JP2010287980A - Antenna device and portable wireless terminal having the same mounted thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna device, capable of equivalently increasing the operation volume of an antenna in a configuration, wherein a monopole antenna element disposed in the vicinity of a hinge part of a portable wireless terminal is operated as the antenna, and is light-weight, low-cost, and wide-band, and to provide a portable wireless terminal having the antenna device mounted thereon. <P>SOLUTION: A portable wireless terminal 100, including a first enclosure 1003, a second enclosure 1004, and a hinge part 1001 rotatably connecting the first enclosure 1003 and the second enclosure 1004, includes a monopole antenna element 106 disposed close to the hinge part 1001; a feeding part which feeds the monopole antenna element 106; and an approximately cylindrical ring conductor 101 which is disposed on the hinge part 1001 and is larger than the monopole antenna element 106. The portable wireless terminal has a configuration wherein the ring conductor 101 is capacitively coupled with the monopole antenna element 106. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a portable wireless terminal provided with a hinge part that connects a case so that the case can be opened and closed, and more particularly to an arrangement configuration of an antenna in the case including the hinge part.

  Mobile wireless terminals such as mobile phones not only have telephone functions, e-mail functions, and access functions to the Internet, but also have short-range wireless communication functions, wireless LAN functions, GPS functions, TV viewing functions, IC card payment functions, etc. As the number of functions increases, it is desired to further reduce the size and the integration of the apparatus. With such multi-functionality, the number of antennas mounted on portable wireless terminals is increasing, but in order to maintain good antenna characteristics while reducing the size of the device, antenna arrangement At that time, various ideas are required.

  In addition, with the dramatic increase in mobile phones, there is a problem of insufficient frequency used for communication, and the current cellular antenna for communication has four bands (800M, 1.5G, 1.7G, 2G bands). System support is required. As mobile phones become thinner, a plurality of antennas corresponding to the frequency band of the 4-band system cannot be mounted on a small mobile phone. Therefore, a multiband broadband antenna corresponding to a plurality of frequency bands is required.

  In such a portable wireless terminal, for example, as shown in FIG. 10, a configuration is known in which a metal rotating shaft 1002 constituting the axis of the hinge part 1001 of the portable wireless terminal 1000 is operated as an antenna. In FIG. 10, the shaft of the hinge portion 1001 that connects the first housing 1003 and the second housing 1004 so as to be openable and closable is configured by a general small-diameter metal rotating shaft 1002. The first circuit board 1005 mounts the wireless circuit 1008 connected to the matching circuit 1007 and is installed in the first housing 1003. The second circuit board 1006 is installed in the second housing 1004 and is connected to the first circuit board 1005 through the signal line 1009. The metal rotating shaft 1002 is connected to the matching circuit 1007 via the contact spring 1010.

  With this configuration, since the metal rotating shaft 1002 can be operated as an antenna, the antenna-dedicated element can be deleted, and the portable wireless terminal can be downsized.

  Further, in a similar portable wireless terminal, for example, as described in Patent Document 1, in FIG. 11, the metal rotating shaft 1102 has a mechanism for generating a rotating force by itself, and one end portion is When pressed, the metal rotation shaft 1102 rotates by itself and the first housing 1003 and the second housing 1004 open, so that the diameter is larger than that of a general metal rotation shaft.

  With this configuration, since the diameter of the metal rotating shaft 1102 that operates as an antenna is large, a broadband antenna can be realized as compared with the metal rotating shaft 1002 having a small diameter.

Japanese Patent Laid-Open No. 2007-88692 (FIG. 1)

  However, in the conventional configuration shown in FIG. 10, the metal rotating shaft 1002 is operated as an antenna, and the configuration as a component of the metal rotating shaft 1002 is determined. was there.

  Further, in the conventional configuration described in Patent Document 1, in addition to the above-described problems, the volume of the metal constituting the metal rotating shaft 1102 is large, so that there is a problem that the mass is heavy and the cost is high.

  In order to solve the above problems, the present invention hinges a substantially cylindrical ring conductor having the same rotation center as that of the small-diameter metal rotating shaft constituting the shaft of the hinge portion and having a diameter larger than that of the metal rotating shaft. And a power supply monopole antenna element that is disposed close to the hinge portion and is capacitively coupled. Accordingly, an antenna having an equivalently large diameter can be configured using the inner diameter of the hinge portion, and a lightweight, low-cost, wide-band antenna device and a portable wireless terminal equipped with the antenna device are provided.

  An antenna device of the present invention and a portable wireless terminal equipped with the antenna device include a first housing, a second housing, and a hinge portion that rotatably connects the first housing and the second housing. A mobile wireless terminal having a metal rotation shaft provided on the hinge portion and constituting a rotation center of the hinge portion, substantially the same as the rotation center of the metal rotation shaft and having a diameter larger than that of the metal rotation shaft. A substantially cylindrical ring conductor; a monopole antenna element that is provided in the first housing and is substantially parallel to the ring conductor; and a power feeding unit that feeds power to the monopole antenna element. Is configured by connecting a first member and a second member, which are substantially cylindrical or substantially columnar, rotating with respect to each other, the first member being connected to the first housing, and the second member being the second housing. Each mechanically fixed to the body, A radio circuit disposed in the first housing is electrically connected to the monopole antenna element, and the ring conductor is mechanically fixed to the second housing and capacitively coupled to the monopole antenna element. It has the composition which is done. With this configuration, it is possible to realize a broadband antenna that is lightweight, low-cost, and has a high degree of design freedom.

  Further, the antenna device of the present invention and a portable wireless terminal equipped with the antenna device are configured such that the ring conductor is connected to the first ring conductor and the second ring conductor via a trap circuit, and the monopole antenna element and the capacitor It has a combined configuration. With this configuration, the antenna can be operated at two resonances, and a wider band antenna characteristic can be realized.

  Further, in the antenna device of the present invention and the portable wireless terminal equipped with the antenna device, the ring conductor is formed by cutting a part or all of the ring conductor so that the first housing and the second housing can rotate. Accordingly, there is a configuration in which the magnitude of capacitive coupling between the ring conductor and the monopole antenna element changes. With this configuration, the input impedance of the monopole antenna element can be adjusted according to the open / closed state of the portable wireless terminal, and broadband antenna characteristics can be realized in any open / closed state.

  Further, in the antenna device of the present invention and the portable wireless terminal equipped with the antenna device, the ring conductor is formed by cutting a part or all of the ring conductor so that the first housing and the second housing can rotate. Accordingly, there is a configuration in which the magnitude of electrical coupling between the ring conductor and the wireless circuit disposed in the first housing changes. With this configuration, the radiation impedance of the monopole antenna element can be adjusted according to the open / closed state of the portable wireless terminal, and wideband antenna characteristics can be realized in any open / closed state.

  According to the antenna device of the present invention and the portable wireless terminal equipped with the antenna device, it is possible to realize a wide-band antenna that is lightweight, low in cost, and high in design freedom.

Front view of portable wireless terminal according to Embodiment 1 of the present invention The expanded sectional view of the hinge part of the portable radio | wireless terminal in Embodiment 1 of this invention Antenna characteristics with respect to the diameter of the C-ring conductor in the first embodiment of the present invention The enlarged front view of the hinge part of the portable radio | wireless terminal in Embodiment 2 of this invention Antenna current distribution diagram in Embodiment 2 of the present invention Frequency characteristic diagram of trap circuit in embodiment 2 of the present invention Front view of portable wireless terminal according to Embodiment 3 of the present invention The expanded sectional view of the hinge part of the portable radio | wireless terminal in Embodiment 3 of this invention The enlarged front view of the hinge part of the portable radio | wireless terminal in Embodiment 3 of this invention Front view of a portable wireless terminal using a conventional small-diameter metal rotating shaft as an antenna Front view of a portable wireless terminal using a metal rotating shaft with a large diameter as an antenna

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

(Embodiment 1)
1 is a front view of a portable wireless terminal according to Embodiment 1 of the present invention, FIG. 2 is an enlarged cross-sectional view of a hinge portion of the portable wireless terminal according to Embodiment 1 of the present invention, and FIG. 3 is an embodiment of the present invention. It is an antenna characteristic figure with respect to the diameter of the C-ring conductor in the form 1. 1 to 3, the same components as those in FIGS. 10 and 11 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 1, the hinge part 1001 of the mobile wireless terminal 100 is connected to the first resin part 103 and the third resin part 105 having a substantially cylindrical shape at the end part of the first casing 1003, and the end of the second casing 1004. The substantially cylindrical second resin part 104 is coupled so as to be rotatable, and each coupling part has a structure serving as a rotating part, and a metal rotating shaft 1002 constituting the axis of the hinge part 1001 is installed therein. ing. The metal rotation shaft 1002 is formed in a substantially cylindrical shape or a substantially columnar shape, and the second resin portion 104 of the second housing 1004 and the first resin portion 103 of the first housing 1003 that mechanically rotate with each other are mechanically connected. It has a connected structure.

  As shown in FIGS. 1 and 2, the C-ring conductor 101 has a C-shaped cross section and is formed in a substantially cylindrical shape having a diameter larger than that of the metal rotation shaft 1002. The rotation center is the same as that of the metal rotation shaft 1002. It arrange | positions inside the 2nd resin part 104 so that it may become.

  In the first housing 1003, a monopole antenna element 106 is provided in a portion that is substantially parallel to the C ring conductor 101 and close to the second resin portion 104, and is capacitively coupled to the C ring conductor 101.

  One of the signal lines 1009 is connected to the first circuit board 1005, and the other is connected to the inside of the C-ring conductor 101 in the third resin portion 105 and the second resin portion 104, and has a C-shaped ring shape. It is connected to the second circuit board 1006 through the open part.

  The distance D2 between the C-ring conductor 101 and the second circuit board 1006 in the z-axis direction is configured to be 0.029 wavelength or more in the frequency band to be used.

  The C-ring conductor 101 has a diameter D1 of about 7 mm (0.033 wavelength at 1.45 GHz) and a length L of about 25 mm (0.12 wavelength at 1.45 GHz). For example, when the width is about 4 mm (0.002 wavelength in the 1.45 GHz band) and the length is 15 mm (0.07 wavelength at 1.45 GHz), the monopole antenna element 106 and the C-ring conductor 101 overlap each other by about 7 mm in the y-axis direction. Configured.

  The antenna operation of the mobile radio terminal 100 configured as described above will be described. As described above, the C-ring conductor 101 having a diameter larger than that of the monopole antenna element 106 is capacitively coupled to the monopole antenna element 106, so that the antenna current is applied to the C-ring conductor 101 in addition to the monopole antenna element 106. Is distributed, and the volume operating as an antenna can be increased equivalently.

  FIG. 3 shows the change characteristics of the resonance frequency f0 and the relative bandwidth Δf / f0 when the diameter D1 of the C-ring conductor 101 is changed under the above-described conditions. It can be seen that as the diameter D1 of the C-ring conductor 101 increases, the resonance frequency f0 decreases and the specific bandwidth Δf / f0 also increases. Since the length including the overlapping portion of the length L of the C-ring conductor 101 and the monopole antenna element 106 is 40 mm (0.25 wavelength at 1.85 GHz), 1.85 GHz when D1 is as thin as 2 mm. And the specific bandwidth is narrowed to 17%. On the other hand, when D1 is 7 mm, the resonance frequency f0 is lowered to 1.45 GHz and the specific band is 50%, and a wide band antenna characteristic can be realized as compared with the case where the C-ring conductor 101 is not provided.

  As described above, according to the first embodiment, the substantially cylindrical C-ring conductor 101 larger than the monopole antenna element 106 is configured to operate as an antenna by capacitive coupling, thereby adding to the monopole antenna element 106. The antenna current is also distributed to the C ring conductor 101, and a wide band antenna characteristic can be realized as compared with the case where the C ring conductor 101 is not provided. Here, if the metal rotating shaft 1002 is configured with a large diameter equivalent to that of the C-ring conductor 101 as shown in FIG. 11, a similar broadband characteristic can be obtained, but with this configuration, a lighter and lower cost antenna can be realized.

  In this embodiment, the C-shaped ring of the C-ring conductor 101 is all open with respect to the y-axis direction of the portable wireless terminal 100, but a space sufficient for the signal line 1009 to pass through can be secured. If it is not all open.

(Embodiment 2)
4 is an enlarged front view of the hinge portion of the portable wireless terminal according to the second embodiment of the present invention, FIG. 5 is a current distribution diagram of the antenna according to the second embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. It is a frequency characteristic of the trap circuit in the form 2. 4 to 6, the same components as those in FIGS. 1, 2, 10, and 11 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 4, the C-ring conductor is divided into two parts, a first C-ring conductor 401 and a second C-ring conductor 402, and the first resin part 103 side and the third resin part 105 side in the second resin part 104, respectively. To place. The first C ring conductor 401 is capacitively coupled to the monopole antenna element 106, and the first C ring conductor 401 and the second C ring conductor 402 are connected via a trap circuit 403. As shown in FIG. 6, the trap circuit 403 is configured to cut off the first frequency band and pass the second frequency band lower than the first frequency band.

  The antenna operation of the portable wireless terminal configured as described above will be described. As described above, by providing the trap circuit 403 that passes through the second frequency band and blocks the first frequency band between the first C ring conductor 401 and the second C ring conductor 402, the monopole antenna element 106, the first C A first frequency band current 501 is distributed in the ring conductor 401, and a second frequency band current 502 is distributed in the monopole antenna element 106, the first C ring conductor 401, and the second C ring conductor 402. As a result, the antenna can be operated at two resonances, and a broadband antenna characteristic can be realized.

  Specifically, both the diameters of the first C ring conductor 401 and the second C ring conductor 402 are, for example, about 7 mm, the length of the first C ring conductor 401 is about 18 mm (0.12 wavelength at 2 GHz), and the second C The length of the ring conductor 402 is about 7 mm, and the length of the ring conductor 402 together with the length of the first C ring conductor 401 is about 25 mm (0.12 wavelength at 1.45 GHz). The trap circuit 403 is configured by an LC trap circuit having a capacitance of about 6 pF and a reactance of about 1 nH, for example. With this configuration, the trap circuit 403 can block the 2 GHz band corresponding to the first frequency band and pass the 1.45 GHz band corresponding to the second frequency band. It can be operated and a broadband antenna characteristic can be realized.

  As described above, according to the second embodiment, by dividing the C-ring conductor into two and providing the trap circuit 403 therebetween, the antenna can be operated with two resonances, and a wide band antenna characteristic can be realized.

  In the present embodiment, the C-shaped rings of the first C-ring conductor 401 and the second C-ring conductor 402 are all open with respect to the y-axis direction of the mobile radio terminal 100, but the same as in the first embodiment. In addition, as long as a space sufficient for the signal line 1009 to pass through can be secured, it is not necessary to open all of them.

(Embodiment 3)
7 is a front view of the portable wireless terminal according to the third embodiment of the present invention, FIG. 8 is an enlarged cross-sectional view of the hinge portion of the portable wireless terminal according to the third embodiment of the present invention, and FIG. 9 is an embodiment of the present invention. It is an enlarged front view of the hinge part of the portable radio | wireless terminal in the form 3. 7-9, the same code | symbol is used about the same structure as FIG.1, FIG.2, FIG.10, FIG.11, and description is abbreviate | omitted.

  As shown in FIGS. 7 and 8, the C-shaped ring in the C-ring conductor 101 is formed with a cut so that the cross section is a semicircle. With this configuration, when the portable wireless terminal 100 is opened so that the first housing 1003 and the second housing 1004 are separated from each other, the monopole antenna element 106 and the C-ring conductor 101 in the z-axis direction Although the capacitive coupling increases as the distance D3 is close, the distance D3 between the monopole antenna element 106 and the C-ring conductor 101 increases when the portable radio terminal 100 is closed, so that the value of the capacitive coupling decreases. It becomes difficult for the antenna current to flow through the ring conductor 101.

  In FIG. 9A, the semicircular cut in the C-ring conductor 101 is inserted in a portion overlapping the monopole antenna element 106, and the other portion is configured in a C-ring shape. By adopting such a configuration, the distance D3 between the monopole antenna element 106 and the C-ring conductor 101 changes as in FIGS. 7 and 8, and the value of capacitive coupling can be changed. Note that in the portion where the monopole antenna element 106 and the C ring conductor 101 do not overlap, the C ring conductor 101 does not have a semicircular cut, so that the effect of increasing the equivalent diameter of the antenna by the C ring conductor 101 is maintained. In this state, the value of capacitive coupling between the monopole antenna element 106 and the C-ring conductor 101 is changed according to the rotation state of the first housing 1003 and the second housing 1004, and the opening angle of the portable wireless terminal Accordingly, the input impedance of the antenna can be adjusted, and a wide-band antenna can be configured.

  9B and 9C, the size of the semicircular cut ring in the C-ring conductor 101 is gradually changed in the y-axis direction. With such a configuration, the average distance between the monopole antenna element 106 and the C-ring conductor 101 is changed according to the opening / closing of the mobile radio terminal 100, and the monopole antenna element 106 and the C-ring conductor 101 are changed. Since the overlapping length changes with the place where the and overlap, the value of capacitive coupling can be changed stepwise. In FIG. 9B, since the size of the semicircular cut ring in the C-ring conductor 101 is increased toward the side closer to the first resin portion 103, the capacitive coupling is small when the portable wireless terminal 100 is closed. However, the capacitive coupling gradually increases as the portable wireless terminal 100 is fully opened. In FIG. 9C, the closer to the first resin portion 103, the smaller the size of the semi-circular cut ring in the C-ring conductor 101, so that the capacitive coupling is small when the portable radio terminal 100 is closed. However, as the portable wireless terminal 100 starts to open, capacitive coupling increases rapidly. Note that in the portion where the monopole antenna element 106 and the C ring conductor 101 do not overlap, the C ring conductor 101 does not have a semicircular cut, so that the effect of increasing the equivalent diameter of the antenna by the C ring conductor 101 is maintained. The value of the capacitive coupling between the monopole antenna element 106 and the C-ring conductor 101 is changed stepwise in accordance with the rotation state of the first housing 1003 and the second housing 1004, and the portable wireless terminal The input impedance of the antenna can be adjusted according to the opening angle of the antenna, and a broadband antenna can be configured.

  In FIG. 9D, the semicircular cut in the C-ring conductor 101 is put in a portion that does not overlap with the monopole antenna element 106, and the portion that overlaps with the monopole antenna element 106 is formed in a C-ring shape. . With such a configuration, even if the rotation state of the first housing 1003 and the second housing 1004 changes, the C-ring conductor 101 and the first circuit board 1005 are maintained while maintaining the capacitive coupling value. And the distance D4 in the z-axis direction can be changed, and the radiation impedance of the antenna can be adjusted according to the opening angle of the portable wireless terminal. In the portion where the monopole antenna element 106 and the C-ring conductor 101 overlap, the C-ring conductor 101 is not cut in a semicircular shape, so that the effect of increasing the equivalent diameter of the antenna is maintained, and the broadband A simple antenna.

  As described above, according to the third embodiment, the antenna associated with the capacitive coupling composed of the C-ring conductor 101 and the monopole antenna element 106 according to the rotation of the first casing 1003 and the second casing 1004. The input impedance of the antenna or the radiation impedance of the antenna due to the electrical coupling constituted by the C-ring conductor 101 and the first circuit board 1005 can be adjusted, and a wide band antenna characteristic can be realized in any state of opening and closing.

  An antenna device of the present invention and a portable wireless terminal equipped with the antenna device include a first housing, a second housing, and a hinge portion that rotatably connects the first housing and the second housing. A mobile wireless terminal having a metal rotation shaft provided on the hinge portion and constituting a rotation center of the hinge portion, substantially the same as the rotation center of the metal rotation shaft and having a diameter larger than that of the metal rotation shaft. A substantially cylindrical ring conductor; a monopole antenna element that is provided in the first housing and is substantially parallel to the ring conductor; and a power feeding unit that feeds power to the monopole antenna element. Is configured by connecting a first member and a second member, which are substantially cylindrical or substantially columnar, rotating with respect to each other, the first member being connected to the first housing, and the second member being the second housing. Each mechanically fixed to the body, A radio circuit disposed in the first housing is electrically connected to the monopole antenna element, and the ring conductor is mechanically fixed to the second housing and capacitively coupled to the monopole antenna element. It has the composition which is done. With this configuration, it is possible to realize a wide-band antenna that is lightweight, low-cost, and has a high degree of design freedom, and is useful for reducing the weight and cost of an antenna device and a portable wireless terminal equipped with the antenna device.

DESCRIPTION OF SYMBOLS 100 Portable radio terminal 101 C ring conductor 102 Center of rotation 103 1st resin part 104 2nd resin part 105 3rd resin part 106 Monopole antenna element 401 1st C ring conductor 402 2nd C ring conductor 403 Trap circuit 501 1st frequency band current 502 Second frequency band current

Claims (5)

A first housing;
A second housing;
A hinge unit that rotatably connects the first housing and the second housing;
A metal rotation shaft provided on the hinge portion and constituting a rotation center of the hinge portion;
A ring conductor having a substantially cylindrical shape that is substantially the same as the rotation center of the metal rotation shaft and has a diameter larger than that of the metal rotation shaft;
A monopole antenna element provided in the first housing and substantially parallel to the ring conductor;
A power feeding unit that feeds power to the monopole antenna element,
The metal rotation shaft is configured by connecting a first member and a second member having a substantially cylindrical shape or a substantially columnar shape that rotate with respect to each other. The first member is connected to the first housing, and the second member is Each mechanically fixed to the second housing,
The power feeding unit is electrically connected to the radio circuit disposed in the first housing and the monopole antenna element,
The antenna device, wherein the ring conductor is mechanically fixed to the second casing and capacitively coupled to the monopole antenna element. The ring conductor is configured by connecting a first ring conductor and a second ring conductor via a trap circuit;
The antenna device according to claim 1, wherein the first ring conductor is capacitively coupled to the monopole antenna element. The ring conductor is configured by cutting a part or the whole,
2. The antenna device according to claim 1, wherein the magnitude of capacitive coupling between the ring conductor and the monopole antenna element changes according to the rotation of the first casing and the second casing. . The ring conductor is configured by cutting a part or the whole,
The magnitude of the electrical coupling between the ring conductor and the radio circuit disposed in the first casing changes according to the rotation of the first casing and the second casing. The antenna device according to claim 1. The portable radio terminal according to any one of claims 1 to 4, wherein the antenna device is mounted.

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