JP2009171069A - Communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication device capable of being arranged with a plurality of communication systems, while suppressing an increase in the manufacturing cost, and being miniaturized. <P>SOLUTION: The communication device comprises a first antenna 11, a first connecting portion 110 for connecting the first antenna 11 to transmitting-receiving circuits 12A and 12B at the first antenna 11 and delivering transmit and receive signals of the first antenna 11, a second antenna 21, and a second connecting portion 120 for connecting the second antenna 21 to transmitting-receiving circuits 22A and 22B at the second antenna 21 and delivering transmit and receive signals of the second antenna 21. The first connecting portion 110 and the second connecting portion 120 are formed by coplanar lines 111, 112, 121, 122, and 123 formed on an identical substrate B. According to this configuration, the first connecting portion 110 and the second connecting portion 120 are configured by the coplanar lines 111, 112, 121, 122, and 123 formed on the identical substrate B. Accordingly, it is not necessary to prepare a plurality of kinds of connection lines and arrange them within the communication device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication device.

  In recent years, not only communication devices that perform long-distance wireless communication, but also communication devices that perform non-contact communication such as a non-contact type IC card and RFID (Radio Frequency IDentification) have become widespread. On the other hand, with the development of information technology, in these communication devices, it is also demanded to transmit and receive a larger amount of data at high speed. For example, a plurality of communication systems (for example, a plurality of communication lines, In some cases, a communication device (composite radio) that transmits and receives data via a plurality of communication systems) is desired.

  When incorporating a plurality of communication systems into one communication device, the communication device is often provided with a plurality of antennas, and each antenna is often driven in a different frequency band. For example, in the communication apparatus according to the related art, a frequency band of several to several tens of MHz is used for one antenna, and a GHz band of about 100 times or more is used for the other antenna, for example. In this case, differential transmission is used for connection between the antenna of several to several tens of MHz and its transmission / reception circuit, and differential transmission is difficult for connection between the antenna of GHz band and its transmission / reception circuit. Dynamic transmission was used, and coaxial lines were used to reduce the external influence of high frequencies.

  On the other hand, for example, in communication devices where portability is regarded as important, downsizing of the device is important and low manufacturing cost is also required.

  However, using a plurality of types of connection lines for a plurality of antennas as described above not only increases the manufacturing cost but also hinders downsizing of the communication device.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to arrange a plurality of communication systems and reduce the size while suppressing an increase in manufacturing cost. It is an object of the present invention to provide a new and improved communication device.

  In order to solve the above-described problem, according to an aspect of the present invention, a first connection unit that connects a first antenna, a transmission / reception circuit of the first antenna, and the first antenna and transmits a transmission / reception signal of the first antenna. And a second antenna, a transmission / reception circuit of the second antenna, and a second antenna connected to each other and transmitting a transmission / reception signal of the second antenna, the first connection unit and the second connection unit Are provided by a coplanar line formed on the same base material, and a communication device is provided.

  According to this structure, the 1st connection part and the 2nd connection part are comprised by the coplanar track | line formed on the same base material. Therefore, it is not necessary to prepare a plurality of types of connection lines and arrange them inside the communication device.

The first antenna is driven at a frequency lower than that of the second antenna, the first connection unit differentially transmits the transmission / reception signal of the first antenna, and the second connection unit does not transmit / receive the transmission / reception signal of the second antenna. May be transmitted dynamically.
According to this configuration, the first antenna is driven at a frequency lower than that of the second antenna, the first connection portion is configured by a connection line for differential transmission, and the second connection portion is for non-differential transmission. Consists of connection lines. However, the connection line for differential transmission of the first connection part and the connection line for non-differential transmission of the second connection part can be configured by a coplanar line formed on the same substrate. Therefore, it is not necessary to prepare a connection line for differential transmission and a connection line for non-differential and arrange them inside the communication apparatus.

The second connection portion is disposed between two grounded coplanar lines that are grounded and the two coplanar lines, and a connection coplanar line that connects the second antenna transmission / reception circuit and the second antenna. You may have.
According to this configuration, the two grounded coplanar lines that are grounded are arranged on both sides of the connecting coplanar line. Therefore, the grounding coplanar line can shield the electromagnetic wave emitted from the connecting coplanar line, and the second connecting portion can be operated like a coaxial line, for example.

In addition, an electric capacity that is cut off in a frequency band in which the first antenna is driven may be disposed in a loop that is at least partially configured by two grounding coplanar lines of the second connection portion.
According to this configuration, the two grounding coplanar lines form a ground loop connected to or connected to the ground, but this loop is blocked in the frequency band of the first antenna by the electric capacity. . Therefore, it is possible to prevent an induced current caused by an electromagnetic wave generated by the first connection portion of the first antenna from flowing through the grounding coplanar line.

The first connection unit includes a pair of differential coplanar lines that connect the transmission / reception circuit of the first antenna and the first antenna, and at least one of the pair of differential coplanar lines and the first antenna is The second antenna may be grounded with respect to the ground of the second antenna through an electric capacitance conducted in a frequency band in which the second antenna is driven.
According to this configuration, the differential coplanar line is grounded in the frequency band of the second antenna, so that the first antenna, the differential coplanar line, etc. behave like floating metals with respect to the second antenna. Can be prevented.

The first connection portion of the first antenna is formed by two grounding coplanar lines of the second connection portion having one end connected to the transmission / reception circuit of the first antenna and the other end connected to the first antenna. Also good.
According to this structure, a 1st connection part and a 2nd connection part can be integrated. Accordingly, the first connection portion and the second connection portion can be constituted by two grounding coplanar lines and a connection coplanar line.

  As described above, according to the present invention, it is possible to arrange a plurality of communication systems and reduce the size while suppressing an increase in manufacturing cost.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<Communication device related technology>
Before describing communication apparatuses according to the embodiments of the present invention, communication apparatuses according to these related techniques will be described with reference to FIGS. 5A and 5B.

  FIG. 5A and FIG. 5B are explanatory diagrams for explaining the configuration of a communication apparatus according to related technology. 5A shows a communication device 500 of one communication system, and FIG. 5B shows a communication device 600 of another communication system.

(Communication device 500)
As illustrated in FIG. 5A, the communication device 500 includes a loop antenna 11, a transmission circuit 12A, a reception circuit 12B, a connection unit 13, and capacitors 14A and 14B as an example of one communication system 10.

  The loop antenna 11 is an example of a first antenna, is also called a coil antenna, and is driven in a frequency band of several to several tens of MHz such as 13.56 MHz. The loop antenna 11 can perform non-contact communication using magnetic field coupling.

  The connection part 13 has two connection lines 13A and 13B extending in parallel. The connection line 13A and the connection line 13B connect the loop antenna 11, the transmission circuit 12A, and the reception circuit 12B, respectively, and perform differential transmission of transmission / reception signals of the loop antenna 11. The connection lines 13A and 13B are grounded through capacitors 14A and 14B, respectively. The capacitors 14A and 14B and the connection lines 13A and 13B are combined with the loop antenna 11 to form a resonance circuit, and the material, dimensions, and capacitance are set so as to resonate in the driving frequency band of the loop antenna 11.

That is, the communication device 500 can perform non-contact communication in a frequency band of several to several tens of MHz by one communication system 10. Furthermore, since the parallel connection lines 13A and 13B, the capacitors 14A and 14B, and the loop antenna 11 function as a resonance circuit during driving, the antenna efficiency can be increased. The transmission circuit 12A and the reception circuit 12B are the transmission / reception circuit of the first antenna.
It is an example.

(Communication device 600)
On the other hand, as illustrated in FIG. 5B, the communication device 600 includes an antenna 21, a transmission circuit 22 </ b> A, a reception circuit 22 </ b> B, a connection unit 23, and a switch 24 as an example of another communication system 20.

  The antenna 21 is an example of a second antenna, and may be various antennas such as a patch antenna and an electric field coupler (antenna that performs non-contact communication by electric field coupling). For example, an antenna different from the loop antenna 11 is preferably used as the antenna 21. The antenna 21 is driven in a frequency band about 100 times that of the loop antenna 11, for example, in the GHz band. The antenna 21 can perform non-contact communication using electric field coupling or magnetic field coupling. Thus, the reason for using the antenna 21 different from the loop antenna 11 or using a higher frequency band than the loop antenna 11 is, for example, between antennas in the same communication device or between antennas straddling the communication system. This is to prevent the occurrence of coupling and decrease the antenna efficiency and the S / N ratio.

  A connection line for non-differential transmission is used for a connection line of such a high-frequency communication device, not a parallel transmission line for differential transmission (for example, connection lines 13A and 13B) similar to the loop antenna 11. It is common to do. This is because a non-differential antenna is often used in a high frequency band such as the GHz band. In addition, since non-reflective energy transmission is important in antennas, connection lines, and transmission / reception circuits, impedance matching is required, and non-differential transmission is preferred because connection lines with good impedance characteristics can be easily obtained. .

  The connection unit 23 connects the antenna 21 to the transmission circuit 22A and the reception circuit 22B, and performs non-differential transmission of transmission / reception signals of the antenna 21. Since this communication device 600 uses a very high frequency band in the GHz band, it is necessary to reduce the influence on other drive circuits and connection lines due to electromagnetic waves generated when transmitting / receiving signals are transmitted. Therefore, in the communication device 600, a coaxial line that is non-differential transmission and has a shielding effect is used as the connection unit 23. The transmission circuit 22A and the reception circuit 22B are examples of a second antenna transmission / reception circuit.

  The switch 24 is disposed between the connection unit 23 and the transmission circuit 22A and the reception circuit 22B, and connects either the transmission circuit 22A or the reception circuit 22B to the antenna 21. The switch 24 is controlled by a host control device (not shown) or the like, and when the communication device 600 is used as a transmission side, the antenna 21 and the transmission circuit 22A are connected, and the communication device 600 is a reception side. Are used, the antenna 21 and the receiving circuit 22B are connected.

(When two communication systems 10 and 20 are provided)
Even if the one communication system 10 (communication device 500) and the other communication system 20 (communication device 600) according to the related art are formed separately or mounted on one communication device, the antenna efficiency decreases. In order to prevent a decrease in the S / N ratio, etc., the antenna types and the frequency bands used in the respective communication systems are often different from each other. Here, antenna efficiency, S / N ratio, and the like are collectively referred to as “antenna characteristics”.

  When a plurality of communication systems are mounted on one communication device, connection between the transmission / reception circuit and the antenna becomes a problem. If the communication system 10 and the communication system 20 are simply mounted on one communication device, it is necessary to mount the connection lines 13A and 13B, which are parallel lines, and the connection part 23 of the coaxial line. Using two types of connection lines in this way not only increases the manufacturing cost, but also requires an arrangement space, which hinders downsizing of the apparatus.

  Accordingly, the inventors of the present invention have come up with the present invention as a result of intensive studies on problems that occur when the above-described plurality of communication devices are mounted. Hereinafter, the communication apparatus according to the first embodiment of the present invention will be described with reference to FIG.

<Communication apparatus according to the first embodiment>
FIG. 1 is an explanatory diagram for explaining a configuration of a communication apparatus according to the first embodiment of the present invention. As illustrated in FIG. 1, the communication device 100 according to the present embodiment includes two communication systems 10 and 20.

  The communication system 10 includes a loop antenna 11, a transmission circuit 12A, a reception circuit 12B, a first connection unit 110, and capacitors 14A and 14B. The communication system 20 includes an antenna 21, a transmission circuit 22A, a reception circuit 22B, a second connection unit 120, and a switch 24. That is, the communication system 10 includes the first connection unit 110 instead of the connection unit 13 included in the communication device 500 illustrated in FIG. 5A. And the communication system 20 has the 2nd connection part 120 instead of the connection part 23 which the communication apparatus 600 shown to FIG. 5B has. And the communication apparatus 100 arrange | positions the antenna of the two communication systems 10 and 20, ie, the loop antenna 11, and the antenna 21, adjacent. Since the other configuration is the same as that of the communication device 500 or the communication device 600, detailed description thereof will be omitted, and the first connection unit 110 and the second connection unit 120 will be mainly described below. .

  The 1st connection part 110 and the 2nd connection part 120 are comprised by the coplanar structure part C1. More specifically, the first connection unit 110 and the second connection unit 120 will be described as follows.

(First connection part 110)
The first connection part 110 has two differential coplanar lines 111 and 112. The two differential coplanar lines 111 and 112 are extended substantially in parallel at a predetermined interval, and connect the transmission circuit 12A and the reception circuit 12B to the loop antenna 11.

  Each of the differential coplanar lines 111 and 112 is formed with a predetermined width, height, and length by a conductive material. The material, width, height, length, and interval of the differential coplanar lines 111 and 112 are set so as to function as a part of the resonance circuit in the several to several tens of MHz band in one communication system 10. Is done. Such differential coplanar lines 111 and 112 can operate in the same manner as the connection lines 13 </ b> A and 13 </ b> B of the connection unit 13 of the communication device 500.

(Second connection unit 120)
The second connection unit 120 includes two grounding coplanar lines 121 and 122 and a connecting coplanar line 123. The two grounding coplanar lines 121 and 122 extend substantially in parallel with a predetermined interval, and are connected to each other at both ends. The two grounding coplanar lines 121 and 122 are grounded at both ends.

  The connecting coplanar line 123 is disposed between the two grounded coplanar lines 121 and 122 and extends so as to be substantially parallel to both the grounded coplanar lines 121 and 122. Then, the connection coplanar line 123 connects the switch 24 (that is, the transmission circuit 22A or the reception circuit 22B via the switch 24) and the antenna 21. The connecting coplanar line 123 is preferably arranged at a position equidistant from both grounded coplanar lines 121 and 122.

  The grounding coplanar lines 121 and 122 and the connecting coplanar lines 123 are formed of a conductive material with a predetermined interval, width, height, and length. With such a configuration, the connecting coplanar line 123 can function as a signal line for non-differential transmission with respect to the antenna 21, and the both-grounded coplanar lines 121 and 122 are not connected to the connecting coplanar line 123. It plays a role of shielding electromagnetic waves generated by differentially transmitted GHz band signals and reducing the influence on other electronic circuits. The grounded coplanar lines 121 and 122 further play a role of preventing electromagnetic waves or the like generated by other circuits from affecting the connecting coplanar lines 123. That is, the grounding coplanar lines 121 and 122 and the connecting coplanar lines 123 can operate in the same manner as the coaxial line by being configured as described above.

(Coplanar structure)
The coplanar structure C1, that is, the coplanar structure will be described.
The coplanar structure C1 includes a base material B, the differential coplanar lines 111 and 112, the grounding coplanar lines 121 and 122, and the connection coplanar lines 123 (hereinafter also collectively referred to as “coplanar lines”).

  The base material B is formed of a dielectric material. A coplanar line made of a conductor is formed on one surface of the base material B. For example, a ground layer made of a conductor may be formed on the other surface of the base material B (the surface opposite to the surface on which the coplanar line is formed).

  The coplanar line is formed by determining the material, the interval, the width, the height, the length, etc. according to the desired impedance. The impedance of the coplanar line also depends on the dielectric constant and thickness of the base material B. Therefore, the differential coplanar lines 111 and 112, the ground coplanar lines 121 and 122, and the connection coplanar lines 123 are the transmission circuit 12A, 22A, the reception circuits 12B and 22B, the loop antenna 11 and the antenna 21, respectively. The spacing, width, height, and length, the material and thickness of the base material B, and the presence or absence of the ground layer can be designed so that impedance matching is possible. Therefore, the communication device 100 can easily perform impedance matching between the communication circuit and the antenna by including the coplanar structure C1.

(Example of effects of this embodiment)
According to the communication device 100 according to the present embodiment, a plurality of antennas and a communication circuit can be connected by a coplanar line without using a plurality of types of connection lines (for example, the connection units 13 and 23). Therefore, since the connection portions of a plurality of antennas can be easily integrated into one coplanar structure portion C1, it is possible to reduce the space for handling a plurality of types of connection lines and make the configuration of the device itself compact. it can. Further, as described above, the impedance can be easily changed by adjusting the material and dimensions of each coplanar line and the base material B, the presence / absence of a ground layer, etc., so that it is easy to guarantee impedance matching. It is. In addition, since the coupling relationship between the lines is uniquely determined as compared with the case of connecting with a plurality of types of connection lines, stable antenna characteristics can be realized. More specifically, for example, when a plurality of types of connection lines are used, each antenna to be manufactured is affected by the length of each line, the influence of electromagnetic waves due to the arrangement position of each line, the influence of connection means in the connection portion, etc. The characteristics may change. However, the coplanar structure C1 according to this embodiment can stabilize the antenna characteristics because the length of each line, the influence of electromagnetic waves depending on the arrangement position of each line, the connection means in the connection, and the like are uniquely determined.

  As described above, the communication device 100 according to the present embodiment can achieve a very advantageous effect compared to the case where a plurality of types of connection lines are used. However, as a result of intensive studies to further stabilize the antenna characteristics of the communication device 100, the present inventors have conceived the communication device according to the second and third embodiments of the present invention. Below, the communication apparatus which concerns on 2nd Embodiment of this invention is demonstrated first.

<Communication apparatus according to the second embodiment>
FIG. 2 is an explanatory diagram for explaining a configuration of a communication apparatus according to the second embodiment of the present invention. As illustrated in FIG. 2, the communication device 200 according to the present embodiment further includes a capacitor 131 in addition to the configuration of the communication device 100 according to the first embodiment. Since the configuration other than the capacitor 131 is the same as that of the communication device 100 according to the first embodiment, a detailed description thereof is omitted here.

  The capacitor 131 is an example of an electric capacity, and is arranged in a loop formed by the grounding coplanar line 121 and the grounding coplanar line 122. At the same time, the capacitor 131 is arranged so that at least one of the two grounding coplanar lines 121 and 122 is grounded through the capacitor 131. That is, the capacitor 131 is composed of two grounding coplanar lines 121 and 122 and is disposed in a grounded ground loop.

  The electric capacity of the capacitor 131 behaves as if it is disconnected in the several to several tens of MHz band of the loop antenna 11 of one communication system 10 and is conductive in the GHz band of the antenna 21 of the other communication system 20. Is set to a capacity that behaves like More specifically, the capacitor 131 is set to an electric capacity that behaves as a capacitor having an impedance of several hundreds Ω or more in the several to several tens of MZZ band, and behaves as a capacitor having an impedance of several Ω or less in the GHz band. . As a result, the capacitor 131 is conducted to the antenna 21 so that the grounding coplanar lines 121 and 122 perform the shielding function, and the grounding coplanar lines 121 and 122 are grounded. On the other hand, for the loop antenna 11, the loop formed by the grounding coplanar lines 121 and 122 is cut off, and either one of the grounding coplanar lines 121 and 122 is cut off from the ground.

  By having such a capacitor 131, the communication apparatus 200 according to the present embodiment can reduce the induced current generated in the coplanar line while suppressing the deterioration of the characteristics of the coplanar line. This will be described in more detail as follows.

A case where the capacitor 131 is not provided will be described.
Since the loop antenna 11 is driven in the several to several tens of MHz band, the magnetic field is generated in the surrounding space including the first connection unit 110 and the second connection unit 120. When the fluctuation of the magnetic field enters the ground loop formed by the coplanar line, a current is generated by the induction machine power. This current causes heat loss and degrades the antenna characteristics of the loop antenna 11.

  On the other hand, in the communication device 200 according to the present embodiment, the capacitor 131 is disposed in the ground loop formed by the coplanar line, thereby cutting the ground loop against fluctuations in the magnetic field of several to several tens of MHz. Can do. Therefore, it is possible to prevent the loss and characteristics from deteriorating by suppressing the induced current from flowing.

(Example of effects of this embodiment)
As described above, according to the communication device 200 according to the present embodiment, in addition to the effects exhibited by the communication device 100 according to the first embodiment, the second connection unit 120 includes the capacitor 131. Loss and deterioration of characteristics that can occur can be prevented. The capacitor 131 is not limited to the position shown in FIG. 2, but may be disposed at any position as long as the ground loop formed by the ground coplanar lines 121 and 122 and the ground can be cut. Needless to say. In FIG. 2, the ground loop is configured by grounding coplanar lines 121 and 122, but the ground loop may be formed via the ground. In the fourth embodiment to be described later, the grounding coplanar lines 121 and 122 form a ground loop via the ground (see FIG. 4).

<Communication apparatus according to the third embodiment>
Next, a communication device according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 3 is an explanatory diagram for explaining a configuration of a communication apparatus according to the third embodiment of the present invention. As shown in FIG. 3, the communication device 300 according to the present embodiment further includes two capacitors 132A and 132B in addition to the configuration of the communication device 100 according to the first embodiment. Since the configuration other than the capacitors 132A and 132B is the same as that of the communication device 100 according to the first embodiment, a detailed description thereof is omitted here.

  Capacitors 132A and 132B are examples of electric capacity, and are connected to one of differential coplanar lines 111 and 112, respectively. The differential coplanar lines 111 and 112 and the loop antenna 11 are connected to the ground of the antenna 21 through the capacitors 132A and 132B.

  The electric capacities of the capacitors 132A and 132B behave as resonance capacities in the several to several tens of MHz of the loop antenna 11 of one communication system 10, and are electrically connected in the GHz band of the antennas 21 of the other communication systems 20 to be grounded. Is set to the capacity to behave as That is, for the loop antenna 11, the capacitors 132A and 132B function as a resonance capacitor, and for the antenna 21, the capacitors 132A and 132B are conductive, and equivalently, the difference between the loop antenna 11 and the two antennas. The dynamic coplanar lines 111 and 112 are grounded.

  By having such capacitors 132A and 132B, the communication device 300 according to the present embodiment can further improve the antenna characteristics. This will be described in more detail as follows.

A case where the capacitors 132A and 132B are not provided will be described.
When the antenna 21 using the GHz band and the loop antenna 11 using several to several tens of MHz are arranged close to each other, conductors such as the loop antenna 11 and the differential coplanar lines 111 and 112 are in the GHz band. It behaves like a floating metal with respect to the antenna 21. When such a floating metal is disposed in close proximity, the floating metal can deteriorate the antenna characteristics of the antenna 21 in the GHz band.

  On the other hand, in the communication apparatus 300 according to the present embodiment, the differential coplanar lines 111 and 112 and the loop antenna 11 are grounded to the ground of the antenna 21 via the capacitors 132A and 132B, so that the loop antenna 11 and the differential antenna are differentially connected. The coplanar lines 111 and 112 can be prevented from acting as floating metals. Therefore, deterioration of the antenna characteristics of the antenna 21 can be prevented. Note that the antenna characteristics of the loop antenna 11 are not affected by making the capacitors 132A and 132B behave as the resonance capacitance of the loop antenna 11.

(Example of effects of this embodiment)
As described above, according to the communication device 300 according to the present embodiment, in addition to the effects exhibited by the communication device 100 according to the first embodiment, the communication device 300 further includes the capacitors 132A and 132B and each communication system. The antenna characteristics can be improved by utilizing the difference in frequency used by 10 and 20.

  As described above, the communication device 200 according to the second embodiment can prevent loss and deterioration of characteristics that may occur in the second connection unit 120, and the communication device 300 according to the third embodiment. Can improve the antenna characteristics. As a result of intensive studies on a communication device that has these effects and is more effective, the present inventors have come up with the communication device according to the fourth embodiment of the present invention. The communication apparatus according to the fourth embodiment of the present invention will be described below.

<Communication apparatus according to the fourth embodiment>
FIG. 4 is an explanatory diagram for explaining a configuration of a communication apparatus according to the fourth embodiment of the present invention. As illustrated in FIG. 4, the communication device 400 according to the present embodiment includes a coplanar structure portion C2 instead of the coplanar structure portion C1 in the configuration of the communication device 300 according to the third embodiment. In the coplanar structure C2, only the grounding coplanar lines 121 and 122 and the connecting coplanar line 123 that constitute the second connecting part 120 in the first to third embodiments are formed as coplanar lines. The difference from the coplanar structure C1 is that the differential coplanar lines 111 and 112 constituting the first connection unit 110 are omitted.

  In the communication device 400 according to the present embodiment, the two grounding coplanar lines 121 and 122 connect the transmission circuit 12A and the reception circuit 12B to the loop antenna 11. In other words, in the communication device 400, the grounding coplanar lines 121 and 122 of the second connection unit 120 are also functioned as differential coplanar lines of the first connection unit 110. That is, in the communication apparatus 400 according to the present embodiment, the first connection unit 110 is configured by two grounding coplanar lines 121 and 122 (that is, two differential coplanar lines), and the second connection unit 120. Consists of two grounding coplanar lines 121 and 122 and a connecting coplanar line 123.

  In addition, in the communication device 400 according to the present embodiment, capacitors 133A and 133B are used instead of the capacitor 131 included in the communication device 200 according to the second embodiment and the capacitors 132A and 132B included in the communication device 300 according to the third embodiment. Have.

  Capacitors 133A and 133B are examples of electric capacities, and are respectively connected to one of two grounding coplanar lines 121 and 122 that function as differential coplanar lines. The grounding coplanar lines 121 and 122 and the loop antenna 11 are connected to the ground of the antenna 21 via the capacitors 133A and 133B.

  The electric capacities of the capacitors 133A and 133B behave like resonance capacities in the several to several tens of MHz of the loop antenna 11 of one communication system 10, and are conducted in the GHz band of the antennas 21 of the other communication systems 20. It is set to the capacity that behaves like. In other words, for the loop antenna 11, the capacitors 133A and 133B function as a resonance capacitor, and for the antenna 21, the capacitors 133A and 133B are conductive, and equivalently, the difference between the loop antenna 11 and the two antennas. The dynamic coplanar lines (that is, the grounding coplanar lines 121 and 122) are grounded. Therefore, the communication device 400 according to the present embodiment can improve the antenna characteristics, like the communication device 300 according to the third embodiment.

  The total electric capacity of the capacitors 133A and 133B and the capacitors 14A and 14B in one communication system 10 is, for example, equal to the capacity for the loop antenna 11 to resonate in the several to several tens of MHz band. Can be determined. On the other hand, from the viewpoint that the ground coplanar lines 121 and 122 and the connection coplanar lines 123 have sufficient characteristics as non-differential coplanar lines in the GHz band used in other communication systems 20. The coplanar lines 121 and 122 are preferably good ground lines. This is equivalent to lowering the series impedance of the ground loop composed of the grounding coplanar lines 121 and 122, the capacitors 133A and 133B, and the capacitors 14A and 14B. Therefore, it is desirable that the four electric capacities of the capacitor 133A and the capacitor 133B, and the capacitor 14A and the capacitor 14B are equal. Therefore, the electric capacities of the capacitors 133A and 133B, and the capacitors 14A and 14B may be determined so that the total is a value at which the loop antenna resonates satisfactorily, and each has the same capacitance.

  It can also be said that the capacitors 133A and 133B are arranged in a ground loop constituted by the ground coplanar lines 121 and 122 and the ground. However, the grounding coplanar lines 121 and 122 function as differential coplanar lines to the loop antenna 11 and function as a part of a resonance circuit including the loop antenna. Therefore, the communication device 400 is equivalent to removing the source of loss due to the induced current, and can achieve the same effect as the communication device 200 according to the second embodiment.

(Example of effects of this embodiment)
As described above, according to the communication device 400 according to the present embodiment, in addition to the effects exhibited by the communication devices 100, 200, and 300 according to the first to third embodiments, the first connection unit 110 and the first The configuration of the two connecting portions 120 can be reduced in size, and the entire apparatus can be configured in a compact manner.

  As mentioned above, although preferred embodiment of this invention was described in detail, referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above embodiment, the loop antenna 11 is illustrated as an antenna of one communication system 10, and the antenna 21 is illustrated as an antenna of another communication system 20. However, the present invention is not limited to such an example. The two antennas may be any antennas. Further, when the antenna efficiency and the S / N ratio decrease are not considered, the two antennas are, for example, the same type of antenna, and may be driven in close frequency bands.

  Moreover, although the said embodiment demonstrated the case where two antennas, the loop antenna 11 and the antenna 21, were arrange | positioned in each communication apparatus, this invention is not limited to this example. That is, for example, a communication device having three or more antennas can be connected to each antenna and a communication circuit using a connection line (coplanar line) formed with a coplanar structure.

  Moreover, in the said 4th Embodiment, as the structure which can have the effect of both the communication apparatus 200 which concerns on 2nd Embodiment, and the communication apparatus 300 which concerns on 3rd Embodiment, and can further miniaturize an apparatus, The communication device 400 having the coplanar structure C2 has been described. However, the present invention is not limited to such an example. That is, the capacitors 132A and 132B included in the communication device 300 according to the third embodiment can be further arranged in the communication device 200 according to the second embodiment. According to this configuration, the effects of both the communication device 200 according to the second embodiment and the communication device 300 according to the third embodiment can be achieved.

It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on 1st Embodiment of this invention. It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on 2nd Embodiment of this invention. It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on 3rd Embodiment of this invention. It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on 4th Embodiment of this invention. It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on related technology. It is explanatory drawing for demonstrating the structure of the communication apparatus which concerns on related technology.

Explanation of symbols

100, 200, 300, 400 Communication device 10, 20 Communication system 11 Loop antenna 12A Transmission circuit 12B Reception circuit 14A, 14B Capacitor 21 Antenna 22A Transmission circuit 22B Reception circuit 24 Switch 110 First connection 111, 112 Differential coplanar line 120 Second connection portion 121, 122 Grounding coplanar line 123 Connection coplanar line 131 Capacitor 132A, 132B Capacitor 133A, 133B Capacitor C1, C2 Coplanar structure B Base material

Claims (6)

A first antenna;
A first connection unit for connecting a transmission / reception circuit of the first antenna and the first antenna, and transmitting a transmission / reception signal of the first antenna;
A second antenna;
A second connection unit for connecting a transmission / reception circuit of the second antenna and the second antenna, and transmitting a transmission / reception signal of the second antenna;
Have
The communication device, wherein the first connection part and the second connection part are formed by a coplanar line formed on the same base material. The first antenna is driven at a lower frequency than the second antenna;
The first connection unit differentially transmits a transmission / reception signal of the first antenna,
The communication apparatus according to claim 1, wherein the second connection unit performs non-differential transmission of a transmission / reception signal of the second antenna. The second connection portion is
Two grounded coplanar lines that are grounded;
A connection coplanar line that is disposed between the two coplanar lines and connects the transmission / reception circuit of the second antenna and the second antenna;
The communication apparatus according to claim 2, further comprising:   An electric capacity that is cut off in a frequency band in which the first antenna is driven is disposed in a loop that is at least partially constituted by the two grounding coplanar lines of the second connection portion. The communication device according to claim 3. The first connection unit includes a pair of differential coplanar lines that connect the transmission / reception circuit of the first antenna and the first antenna;
At least one of the pair of differential coplanar lines and the first antenna is grounded with respect to the ground of the second antenna through an electric capacitance that is conducted in a frequency band in which the second antenna is driven. The communication apparatus according to claim 3, wherein:   The first connection portion of the first antenna has one end connected to the transmission / reception circuit of the first antenna and the other end connected to the first antenna. The two ground coplanar lines of the second connection portion. The communication device according to claim 3, wherein the communication device is formed by:

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