JP2003304171A - Communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide communication equipment capable of performing transmission and reception in a wide band even though the full length of a mounted circuit board in a longitudinal direction is shorter than a wavelength of 1/4λ of a radio wave to be transmitted/received regarding the communication equipment provided with an antenna including a portable telephone. <P>SOLUTION: This circuit board 12 mounted with the antenna 3 consists of a first region 13 coupled parallelly to the longitudinal direction of the board in a high frequency manner and a second region 14 coupled in a direction different from the first region 13. The total effective length of the first and second regions 13 and 14 including the antenna 3 mounted on the second region 14 in a high frequency manner is made to match with a wavelength of 1/4λ of a radio wave to be transmitted/received, therefore making it possible to perform transmission and reception in a wide band. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device including an antenna such as a mobile phone.

[0002]

2. Description of the Related Art In recent years, communication devices typified by mobile phones have been remarkably spread, and in particular, small, thin and lightweight devices have been favored.

The communication device usually has an antenna for transmitting and receiving radio waves, and it is preferable that the communication device has a small outer shape including this antenna. The built-in antenna is also accommodated in the device housing. Types are popular.

A mobile phone as a communication device equipped with the conventional built-in type antenna will be described below with reference to the drawings.

FIG. 7 is an exploded perspective view of a mobile phone as a communication device having a conventional built-in type antenna, and FIG.
FIG. 4 is a bottom view of the circuit board showing a mounted state of the antenna which is the main part.

In FIG. 1, reference numeral 1 is a housing of a mobile phone which is constructed by combining an upper case 1A and a lower case 1B, and a circuit board 2 is positioned and housed in the housing 1.

As the circuit board 2, a double-sided wiring board or a double-sided multilayer wiring board on which various components can be mounted on the upper and lower surfaces is used. Normally, the ground line (not shown) of the circuit board 2 is the circuit board 2. It is arranged over the entire surface.

A built-in type antenna 3 is mounted above the lower surface of the circuit board 2.

The illustration and description of other electronic components and integrated circuits mounted on the circuit board 2 are omitted.

Next, the antenna 3 mounted on the circuit board 2 as described above will be described with reference to FIG.

As shown in the figure, this antenna 3 is generally called an inverted F antenna, and a conductive metal plate 4 formed into a substantially rectangular shape is formed into a substantially rectangular parallelepiped. It is fixed to the upper surface of the resin portion 5 made of the insulating resin.

Then, two arm portions integrally extending from the end portion of the conductive metal plate 4 are bent downward to be formed as a power supply terminal 6 and a ground terminal 7, respectively.

In the built-in type antenna 3 thus constructed, the power supply terminal 6 is connected to a conductive line (not shown) of the circuit board 2, and the ground terminal 7 is connected to the ground line of the circuit board 2 ( (Not shown), it is electrically connected to the lower surface of the circuit board 2.

The circuit board 2 on which various electronic components including the antenna 3 are mounted is housed and held in the lower case 1B, and the upper part thereof is covered by the upper case 1A. It is stored.

Although the upper housing 1A is provided with a display section and a switch group serving as an operating section, the description thereof will be omitted.

[0016]

In recent years, miniaturization of mobile devices has progressed, and the total length of the circuit board 2 mounted on the mobile device is required to be shorter than ¼λ of the wavelength of radio waves to be transmitted and received. Has become.

However, during transmission and reception of radio waves, the high frequency current resonates not only with the antenna 3 but also with the ground line of the circuit board 2, and in terms of high frequency, the ground lines are coupled and the wavelength of the radio wave is the length in the longitudinal direction. Therefore, when the total length of the circuit board 2 becomes shorter than ¼λ of the wavelength of the transmitted / received radio wave, the transmission / reception band of the antenna 3 becomes narrow.

The present invention is to solve such a conventional problem, and provides a communication device capable of transmitting and receiving in a wide band even if the length of the circuit board is shorter than ¼λ of the wavelength of the radio wave to be transmitted and received. The purpose is to do.

[0019]

In order to achieve the above object, the present invention has the following constitution.

The invention according to claim 1 of the present invention is an antenna for transmitting and receiving radio waves, and when the antenna is mounted, the wavelength of radio waves transmitted and received via the antenna is 1 /
A communication device having a circuit board having a total length in a longitudinal direction shorter than 4λ, wherein the circuit board has a first region in which effective ground directions are different from each other in a state where ground lines are coupled in high frequency. And a second region, and the ground line of the second region includes the above antenna mounted in the second region in a high frequency in the same pattern in a top view including the inside of the plate thickness. The sum of the high-frequency effective lengths of the first and second regions is a communication device that is matched with ¼λ of the wavelength of the radio wave, and the ground line in the second region of the circuit board is In terms of high frequency, they are connected in the same pattern in a different direction from the first region, and the total of the first region including the mounted antenna is matched with the quarter wave of the transmitted and received radio waves. Because of the length of the circuit board That even shorter than 1 / 4.lamda the wavelength of the radio wave, such an action can be capable of sending and receiving communication devices in a wide band.

According to a second aspect of the present invention, in the first aspect of the invention, the other end of the second region is connected to the one end side of the second region which is connected to the first region of the circuit board in a high frequency manner. ,
The conductive metal plate is connected to the ground terminal of the antenna configured by being fixed to the resin portion. Since the ground terminal of the antenna is connected to the first area through the second area, the ground path is the most It has an effect that it can be efficiently taken for a long time.

According to a third aspect of the present invention, in the second aspect of the invention, the ground line in the second area of the circuit board is eliminated and only the first area is provided, and the wavelength of the radio wave to be transmitted and received is changed. A shielded coaxial cable having a shield part having a high-frequency ground length for compensating for the difference between 1 / 4λ and the first region is arranged in the second region,
One end of the shield part is connected to the ground line of the first region in high frequency, and the other end of the shield part is connected to the ground terminal of the antenna so as not to be connected to the first region in high frequency. Yes, the shield part of this coaxial cable can match the 1/4 λ of the transmitted and received radio waves to widen the transmission and reception band,
Since the input impedance to the antenna also becomes a constant value,
This has the effect of facilitating impedance matching between the antenna side and the transmitting / receiving circuit side.

According to a fourth aspect of the present invention, in the invention according to the second aspect, the ground line in the second region of the circuit board is constituted by the ground portion of the microstrip line, and the conductive portion and the ground of the microstrip line. This part is connected to the feeding terminal and the ground terminal of the antenna, and this microstrip line structure can have a constant input impedance like the coaxial cable, so the impedance matching between the antenna side and the transmitting / receiving circuit side is It has the effect of making it easier.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

The same components as those described in the section of the prior art are designated by the same reference numerals and detailed description thereof will be omitted.

(First Embodiment) Using the first embodiment,
The invention of claims 1 and 2 will be described.

FIG. 1 is an exploded perspective view of a mobile phone as a communication device according to a first embodiment of the present invention, and FIG. 2 is a schematic diagram showing a high frequency coupling state of ground lines of a circuit board, which is a main part of the same. It is a figure.

In FIG. 1, reference numeral 11 denotes a casing formed by combining an upper casing 11A and a lower casing 11B, in which a circuit board 12 is positioned and housed.

The casing 11 is formed into a substantially rectangular parallelepiped having a total length shorter than the dimension of 1 / 4λ of the wavelength of radio waves transmitted and received in the longitudinal direction, and the circuit board 12 arranged in the casing 11 Also, it is composed of a double-sided multilayer wiring board having a substantially rectangular shape when viewed from above and having a total length in the longitudinal direction shorter than the dimension of ¼λ of the wavelength of radio waves transmitted and received.

The upper housing 11A is provided with a display unit, various operation keys and the like, and parts for operating them and various electronic parts are provided at predetermined positions on the upper and lower surfaces of the circuit board 12. Although attached, illustration and description are omitted.

An inverted F antenna (hereinafter referred to as antenna 3) having a conductive metal plate 4 fixed to a resin portion 5 is mounted above the lower surface of the circuit board 12.

Since this antenna 3 is the same as the conventional one, the description of its configuration is omitted.

The antenna 3 is mounted on the circuit board 12 so as to cover the entire area in the lateral direction.

As shown in FIG. 2, the ground line of the circuit board 12, except for the space where the antenna 3 is mounted, is arranged in parallel with the longitudinal direction of the circuit board 12 in a high frequency manner. They are arranged in an installed state, and this range becomes the high-frequency first region 13.

On the other hand, the ground line in the space in which the antenna 3 is mounted should not be parallel to the longitudinal direction of the circuit board 12 but should be coupled at a high frequency in a direction different from the longitudinal direction. It is arranged, and this range becomes the second region 14 having a high frequency.

In the second area 14, in terms of high frequency, the upper and lower surfaces of the circuit board 12 and the ground lines of the intermediate layers thereof are all inclined to the longitudinal direction of the board in a top view of the circuit board 12. The end portions 13A of the first region 13 are configured to be combined in the same linear pattern of angles.
Are connected to the one end side 15 of the second region 14 in terms of high frequency.

Then, the other end side 16 of the second region 14
Are electrically connected to the ground terminal 7 of the antenna 3.

The power supply terminal 6 of the antenna 3 is electrically connected to a conductive line (not shown) arranged in the second region 14, and the second region 14 including the conductive line is above-mentioned. As described above, they are coupled in high frequency.

The effective length in high frequency of the second region 14 is 1/4 of the radio wave transmitted / received via the antenna 3.
With respect to λ, the total sum of the high-frequency effective lengths of the first and second regions 13 and 14 including the antenna 3 is adjusted and set to match.

The high frequency effective length direction in the second region 14 may be any direction,
It may be curved.

The communication device according to this embodiment has the circuit board 12 having the antenna 3 mounted thereon as described above.

In this communication device, although the length of the circuit board 12 in the longitudinal direction is shorter than 1 / 4λ of the wavelength of the radio wave to be transmitted / received, when transmitting / receiving the radio wave via the antenna 3, a high frequency wave is transmitted. First region 1 electrically connected
3 and the second region 14 are separated, and the antenna 3 is included and matched with the above 1 / 4λ, so that radio waves can be transmitted and received through the antenna 3 in a wide band.

Further, with the above configuration, the ground terminal 7 of the antenna 3 connected to the other end side 16 of the second region 14
In terms of high frequency, since it is connected to the first region 13 via the second region 14 of the circuit board 12, the ground path can be lengthened most efficiently, so that the wavelength of the transmitted and received radio waves is 1 / 4λ. It is easy to match.

The setting position of the second region 14 may be other than the mounting space of the antenna 3, and the sum of the high frequency effective lengths of the first region and the second region including the antenna is the radio wave to be transmitted and received. It suffices that it is matched with ¼λ of the wavelength.

(Second Embodiment) Using the second embodiment,
The invention of claim 3 will be described.

FIG. 3 is a schematic diagram showing a high-frequency coupling state of the ground lines of the circuit board which is a main part of a mobile phone as a communication device according to the second embodiment of the present invention, and FIG.
FIG. 3 is a conceptual diagram showing a mounted state of an antenna, which is a main part of the same.

According to the present embodiment, the first embodiment
The configuration of the circuit board 21 and the mounting state of the antenna 3 are different from those of the first embodiment, and detailed description of the portions having the same configurations as those of the first embodiment will be omitted.

As shown in FIG. 3, the circuit board 21 accommodated in the housing 11 of the communication device has the antenna 3 mounted over the entire upper position of the lower surface thereof, and has the entire length in the longitudinal direction. It is shorter than ¼λ of the wavelength of the transmitted and received radio waves.

The circuit board 21 is used for the antenna 3
In the space in which is mounted, the ground line is not provided including the thickness thereof, and this region is the second region 22.

The remaining portion on which the antenna 3 is not mounted becomes the first region 23 of the circuit board 21 as in the first embodiment, and is coupled in parallel with the longitudinal direction of the circuit board 21 in terms of high frequency. Ground line (not shown)
Are arranged.

A shielded coaxial cable 24 is arranged in the second region 22 on the lower surface of the circuit board 21, and one end of the shield portion 25 of the shielded coaxial cable 24 is provided on the lower surface of the circuit board 21. First area 2
3 is connected to the end portion 26 (see FIG. 3), and the other end of the shield portion 25 is connected to the antenna 3 as shown in FIG.
Is connected to the ground terminal 7.

In FIG. 4, the antenna 3 is illustrated by hatching only the conductive metal plate 4.

Further, one end of the conductor portion 26 of the shielded coaxial cable 24 is connected to the conductive line (not shown) of the first region 23, and the other end is connected to the power feeding terminal 6 of the antenna 3. ing.

The shielded coaxial cable 24
Indicates that the length of the shield portion 25 is equal to 1 / 4λ of the wavelength of the radio wave transmitted / received including the mounted antenna 3 and the first antenna.
It is set to have a high-frequency ground length that compensates for the difference from the region 23.

That is, according to the present embodiment, the sum of the high-frequency effective lengths of the first region 23, the shield portion 25 of the shielded coaxial cable 24, and the antenna 3 is the wavelength of the radio wave to be transmitted and received. Therefore, the band for transmission and reception is widened as in the first embodiment.

The above-mentioned shielded coaxial cable 24
Can be freely installed in the second region 22 in a linear shape or a curved shape directed in a direction different from the longitudinal direction of the circuit board 21 to obtain a high frequency required effective length.
It is essential that the other end of the shield part 25 connected to the ground terminal 7 is disposed so as not to be coupled to the first region 23 in terms of high frequency.

Since the antenna 3 is electrically connected to the shielded coaxial cable 24 in the present embodiment, the input impedance to the antenna 3 can be made a constant value, and the antenna side and the transmitting / receiving circuit side can be made. The effect of facilitating impedance matching with

The circuit board 1 described in the first embodiment
2, the shielded coaxial cable 24 is arranged in accordance with the high frequency coupling pattern of the second region 14, and the shield part 25 and the conductor part 26 are electrically connected to the ground terminal 7 and the power supply terminal 6 of the antenna 3. You may.

(Third Embodiment) Using the third embodiment,
The invention of claim 4 will be described.

FIG. 5 is a schematic diagram showing a high-frequency coupling state of the ground lines of the circuit board which is the main part of the mobile phone as the communication device according to the third embodiment of the present invention, and FIG.
FIG. 3 is a conceptual diagram showing a mounted state of an antenna, which is a main part of the same.

According to the present embodiment, the first embodiment
The circuit board 31 that is the main part of the
The total length in the longitudinal direction is 1 of the wavelength of the transmitted / received radio wave.
Shorter than / 4λ, but in terms of high frequency, a first region 32 that is coupled in parallel with the longitudinal direction of the substrate and a second region 33 that is linearly coupled in a predetermined inclined state with respect to the longitudinal direction. Have.

The antenna 3 is mounted in the second region 33 on the lower surface of the circuit board 31, and the high-frequency effective length of the first region 32 and the second region 33 including the antenna 3 is high. Is 1/4 λ of the wavelength of the transmitted and received radio waves
It is the same as the case of the first embodiment that is matched with.

The second region 33 of the circuit board 31 according to the present embodiment has a simple microstrip line structure.

That is, as shown in FIG. 5, the circuit board 31
In the second area 33 on the upper surface, the upper surface ground line 35, one end of which is connected to the end 34 of the first area 32, extends in an oblique straight line at a predetermined inclination angle with respect to the longitudinal direction of the substrate. It is arranged.

Then, the upper surface ground line 35 is
The other end of the upper surface of the circuit board 31 is provided up to a portion where the ground of the antenna 3 and the power supply terminals 7 and 6 are located. The ground terminal 7 is connected to the upper surface ground line 35 via the side portion of the board. ing.

Then, the second region 3 on the lower surface side of the circuit board 31.
In 3, the conductive line 36 is arranged within the range where the upper surface ground line 35 is provided on the facing surface,
Its end is connected to the power supply terminal 6 of the antenna 3.

A ground line may be provided at both ends of the conductive line 36 with a predetermined space.

As described above, the second region 33 according to the present embodiment has a simple structure of a microstrip line in which the conductive line 36 and the upper surface ground line 35 are provided via the substrate. It is a thing.

Even the circuit board 31 of this configuration can be matched with 1 / 4λ of the wavelength of the radio wave to be transmitted / received in the high frequency range. Therefore, the same as in the case of the first and second embodiments. , Can be a communication device capable of transmitting and receiving in a wide band.

Further, since the pattern of the second region 33 is constituted by a simple structure of the microstrip line, the input impedance to the antenna 3 can be easily made constant and impedance matching between the antenna side and the transmitting / receiving circuit side can be achieved. It also has the effect of making it easier.

The same effect can be expected by providing the upper surface ground line 35 in the intermediate layer of the substrate.

[0072]

As described above, according to the present invention, even if the length of the circuit board is shorter than ¼λ of the wavelength of the radio wave to be transmitted and received, the effective length matching at high frequency including the antenna can be matched. Since it can be obtained, the advantageous effect that it can be a communication device capable of transmitting and receiving in a wide band is obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a mobile phone as a communication device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a high-frequency coupling state of a ground line of a circuit board, which is a main part of the same.

FIG. 3 is a schematic diagram showing a high-frequency coupling state of a ground line of a circuit board which is a main part of a mobile phone as a communication device according to a second embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a mounted state of an antenna, which is a main part of the same.

FIG. 5 is a schematic diagram showing a high frequency coupling state of ground lines of a circuit board, which is a main part of a mobile phone as a communication device according to a third embodiment of the present invention.

FIG. 6 is a conceptual diagram showing a mounted state of an antenna, which is a main part of the same.

FIG. 7 is an exploded perspective view of a mobile phone as a communication device including a conventional built-in type antenna.

FIG. 8 is a bottom view of the circuit board showing a mounted state of the antenna, which is a main part of the same.

FIG. 9 is an external perspective view of the antenna, which is the main part of the same.

[Explanation of symbols]

3 antennas 4 Conductive metal plate 5 Resin part 6 power supply terminals 7 ground terminal 11 housing 11A Upper case 11B lower housing 12, 21, 31 Circuit board 13, 23, 32 1st area 13A, 34 end 14, 22, 33 Second area 15 One end side 16 other end 24 Shielded coaxial cable 25 Shield 26 Conductor 35 Top ground line 36 Conductive line

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor ▲ Takagi Naoshi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5J047 AA04 AB13 FD01                 5K011 AA06 AA15 AA16 DA02 JA01                 5K023 AA07 BB06 LL01 LL05

Claims (4)

[Claims] 1. A communication device having an antenna for transmitting and receiving radio waves, and a circuit board to which the antenna is attached and which has a total length in a longitudinal direction shorter than ¼λ of the wavelength of radio waves transmitted and received through the antenna. The circuit board has a first region and a second region in which the directions of the effective lengths are different in the state where the ground lines are coupled in high frequency, and the ground lines in the second region are , The total of the high-frequency effective lengths of the first and second regions including the mounted antenna, which are coupled in high frequency in the second region in the same pattern in a top view including the plate thickness, , A communication device matching 1 / 4λ of the wavelength of the radio wave. 2. The other end of the second region, which is connected to the first region of the circuit board in a high frequency manner with respect to one end side of the second region,
The communication device according to claim 1, wherein the conductive metal plate is connected to a ground terminal of an antenna configured by being fixed to a resin portion. 3. A high frequency wave which eliminates the ground line in the second area of the circuit board and has only the first area, and compensates for the difference between the quarter wavelength of the radio wave to be transmitted and received and the first area. A shielded coaxial cable having a shield portion with a typical ground length is arranged in the second region,
The one end of the shield part is connected to the ground line of the first region at high frequency, and the other end of the shield part is connected to the ground terminal of the antenna so as not to be connected at high frequency to the first region. The communication device according to 2. 4. The ground line in the second region of the circuit board is constituted by the ground portion of the microstrip line, and the conductive portion and the ground portion of the microstrip line are connected to the feeding terminal and the ground terminal of the antenna. Item 2. The communication device according to item 2.