JP2000286624A - Communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide communication equipment which can easily select a matching circuit which matches the impendance of an antenna even when the impedance of a high-frequency circuit varies. SOLUTION: An antenna 10 is constituted by forming an antenna element 25 on a flexible substrate 11 and connecting the base section 25a of the element 25 to all matching circuits 30, 31, and 32. The impedance of a high-frequency circuit rightly matches the antenna 10 by punching the matching circuits 30, 31, 32 except at least one circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device, and more particularly to a communication device having a matching circuit for matching impedance between a transmitting / receiving circuit and an antenna.

[0002]

2. Description of the Related Art Conventionally, a printed antenna formed of a strip line is mainly used as an antenna used for a cordless telephone in the UHF band. Printed antennas are produced by etching a copper material formed on a resin substrate, so that they are small, have uniform characteristics, and are suitable for mass production.

However, in the high-frequency circuit connected to the printed antenna, the use of circuit elements is
The output impedance of the high-frequency circuit varies, so even if it is directly connected to an antenna with a constant feed impedance, it causes impedance mismatch and keeps the transmission and reception characteristics of the communication equipment within a certain range during production. It was difficult. In addition, it is necessary to prepare a printed antenna suitable for each cordless telephone model using a high-frequency circuit having a different feeding impedance, and there is a problem that the printed antenna cannot be shared.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. Even if the impedance of a high-frequency circuit varies, a matching circuit matching the impedance of an antenna can be easily selected to obtain desired communication characteristics. It is an object of the present invention to provide a communication device that can perform the communication.

[0005]

According to a first aspect of the present invention, there is provided a communication apparatus comprising: an antenna;
In a communication device including a transmitting and receiving circuit that transmits or receives a predetermined signal via the antenna, a plurality of matching circuits that match the impedance between the transmitting and receiving circuit and the antenna, and from the plurality of matching circuits, Connecting means for selecting at least one matching circuit and connecting between the transmitting / receiving circuit and the antenna;

In the communication device having the above configuration, the connection means includes:
Matching the impedance between the transmitting and receiving circuit and the antenna by selecting at least one matching circuit from a plurality of matching circuits that match the impedance between the transmitting and receiving circuit and the antenna and connecting the selected circuit between the transmitting and receiving circuit and the antenna can do.

Further, in the communication device according to the second aspect of the present invention, in addition to the configuration according to the first aspect of the present invention, the connection means connects all of the plurality of matching circuits to the transmission / reception circuit and the antenna. A plurality of connecting portions connected between the connecting portions are provided, and at least one of the plurality of connecting portions is cut to be formed.

[0008] In the communication device having the above configuration, in addition to the function of the invention described in claim 1, the communication device further includes a plurality of connecting portions connecting all of the plurality of matching circuits between the transmitting / receiving circuit and the antenna. By disconnecting at least one of the connecting parts, the connecting means can be configured to match the impedance between the transmitting / receiving circuit and the antenna.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the plurality of matching circuits are configured by circuits formed on a flexible printed circuit board. The configuration is characterized by that.

In the communication device having the above-described configuration, in addition to the operation of the first or second aspect of the present invention, since the plurality of matching circuits are constituted by circuits formed on the flexible printed circuit board, the connecting portion is not provided. It becomes easy to cut and punch.

Further, in the communication device according to the fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, the plurality of matching circuits may be strip lines or microstrip lines. The configuration is characterized by being formed.

[0012] In the communication device having the above configuration, in addition to the operation of the invention according to any one of the first to third aspects, since the plurality of matching circuits are formed by strip lines or microstrip lines, A matching circuit can be formed easily and inexpensively.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a case where a cordless telephone is used as a kind of a communication device will be specifically described as an example.

First, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view showing the appearance of a cordless telephone 1 according to the present invention. Cordless phone 1 is a handset 2
And a charging device 3 on which the child device 2 is placed.

FIG. 2 is a front view showing the cordless telephone 1 with the handset 2 removed. The handset 2 is provided with a receiver 4 at the upper part, and a lower part of the handset 2 is provided with a transmitter 5. A key operation input unit 6 having a plurality of keys for inputting a telephone number and inputting a function instruction is provided between the reception unit 4 and the transmission unit 5 of the handset 2.

Next, referring to FIG.
The antenna 10 will be described. FIG. 3 is a perspective view showing an antenna mechanism built in the cordless telephone 1.

Inside the case on the receiver 4 side of the handset 2,
The antenna 10 shown in FIG. The antenna 10 is composed of a flexible board 11 and
The base of the antenna 10 is connected to a feed point 14 of the mounting printed circuit board 13. The mounting printed board 13 is provided with a high-frequency shield 15 for electromagnetically shielding a high-frequency circuit (not shown).
It is connected to a protected high-frequency circuit (not shown) that is electromagnetically shielded by the high-frequency shield 15.

Next, referring to FIG.
The electrical circuit configuration will be described. FIG. 4 is a block diagram showing an electric circuit configuration of the slave unit 2 of the cordless telephone 1, which is formed on a printed circuit board 13. Specifically, the low-frequency input unit 20 is connected to a modulation unit 21 that modulates a low-frequency signal, and the modulation unit 21 further outputs a high-frequency output modulated by the frequency synthesizer 22 that transmits a carrier wave and the modulation unit 21. It is also connected to a power amplifier 23 for power amplification. The power amplifier 23 is connected to a duplexer 24 for sharing the antenna 10 between the transmitting circuit and the receiving circuit, and the duplexer 24 is connected to the feeding point 14. The duplexer 24 is connected to a low-noise amplifier 28 for amplifying the received high-frequency wave. The low-noise amplifier 28 mixes the amplified high-frequency wave with the output from the frequency synthesizer 22 and converts it to an intermediate frequency. 27, the down converter 27 is connected to the demodulator 26,
The demodulator 26 is connected to the low frequency output unit 29. For convenience of description, the power amplifier 23, the low-noise amplifier 28, the duplexer 24, and the feed point 14 are hereinafter referred to as a "high-frequency circuit".

Next, the antenna 10 of the present invention will be described with reference to the drawings. First, with reference to FIG. 5, the antenna 10 used in the slave unit 2 of the cordless telephone 1 according to the first embodiment of the present invention will be described in detail. FIG.
2 is a plan view of the antenna 10. FIG.

In the antenna 10, an antenna element 25 formed by a copper foil print pattern is formed on a flexible substrate 11, and a base 25a of the antenna element 25 is connected to all of the matching circuits 30, 31, and 32. I have. Each of the matching circuits 30, 31, and 32 is formed of a strip line or a microstrip line. When the antenna element 25 of the antenna 10 is formed by etching, the copper foil is simultaneously etched. Is done.

The matching characteristics of the matching circuits 30, 31, and 32 are different from each other, and
Any one of them is selected at the time of assembling according to the impedance of the feeding point 14 of.

The matching circuits 30, 31, and 32 are integrated together on the power supply side and connected to a matching circuit connecting portion 34. The matching circuit connecting portion 34
3 is connected to the matching circuit connection terminal 50 which is the feeding point 14. The matching circuit connecting portion 34 and the matching circuit connecting terminal 5
Various connection methods, such as soldering, screwing, and connector connection, are possible for connection with 0.

Next, a method of selecting one of the matching circuits 30, 31, 32 will be described. This method has two methods.

The first method is that, before connecting the matching circuit connecting portion 34 and the matching circuit connecting terminal 50, at least one of the matching circuits 30, 31, 32 that is not used beforehand is used. Is punched out with a punching device such as a punch. For example, by punching out the punched portion 52 and the punched portion 54 shown in FIG.
Only 0 will function as a matching circuit.

After the punching, the matching circuit connecting portion 34 and the matching circuit connecting terminal 50 are connected. It should be noted that which of the matching circuits 30, 31, 32 is punched can be determined in advance according to the impedance of the high-frequency circuit of the mounting printed circuit board 13.

Next, a second method is to use a matching circuit connecting section 34.
After connecting to the matching circuit connection terminal 50, the matching circuit 3
At least one of 0, 31, and 32 is punched.

Therefore, the matching circuits 30, 31, 32
Can correspond to a high-frequency circuit having three kinds of impedances. The matching characteristics of each of the matching circuits 30, 31, and 32 can be determined in advance at the design stage based on the shape of the strip line or the microstrip line. Therefore, the antenna 10 can correspond to a high-frequency circuit having three kinds of impedances.

It is to be noted that one of the matching circuits 30, 31, 32 is punched out, and the remaining two are used, and each of the matching circuits 30, 31, 32 is used with its combined capacity. Time can correspond to a high-frequency circuit having a different impedance. Also, if the three matching circuits 30, 31, and 32 are not punched, but are left as they are, matching can be performed with the combined capacitance of the matching circuits 30, 31, and 32.

Therefore, the matching circuits 30, 31, and 32 of the antenna 10 shown in FIG. 5 can realize seven types of matching circuits with a simple configuration. Further, by performing the punching process, an appropriate matching circuit can be easily selected, so that the efficiency of the assembling operation can be improved.

The number of matching circuits is not necessarily limited to three, but may be any number such as two, four, five, etc.

Next, a second embodiment will be described with reference to FIG. FIG. 6 is a plan view of an antenna 60 according to the second embodiment.

In the antenna 60, an antenna element 62 formed by a copper foil printed pattern is formed on a flexible substrate 61, and a base 62a of the antenna element 62 is connected to all of the matching circuits 70, 71, 72. I have. The matching circuits 70, 71, and 72 are formed of either a strip line or a microstrip line. When the antenna element 62 of the antenna 60 is formed by etching, the copper foil is simultaneously etched. Is done.

The matching characteristics of the matching circuits 70, 71, 72 differ from the matching circuits 30, 31, 32, respectively, in accordance with the impedance of the feeding point 14 of the printed circuit board 13 of the slave unit 2. One of them is selected at the time of assembly.

The matching circuits 70, 71, 72 are provided with matching circuit connecting portions 70a, 71a, 72a, respectively. The matching circuit connecting parts 70a, 71a, 72a
It is connected to matching circuit connection terminals 80, 81, 82 which are power supply points 14 of the mounting printed board 13. The connection between the matching circuit connecting portions 70a, 71a, 72a and the matching circuit connecting terminals 80, 81, 82 can be made by various connection methods such as soldering, screwing, and connector connection. here,
The matching circuit connection terminals 80, 81, and 82 are connected together at a high-frequency circuit portion (not shown) of the mounting printed circuit board 83.

Next, a method for selecting one of the matching circuits 70, 71, 72 will be described. This method includes two methods as described above.

The first method is that the matching circuit connecting section 70
a, 71a, 72a and matching circuit connection terminals 80, 81, 8
2 before connecting the matching circuits 70, 71,
The wiring portion of the matching circuit portion which is not used except at least one of 72 is punched out by a punching device such as a punch. For example, by punching out the punched portion 92 and the punched portion 94 shown in FIG. 6, only the matching circuit 70 functions as a matching circuit. After the punching process, the matching circuit connecting portions 70a, 71a, 72a and the matching circuit connecting terminals 80, 81, 82 are connected. It should be noted that which of the matching circuits 70, 71, 72 is punched is determined in advance according to the impedance of the high-frequency circuit of the mounting printed circuit board 13.

Next, a second method is to use a matching circuit connecting section 70.
a, 71a, 72a and matching circuit connection terminals 80, 81, 8
After the connection with No. 2, at least one of the matching circuits 70, 71, 72 is punched. Therefore,
The matching circuits 70, 71, and 72 can correspond to high-frequency circuits having three types of impedances. The matching characteristics of each of the matching circuits 70, 71, and 72 can be determined in advance in the design stage based on the shape of the strip line or the microstrip line. Therefore, the antenna 60 can also correspond to a high-frequency circuit having three types of impedance.

It should be noted that one of the matching circuits 70, 71, 72 was punched out, and one of the matching circuits 70, 71, 72 was used with the combined capacity if the remaining two were left. Time can correspond to a high-frequency circuit having a different impedance. Also, if the three matching circuits 70, 71, 72 are not punched, and are left as they are, matching can be performed with the combined capacitance of the matching circuits 70, 71, 72.

Therefore, the matching circuits 70, 71, 72 of the antenna 60 shown in FIG. 6 can realize seven types of matching circuits.

The number of matching circuits is not limited to three, but may be any number such as two, four, five, and the like.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a plan view showing a state before connection between the antenna 90 and the matching circuit connection terminal 100, and FIG.
It is a schematic diagram which shows the state connected with 0.

In this embodiment, the antenna 90 has an antenna element 92 formed by a printed pattern of copper foil on a flexible substrate 91, and is orthogonal to the antenna element 92 from the base 92 a of the antenna element 92. The matching circuit connecting portion 93 is extended so as to have a substantially inverted L-shape in the direction in which the matching circuit is connected.

On the other hand, a matching circuit connection terminal 100 connected to a high-frequency circuit (not shown) of the mounting printed board 13 has a connection line 102 formed by a copper foil print pattern on a linear flexible board 101 having a predetermined width. At the tip of the matching circuit connection terminal 100,
The three connection portions 100a, 100b, 100c extend in a direction orthogonal to the longitudinal direction of the matching circuit connection terminal 100. These connection parts 100a, 100b, 100c
Are made of the same material integrally formed with the matching circuit connection terminal 100, and are formed by a printed pattern of a flexible board and a copper foil formed in the shape of the flexible board.

As shown in FIG. 8, the matching circuit connection terminal 100 is spirally wound (coiled) to form a connection portion 100.
a, 100b, or 100c is connected to the antenna 90.
Is connected to the tip 93a of the matching circuit connecting portion 93 of FIG. The spirally wound matching circuit connection terminal 100 functions as a spiral inductor, obtains a predetermined inductance value, and functions as a matching circuit 102. Therefore, in the present embodiment, if the connection portion 100a is connected to the distal end portion 93a of the matching circuit connection portion 93, the number of turns is maximized, and the inductance is also maximized. Also, connection part 1
If 00c is connected to the tip 93a of the matching circuit connecting portion 93, the number of turns of the coil is minimized, and the inductance is also minimized. Also, the connecting portion 100b is connected to the matching circuit connecting portion 9
3, the number of turns of the coil is intermediate between the two, and the inductance is also an intermediate value between the two.

Therefore, according to the present embodiment, three types of matching circuits 102 can be formed by simply connecting any one of the connection portions 100a, 100b, and 100c to the tip 93a of the matching circuit connection portion 93 of the antenna 90. Can be realized.

The number of connection portions is not necessarily limited to three, but may be any number such as two, four, five, or the like. Further, the number of connection portions may be one.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a plan view showing a state before the antenna 110 and the matching circuit connection terminal 111 are opposed to each other (before the bending of the matching substrate 112a).
FIG. 10 is a plan view showing a state after the bending of the matching substrate portion 112a.

In the present embodiment, the antenna element 113 of the antenna 110 and the matching circuit connection terminal 111
Both are formed on the same flexible substrate 112 by a printed pattern of copper foil. Here, a wiring portion 113b is extended from the base portion 113a of the antenna element 113 in a direction perpendicular to the antenna element 113 so as to form a substantially inverted L-shape. The second wiring portion 113c extends in a direction orthogonal to the longitudinal direction of the portion 113b, and the second wiring portion 113c
After that, matching circuit connecting portions 114a, 114b, and 114c having different lengths extend in parallel to the direction perpendicular to the longitudinal direction of the second wiring portion 113c at regular intervals on the matching substrate portion 112a of the flexible substrate 112. Has been established. The matching circuit connection portions 114a, 114b, and 114c are formed by a printed pattern of a copper foil formed on the flexible substrate 112. The length of the matching circuit connection portion 114a is the longest, and the matching circuit connection portion 114c is the longest. Is the shortest, and the matching circuit connection portion 114b has an intermediate length.

On the other hand, matching circuit connecting terminals 111 connected to a high-frequency circuit (not shown) of the mounting printed board 13 are formed on a flexible board 112 by a printed pattern of a strip-shaped copper foil. By folding as shown in FIG.
Any one of 4a, 114b, and 114c is opposed to and contacts the matching circuit connection terminal 111. By insulating the contact surface with an insulator, it is possible to provide a capacitor. As for insulation, matching circuit connecting portions 114a, 114b, 11
An insulator may be applied only to the surface of 4c, an insulator may be applied only to the surface of matching circuit connection terminal 111, or an insulator may be applied to both surfaces.

Here, the longest matching circuit connecting portion 114a
Is in opposition to the matching circuit connection terminal 111,
When the reactance is the largest and the shortest matching circuit connecting portion 114c is in opposing contact with the matching circuit connecting terminal 111, the reactance is the smallest and the matching circuit connecting portion 114c is in opposing contact with the matching circuit connecting terminal 111. In such a case, the value becomes an intermediate value.

Therefore, according to the present embodiment, it is possible to realize three types of matching circuits simply by bringing any one of the matching circuit connecting portions 114a, 114b and 114c into opposing contact with the matching circuit connecting terminal 111. .

As described above, the matching circuit connecting section 11
Opposite contact to any one of the matching circuit connection terminals 111 of 4a, 114b, and 114c can be realized by an extremely simple operation by simply folding the matching substrate 112a as shown in FIG. Further, after the matching substrate portion 112a is folded, the matching substrate portion has a planar shape, and the space efficiency of the matching circuit is improved.

The number of matching circuit connecting portions is not necessarily limited to three, but may be any number such as two, four, five, or the like. In addition, the number of matching circuit connection units may be one.

Next, a fifth embodiment and a sixth embodiment of the present invention will be described with reference to FIGS.

FIG. 11 is a plan view of an antenna 120 according to the fifth embodiment of the present invention. The antenna 120 is shown in FIG.
1 is different from the antenna 10 of the first embodiment only in the matching circuits 130, 131, and 132, and the other structure is the same. That is, in the antenna 120, an antenna element 125 formed by a copper foil print pattern is formed on a flexible substrate 119, and the base 125a of the antenna element 125 is
31 and 132 are connected. This matching circuit 1
30, 131 and 132 are strip lines or
It is composed of one of microstrip lines. Details of the matching circuits 130, 131, 132 will be described later.

FIG. 12 is a plan view of an antenna 160 according to the sixth embodiment of the present invention. The antenna 160 shown in FIG.
21 is different from the antenna 60 of the second embodiment only in the matching circuits 170, 171 and 172, and the other structure is the same. That is, in the antenna 160, an antenna element 162 formed by a printed pattern of a copper foil is formed on a flexible substrate 161, and a base 162a of the antenna element 162 is provided with a matching circuit 170, 1
71 and 172 are connected. This matching circuit 1
70, 171, 172 are strip lines or
It is composed of one of microstrip lines. Details of the matching circuits 170, 171, 172 will be described later.

Next, the matching circuit 13 of the fifth embodiment
0, 131, 132 and matching circuit 1 of the sixth embodiment
70, 171, and 172 will be described with reference to FIGS. Matching circuit 130 and matching circuit 170 are the same circuit, matching circuit 131 and matching circuit 171 are the same circuit, and matching circuit 132 and matching circuit 172 are the same circuit.

FIG. 13 shows the matching circuit 130 and the matching circuit 1
14 is a front view showing details of the matching circuit 131 and the matching circuit 171. FIG. 15 is a front view showing details of the matching circuit 132 and the matching circuit 172. FIG. 16 is an equivalent circuit of the matching circuit 130 and the matching circuit 170 shown in FIG. 13, FIG. 17 is an equivalent circuit of the matching circuit 131 and the matching circuit 171 shown in FIG. 14, and FIG. 5 is an equivalent circuit of the matching circuit 132 and the matching circuit 172 shown in FIG.

First, referring to FIG.
And the matching circuit 170 will be described. Matching circuit 170
Is the same circuit as the matching circuit 130, so that the matching circuit 130 will be described below, and the description of the matching circuit 170 will be omitted.

The matching circuit 130 is formed by forming elements 144 and 145 formed of a copper foil printed pattern in parallel in a rectangular spiral shape on a flexible substrate (not shown in FIG. 13) with a certain distance therebetween. , A strip line or a microstrip line. One end of the element 144 is connected to the base 125 a of the antenna element 125, and the other end is connected to GND (ground), which is a ground conductor of a strip line or a micro strip line, through a through hole 146 at the center of the spiral. Grounded. One end of the element 145 is connected to the high-frequency circuit, and the other end is open at the center of the spiral.

Therefore, the element 144 and the element 1
The capacitor 45 is capacitively joined to form an equivalent circuit shown in FIG.
In this equivalent circuit, the high frequency circuit is capacitively connected, and the antenna side is grounded by an inductance component.

Next, referring to FIG.
And the matching circuit 171 will be described. Matching circuit 171
Is the same circuit as the matching circuit 131, the matching circuit 131 will be described below, and the description of the matching circuit 171 will be omitted.

The matching circuit 131 is formed by forming an element 147 and an element 148 of a copper foil printed pattern in parallel in a rectangular spiral shape on a flexible substrate (not shown in FIG. 14) with a certain distance therebetween. , A strip line or a microstrip line. One end of the element 147 is connected to the base 125a of the antenna element 125, and the other end is connected to a high frequency circuit via a through hole 149 at the center of the spiral. Also, one end of the element 148 is grounded to the GND (ground) of the mounting printed circuit board 13, and the other end is open at the center of the spiral.

Therefore, element 147 and element 1
The capacitor 48 is capacitively joined to form an equivalent circuit shown in FIG.
In this equivalent circuit, the high frequency circuit is joined by an inductance component, and is grounded by a capacitive junction on the antenna side.

Next, referring to FIG.
And the matching circuit 172 will be described. Matching circuit 172
Is the same circuit as the matching circuit 132, the matching circuit 132 will be described below, and the description of the matching circuit 172 will be omitted.

The matching circuit 132 is formed by bending an element 150 and an element 151 formed of a copper foil printed pattern on a flexible substrate (not shown in FIG. 15) in parallel at a predetermined interval and bending two rectangular portions in parallel. is there. In the matching circuit 132, one end of the element 150 is connected to the base 125a of the antenna element 125, and the other end is open. One end of the element 151 is grounded to GND (ground), which is a ground conductor of a strip line or a microstrip line, and the other end is connected to a high frequency circuit.

Therefore, the element 150 and the element 1
The capacitor 51 is capacitively joined, and becomes an equivalent circuit shown in FIG.
In this equivalent circuit, the antenna element 125 is capacitively connected, and is grounded by an inductance component.
The high frequency circuit is joined at an intermediate point between the capacitance component and the inductance component.

According to the above-described fifth and sixth embodiments, the selection of the matching circuit is performed by punching at least one of the matching circuits, as in the first and second embodiments. Leave the matching circuit. Therefore, also in the fifth embodiment and the sixth embodiment, seven types of matching can be performed similarly to the first embodiment and the second embodiment.

It should be noted that the punching process is performed in advance or
Alternatively, the connection after the connection with the matching circuit connection terminal 50 is arbitrary as in the first embodiment.

As described above, according to the fifth embodiment and the sixth embodiment, three types of matching circuits can be easily realized by the copper foil printed pattern. Manufacturing is easy, and a matching circuit can be simply selected by punching. Therefore, a matching circuit can be quickly selected during mass production, and production efficiency can be improved. Note that the number of matching circuits is not necessarily limited to three, but two, four,
Any number such as five may be used. Further, the above matching circuits are all formed by strip lines or microstrip lines.

It is needless to say that the present invention is not limited to a cordless telephone but can be applied to a portable telephone, a PHS, a handy transceiver, a portable radio, and the like.

[0073]

As described above, in the communication apparatus according to the first aspect of the present invention, the connection means selects at least one matching circuit from a plurality of matching circuits for matching the impedance between the transmitting / receiving circuit and the antenna. By connecting the antenna between the transmitting and receiving circuit and the antenna, the impedance between the transmitting and receiving circuit and the antenna can be easily matched. Therefore, a matching circuit can be quickly selected at the time of mass production, and the production efficiency can be improved.

Further, in the communication device according to the second aspect of the present invention, in addition to the effects of the first aspect, a plurality of connecting sections in which all of the plurality of matching circuits are connected between the transmitting / receiving circuit and the antenna. And connecting means can be configured by cutting at least one of the plurality of connecting parts to match the impedance between the transmitting / receiving circuit and the antenna. Therefore, by a simple process of cutting at least one connection portion, a matching circuit can be quickly selected at the time of mass production, and the production efficiency can be further improved.

Further, in the communication device according to the third aspect of the present invention, in addition to the effects of the first or second aspect, the plurality of matching circuits are constituted by circuits formed on a flexible printed circuit board. Therefore, it is very easy to cut or punch out the connection part. Therefore, a matching circuit can be quickly selected at the time of mass production, and the production efficiency can be further improved.

In the communication device according to the fourth aspect of the present invention, in addition to the effects of the first aspect, the plurality of matching circuits may include a strip line or
Since it is formed of a microstrip line, it is possible to easily and inexpensively form a matching circuit.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a cordless telephone 1 according to the present invention.

FIG. 2 is a front view showing the cordless telephone 1 with a handset 2 removed.

FIG. 3 is a perspective view showing an antenna mechanism built in the cordless telephone 1;

FIG. 4 is a block diagram showing an electric circuit of the cordless telephone 1;

FIG. 5 is a plan view of the antenna 10. FIG.

FIG. 6 is a plan view of an antenna 60;

FIG. 7 shows an antenna 90 and a matching circuit connection terminal 1;
It is a top view which shows 00.

FIG. 8 is a plan view showing a state after the antenna 90 and the matching circuit 102 are connected.

FIG. 9 is a plan view showing a state before bending of a matching substrate portion 112a.

FIG. 10 is a plan view showing a state after the matching substrate portion 112a is bent.

FIG. 11 is a plan view of an antenna 120 according to a fifth embodiment of the present invention.

FIG. 12 is a plan view of an antenna 160 according to a sixth embodiment of the present invention.

FIG. 13 shows a matching circuit 130 and a matching circuit 17;
FIG. 2 is a plan view showing details of a zero.

FIG. 14 shows a matching circuit 131 and a matching circuit 17;
FIG. 2 is a plan view showing the details of No. 1.

FIG. 15 shows a matching circuit 132 and a matching circuit 17;
FIG. 2 is a plan view showing details of a second example.

FIG. 16 shows a matching circuit 130 and a matching circuit 17;
It is a figure showing an equivalent circuit of 0.

FIG. 17 shows a matching circuit 131 and a matching circuit 17;
FIG. 3 is a diagram showing an equivalent circuit of No. 1;

FIG. 18 shows a matching circuit 132 and a matching circuit 17;
2 is a diagram illustrating an equivalent circuit of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cordless telephone 2 Handset 3 Charging device 4 Receiver 5 Transmitter 6 Key operation input unit 10 Antenna 11 Flexible board 13 Mounting printed board 14 Feeding point 15 High frequency shield 20 Low frequency input unit 21 Modulation unit 22 Frequency synthesizer 23 Power amplifier 24 Duplexer 25 Antenna Element 26 Demodulator 27 Down Converter 28 Low Noise Amplifier 29 Low Frequency Output Unit 30 Matching Circuit 31 Matching Circuit 32 Matching Circuit 34 Matching Circuit Connection 50 Matching Circuit Connection Terminal 60 Antenna 61 Flexible Board 62 Antenna Element 70 Matching Circuit 71 Matching circuit 72 Matching circuit 70a Matching circuit connection 71a Matching circuit connection 72a Matching circuit connection 80 Matching circuit connection terminal 81 Matching circuit connection terminal 82 Matching circuit connection terminal 83 Mounting printed circuit board 90 Antenna Na 92 Flexible board 93 Matching circuit connecting part 93a Tip part 100 Matching circuit connecting terminal 101 Flexible board 102 Matching circuit 100a Connecting part 100b Connecting part 100c Connecting part 110 Antenna 111 Matching circuit connecting terminal 112 Flexible board 112a Matching substrate part 113 Antenna element 113a Base part 113b Wiring part 113c Second wiring part 114a Matching circuit connecting part 114b Matching circuit connecting part 114c Matching circuit connecting part 119 Flexible board 120 Antenna 125 Antenna element 125a Base part 130 Matching circuit 131 Matching circuit 132 Matching circuit 144 Element 145 Element 146 Through hole 147 element 148 element 149 Through hole 150 element 151 element 16 Antenna 161 flexible substrate 162 antenna element 162a base 170 matching circuit 171 matching circuit 172 matching circuit

Continuation of the front page (72) Inventor Yoshitsugu Tomomatsu 15-1, Naeshiro-cho, Mizuho-ku, Nagoya-shi, Aichi Prefecture Inside the Brother Industries, Ltd. Industrial Co., Ltd. F term (reference) 5J021 AA01 AB06 CA04 CA06 FA17 FA26 HA05 HA10 JA00 5J047 AA00 AA19 AB13 FD01 FD02 FD06 5K027 AA12 BB14 KK01 KK06 5K067 AA23 EE02 KK01

Claims (4)

[Claims] 1. A communication device comprising: an antenna; and a transmission / reception circuit for transmitting or receiving a predetermined signal via the antenna, wherein: a plurality of matching circuits for matching impedance between the transmission / reception circuit and the antenna; A communication device comprising: a connection unit that selects at least one matching circuit from the plurality of matching circuits and connects the selected matching circuit between the transmitting / receiving circuit and the antenna. 2. The connecting means comprises a plurality of connecting portions connecting all of the plurality of matching circuits between the transmitting / receiving circuit and the antenna, and at least one connecting portion among the plurality of connecting portions. The communication device according to claim 1, wherein the communication device is formed by cutting the communication device. 3. The communication device according to claim 1, wherein the plurality of matching circuits are configured by a circuit formed on a flexible printed circuit board. 4. The communication device according to claim 1, wherein the plurality of matching circuits are formed of a strip line or a microstrip line.