JP7309386B2 - Wireless communication system, communication device, and communication method - Google Patents

Description

The present invention relates to a wireless communication system for wireless power transmission and communication.

2. Description of the Related Art In recent years, a close proximity wireless communication system has been proposed in which wireless communication is performed by electromagnetic field coupling between adjacent antennas. It is also considered to wirelessize both communication and power transmission between communication devices by providing a communication device with a communication antenna for wireless communication and a power transmission antenna for wireless power transmission. .

In Patent Document 1, by performing wireless power transmission and wireless communication between the rotating portion and the mounting portion of the camera device, the rotating portion can be freely turned, and the cable connecting the rotating portion and the mounting portion is unnecessary. A wireless communication system is disclosed. In addition, in order to reduce the influence of the electromagnetic field generated from the power transmission antenna on the communication by the wireless communication antenna, the power transmission antenna and the wireless communication antenna are placed in different positions in three dimensions to increase the distance between the antennas. A configuration is disclosed.

Japanese Patent No. 6348734

As in the technique described in Patent Literature 1, when a configuration in which the power transmission antenna and the communication antenna are kept away is applied, it is difficult to reduce the size of the wireless communication system.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to suppress the influence of wireless power transmission on wireless communication without increasing the distance between a power transmission antenna and a communication antenna in a wireless communication system.

In order to solve the above problems, a communication device according to the present invention has, for example, the following configuration. That is, a communication antenna having a power transmission antenna for wireless power transmission, a first electrode forming at least a part of a first ring shape, and a second electrode forming at least a part of a second ring shape and a potential generated by electromagnetic field coupling between the first electrode and a third electrode of the other communication device, and an electromagnetic field between the second electrode and a fourth electrode of the other communication device communication control means for controlling wireless communication based on the difference between the electric potential generated by field coupling, wherein the distance between the power transmission antenna and the first electrode is longer than the distance between the power transmission antenna and the second electrode. It is long and the width of the first electrode in the radial direction of the first ring is greater than the width of the second electrode in the radial direction of the second ring .

According to the present invention, the influence of the electromagnetic field generated by the wireless power transmission on the first electrode and the influence of the second electrode are at least partially offset, thereby suppressing the influence of the wireless power transmission on the wireless communication. At the same time, miniaturization of the wireless communication system can be realized.

1 is a diagram showing a system configuration of a radio communication system; FIG. It is a figure which shows the structure of an antenna part. It is a figure which shows the structure of the antenna part in simulation. It is a figure which shows the result of a simulation. It is a figure which shows the modification of an antenna part. FIG. 10 is a diagram showing a modification of the radio communication system; It is a figure which shows the modification of an antenna part. It is a figure which shows the modification of arrangement|positioning of a coil and a coupler.

[System configuration]
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a system configuration of a wireless communication system 100 (hereinafter referred to as system 100) according to this embodiment. The system 100 has a communication device 101 and a communication device 102 that wirelessly communicates with the communication device 101 . The communication device 101 has an antenna section 201 and a circuit section 202 . The communication device 102 has an antenna section 301 , a circuit section 302 and a control section 303 .

In this embodiment, an example in which the system 100 is mounted on a robot arm will be described. In this example, the communication device 101 is included in the arm portion of the robot arm and the communication device 102 is included in the hand portion of the robot arm. Between the communication device 101 and the communication device 102, wireless communication for transmitting control signals for controlling the operation of the robot arm and power transmission for operating the hand portion are performed.

The antenna section 201 of the communication device 101 has a substrate 281 and a communication antenna 282 and a power transmission antenna 283 installed on the substrate 281 . The antenna section 301 of the communication device 102 has a substrate 381 and a communication antenna 382 and a power transmission antenna 383 installed on the substrate 381 . The power transmission antenna 283 and the power transmission antenna 383 are coiled conductors that function as antennas for wireless power transmission by magnetic resonance, electromagnetic induction, or both. The communication antenna 282 and the communication antenna 382 function as communication antennas for performing wireless communication for wirelessly transmitting data based on electromagnetic field coupling.

Electromagnetic field coupling in this embodiment includes both electric field coupling and magnetic field coupling. That is, wireless communication between antennas may be performed by electric field coupling, magnetic field coupling, or both electric field coupling and magnetic field coupling. Further, hereinafter, the power transmission antenna 283 and the power transmission antenna 383 are also denoted as the coil 283 and the coil 383, respectively, and the communication antenna 282 and the communication antenna 382 are also denoted as the coupler 282 and the coupler 382, respectively.

The circuit unit 202 of the communication device 101 has a connector 251 connected to the signal line, a connector 252 connected to the power line, and a power transmission circuit 253 controlling power transmission via the coil 283 . Furthermore, the circuit section 202 has a communication circuit 254 that controls wireless communication via the coupler 282 and a central processing unit 255 . The circuit unit 302 of the communication device 102 has a communication circuit 351 that controls wireless communication via the coupler 382 and a power reception circuit 352 that controls power reception via the coil 383 . That is, power transmission control between devices is performed by the power transmission circuit 253 and the power reception circuit 352 , and communication control between devices is performed by the communication circuit 254 and the communication circuit 351 . The control unit 303 of the communication device 102 includes a motor 354 that drives the hand using power received by the power receiving circuit 352 as a power source, and a sensor 353 that detects pressure applied to the hand. Sensor data obtained by the sensor 353 is transmitted to the communication device 101 by the communication circuit 351 .

The system 100 has a structure for supporting the communication device 101 and the communication device 102 so as to maintain a predetermined relationship (for example, a positional relationship in which the distance between the antenna section 201 and the antenna section 301 is approximately constant). The system 100 also has a drive unit (not shown) that rotates at least one of the arm portion and the hand portion of the robot arm by a motor or the like. Rotation control by the drive section rotates the antenna section 201 and the antenna section 301 relative to each other. The driving unit may be provided inside at least one of the communication devices 101 and 102 , or may be provided separately from the communication devices 101 and 102 .

Note that the number of power transmission antennas and communication antennas included in system 100 is not limited to the example in FIG. Wireless communication and wireless power transfer between the communication device 101 and the communication device 102 may be unidirectional or bidirectional. Also, the application of the system 100 is not limited to a robot arm. For example, the communication device 101 is included in an installation portion of an imaging device such as a network camera, and the communication device 102 is included in a turning portion of the imaging device, and an image acquired by the imaging device between the communication devices 101 and 102 Data may be transmitted by wireless communication.

[Antenna configuration]
FIG. 2A is a diagram showing the configuration of the antenna section 201 and the antenna section 301. FIG. Coupler 282 of antenna section 201 has electrodes 2821 and 2822 . In this embodiment, the case where the communication device 101 performs differential signal communication via the electrodes 2821 and 2822 will be mainly described. That is, signals having opposite phases are input from the communication circuit 254 to the electrodes 2821 and 2822 . Note that the communication device 101 may use one of the electrodes 2821 and 2822 as a ground and perform single-ended signal communication via the other. However, by using differential signals, it becomes easier to suppress the influence of noise from the outside in communication.

The coupler 282 and the coil 283 are arranged concentrically on substantially the same plane on the substrate 281 . In the antenna section 201, a coil 283 and a coupler 282 are formed as copper patterns on a substrate 281 made of FR4. However, the configuration of the antenna section 201 is not limited to this. For example, a conductor wire rod as a coil 283 and a coupler 282 may be fixed to a substrate 281 made of plastic such as ABS. Also, the substrate 281 may have a cavity in its central portion. Also, the coupler 282 and the coil may be configured on different substrates.

In the configuration shown in FIG. 2A, the center of the ring formed by the electrode 2821 and the center of the ring formed by the electrode 2822 are the same, and the radii of these rings are different. Then, the drive section of system 100 rotates electrodes 2821 and 2822 about an axis passing through the centers of these rings. According to such a configuration, stable communication can be performed even while the antenna section 201 or the antenna section 301 is rotating. In this embodiment, the case where the electrode 2821 and the electrode 2822 are rotated by rotating the entire antenna unit 201 by the driving unit will be mainly described. However, the present invention is not limited to this, and the driving section may rotate either one of the electrodes 2821 and 2822 . Also, the drive section may rotate the antenna section 301 instead of rotating the antenna section 201 . Further, the "ring" formed by the electrodes in this embodiment is not limited to a strictly circular shape, and may be, for example, an elliptical shape.

The configuration of the antenna section 301 is similar to that of the antenna section 201, and the antenna section 201 and the antenna section 301 are arranged to face each other. That is, electrode 2821 faces electrode 3821 , electrode 2822 faces electrode 3822 , and coil 283 faces coil 383 . When voltage is applied to the coil 283 by the power transmission circuit 253 , a potential is generated in the coil 383 due to magnetic field resonance or electromagnetic induction, and power is received by the power reception circuit 352 . On the other hand, when a voltage is applied to the electrodes 3821 and 3822 by the communication circuit 351, a positive potential is generated in the electrode 2821 due to electromagnetic field coupling between the electrodes 2821 and 3821, and a positive potential is generated between the electrodes 2822 and 3822. Electromagnetic field coupling at produces a negative potential on electrode 2822 . The communication circuit 254 controls wireless communication based on the difference between the potential generated at the electrode 2822 and the potential generated at the electrode 3822 and receives a signal. Note that the electrode 2821 may be used as a negative electrode and the electrode 2822 may be used as a positive electrode. The direction of communication is not limited to the above, and the communication circuit 254 may apply voltage to the electrodes 2821 and 2822 to transmit signals, or may switch between signal transmission and reception. In this embodiment, it is assumed that communication is performed between the coupler 282 and the coupler 382 according to the baseband system.

FIG. 2(b) shows a cross-sectional view along AB in FIG. 2(a). In FIG. 2B, a coil 283, an electrode 2821, and an electrode 2822 are arranged in order from the center of the substrate 281 toward the outside. A voltage of several hundred volts is applied to the coil 283, for example, when wireless power transmission of 50 W output is performed. On the other hand, the potential generated in the coupler 282 in response to the voltage application to the coupler 382 is smaller than the voltage applied to the coil 283, such as about 1 volt. Therefore, when the distance between the coil 283 and the coupler 282 is short, the potential generated in the coupler 282 due to the influence of the electromagnetic field corresponding to the voltage application to the coil 283 interferes with the signal waveform of communication and becomes noise, resulting in communication failure. Errors can occur. In FIG. 2(b), the influence of the electromagnetic field generated by the coil 283 on the coupler 282 is conceptually represented by arrows.

The effect of the electromagnetic field generated by the coil 283 on the coupler 282 will be described with reference to FIG. 2(c). The electromagnetic field produced by coil 283 affects both electrodes 2821 and 2822 . However, the electrode 2821 closer to the coil 283 is affected more than the electrode 2822 farther away. FIG. 2(c) shows the magnitude of the potential generated as noise in each electrode in response to voltage application to the coil 283, assuming that the electrode 2821 is the positive electrode and the electrode 2822 is the negative electrode. Since the communication circuit 254 performs differential communication, a waveform obtained by subtracting the potential at the negative electrode from the potential at the positive electrode is processed as a signal for communication. Therefore, if the potential of the noise received by the positive electrode and the potential of the noise received by the negative electrode are different, the influence of the noise from the coil 283 remains in the waveform after subtraction. This noise may interfere with signals communicated by electromagnetic field coupling between coupler 282 and coupler 382, resulting in communication errors.

On the other hand, FIG. 2(d) shows a configuration in which the electrode 2822 is made thicker than the configuration of the antenna section 201 shown in FIG. 2(b). That is, the surface area of electrode 2822 with a longer distance from coil 283 is larger than the surface area of electrode 2821 with a shorter distance from coil 283 . As a result, the electromagnetic field generated by the coil 283 has a greater influence on the electrode 2822 than in the case of the configuration of FIG. 2(b). As a result, as shown in FIG. 2(e), the potential of the noise received by the positive electrode and the potential of the noise received by the negative electrode are approximately the same in magnitude, and the waveform obtained by subtracting the potential of the negative electrode from the potential of the positive electrode is the noise. The effects are canceled and interference between noise and communication signals is suppressed.

In this way, by increasing the thickness of each of the two electrodes of the coupler 282 as the distance from the coil 283, which is the noise source, increases, the influence of noise can be suppressed. Here, the description has been given assuming that the negative electrode is located outside the positive electrode (position far from the noise source), but the positional relationship between the positive electrode and the negative electrode is not limited to this. 2(d) shows an example in which the electrode 2822 farther from the coil 283 is made thicker than the configuration of FIG. 2(b) without changing the width of the electrode 2821 closer to the coil 283. However, it is sufficient if the electrode 2822 is relatively thicker than the electrode 2821 . For example, the electrode 2821 may be made thin without changing the width of the electrode 2822, or the electrode 2822 may be made thick while making the electrode 2821 thin. With such a configuration, it is also possible to suppress interference between noise and communication signals due to wireless power transmission based on the same principle as in the case of FIG. 2(d).

[simulation result]
Next, the result of an electromagnetic field simulation will be described regarding the effect of interference suppression by the above-described configuration. FIG. 3 shows the configuration of the antenna section 301 in the simulation. FIG. 3A shows the overall configuration of the antenna section 301, and FIGS. It is the figure which expanded the broken line part of 3 (a). Below, the configuration of FIG. 3(b) is referred to as configuration A, and the configuration of FIG. 3(c) is referred to as configuration B. Electrode 3822 is used as a positive electrode and electrode 3821 is used as a negative electrode. In both configuration A and configuration B, the pattern width of the electrode 3821 is 1.3 mm. On the other hand, the pattern width of the electrodes 3822 in configuration A is 1.3 mm, and the pattern width of the electrodes 3822 in configuration B is 1.45 mm. In both configuration A and configuration B, the distance between electrodes 3822 and 3821 is 0.4 mm. In addition, in each of configuration A and configuration B, antenna section 201 is assumed to have the same configuration as antenna section 301 .

(a) of FIG. 4 shows a state in which the antenna section 201 and the antenna section 301 are opposed to each other. However, the distance between the coupler 282 and the coupler 382 in the simulation is 1.3 mm, and the distance is shown larger than that in FIG. 4(a) for the sake of convenience. When a voltage is applied to coupler 382, a signal is transmitted to coupler 282 by electromagnetic field coupling. The transmission characteristic of the signal at this time is expressed as S21(CC). On the other hand, when voltage is applied to the coil 383, noise is generated in the electrode 3822. FIG. This noise transfer characteristic is denoted as S21(P-). At the same time, noise also occurs in the electrode 3821, and the transmission characteristic of this noise is denoted as S21(P+). The degree of interference from coil 283 to coupler 382 is obtained as follows. The result of subtracting S21 (P-) from S21 (P+) is S21 (P±), and the isolation between S21 (CC) and S21 (P±) is measured. can be determined to be low.

FIG. 4(b) shows a simulation result of the degree of interference in the configuration A shown in FIG. 3(b). S21(CC) is -21.1 db when the center frequency of the signal transmitted from the coupler 382 to the coupler 282 is 100 MHz. On the other hand, when the carrier frequency of wireless power transmission by the coil 383 is 3 MHz, S21(P±) is −95.9 db. Therefore, the isolation between S21(CC) and S21(P±) is -74.8db.

FIG. 4(e) shows a simulation result of the degree of interference for the configuration B shown in FIG. 3(c). S21(CC) is -20.8 db when the central frequency of the signal transmitted from the coupler 382 to the coupler 282 is 100 MHz. On the other hand, when the carrier frequency of wireless power transmission by the coil 383 is 3 MHz, S21(P±) is −106.2 db. Therefore, the isolation between S21(CC) and S21(P±) is -85.3db.

Comparing FIG. 4B and FIG. 4C, it can be seen that the configuration B, in which the electrodes 3822 and 2822 are thicker, has better isolation characteristics by 10.5 dB. That is, it can be seen that interference between wireless power transmission and wireless communication can be suppressed by making the width of the electrode farther from the coil 383 thicker than the width of the electrode closer to the coil 383 of the two electrodes of the coupler 382 .

[Modification]
The configuration of the system 100 described above is an example, and the method of suppressing interference by varying the width of the electrodes can also be applied to other configurations. A modification of the configuration of the system 100 will be described below. A modified example of the antenna section 201 described below can also be applied to the antenna section 301 in the same manner.

In the description using FIG. 2 and the like, the electrodes 2821 and 2822 each form a ring shape, and the width of the electrode 2822 in the radial direction of the ring formed by the electrode 2822 is the width of the electrode 2821 in the radial direction of the ring formed by the electrode 2821. The width of the However, the shape of the electrodes is not limited to this, and as shown in FIG. ) may be used. With such a configuration, the influence of the electromagnetic field generated by the coil 283 on the communication by the coupler 282 can be further suppressed.

Further, as shown in FIG. 5B, by providing a plurality of couplers in the antenna section 201, a configuration in which two-way communication can be executed at the same time may be employed. In FIG. 5B, a pair of electrodes 2821 and 2822 constitute a coupler 282 for receiving differential signals, and a pair of electrodes 2831 and 2832 constitute a coupler 284 for transmitting differential signals. Note that the arrangement of the coupler for transmission and the coupler for reception may be reversed. In this configuration, by making the electrode 2822 thicker than the electrode 2821 and making the electrode 2832 thicker than the electrode 2831, it is possible to suppress the influence of the wireless power transmission by the coil 283 on the communication via the coupler as described above. In addition, the electrode 2831 may be made thinner than the electrode 2822 in order to make the signal of communication in each direction nearly uniform. For example, the widths of the electrodes 2821 and 2831 may be substantially the same, the widths of the electrodes 2822 and 2832 may be substantially the same, and the width of the electrode 2822 may be wider than that of the electrode 2821 . Also, these two couplers may be used to enable unidirectional two-system communication. As shown in FIG. 5(c), even in the configuration using two pairs of couplers, the electrodes may form a part of the ring shape as in the case of FIG. 5(a).

Also, the above configuration, which has been described mainly for the case of transmitting differential signals, may be applied to the transmission of single-ended signals. For example, one of the electrodes 2821 and 2822 in FIGS. 5(a) to 5(c) may be used as a ground and the other may receive a single-ended signal.

Also, the positional relationship between the coupler 282 and the coil 283 is not limited to the above example. For example, in the above example, the ring formed by the electrode 2821 and the ring formed by the electrode 2822 are positioned outside the ring formed by the coil 283 when viewed from the direction perpendicular to the radial direction of the ring formed by the electrode 2821. . However, as shown in FIG. 5(d), the ring formed by the electrodes 2821 and the ring formed by the electrodes 2822 may be positioned inside the ring formed by the coil 283. FIG. In this case, by making the width of the electrode farther from the coil 283, that is, the inner electrode 2822, wider than the width of the electrode closer to the coil 283, that is, the outer electrode 2821, interference between wireless power transmission and wireless communication is eliminated. can be suppressed. In addition, as shown in FIG. 5(e), even in a configuration using two couplers, the coil 283 may be arranged outside the couplers. Furthermore, a configuration in which the ring formed by the electrodes in FIG. 5D is cut (configuration in FIG. ) configuration) is also applicable. Also, as shown in FIG. 5(h) and FIG. 5(i), the shape of the electrode may be arcuate.

In the system 100 described above, the coupler 282 and the coil 283 are positioned substantially on the same plane, and the coupler 382 and the coil 383 are positioned substantially on the same plane. On the other hand, in a system 600 shown in FIG. 6, an antenna section 601 that performs wireless power transmission and wireless communication is three-dimensionally configured. The antenna section 601 may be fixed or rotatable. The configuration of the system 600 other than the antenna section 601 is the same as that of the system 100, and is given the same reference numerals.

An example of the configuration of the antenna section 601 is shown in FIG. In the configuration of FIG. 7A, the coil 283 and the coil 383 are arranged vertically, and wireless power transmission is performed between these coils. The coil 283 and the electrode 3821, the electrode 3822, the electrode 2821, and the electrode 2822 are arranged in the vertical direction in order from the coil 283 and the coil 383 closer to it. Here, the direction (vertical direction) perpendicular to the ring formed by the electrode 2821 is the same direction as the direction perpendicular to the ring formed by the electrode 2822 . In this case, by making the width of the electrode 3822 farther from the coil 383 in the vertical direction out of the two electrodes of the coupler 382 wider than the width of the electrode 2821 closer to the coil 383, wireless power transmission and wireless communication can be achieved. interference can be suppressed. The same applies to the electrodes 2821 and 2822 that the coupler 282 has.

In addition, as shown in FIG. 7B, the electrode in the antenna section 601 may form a part of the ring shape. Also, coupler 282 may be placed closer to the coil than coupler 382 . Also, coil 383 may be located closer to the coupler than coil 283. Furthermore, the vertical relationship between the coil and the coupler may be reversed. Further, the electrodes of the coupler 282 and the electrodes of the coupler 382 may have different shapes. For example, as shown in FIG. 7C, the electrodes 3821 and 3822 may be arc-shaped.

Further, as shown in FIG. 7(d), a pair of couplers may be provided above and below the coil 283 and the coil 383, respectively, to enable bidirectional communication or unidirectional two-system communication. In this case, the upper electrodes of the couplers 282 and 382 are made thicker than the lower electrodes, and the lower electrodes of the couplers 384 and 284 are made thicker than the upper electrodes. Communication interference can be suppressed. Even in such a configuration in which couplers are arranged above and below the coil, the electrodes may form part of a ring shape as shown in FIG. and the shape of the coupler 284 may be different.

In each of the configurations described above, the case where the coil and the coupler are configured concentrically has been mainly described, but the arrangement of the coil and the coupler is not limited to this. For example, as shown in FIG. 8, in the antenna section 201, the coil 283 and the coupler 282 may be arranged side by side on a plane. 8(a) shows a view of the antenna section 201 from a direction perpendicular to the plane on which the coil 283 and the coupler 282 are arranged, and FIG. 8(b) shows a view from a direction horizontal to the plane. showing. In this case, by making the width of the electrode 2822 farther from the coil 283 of the two electrodes of the coupler 282 wider than the width of the electrode 2821 closer to the coil 283, interference between wireless power transmission and wireless communication can be prevented. can be suppressed.

The shape of the electrodes of the coupler 282 and the coupler 382 is not limited to a ring shape or a part of a ring shape. For example, the shape of the electrodes 2822 and 3822 may be circular, polygonal, or flat. Also, the shape of the coil 283 is not limited to the above example, and may be polygonal, for example.

As described above, the wireless communication system (system 100 and system 600) according to this embodiment includes coil 283, coil 383, electrode 2821, electrode 2822, electrode 3821, and electrode 3822. The distance between coil 283 and electrode 2822 is greater than the distance between coil 283 and electrode 2821 , and the surface area of electrode 2822 is greater than the surface area of electrode 2821 . Wireless communication is performed based on the difference between the potential generated by the electromagnetic field coupling between the electrodes 2822 and 3822 and the potential generated by the electromagnetic field coupling between the electrodes 2821 and 3821 .

Further, the antenna section 201 having each configuration described above can be manufactured by, for example, the following method. In order to manufacture the antenna section 201 shown in FIG. 2A, the coil 283 is first arranged on the substrate 281 . A pattern of electrodes 2821 is arranged concentrically with respect to the coil 283 . Further, an electrode 2822 having a surface area larger than that of the electrode 2821 is arranged so as to be concentric with the coil 283 and the electrode 2821 . Here, by making the radius of the electrode 2822 larger than the radius of the electrode 2821 , the distance between the coil 283 and the electrode 2822 is made longer than the distance between the coil 283 and the electrode 2821 . A power transmission circuit 253 is connected to the coil 283 , and a communication circuit 254 is connected to the electrodes 2821 and 2822 . By using the antenna unit 201 configured in this manner, interference between wireless power transmission and wireless communication can be suppressed as described above. Note that the order of arranging each member on the substrate and the order of connecting the members are not limited to the above example, and can be changed. Also, the antenna section 301 can be manufactured by the same method as described above. The antenna portions shown in FIGS. 5(a) to 5(i) and FIGS. 7(a) to 7(f) can also be manufactured in a similar manner.

According to the above configuration, the influence of the electromagnetic field generated by the wireless power transmission on the electrode 2821 and the influence of the electrode 2822 are at least partially offset, thereby suppressing the influence of the wireless power transmission on the wireless communication. can do. This makes it possible to arrange the coil 283 and the coupler 282 close to each other. As a result, it is possible to reduce the size of the wireless communication system that performs wireless power transmission and wireless communication, and it is possible to reduce the thickness, size, and weight of the device on which the system is installed.

In this embodiment, a case has been described in which electrical signals are transmitted and received between the coupler for transmission and the coupler for reception according to the baseband system. Since the baseband system does not require modulation or demodulation of electrical signals, the circuit scale can be reduced and communication can be performed with low delay. However, the baseband system is more susceptible to noise than the system that modulates and demodulates electrical signals for communication, and there is a strong need to suppress interference between wireless power transmission and wireless communication. Therefore, by applying the configuration for suppressing interference as described in this embodiment, wireless power transmission and baseband communication can be performed stably at the same time. However, the communication method is not limited to this. For example, carrier communication may be performed by modulating a carrier wave transmitted from a transmission coupler to a reception coupler with an electrical signal generated by a transmission circuit. When carrier communication is performed, interference in communication can be suppressed by making the frequency of the carrier wave transmitted in wireless communication different from the frequency of the carrier wave in wireless power transmission.

100 wireless communication system 282, 382 communication antenna 283, 383 power transmission antenna 2821, 2822, 3821, 3822 electrode

Claims (14)

a power transmission antenna for wireless power transmission;
a communication antenna having a first electrode forming at least a portion of a first ring shape and a second electrode forming at least a portion of a second ring shape ;
A potential generated by electromagnetic field coupling between the first electrode and a third electrode of another communication device, and an electromagnetic field coupling between the second electrode and a fourth electrode of the other communication device and a communication control means for controlling wireless communication based on the difference between the potential generated by
The distance between the power transmission antenna and the first electrode is longer than the distance between the power transmission antenna and the second electrode, and the width of the first electrode in the radial direction of the first ring is the first electrode. A communication device, wherein the width of the second electrode in the radial direction of two rings is larger than that of the second electrode. the center of the first ring and the center of the second ring are aligned,
2. The communication device according to claim 1 , wherein the radius of said first ring and the radius of said second ring are different. The power transmission antenna forms a third ring shape,
3. The method according to claim 2 , wherein the first ring and the second ring are positioned outside the third ring when viewed from a direction perpendicular to the radial direction of the first ring. Communication device. the power transmission antenna is shaped like a third ring;
3. The method according to claim 2 , wherein the first ring and the second ring are positioned inside the third ring when viewed from a direction perpendicular to the radial direction of the first ring. Communication device. 5. The communication device according to any one of claims 1 to 4, wherein the power transmission antenna, the first electrode, and the second electrode are located on the same substrate. The direction perpendicular to the radius of the first ring and the direction perpendicular to the radius of the second ring are the same direction,
The distance between the power transmission antenna and the first electrode in the same direction is longer than the distance between the power transmission antenna and the second electrode in the same direction. Communication device. the first electrode and the second electrode around an axis passing through the center of the first ring and the center of the second ring;
The communication device according to any one of claims 1 to 6 , further comprising rotation control means for rotating at least one of the electrodes. 8. The communication device according to claim 1, wherein said communication control means performs differential signal communication via said first electrode and said second electrode. 8. The communication control means uses one of the first electrode and the second electrode as a ground, and performs single-ended signal communication via the other. A communication device according to any one of claims 1 to 3. A wireless communication system comprising the communication device according to any one of claims 1 to 9 and the other communication device,
The wireless communication system, wherein the other communication device has another power transmission antenna for performing the wireless power transmission with the power transmission antenna. the communication device is included in a first portion of a robotic arm;
the other communication device is included in a second portion of the robotic arm;
11. The wireless communication system according to claim 10 , wherein said communication control means controls said wireless communication for transmitting a control signal for controlling the operation of said robot arm. the communication device is included in a first portion of an imaging device;
the communication device is included in a second portion of the imaging device;
11. The wireless communication system according to claim 10 , wherein said communication control means controls said wireless communication for transmitting image data acquired by said imaging device. a first power transmission antenna, a second power transmission antenna, a first electrode forming at least a portion of a first ring shape , a second electrode forming at least a portion of a second ring shape , and a third A communication method by a wireless communication system having an electrode and a fourth electrode,
The distance between the first power transmission antenna and the first electrode is longer than the distance between the first power transmission antenna and the second electrode, and the surface of the first electrode in the radial direction of the first ring the width is greater than the width of the second electrode in the radial direction of the second ring ;
Wireless communication based on a difference between a potential generated by electromagnetic field coupling between the first electrode and the third electrode and a potential generated by electromagnetic field coupling between the second electrode and the fourth electrode A communication method characterized by having a communication control step for controlling. 14. The method according to claim 13 , further comprising a rotation control step of rotating the first electrode and the second electrode around an axis passing through the center of the first ring and the center of the second ring. Communication method as described.

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