JP4400427B2 - Portable radio - Google Patents

Description

The present invention relates to a portable wireless device having an antenna, and more particularly to a portable wireless device that can ensure good antenna characteristics even when placed on a metal plate.

Usually, a portable wireless device such as a mobile phone has an antenna, and when placed on a metal plate, the antenna becomes close to the metal plate. Therefore, the portable wireless device and the iron plate are coupled to each other to connect the antenna. A current having an opposite phase to the flowing current flows on the surface of the metal plate, and the radiation directivity of the antenna changes and the impedance characteristic changes. For this reason, when the portable wireless device is placed on the metal plate, the antenna characteristic of the portable wireless device is deteriorated.

  In order to solve this problem, when the whip antenna is provided on the upper back of the small radio main unit, the upper side of the small radio main unit may float with respect to the ground plane when the small radio main unit is laid down. There is one that improves deterioration of antenna performance even if a small wireless device is placed on a metal plate by installing a rib for adjusting the antenna performance of the whip antenna at a balanced position (for example, Patent Document 1). .

In addition, in a communication terminal, a conductor exposed on the bottom surface and the back surface of the housing or a conductor along the bottom surface and the back surface is inserted and electrically connected to the substrate to which the antenna is connected. When placed on a plate, the dipole antenna is configured by the current that flows perpendicularly to the metal plate by the conductor in the bottom direction of the housing, and even if the communication terminal body is placed on the metal plate, the deterioration of the antenna performance is improved. There is something that can be done.
JP-A-10-126304

  However, in the method of providing a rib on the back side of such a small wireless device, the thickness of the housing increases by the amount of the rib, so the main body of the small wireless device cannot be thinned, and the rib is beautiful. There was a problem of losing.

  In addition, in the technique of inserting the conductor along the bottom surface and the back surface of the communication terminal housing described above or the conductor along the bottom surface and the back surface and electrically connecting the antenna to the substrate connected in recent years, However, it is difficult to secure the effective area of the conductor just to improve the antenna performance on the metal plate, and the vertical current on the metal plate is difficult. It is also necessary to reduce the size of the conductor itself that is exposed or along the bottom surface of the casing that plays a role of flowing current, and the performance as an antenna tends to decrease.

  In addition, even in the method of inserting a passive element into the connection part with the substrate having the antenna and controlling it to a desired band, the band that can be controlled only by the passive element is narrow because the conductor is small, and the performance depends on the performance of the passive element. Fine adjustment was difficult. In addition, since portable wireless devices have been desired to be further reduced in size and thickness since recent years, it has become more difficult to ensure the effective area of the antenna.

  The present invention solves the above-described problems, and there is no need to change the appearance of the portable wireless device. Even when the portable wireless device is placed on a metal plate, the antenna has a finer structure than before. It is an object of the present invention to provide a portable radio that can improve antenna gain degradation by enabling adjustment in a wide band, and can cope with reduction in thickness and size.

  The present invention includes a main body case, a substrate having a ground pattern disposed in the main body case, a radio circuit unit provided on the substrate, an antenna connected to the radio circuit unit via a feeder, and a capacitive coupling with the substrate A battery part provided in a close position where the battery can be connected, a plate metal provided in a close position capable of capacitive coupling with the battery part, and a slit provided in the plate metal for controlling the current distribution of the battery part. It is characterized by providing.

  With the above configuration, the antenna-equipped substrate and the battery are arranged at close positions where capacitive coupling is possible, so that they are capacitively coupled to each other and perpendicular to the metal plate when the portable wireless device body is placed on the metal plate. A large current component.

  Furthermore, by arranging the plate metal at a position close to the battery where capacitive coupling is possible, the current distribution perpendicular to the metal plate can be controlled by the shape of the plate metal. The shape of the plate-shaped metal has a high degree of freedom, and since the capacitance is not determined as in the passive element, fine adjustment is possible.

  In addition, since a current component perpendicular to the metal plate is generated by capacitive coupling of the substrate, the battery, and the plate metal, it is possible to cope with a reduction in the thickness of the portable wireless device.

  As described above, according to the portable wireless device according to the present invention, it is not necessary to change the appearance of the portable wireless device, and even when the main body is laid on a metal plate, finer adjustment than before is possible. The antenna gain degradation can be improved by making it possible in a wide band, and the portable radio main body can be made thinner and smaller.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a folding portable wireless device according to the present invention will be described in detail with reference to the drawings.

(Example 1)
FIG. 1 is a side view showing a closed state of the folding portable wireless device of the present embodiment according to the present invention. As shown in the figure, the folding portable wireless device of the present embodiment includes an upper housing 101, The upper casing 101 and the lower casing 102 are connected by a hinge section 104.

  The upper housing 101 and the lower housing 102 have an upper substrate 105 and a lower substrate 106, respectively. The upper housing 101 and the lower housing 102 are made of an insulating resin and have a length of about 70 mm and a width of about 45 mm.

  Further, the upper substrate 105 and the lower substrate 106 are composed of, for example, a printed circuit board having a thickness of 1 mm, and the dimensions are about 65 mm in length and about 40 mm in width. The upper substrate 105 and the lower substrate 106 are electrically connected by a flexible connection line 107. The lower substrate 106 has a wireless circuit, and a feeding point 108 is arranged in a part of the wireless circuit. The antenna unit 103 is located on the upper surface of the lower housing 102, and a ground pattern (hereinafter referred to as GND) which is a conductor pattern having a ground potential of the lower substrate 106 is used as a ground conductor of the antenna, and power is fed from a feeding point 108. . The antenna unit 103 is formed of a spiral copper wire having high conductivity and a certain degree of strength. For example, in the 800 MHz band, the total length is about 50 mm and the width is about 3 mm. The antenna unit 103 is not particularly limited, and the example shown in FIG. 1 shows a helical antenna composed of a spiral copper wire.

  In the folding portable wireless device of this embodiment, a battery 109 is disposed on the bottom surface inside the lower housing 102 opposite to the antenna unit 103, and the dimensions of the battery 109 are about 35 mm × 25 mm and a thickness of about 5 mm.

  Further, by disposing the battery 109 close to the lower substrate 106, for example, at a position of about 1 mm, the battery 109 and the lower substrate 106 are capacitively coupled, and the high frequency current becomes equal to a short-circuited state.

  In addition, when the folding portable wireless device of this embodiment is placed on the metal plate 201, the lower substrate 106 and the battery 109 are components perpendicular to the metal plate 201, and are mirror images as shown in FIG. Due to the effect, a dipole antenna can be configured with a vertical component and a mirror image on the metal plate 201.

  Furthermore, a resin battery lid 110 is disposed between the battery 109 and the metal plate 201, and the dimensions are about 45 mm × 35 mm and the thickness is about 1 mm. The distance between the battery 109 and the battery cover 110 is about 0.2 mm, and capacitive coupling is performed because the distance between the battery 109 and the battery cover 110 is close by inserting a sheet metal 111 that is a plate-like metal. However, if the size of the sheet metal 111 is the same as that of the battery 109, the distance from the metal plate 201 is almost equal to that of the battery 109, so that almost no effect is obtained.

Details of the shape of the sheet metal 111 will be described below. FIG. 3 is a view showing the shape of the sheet metal 111 located in the gap between the battery 109 and the battery lid 110 of the folding portable wireless device of this embodiment.
A dotted line on the battery lid 110 indicates a portion overlapping with the battery 109. The vertical direction of the portable wireless device main body of the present embodiment is XX ′ and the horizontal direction is YY ′. First, the size of the sheet metal 111 in the portable wireless device of this embodiment is limited by the size of the battery lid 110 so as not to impair the beauty, and is about 45 mm × 35 mm at the maximum. Further, the capacitive coupling between the metal plate 201 and the battery 109 can be controlled by the size of the sheet metal 111 existing therebetween, and is mainly controlled by the peripheral length of the sheet metal 111.

  In order not to weaken the capacitive coupling between the battery 109 and the sheet metal 111, to secure an area where the battery 109 overlaps and to increase the circumference of the sheet metal 111, the circumference is controlled by a slit having a width of about 2 mm. The effect is increased by lengthening the portion where the battery 109 does not overlap.

  FIG. 4 shows the antenna performance depending on the perimeter of the slit. The graph shows the frequency (MHz) on the horizontal axis and the voltage standing wave ratio (VSWR) on the vertical axis. The longer the perimeter of the sheet metal 111, the lower the resonance frequency moves and shortens it. To move to the high frequency side.

  As described above, in the folding portable wireless device of this embodiment, it is not necessary to change the appearance of the portable wireless device, and even when the main body is placed on the metal plate 201, it is finer than before. It is possible to improve the antenna gain degradation by enabling a wide range of control, and to cope with the reduction in thickness and size of the portable radio main body.

(Example 2)
FIG. 5 is a plan view showing the portable wireless device according to the second embodiment of the present invention, and shows the vicinity of the battery inside the lower housing 102 in more detail than FIG. 5, the same reference numerals as those shown in FIG. 1 denote the same components, and the detailed description thereof is omitted.
A ground terminal 112 is provided on the surface of the battery 109 and is connected to the GND of the substrate through the battery terminal 113. The shape of the battery terminal 113 is divided into two parts, one is a battery terminal 113A, the battery terminal 113A is connected to the GND of the substrate, the other is a battery terminal 113B, and the battery terminal 113B extends to the surface of the lower housing 102, It is arranged at a position close to the battery lid 110.

  FIG. 6 is a diagram of the battery lid 110 and the sheet metal 111 according to the second embodiment of the present invention. By mounting the spring 114 on the sheet metal 111, the battery terminal 113B located on the surface of the lower housing 102 and the spring 114 come into contact with each other and can be electrically connected. By directly connecting electrically, even when the distance between the battery 109 and the sheet metal 111 is not extremely close, the portable radio of this embodiment is placed on a metal sheet by changing the peripheral length of the sheet metal 111. In this state, the capacitive coupling with the metal plate 201 can be controlled, and the metal plate 201 can be adjusted in a wider band and finer than before, and the deterioration of the antenna gain can be improved.

(Example 3)
FIG. 7 is a diagram of the battery lid 110 and the sheet metal 111 according to the third embodiment of the present invention. The battery 109, the battery terminal 113B, and the spring 114 are electrically directly connected with a structure equivalent to that of the second embodiment, and the passive element 115 is inserted between the metal plate 111 and the spring 114, so that the metal plate 201 is placed on the metal plate 201. Capacitative coupling with the metal plate 201 can be controlled in the state of being laid down, and it is possible to make finer adjustment on the metal plate 201 with a wider band and finer than the above-described embodiment, thereby improving antenna gain degradation. it can.

  The portable wireless device according to the present invention enables finer control over a wider band than before even when the main body is placed on a metal plate without changing the appearance of the portable wireless device. Therefore, it is possible to improve the deterioration of the antenna gain and to cope with the thinning and miniaturization of the portable radio main body.

Sectional drawing of the folding-type portable radio in the Example of this invention Explanatory drawing of the mirror image effect on the metal plate of the folding portable wireless device in the embodiment of the present invention The perspective view of the battery in the Example of this invention, a sheet metal, and a battery cover Frequency characteristic diagram of voltage standing wave ratio (VSWR) of antenna in an embodiment of the present invention Sectional drawing of battery vicinity in Example 2 of this invention Front view of sheet metal and battery cover in Example 2 of the present invention Front view of sheet metal and battery cover in Example 3 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Upper housing | casing 102 Lower housing | casing 103 Antenna part 104 Hinge part 105 Upper board | substrate 106 Lower board | substrate 107 Flexible connection line 108 Feed point 109 Battery 110 Battery cover 111 Sheet metal 112 Ground terminal 113A Battery terminal 113B Battery terminal 114 Spring 115 Passive element 201 Metal plate

Claims (3)

A body conductor;
A substrate having a ground pattern disposed in the body conductor;
A radio circuit unit provided on the substrate;
An antenna connected to the wireless circuit unit via a feeder line;
A battery part provided at a close position capable of capacitive coupling with the ground pattern of the substrate, which is a conductor pattern having a ground potential with respect to the antenna ;
The battery unit is located close to the surface opposite to the surface facing the ground pattern, and is provided between the battery unit and a casing of the portable wireless device, and capacitive coupling with the battery unit is provided. Possible plate metal,
A portable radio having a slit provided in the plate-like metal.   The portable wireless device according to claim 1, wherein a ground terminal of the battery unit and the plate metal are electrically connected by a conductor.   The portable wireless device according to claim 1, wherein the ground terminal of the battery unit and the plate metal are electrically connected by the conductor via a passive element.

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