JP2012235258A - Portable radio apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable radio apparatus capable of obtaining a wideband antenna characteristic without increasing the size of the apparatus and the cost.SOLUTION: The portable radio apparatus includes a first metal frame 6 having a length of substantially a half of an upper outer side face of a housing 2 therealong, and a second metal frame 7 having a length of substantially a half of a lower outer side face of a housing 2 therealong. One end 6a of the first metal frame 6 is connected to a power supply terminal 9 which is connected to a matching circuit portion 5 on a circuit board 3, and the other end 6b thereof is connected to a ground 3G of the circuit board 3 via a first grounding terminal 10. One end 7a of the second metal frame 7 is connected to the ground 3G of the circuit board 3 adjacent to the power supply terminal 9 via a second grounding terminal 11, the other end 7b thereof is disposed adjacent to the first grounding terminal 10 as an open terminal. Thus, the electric length of the first and second metal frames 6 and 7 is identical to each other.

Description

  The present invention relates to a portable radio having broadband antenna characteristics.

  As a portable wireless device having a wideband antenna characteristic having an operation bandwidth of a plurality of resonance frequencies, for example, there is one described in Patent Document 1. The portable wireless device described in Patent Document 1 includes a planar inverted F antenna having an operation bandwidth of a plurality of resonance frequencies. The planar inverted F antenna has a resonance of about ¼ wavelength in a low frequency band. It operates as two resonators of about ½ wavelength in the high frequency band.

  In addition, there is a multi-frequency band antenna described in Patent Document 2 as another antenna with a wide band. This multi-frequency band antenna has a first antenna element for a low frequency band and a second antenna element for a high frequency band, and the base end of the first antenna element and the base end of the second antenna element Are electrically connected to the same feeding point, and the first antenna element is set to an electrical length of ½ wavelength in a high frequency band, and its tip is released without being short-circuited to the ground. Is set to an electrical length of ¼ wavelength in a low frequency band, and its tip is shorted to ground. In this multi-frequency band antenna, the impedance of the second antenna element is infinite for the low frequency band, and the impedance of the first antenna element is infinite for the high frequency band. The first and second antenna elements do not cause mutual interference and perform antenna operations independently of each other.

  Although broadband antenna characteristics cannot be obtained, the antenna device described in Patent Document 3 adopts a configuration that combines an antenna element and a parasitic element, and suppresses the casing current by loading the parasitic element, The radiation pattern characteristics are prevented from deteriorating due to the casing current.

International Publication No. 2004/109855 JP 2007-288649 A JP 2006-033798 A

However, although the planar inverted-F antenna of the wireless terminal described in Patent Document 1 described above can obtain wideband antenna characteristics, an occupied space for arranging the antenna in the terminal is required. There is a problem of increasing the size.
Moreover, since the antenna for multiple frequency bands described in Patent Document 2 described above requires a dedicated antenna element component when incorporated in a portable wireless terminal, it inhibits the miniaturization of the terminal itself and the component. There is a problem that the cost increases due to the use of.
Further, the antenna device described in Patent Document 3 described above cannot obtain wideband antenna characteristics.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a portable wireless device capable of obtaining broadband antenna characteristics without increasing the size and cost of the device itself.

  The portable wireless device of the present invention includes a housing, a circuit board provided in the housing and having a ground, a wireless circuit unit provided in the housing and configured on the circuit board, A matching circuit unit provided inside the housing and configured on the circuit board and connected to the wireless circuit unit; and provided in a length of approximately half a circumference along the housing; and a ground of the circuit board And a first metal plate disposed at a predetermined interval and a length of approximately half a circumference along the housing, and a second metal plate disposed at a predetermined interval from the ground of the circuit board. A metal plate, and one end of the first metal plate is connected to a power supply terminal connected to the matching circuit unit on the circuit board, and the other end is connected to the ground of the circuit board and the first ground terminal. And the second metal plate has one end near the power supply terminal and a second ground end. Is connected to the ground of the circuit board, the other end is an open end and is disposed in the vicinity of the first ground terminal, and the electrical length of the first metal plate and the electrical length of the second metal plate are The structure is substantially the same.

  According to the above configuration, by grounding the other end of the first metal plate to the ground of the circuit board, the total length operates as a transmission line antenna that resonates at (n / 2) λ (n is a positive integer), By making the other end of the second metal plate an open end, the second metal plate operates as a monopole antenna that resonates with a total length of (n / 2−1 / 4) λ (n is a positive integer), and the earth current is first. Since a balance operation is performed by flowing through one metal plate, wideband antenna characteristics can be obtained. Further, since the first metal plate and the second metal plate are provided along the housing, the device main body does not increase in size. In addition, since the first metal plate and the second metal plate can be used as parts for increasing the strength of the housing, the antenna for a plurality of frequency bands described in Patent Document 2 (Japanese Patent Laid-Open No. 2007-288649). Unlike the case of providing a dedicated antenna element part as described above, the cost increase can be minimized.

  The said structure WHEREIN: The said 1st metal plate and the said 2nd metal plate were each provided along the outer periphery of the said housing | casing.

  According to the said structure, the intensity | strength improvement of a housing | casing can be aimed at by providing a 1st metal plate and a 2nd metal plate along the outer periphery of a housing | casing.

  The said structure WHEREIN: The said 1st metal plate and the said 2nd metal plate were each provided along the inner periphery of the said housing | casing.

  According to the above configuration, since the first metal plate and the second metal plate are provided along the inner periphery of the housing, it is not necessary to give the first metal plate and the second metal plate strength. These can be formed of copper foil by plating or vapor deposition, FPC (Flexible Printed Circuits), etc., and the cost can be reduced by providing these.

  In the above configuration, the power supply terminal and the second ground terminal are arranged close to each other at 0.1 wavelength or less of the maximum operating frequency of the wireless circuit unit.

  According to the above configuration, broadband antenna characteristics can be obtained.

  In the above-described configuration, the first ground terminal and the open end are arranged close to each other at 0.1 wavelength or less of the maximum operating frequency of the wireless circuit unit.

  According to the above configuration, broadband antenna characteristics can be obtained.

  In the above configuration, the power supply terminal and the second ground terminal are disposed on the short side of the circuit board, and the first ground terminal and the open end are opposed to the short side of the circuit board. Arranged on the short side.

  According to the above configuration, broadband antenna characteristics can be obtained.

  In the above configuration, the power supply terminal and the second ground terminal are arranged at corners of the circuit board, and the first ground terminal and the open end are corner parts facing the corners of the circuit board. Arranged.

  According to the above configuration, broadband antenna characteristics can be obtained.

  In the above configuration, the power supply terminal and the second ground terminal are disposed on the long side of the circuit board, and the first ground terminal and the open end are the long side with respect to the center of the circuit board. It is arranged at a position that is point-symmetric with the side position.

  According to the above configuration, broadband antenna characteristics can be obtained.

  In the above configuration, the first metal plate and the second metal plate have a meander shape in the middle of at least one of the first metal plate and the second metal plate.

  According to the above configuration, since the electrical lengths of the first metal plate and the second metal plate can be adjusted, the resonance frequency can be easily adjusted.

  In the above configuration, the first metal plate and the second metal plate have a capacitive coupling structure in the middle of at least one of the first metal plate and the second metal plate.

  According to the above configuration, since the electrical lengths of the first metal plate and the second metal plate can be adjusted, the resonance frequency can be easily adjusted.

  In the above configuration, between at least one of the first ground terminal and the ground, between the second ground terminal and the ground, and between the first ground terminal and the open end. A reactance element was loaded.

  According to the above configuration, since the electrical lengths of the first metal plate and the second metal plate can be adjusted, the resonance frequency can be easily adjusted.

  According to the present invention, it is possible to realize a portable radio having broadband antenna characteristics without increasing the size and cost of the portable radio itself.

1 is a perspective view showing an overview of a portable wireless device according to an embodiment of the present invention. Main part block diagram which shows the portable radio | wireless machine of FIG. (A), (b) is a figure which shows the high frequency current distribution of the various frequency bands in the 1st, 2nd metal frame of the portable radio | wireless machine of FIG. It is a figure which shows the specific analysis example of the portable radio | wireless machine of FIG. 1, (a) is a dimension figure, (b) is a VSWR characteristic figure. FIG. 1 is a diagram showing high-frequency current distributions in various frequency bands when the portable wireless device of FIG. 1 has the dimensions shown in FIG. It is a figure which shows an example of the structure provided in each part of the 1st metal frame and 2nd metal frame of the portable radio | wireless machine of FIG. 1, (a) is a figure which shows the structure made into meander shape, (b) is a capacity | capacitance. Diagram showing the bond structure It is a principal part block diagram which shows the modification 1 of the portable radio | wireless machine of FIG. 1, and is a figure which shows the example which provided the 1st metal frame and the 2nd metal frame along the inner periphery of a housing | casing Main part block diagram which shows the modification 2 of the portable radio | wireless machine of FIG. Main part block diagram which shows the modification 3 of the portable radio | wireless machine of FIG. Main part block diagram which shows the modification 4 of the portable radio | wireless machine of FIG. The principal part block diagram which shows the modification 5 of the portable radio | wireless machine of FIG. The principal part block diagram which shows the modification 6 of the portable radio | wireless machine of FIG. 1, between the first ground terminal and the ground of the circuit board, between the second ground terminal and the ground of the circuit board, and between the first ground terminal and the second metal frame. Main part configuration diagram showing an example of loading a reactance element between each of the open ends

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an overview of a portable wireless device according to an embodiment of the present invention. FIG. 2 is a main part configuration diagram showing the portable wireless device of FIG. In FIG. 1, the interior is exposed at two locations of the portable wireless device so that each member can be seen.

  1 and 2, a portable wireless device 1 according to the present embodiment is a straight-type portable wireless device called a smartphone, and is provided with a housing 2 and a circuit board that is provided inside the housing 2 and has a ground 3G. 3, a wireless circuit unit 4 configured on the circuit board 3, a matching circuit unit 5 configured on the circuit board 3 and connected to the wireless circuit unit 4, and an outer surface of the upper portion of the housing 2. A first metal frame (first metal plate) 6 provided with a substantially half circumference length and spaced from the ground 3G of the circuit board 3 by a predetermined distance, and along the outer surface of the lower portion of the housing 2 A second metal frame (second metal plate) 7 provided with a substantially half-circular length and arranged at a predetermined interval from the ground 3G of the circuit board 3, and one surface side of the housing 2 ( Provided on the front side) for various displays and displays when using the wireless communication function as a mobile phone. Comprises a liquid crystal display device 8 for performing various displays in the use of such Joule functions and personal information management functions, the.

  The first metal frame 6 has one end 6 a connected to a power supply terminal 9 connected to the matching circuit section 5 on the circuit board 3, and the other end 6 b via the ground 3 G and the first ground terminal 10 of the circuit board 3. Connected. The second metal frame 7 has one end 7a connected to the ground 3G of the circuit board 3 by the second ground terminal 11 in the vicinity of the power supply terminal 9, and the other end 7b disposed near the first ground terminal 10 as an open end. Is done. The electrical length of the first metal frame 6 and the electrical length of the second metal frame 7 are substantially the same. The power feeding terminal 9 and the second ground terminal 11 are arranged close to each other at 0.1 wavelength or less of the maximum operating frequency of the radio circuit unit 4. Further, the first ground terminal 10 and the open end 7 b of the second metal frame 7 are arranged close to each other at a maximum operating frequency of 0.1 wavelength or less of the radio circuit unit 4.

  For the first and second metal frames 6 and 7, for example, a metal material such as aluminum, copper, stainless steel, magnesium, or an alloy thereof is used. A touch panel (not shown) is provided on the surface side of the liquid crystal display device 8.

  With the above configuration, the portable wireless device 1 according to the present embodiment allows a wideband current to flow on the first and second metal frames 6 and 7 that surround the periphery of the side surface of the housing 2. Operates as an antenna. That is, by grounding the tip (the other end 6b) of the first metal frame 6, it operates as a transmission line antenna that resonates at a total length of (n / 2) λ, and the tip (the open end) of the second metal frame 7 is operated. By setting 7b) as an open end, it operates as a monopole antenna that resonates with a total length of (n / 2−1 / 4) λ, and a ground current flows through the first metal frame 6 to perform a balance operation. Thereby, a broadband antenna characteristic is obtained. FIGS. 3A and 3B are diagrams showing high-frequency current distributions in various frequency bands in the first and second metal frames 6 and 7. As shown in the figure, it resonates at a plurality of frequencies.

  4A and 4B are diagrams illustrating a specific analysis example of the portable wireless device 1 according to the present embodiment, in which FIG. 4A is a dimensional diagram and FIG. 4B is a VSWR characteristic diagram. As shown in the dimensional diagram of (a), the ground 3G of the circuit board 3 has a rectangular shape, the length in the vertical direction is 112 mm, and the length in the horizontal direction is 52 mm. The total length of the first metal frame 6 is 184 (61 + 61 + 62) mm, and the total length of the second metal frame 7 is 182 (60 + 60 + 62) mm. The distance between the ground 3G of the circuit board 3 and each of the first metal frame 6 and the second metal frame 7 is 5 mm. By setting it as such a dimension, as shown in the VSWR characteristic diagram of (b), it resonates in each frequency band of 800 MHz, 1200 MHz, 1700 MHz, 2020 MHz, and 2500 MHz.

  FIG. 5 is a diagram showing high-frequency current distributions (A / m) in various frequency bands when the dimensions shown in FIG. As can be seen from the current distribution shown in the figure, the first metal frame 6 operates in the 800 MHz band, the first and second metal frames 6 and 7 operate in the 1200 MHz band, and the first metal frame in the 1700 MHz band. 6 operates, the first and second metal frames 6 and 7 operate in the 2020 MHz band, and the first metal frame 6 operates in the 2500 MHz band. Resonant mode is 1/2 wavelength transmission line (1 wavelength loop) in the 800 MHz band, 3/4 wavelength monopole (3/2 wavelength dipole) in the 1200 MHz band, and 2/2 wavelength transmission line (2 wavelength loop) in the 1700 MHz band. In the 2020 MHz band, a 5/4 wavelength monopole (5/2 wavelength dipole) becomes a 3/2 wavelength transmission line (3 wavelength loop) in the 2500 MHz band. Although not shown in FIG. 5, there is a 1/4 wavelength monopole (1/2 wavelength dipole) resonance mode in the 400 MHz band.

  As described above, according to the portable wireless device 1 of the present embodiment, the first metal frame 6 is provided with a length of substantially half the circumference along the outer surface of the upper portion of the housing 2, and the outside of the lower portion of the housing 2 is provided. A second metal frame 7 is provided with a length of approximately half a circumference along the side surface, one end 6a of the first metal frame 6 is connected to a power supply terminal 9 connected to the matching circuit portion 5 on the circuit board 3, and the like. The end 6b is connected to the ground 3G of the circuit board 3 via the first ground terminal 10, and the one end 7a of the second metal frame 7 is connected to the ground 3G of the circuit board 3 by the second ground terminal 11 near the power supply terminal 9. The other end 7b is an open end and is disposed in the vicinity of the first ground terminal 10, and the electrical lengths of the first and second metal frames 6 and 7 are substantially the same. can get. In addition, since the first metal frame 6 and the second metal frame 7 are provided around the housing 2, the portable wireless device 1 itself does not increase in size. Moreover, since the 1st metal frame 6 and the 2nd metal frame 7 can be combined as components for raising the intensity | strength of the housing | casing 2, it is the multiple frequency described in patent document 2 (Unexamined-Japanese-Patent No. 2007-288649). Unlike the case where a dedicated antenna element component such as a band antenna is provided, the cost increase can be minimized.

  In the present embodiment, the middle part of at least one of the first metal frame 6 and the second metal frame 7 may have a meander shape, or the part may have a capacitive coupling structure. By doing in this way, the electrical length of the 1st metal frame 6 and the 2nd metal frame 7 can be adjusted, and adjustment of a resonant frequency becomes easy. FIG. 6 is a diagram showing an example of a meander shape (FIG. 6A) and an example of a capacitive coupling structure (FIG. 6B).

(Modification 1)
In the above-described embodiment, the first metal frame 6 and the second metal frame 7 are provided along the outer periphery of the housing 2, but may be provided along the inner periphery of the housing 2. FIG. 7 is a main part configuration diagram showing a portable wireless device 20 of Modification 1 of the portable wireless device 1 of FIG. 1, and the first metal frame 6 and the second metal frame 7 are arranged on the inner periphery of the housing 2. It is an example provided along. In the figure, the same reference numerals are given to the portions common to FIG. 2 described above. By providing the first metal frame 6 and the second metal frame 7 along the inner periphery of the housing 2, it is not necessary to give the first metal frame 6 and the second metal frame 7 strength, These can be formed by copper foil or FPC by plating or vapor deposition, and the cost can be reduced by providing these.

  In the above-described embodiment, the power supply terminal 9 is connected to the matching circuit unit 5 and the one end 6a of the first metal frame 6, and the first ground terminal 10 is connected to the ground 3G of the circuit board 3 and the first metal frame. The second grounding terminal 11 is connected to the ground 3G on the side opposite to the first grounding terminal 10 and the one end 7a of the second metal frame 7 at the connection position. There is no limitation. Examples of such modifications are given below.

(Modification 2)
FIG. 8 is a main part configuration diagram showing a modification 2 of the portable wireless device 1 of FIG. 1. In the figure, the portable wireless device 30 according to the modified example 2 has the power supply terminal 9 and the second ground terminal 11 arranged on the short side 3 a of the circuit board 3, and the first ground terminal 10 and the second metal frame 7. The open end 7b is disposed on the short side 3b opposite to the short side 3a of the circuit board 3. Even with this arrangement, broadband antenna characteristics can be obtained.

(Modification 3)
FIG. 9 is a main part configuration diagram showing a third modification of the portable wireless device 1 of FIG. In the figure, the portable wireless device 40 of the modified example 3 has the power supply terminal 9 and the second ground terminal 11 arranged at the corner 3c of the circuit board 3, and the first ground terminal 10 and the second metal frame 7 are arranged. The open end 7b is arranged at a corner 3d facing the corner 3c of the circuit board 3. Even with this arrangement, broadband antenna characteristics can be obtained.

(Modification 4)
FIG. 10 is a main part configuration diagram showing Modification 4 of the portable wireless device 1 of FIG. In the figure, the portable wireless device 50 according to the modified example 4 has the power supply terminal 9 and the second ground terminal 11 arranged on the long side 3e of the circuit board 3, and the first ground terminal 10 and the second metal frame 7 are arranged. The open end 7b is arranged at a position that is point-symmetric with respect to the center of the circuit board 3 on the long side 3f facing the long side 3e of the circuit board 3. Even with this arrangement, broadband antenna characteristics can be obtained.

(Modification 5)
FIG. 11 is a main part configuration diagram showing Modification 5 of the portable wireless device 1 of FIG. In the figure, the portable wireless device 60 of Modification 5 is such that the electrical length of the second metal frame 7 is slightly longer than the electrical length of the first metal frame 6. By giving a slight difference between the electrical length of the first metal frame 6 and the electrical length of the second metal frame 7, the frequency can be finely adjusted.

(Modification 6)
FIG. 12 is a main part configuration diagram showing Modification 6 of the portable wireless device 1 of FIG. In the figure, the portable wireless device 70 of the modification 6 is such that the electrical length of the first metal frame 6 is slightly longer than the electrical length of the second metal frame 7. By giving a slight difference between the electrical length of the first metal frame 6 and the electrical length of the second metal frame 7, the frequency can be finely adjusted.

  The above is a modification of the arrangement of the power supply terminal 9 and the second ground terminal 11, the first ground terminal 10 and the open end 7b. In the present embodiment, it is also possible to load a reactance element on at least one of the first metal frame 6 and the second metal frame 7.

  FIG. 13 is a main part configuration diagram showing a portable radio device loaded with the reactance element. In the figure, the same reference numerals are given to the portions common to FIG. 2 described above. The portable wireless device 80 shown in the figure includes a first ground terminal 10 and a ground 3G of the circuit board 3, a second ground terminal 11 and the ground 3G of the circuit board 3, and a first ground. Reactance elements 21 are loaded between the terminal 10 and the open end 7b of the second metal frame 7, respectively. By loading the actance element 21 on the first metal frame 6 and the second metal frame 7, the electrical length of the first metal frame 6 and the second metal frame 7 can be adjusted, and the resonance frequency can be adjusted. Becomes easier. In addition, it is not necessary to load the reactance element 21 in all the above locations, and it is sufficient to load at least one location.

  The present invention has an effect that a broadband antenna characteristic can be obtained without increasing the size and cost of the device itself, and can be applied to a straight-type portable wireless device such as a smartphone.

1, 20, 30, 40, 50, 60, 70, 80 Portable wireless device 2 Housing 3 Circuit board 3G Circuit board ground 4 Wireless circuit unit 5 Matching circuit unit 6 First metal frame 6a First metal frame One end 6b The other end of the first metal frame 7 The second metal frame 7a One end of the second metal frame 7b The other end (open end) of the second metal frame
8 Liquid crystal display device 9 Power supply terminal 10 First ground terminal 11 Second ground terminal 21 Reactance element

Claims (11)

A housing,
A circuit board provided in the housing and having a ground;
A wireless circuit unit provided inside the housing and configured on the circuit board;
A matching circuit unit provided in the housing, configured on the circuit board, and connected to the wireless circuit unit;
A first metal plate provided in a substantially half-circumferential length along the housing, and disposed at a predetermined interval from the ground of the circuit board;
A second metal plate provided in a substantially half-circumferential length along the housing, and arranged at a predetermined interval from the ground of the circuit board;
The first metal plate has one end connected to a power supply terminal connected to the matching circuit unit on the circuit board, and the other end connected to the ground of the circuit board via a first ground terminal,
The second metal plate has one end connected to the ground of the circuit board by a second ground terminal in the vicinity of the power supply terminal, the other end is an open end, and is disposed in the vicinity of the first ground terminal,
A portable radio having a structure in which the electrical length of the first metal plate and the electrical length of the second metal plate are substantially the same.   The portable wireless device according to claim 1, wherein each of the first metal plate and the second metal plate is provided along an outer periphery of the casing.   The portable wireless device according to claim 1, wherein each of the first metal plate and the second metal plate is provided along an inner periphery of the casing.   The portable wireless device according to any one of claims 1 to 3, wherein the power supply terminal and the second ground terminal are arranged close to each other at a wavelength of 0.1 or less of a maximum operating frequency of the wireless circuit unit.   The portable wireless device according to any one of claims 1 to 4, wherein the first ground terminal and the open end are disposed close to each other at a wavelength of 0.1 wavelength or less of a maximum operating frequency of the wireless circuit unit. The power supply terminal and the second ground terminal are disposed on the short side of the circuit board,
The portable wireless device according to any one of claims 1 to 5, wherein the first ground terminal and the open end are arranged on a short side facing the short side of the circuit board. The power supply terminal and the second ground terminal are disposed at corners of the circuit board,
The portable wireless device according to any one of claims 1 to 5, wherein the first ground terminal and the open end are arranged at a corner facing the corner of the circuit board. The power supply terminal and the second ground terminal are arranged on the long side of the circuit board,
6. The first ground terminal and the open end are arranged at positions that are point-symmetric with respect to a position on the long side with respect to a center of the circuit board. Portable radio.   The first metal plate and the second metal plate have a meander shape in the middle of at least one of the first metal plate and the second metal plate. The portable wireless device according to the item.   The first metal plate and the second metal plate each have a capacitive coupling structure in the middle of at least one of the first metal plate and the second metal plate. The portable wireless device according to one item.   A reactance element is loaded between at least one of the first ground terminal and the ground, between the second ground terminal and the ground, and between the first ground terminal and the open end. The portable wireless device according to any one of claims 1 to 10.

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