JP2007201543A - Mobile wireless terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile wireless terminal provided with an antenna with an excellent antenna characteristic in both opening/closing states of the cases. <P>SOLUTION: The mobile wireless terminal includes: an operating unit case; a display unit case mutually opened from/closed to the operating unit case; an operating unit board 11 incorporated in the operating unit case; a display unit board 10 incorporated in the display unit case; a flexible cable 16 for interconnecting the operating unit board 11 and the display unit board 10; and a dielectric body 14 sandwiched between a set of opposed faces of the flexible cable 16 folded between the operating unit board 11 and the display unit board 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a portable wireless terminal such as a cellular phone.

A slide-type mobile phone, which is an example of a conventional portable wireless terminal, has a flexible cable through the ground of the operation unit board when the antenna element is arranged at the upper part in the longitudinal direction of the operation unit casing and excited by a high-frequency power source. Flowing into the ground layer.
Here, in order to meet the demand for a thinner mobile phone, it is necessary to narrow the space between the operation unit substrate and the display unit substrate.
However, since a very large high-frequency current flows through the ground layer of the flexible cable sandwiched between the operation unit substrate and the display unit substrate, the impedance characteristics of the antenna vary greatly depending on the connection position and length of the flexible cable.
Furthermore, since the current distribution on the display unit board and the operation unit board changes greatly by opening and closing the case, good impedance characteristics are obtained when the case is closed under the conditions of the flexible cable where the impedance characteristic is optimal when the case is open. It ’s difficult.

  For example, a λ / 4 element is provided together with an antenna element. When the casing is opened, the λ / 4 element is disconnected from the ground, and when closed, the λ / 4 element is connected to the ground to operate as a parasitic element. 2. Description of the Related Art Mobile wireless communication terminals that improve antenna characteristics at the time have been provided (see, for example, Patent Document 1).

  In addition, a folding type mobile phone is provided that has a matching circuit for closing the case on the antenna element, and an antenna characteristic switching circuit operates when the case is opened to optimize the antenna characteristic when the case is open. Provided (for example, see Patent Document 2).

  In the portable wireless communication terminal described in Patent Document 1, it is necessary to provide a λ / 4 element and switch the connection to the ground by opening and closing the casing. However, since the λ / 4 element needs to be arranged at some distance from the ground, a space is required in the housing, and the housing size has to be increased.

  Further, in the foldable mobile phone described in Patent Document 2, a matching circuit for closing the casing is provided for the antenna element, and when the casing is opened, the antenna characteristics switching circuit is operated so that the antenna characteristics when the casing is opened are reduced. Although optimization has been made, it is difficult to improve the antenna characteristics only with the switching circuit in a case structure (for example, a slide structure) in which the band changes greatly by opening and closing the case.

JP 2004-72605 A JP 2001-339474 A

  Since the conventional portable wireless terminal is configured as described above, it is difficult to provide an antenna having good antenna characteristics both when the housing is opened and when the housing is closed without increasing the housing size. was there.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a portable wireless terminal including an antenna having good antenna characteristics when the casing is opened and closed.

  A portable wireless terminal according to the present invention includes a first housing, a second housing that opens and closes with the first housing, a first substrate that is housed in the first housing, and a second housing. The first substrate and the second housing are closed by closing the second substrate, the flexible cable connecting the first substrate and the second substrate, and the first housing and the second housing. And a dielectric sandwiched between a pair of opposing surfaces of the flexible cable folded between the substrate and the second substrate.

  According to the present invention, since the dielectric is sandwiched between the flexible cables only when the casing is closed, the flexible cable can be connected only when the casing is closed without affecting the antenna characteristics when the casing is opened. The current distribution is changed, and the current distribution on the first substrate and the second substrate is also changed. As a result, it is possible to obtain a portable wireless terminal including an antenna having a good impedance characteristic (antenna characteristic) when both slides are opened and closed.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below. 1A and 1B are perspective views showing an overview of a portable wireless terminal according to Embodiment 1 of the present invention. FIG. 1A shows a case when the casing is opened (when the slide is opened), and FIG. The closed time (when the slide is closed) is shown. In FIG. 1, a slide-type mobile phone is used as an example of a mobile wireless terminal. In the following description, the XYZ coordinate system shown in FIG. 1 is used. In this XYZ coordinate system, the longitudinal direction of the casing is the Z direction, the width direction is the X direction, and the thickness direction is the Y direction.

In FIG. 1, the portable wireless terminal includes a display unit housing 6 and an operation unit housing 9 that can slide (open and close) with respect to each other.
On the surface of the display unit housing 6, a receiving unit 1 such as a speaker, a display unit 2 such as an LCD, an operation unit 3 such as a button, and a transmitting unit 4 such as a microphone are provided. Further, a display unit substrate (not shown) connected to the display unit 2 and the like is accommodated therein.
The operation unit housing 9 includes an operation unit 8 such as a key, a transmission unit 5 such as a microphone, and an antenna storage unit 7. Furthermore, an operation unit board (not shown) connected to the operation unit 3 and the like is accommodated therein.

2 is a perspective view showing the internal configuration of the portable wireless terminal shown in FIG. 1. FIG. 1 (a) shows the case when the casing is open, and FIG. 2 (b) shows the case when the casing is closed. In FIG. 2, for the sake of easy understanding, the display unit substrate and the operation unit substrate only show the conductor plates serving as the respective grounds.
In FIG. 2, the portable wireless terminal includes a conductor plate (hereinafter, operation unit substrate ground) 11 serving as a ground of the operation unit substrate, a conductor plate (hereinafter referred to as display unit substrate ground) 10 serving as a ground of the display unit substrate, and an operation unit. A flexible cable 16 for connecting between the substrate and the display unit substrate, a linear conductor (hereinafter referred to as an antenna element) 12 connected to the upper part of the operation unit substrate ground 11, and between the operation unit substrate ground 11 and the antenna element 12 A high frequency power source 13 to be excited and a dielectric 14 having an arbitrary dielectric constant provided in a part of the flexible cable 16 are provided.

The display unit substrate ground 10 and the operation unit substrate ground 11 have a length of about 90 mm in the longitudinal direction (Z direction) and about 45 mm in the width direction (X direction), respectively. It corresponds to.
The display unit substrate ground 10 and the operation unit substrate ground 11 respectively occupy at least one layer of the operation unit substrate and the display unit substrate that are formed of multiple layers.

In the case where the antenna element 12 is arranged at the top in the longitudinal direction (Z direction) of the display unit housing 6 (display unit substrate), the antenna storage unit is close to the operator's (user's) head during a call. Performance deteriorates. Further, when the antenna element 12 is arranged at the lower part in the longitudinal direction (Z direction) of the operation unit housing 9 (operation unit substrate), the antenna performance is deteriorated because the antenna housing unit is held by hand. Therefore, the antenna element 12 is arranged at the upper part in the longitudinal direction (Z direction) of the operation unit housing 9 (operation unit substrate) shown in FIG.
The antenna element 12 uses a monopole antenna. As long as it is a monopole antenna, any of a built-in antenna, a whip antenna, a helical antenna, etc. may be used. Furthermore, a monopole antenna may not be used as long as it is an antenna that allows current to flow to the ground.

The flexible cable 16 includes a connector 16a (connector) for connection to the display unit substrate (display unit substrate ground 10) and a connector 16b (connector) for the operation unit substrate (operation unit substrate ground 11). Further, the flexible cable 16 is composed of two or more layers. In the first layer, a signal for driving the display unit 2 in the display unit housing 6 is transmitted. The other layer is a ground layer.
By exciting the antenna element 12 and the operation unit substrate ground 11 with the high frequency power supply 13, a high frequency current as a radiation source flows to the display unit substrate ground 10 through the ground layer of the flexible cable 16.

Next, the operation will be described. FIG. 3 is a top view showing an example of the structure of the operation unit substrate ground 11 in FIG.
As shown in FIG. 2, in the flexible cable 16, when the dielectric 14 is disposed below the connection connector 16 a (connection portion) to the display unit substrate (−Y-axis direction), as shown in FIG. 3, the operation unit substrate A part of the ground 11 is cut out. The size of the notch 11a is approximately the same as the dimension of the XZ plane of the dielectric 14 to be arranged. Specifically, this can be dealt with by removing only the ground layer corresponding to the notch portion 11a from the operation unit substrate.
2 and 3, the presence / absence of the dielectric 14 has little influence on the antenna characteristics when the housing is opened.

FIG. 4 is a diagram for explaining the effect of improving the antenna characteristics when the casing is closed by the dielectric 14 in FIG.
As shown in FIG. 4, when the housing is closed, the dielectric 14 is sandwiched vertically (in the Y-axis direction) by one flexible cable 16. Here, the lower surface of the flexible cable 16 sandwiching the dielectric 14 is a surface B, and the upper surface is a surface C.
The dielectric 14 changes the strength of the electric field between the surfaces B and C, and the current distribution on the flexible cable 16 changes. At the same time, the current distribution on the display unit substrate ground 10 and the operation unit substrate ground 11 also changes, and the antenna characteristics when the casing is closed can be improved. That is, by providing the dielectric 14 in a part of the flexible cable 16, the antenna characteristics when the casing is closed can be improved without affecting the antenna characteristics when the casing is opened.

Next, a specific effect of improving antenna characteristics when the dielectric 14 is sandwiched between the flexible cables 16 will be described. FIG. 5 is a diagram showing an example of the housing condition based on FIG. 4 for the portable wireless terminal according to Embodiment 1 of the present invention.
In FIG. 5, both the display unit substrate 17 and the operation unit substrate 18 have an outer dimension of 90 mm (Z direction) × 40 mm (X direction). The size of the notch 11a of the operation unit substrate ground 11 is 25 mm (Z direction) × 20 mm (X direction).
The antenna element 12 is a monopole antenna extending in an L shape from the operation unit board ground 11 and having a short part of 6 mm (Z direction) and a long part of 37 mm (X direction).
The width of the flexible cable 16 is 20 mm (X direction). The space between the upper and lower surfaces B and C of the folded (folded) flexible cable is 2 mm (Y direction).

6A and 6B are diagrams showing impedance characteristics when the casing is opened and closed when configured under the casing conditions of FIG. 5, FIG. 6A is a Smith chart, and FIG. 6B is a return loss characteristic. Show. The return loss indicates how much the incident power (input signal) to the antenna is reflected in dB.
In FIG. 6, the return loss when the casing is closed (sliding closed) is −6.3 to −7.2 dB at 1.945 to 1.96 GHz which is the transmission band of the W-CDMA portable wireless device, and 2.135 to 2.15 which is the reception band. It is -6.2 to -6.9dB in GHz.

7A and 7B are diagrams showing impedance characteristics when a predetermined dielectric is arranged in the housing conditions of FIG. 5, FIG. 7A shows a Smith chart, and FIG. 7B shows return loss characteristics. ing. The housing condition of FIG. 7 is that the outer dimension is 26 mm (Z direction) × 20 mm (X direction) × 2 mm between the opposed surfaces of the folded flexible cable 16 shown in FIG. 5, that is, between the surfaces B and C. A dielectric having a dielectric constant of 11 in the (Y direction) is arranged.
In FIG. 7, the return loss when the casing is closed (sliding closed) is −7.5 to −9.5 dB at 1.945 to 1.96 GHz which is the transmission band of the W-CDMA portable wireless device, and 2.135 to 2.15 which is the reception band. It is -7.4 to -9.5 dB at GHz, and it can be seen that the impedance characteristics are improved when the casing is closed, as compared with FIG. 6 and 7, the impedance changes when the housing is open (slide open) because the antenna matching circuit is changed.

As described above, according to the first embodiment, the dielectric 14 having an arbitrary dielectric constant is provided between the flexible cable 16 that is bent (folded) between the display unit substrate 17 and the operation unit substrate 18. By inserting, the impedance characteristic when the casing is closed can be improved.
Further, since the dielectric 14 can be arranged in an existing space, it is not necessary to increase the size of the housing.

Embodiment 2. FIG.
The second embodiment of the present invention will be described below. 8A and 8B are perspective views showing the internal configuration of the portable wireless terminal according to Embodiment 2 of the present invention. FIG. 8A shows the case when the casing is open, and FIG. 8B shows the case when the casing is closed. It is a thing. In FIG. 8, only the display unit ground 10 and the operation unit ground 11 are shown for the display unit substrate and the operation unit substrate for easy understanding.
The second embodiment is different from the first embodiment in that the dielectric 14 is arranged on a part of the operation unit substrate.

In FIG. 8, the dielectric 14 does not overlap the flexible cable 16 when the casing is opened, but is sandwiched between the flexible cable 16 and the operation unit substrate (operation unit substrate ground 11) when the casing is closed.
With this configuration, the electric field strength between the operation unit board and the flexible cable 16 changes only when the casing is closed, and the current distribution on the flexible cable changes. At the same time, the current distribution on the display unit substrate ground 10 and the operation unit substrate ground 11 also changes, and the antenna characteristics when the casing is closed can be improved. That is, by providing the dielectric 14 on a part of the operation unit substrate, the antenna characteristics when the casing is closed are improved without affecting the antenna characteristics when the slide is opened (when the casing is opened). be able to.

As described above, according to the second embodiment, when the casing is closed, the dielectric 14 having an arbitrary dielectric constant is inserted between the operation unit substrate and the flexible cable 16 so that the casing is closed. Impedance characteristics can be improved.
Further, since the dielectric 14 can be arranged in an existing space, it is not necessary to increase the size of the housing.

Embodiment 3 FIG.
Embodiment 3 of the present invention will be described below. 9 is a perspective view showing the internal configuration of the portable wireless terminal according to Embodiment 3 of the present invention. FIG. 9 (a) shows the case when the casing is open, and FIG. 9 (b) shows the case when the casing is closed. It is a thing. In FIG. 9, only the display unit ground 10 and the operation unit ground 11 are shown for the display unit substrate and the operation unit substrate for easy understanding.
Unlike the first and second embodiments, the third embodiment has a structure in which a conductor 19 is disposed on a connector 16a that connects the flexible cable 16 to the display unit substrate.

As shown in FIG. 9, in the flexible cable 16, a conductor 19 is attached to the lower part (−Y axis direction) of the connector 16 a connected to the display unit substrate. When the casing is closed, the conductor 19 is connected to the facing surface of the flexible cable 16 (the surface facing the connection connector 16a).
Since the sliding opening and closing is frequently performed, the conductor 19 is preferably composed of a durable material such as a conductor spring or conductive rubber.

FIG. 10 is a diagram for explaining the effect of improving the antenna characteristics when the housing is closed by the conductor 19 in FIG. 9, FIG. 10 (a) shows the case without the conductor 19, and FIG. 10 (b) shows the conductor. The case where there is 19 is shown.
As shown in FIG. 10, the conductor 19 is sandwiched between the connection connector 16 a and the flexible cable 16 when the casing is closed. Then, the conductor 19 and the flexible cable 16 are electrically connected and conducted, and the current distribution flowing through the flexible cable 16 as indicated by the arrow in FIG. 10 (arrow in FIG. 10: high-frequency current vector). ) Will change. As a result, impedance characteristics when the casing is closed are improved.
Since the conductor 19 and the flexible cable 16 are not connected when the casing is opened, the impedance characteristics when the casing is opened are not affected.

As described above, according to the third embodiment, when the casing is closed, the conductor 19 provided on the connection connector 16a is electrically connected to the flexible cable 16, thereby improving the impedance characteristics when the casing is closed. Can do.
Moreover, since the conductor 19 can be arrange | positioned in the existing space, it is not necessary to enlarge a housing | casing.

  In the above description, the slide-type housing structure (mobile phone) has been described as an example. However, in the case of the folding or revolver-type housing structure, any one of the first to third embodiments when the housing is closed. By applying the configuration, impedance characteristics (antenna characteristics) when the casing is closed are improved.

It is a perspective view which shows the external appearance of the portable radio | wireless terminal which concerns on Embodiment 1 of this invention, Fig.1 (a) is when a housing | casing is open (when a slide is open), FIG.1 (b) is when a housing | casing is closed (sliding). (When closed). 2A and 2B are perspective views showing an internal configuration of the portable wireless terminal of FIG. 1, in which FIG. 1A shows when the casing is open, and FIG. FIG. 3 is a top view illustrating an example of a structure of an operation unit substrate ground 11 in FIG. 2. It is a figure for demonstrating the improvement effect of the antenna characteristic at the time of the housing | casing closed by the dielectric material 14 in FIG. It is the figure which showed an example of the housing conditions based on FIG. 4 about the portable radio | wireless terminal which concerns on Embodiment 1 of this invention. 6A and 6B are diagrams showing impedance characteristics when the casing is opened and closed when configured under the casing conditions of FIG. 5, FIG. 6A shows a Smith chart, and FIG. 6B shows a return loss characteristic. FIGS. 7A and 7B are diagrams illustrating impedance characteristics when a predetermined dielectric is disposed in the housing condition of FIG. 5. FIG. 7A illustrates a Smith chart and FIG. 7B illustrates a return loss characteristic. It is a perspective view which shows the internal structure of the portable radio | wireless terminal which concerns on Embodiment 2 of this invention, Fig.8 (a) shows the time of housing | casing opening, FIG.8 (b) shows the time of housing | casing closed. . It is a perspective view which shows the internal structure of the portable radio | wireless terminal which concerns on Embodiment 3 of this invention, FIG.9 (a) shows the time of housing | casing opening, FIG.9 (b) shows the time of housing | casing closed. . FIG. 10A is a diagram for explaining the effect of improving the antenna characteristics when the casing is closed by the conductor 19 in FIG. 9, FIG. 10A shows the case where the conductor 19 is not provided, and FIG. Shows the case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception part, 2 Display part, 3 Operation part (display part housing | casing side), 4 Transmitting part (display part housing | casing side), 5 Transmitting part (operation part housing | casing side), 6 Display part housing | casing, 7 Antenna storage part , 8 operation unit (operation unit casing side), 9 operation unit casing, 10 display unit substrate ground (conductor plate serving as ground of display unit substrate), 11 operation unit substrate ground (conductor plate serving as ground of operation unit substrate) , 11a Notch part, 12 Antenna element (linear conductor), 13 High frequency power supply, 14 Dielectric, 16 Flexible cable, 16a Connection connector (connection part), 16b Connection connector (connection part), 17 Display board, 18 Operation Sub-board, 19 conductors.

Claims (4)

A first housing;
A second housing that opens and closes with the first housing;
A first substrate mounted in a first housing;
A second substrate mounted in the second housing;
A flexible cable connecting the first substrate and the second substrate;
A dielectric sandwiched between a pair of opposing surfaces of the flexible cable folded between the first substrate and the second substrate by closing the first housing and the second housing A portable wireless terminal comprising: A first housing;
A second housing that opens and closes with the first housing;
A first substrate mounted in a first housing;
A second substrate mounted in the second housing;
A flexible cable connecting the first substrate and the second substrate;
A portable wireless terminal comprising: a dielectric sandwiched between a first substrate and the flexible cable by closing the first housing and the second housing. A first housing;
A second housing that opens and closes with the first housing;
A first substrate mounted in a first housing;
A second substrate mounted in the second housing;
A flexible cable connecting the first substrate and the second substrate;
Provided at a connection portion between the second substrate and the flexible cable, and having a conductor connected to the opposing surface of the flexible cable by closing the first casing and the second casing. A portable radio terminal. An antenna element connected to a conductor plate serving as a ground of the first substrate;
The portable radio terminal according to any one of claims 1 to 3, further comprising a high-frequency power source that excites between the conductor plate and the antenna element.

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