battery portion.

  In addition, it is preferable that the power feeding connection portion is arranged at a position farthest from the antenna while being adjacent to the battery portion.

  Furthermore, you may comprise so that an electric power feeding connection part and a ground connection part may be arrange | positioned on the planar view substantially diagonal line of a battery part.

  On the other hand, the ground connection portion can be constituted by a main body of the battery portion and a sheet metal that is connected to the ground of the circuit board and disposed in the housing in a state of being separated from the battery portion by a predetermined distance. In this case, the battery unit and the sheet metal form capacitive coupling when energized.

  In the above configuration, the sheet metal and the ground of the circuit board can be connected via the reactance element. Further, the battery unit can be arranged substantially parallel to the circuit board.

  As described above, according to the present invention, high antenna performance can be ensured regardless of the connection position between the battery unit and the circuit board.

  Hereinafter, embodiments of a portable wireless device according to the present invention will be described in detail with reference to the drawings. The radio frequency is set to 900 MHz.

(First embodiment)
1 and 2 show a basic configuration of the portable wireless device according to the first embodiment of the present invention.

  The portable wireless device of this embodiment includes a housing 101, a circuit board 102, an antenna 103, a matching circuit 104, a wireless unit 105, and a battery pack 106. The casing 101 is made of resin, and assuming a small terminal, the length is set to about 70 mm and the width is set to about 50 mm. A helical antenna is used as the antenna 103, and the antenna 103 is connected to the radio unit 105 via the matching circuit 104.

  In addition, the battery pack 106 includes a battery portion 107 surrounded by a ground inside a case made of resin. The dimensions of the battery pack are 35 mm long x 35 mm wide x 5 mm thick. A resin cover 108 having a thickness of 2 mm is disposed between the circuit board 102 and the battery pack 106 so that the battery pack does not directly contact the circuit board. As shown in FIG. 3, the battery pack 106 includes a ground terminal 301 and a power supply terminal 302 on the surface, and is connected to the power supply line and the ground of the circuit board 102 by the battery terminal 303. The power supply terminal portion 302 and the battery terminal 303 constitute a power supply connection portion. The installation position of the battery terminal 303 is determined by the mounting area and layout of the radio circuit and the logic circuit. Here, the battery terminal 303 is installed at the end of the circuit board 102 on the side opposite to the antenna.

  The power supply connecting portion is indispensable for supplying current from the battery portion 107 to the circuit board 102 and thus to the wireless portion 105. In the present embodiment, the power supply terminal 302 is provided at a position that is substantially farthest from the antenna 103 in the battery unit 107. A battery terminal 303 is provided on the circuit board 102 so as to correspond to this. In other words, the positions of the battery terminal 303 and the power supply terminal 302 are set so that the feeding connection portion is located farthest from the feeding portion of the antenna 103 in a state where the feeding connection portion is adjacent to the battery portion 107.

  As shown in FIG. 4, the ground pin 401 is installed on the circuit board 102 at a position closest to the antenna 103 for the purpose of connection with the ground of the battery unit. In addition to the power supply terminal 302, the battery pack 106 is provided with a ground terminal 402 for connection to the ground pin 401. A ground connection portion is configured by the connection of the ground pin 401 and the ground terminal 402, and the ground of the battery portion is grounded to the circuit board 102 at a position closest to the antenna 103. That is, the ground terminal 402 is provided at a position closest to the antenna 103 in the battery unit 107. And corresponding to this, the ground pin 401 is provided on the circuit board 102. In other words, the positions of the ground pin 401 and the ground terminal 402 are set so that the ground connection portion is adjacent to the battery portion 107 and is closest to the power feeding portion of the antenna 103.

  As will be described later, the ground connection portion is used for high-frequency connection between the ground of the battery portion 107 and the circuit board 102 to generate an antenna current on the battery portion 107 side.

  In the present embodiment, the power supply connection portion and the ground connection portion are arranged on a substantially diagonal line in the plan view of the battery unit 107. Further, the battery unit 107 is disposed in parallel with the circuit board 102 in the longitudinal direction. However, it is not necessary to be arranged strictly in parallel, and may be arranged substantially in parallel.

  The antenna operation in the portable wireless device configured as described above will be described.

  FIG. 5 shows the antenna current distribution in the present embodiment having the ground pin 401, and FIG. 6 shows the antenna current distribution of the conventional configuration without the ground pin 401. Reference numerals 501 and 601 indicate the intensity of the antenna current flowing through the casing. On the other hand, reference numerals 504 and 604 indicate the intensity of the antenna current flowing through the battery unit 107. The antenna 103 has a helical antenna configuration that resonates at a quarter wavelength of the radio frequency. The length of the circuit board 102 is 65 mm, which is equal to or less than ¼ wavelength of the radio frequency. Therefore, when there is no battery pack, the circuit has the maximum current point at the antenna feeding point (connection point P between the casing 101 and the antenna 103 in FIGS. 5 and 6) corresponding to the feeding portion of the antenna, and is on the opposite side of the antenna. At the edge of the substrate, the current is minimal.

  However, as in the conventional configuration, when the battery pack is connected to the ground of the circuit board at the end of the circuit board 102 opposite to the antenna 103 only through the essential power supply connection part, as shown in FIG. Thus, the antenna current does not become the minimum at the substrate end, but also flows through the battery terminal 303 to the battery portion. Since the length of the circuit board is ¼ wavelength or less, there is no current node (minimum point) between the antenna and the battery, and the current is minimized at the end of the battery part opposite to the battery terminal 303. . In addition, since the current concentrates as compared with the case where the circuit board is long, the current flowing through the battery unit becomes large. At this time, the antenna current 602 flowing through the circuit board and the antenna current 603 flowing through the battery unit are in opposite phases and cancel each other, resulting in deterioration of radiation efficiency. In particular, when the circuit board length is ¼ wavelength or less, since the current flowing through the battery unit is large, the radiation efficiency is greatly deteriorated. The radiation efficiency of the conventional configuration at a radio frequency of 900 MHz is −3.0 dB, and the directivity of the vertical component in the XZ plane is as indicated by 1002 in FIG.

  On the other hand, in the present embodiment, the battery unit 107 is connected to the ground of the circuit board 102 at a position close to the antenna not only in the power supply connection unit but also in the ground connection unit. Specifically, the ground of the battery unit 107 and the ground of the circuit board 102 are connected at high frequency at least under the radio frequency of the portable radio. And the ground connection part is arrange | positioned in the position close | similar to an antenna or an antenna electric power feeding part rather than an electric power feeding connection part. Therefore, as shown in FIG. 5, the antenna current flows from the battery unit 107 to the ground pin 401. The antenna current 503 flowing through the battery unit 107 is minimized at the end of the circuit board 102 via the battery terminal 303. Similarly, the antenna current 502 flowing through the circuit board 102 is also minimized at the end of the circuit board, and the current flowing through the battery section and the current flowing through the circuit board are in phase, so that current cancellation does not occur.

  In this embodiment, the radiation efficiency at a radio frequency of 900 MHz is −2.0 dB, and the directivity of the vertical component in the XZ plane is as indicated by 1001 in FIG. Therefore, by using the configuration of the present embodiment, high antenna performance is obtained in a portable wireless device including a battery pack regardless of the connection position between the battery unit and the circuit board. In particular, in the present embodiment, since the battery unit 107 is arranged in parallel with the circuit board 102 in the longitudinal direction, if the two antenna currents are in opposite phases, the two antenna currents cancel each other, and the radiation efficiency is likely to deteriorate. The effect of the invention is great.

  Since the current 503 flows to the battery part through the ground pin 401, a higher effect can be obtained by setting a plurality of ground pin contacts than one point, in other words, by providing a plurality of ground connection parts.

  In the present embodiment, the connection between the battery unit and the circuit board is not limited to the power supply connection unit, but a ground connection unit for high-frequency connection between the battery unit and the circuit board is provided at a location closer to the antenna. Under this configuration, the antenna current can be generated in the battery unit toward the antenna. As a result, compared with the case where only the feeding connection portion is provided, cancellation of the antenna current flowing in the circuit board and the antenna current flowing in the battery portion can be relaxed, and high antenna performance can be secured.

  Note that the relative positional relationship between the power supply connection portion and the ground connection portion is only required to be provided at a position closer to the antenna than the power supply connection portion, and the effect of the present application is achieved as long as this relationship is maintained. Preferably, the ground connection portion is provided at a position as close as possible to the power supply portion of the antenna, and the power supply connection portion is provided as far as possible from the power supply portion of the antenna.

(Second Embodiment)
7 and 8 show the basic configuration of the portable wireless device according to the second embodiment of the present invention.

  7 and 8, the same reference numerals as those shown in FIGS. 1 and 2 denote the same components, and detailed description thereof is omitted.

  Reference numeral 701 denotes a metal sheet metal. The dimension of the sheet metal 701 is substantially the same as that of the battery pack 106, and is 40 mm long × 37 mm wide. The sheet metal 701 is affixed to the battery side of the resin cover 108 and is in close contact with the battery pack 106 at an interval of 0.1 mm or less. As shown in FIG. 9, the sheet metal 701 is connected to a reactance element 702 provided on the circuit board 102 at a position close to the antenna via a connection pin 703. Since the reactance element 702 is connected to the ground of the circuit board 102, the sheet metal 701 is grounded to the ground of the circuit board 102 via the reactance element 702. Specifically, the reactance element 702 is a chip inductor, a chip capacitor, or a 0Ω chip resistor. Here, a chip resistance of 0Ω is used for the reactance element 702, and the sheet metal 701 and the ground of the circuit board 102 are short-circuited.

  The antenna operation in the portable wireless device configured as described above will be described.

  Since the sheet metal 701 and the battery pack 106 are close to each other with an interval of 0.1 mm, capacitive coupling is formed with the sheet metal 701 with the battery unit 107 itself functioning as a ground. Therefore, at the radio frequency, the battery unit 107 and the sheet metal 701 are substantially in a short-circuit state. Therefore, the battery unit 107 is grounded to the ground of the circuit board 102 at a position close to the antenna via the sheet metal 701. That is, the main body of the battery unit 107 and the sheet metal 701 function as a ground connection unit in the first embodiment. The antenna current distribution at this time is equivalent to that in FIG. 5, and the antenna current flowing through the circuit board 102 and the antenna current flowing through the battery unit 107 are in phase. Therefore, there is no deterioration in radiation efficiency due to the influence of the battery pack, and radiation efficiency equivalent to that of the first embodiment can be obtained.

  Moreover, since it is not necessary to newly provide a ground terminal in a battery pack, there exists an advantage that an existing battery pack can be used.

  In this embodiment, a chip resistance of 0Ω is used as the reactance element 702. However, when the optimum reactance constant differs depending on the radio frequency, the housing structure, the shape of the battery pack, and the positional relationship between the sheet metal and the battery pack, the reactance By adjusting the constant, higher antenna performance can be obtained. Furthermore, in this embodiment, a single reactance element is used for connection between the sheet metal 701 and the ground of the circuit board 102. However, a switching circuit that provides a plurality of reactance elements and switches the optimum reactance element according to the frequency. You may connect using.

  In this embodiment, the sheet metal 701 is disposed adjacent to the resin cover 108, but the resin cover 108 may be changed to metal and connected to the reactance element 702. In this case, capacitive coupling is made between the metal cover 108 and the battery unit 107 when energized. In addition, as long as the capacitive coupling with the battery unit and the connection with the ground of the circuit board are stable, a conductive cushion, a conductive sheet, or the like may be used instead of the resin or the metal cover. Etc. are not particularly limited.

  Further, the shape, material, configuration, and number of the connecting portion of the present invention are not limited to those of the embodiment, and various changes can be made. As long as the antenna performance is ensured, various types can be adopted. Further, there are no particular limitations on the connection method between the antenna and the circuit board, the arrangement of the wireless unit on the circuit board, the structure of the housing and the board, the type of the wireless unit, and the like.

  Moreover, the battery part can utilize what used various cells, and the kind is not limited. Also, the number of cells may be single or plural. Moreover, as a part attached to a battery part in order to manufacture a battery pack, although there exist a protection circuit, a sealing resin cover, etc., it does not specifically limit.

  In the above-described embodiment, a portable wireless device that does not include a hinge is used, but a foldable portable wireless device that includes a hinge may be used. Further, in this embodiment, a helical antenna is used as an antenna. However, if the antenna uses a substrate as a ground conductor of the antenna, the same effect can be obtained with other antennas such as an inverted L antenna and an inverted F antenna. The type is not limited. The portable wireless device of the present invention can be used for mobile phones, PHS, and other various portable terminals.

  Although various embodiments of the present invention have been described above, the present invention is not limited to the matters shown in the above-described embodiments, and those skilled in the art will be able to understand based on the claims and the description of the specification and well-known techniques. Such changes and applications are also within the scope of the present invention, and are included in the scope for which protection is sought.

  In a portable wireless device including a battery unit, it is useful for obtaining high antenna performance regardless of the connection position between the battery unit and the circuit board.

It is a side view of the portable radio of a 1st embodiment. It is a front view of the portable radio of a 1st embodiment. It is an enlarged view of the battery part seen from the battery terminal side in 1st Embodiment. It is an enlarged view of the battery part seen from the antenna side in 1st Embodiment. It is a figure explaining the antenna current of the portable radio | wireless machine of 1st Embodiment. It is a figure explaining the antenna current of the prior art example. It is a side view of the portable radio of a 2nd embodiment. It is a front view of the portable wireless apparatus of 2nd Embodiment. It is an enlarged view of the vicinity of the sheet metal in 2nd Embodiment. It is a figure which shows the directivity comparison of 1st Embodiment and a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Case 102 Circuit board 103 Antenna 104 Matching circuit 105 Radio | wireless part 106 Battery pack 107 Battery part 108 Resin cover 301 Ground terminal 302 Power supply terminal 303 Battery terminal 401 Ground pin 402 Ground terminal 501,502,503,504,604,601 602, 603 Current 701 Sheet metal 702 Inductance element 703 Connection pin 1001, 1002 Directivity of vertical component

Claims (2)

A housing,
A circuit board housed in the housing;
A battery unit housed in the housing;
An antenna electrically connected to the circuit board;
A power supply connection part for connecting a power supply terminal of the battery part and the circuit board, and supplying a current from the battery part to the circuit board;
A ground connection portion disposed closer to the antenna than the power supply connection portion, and
The ground connection portion is connected between the battery portion and the circuit board in a state of being connected to the main body of the battery portion and the ground of the circuit board and spaced apart from the battery portion by a predetermined distance. A portable wireless device comprising a sheet metal, wherein the battery part and the sheet metal form capacitive coupling when energized, and the ground of the battery part and the ground of the circuit board are connected at a high frequency at least under a radio frequency. .   The portable wireless device according to claim 1, wherein the sheet metal and the ground of the circuit board are connected via a reactance element.

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