JP7483456B2 - Communication device, communication system and control method - Google Patents

Description

This application relates to a communication device, a communication system, and a control method.

It is known to transmit and receive information by non-contact communication from a recording means attached to an item or the like. Patent Document 1 discloses a non-contact communication system having a storage means for storing management information of the item, an antenna for generating an induced magnetic field provided in a storage body for storing the item with the storage means, and a reader/writer device for communicating with the storage means by non-contact communication via the antenna.

JP 2020-10268 A

In conventional non-contact communication, multiple recording means, etc. may be placed in different locations, rather than stored in a storage body. For this reason, conventional communication devices have room for improvement in wireless communication between multiple communication devices in different locations.

A communication device according to one aspect includes a plurality of antennas, each having a transmitting terminal configured to be capable of feeding a transmitting signal and a receiving terminal configured to be capable of supplying a receiving signal, a control unit configured to control wireless communication with a plurality of external communication devices, and a connection unit configured to be capable of connecting any of the transmitting terminals of the plurality of antennas to the control unit and any of the receiving terminals of the plurality of antennas to the control unit, and the transmitting terminal of one of the plurality of antennas is arranged so as to ensure isolation between the transmitting terminal of the other of the plurality of antennas.

A communication system according to one aspect includes a first communication device and a plurality of second communication devices configured to be capable of wireless communication with the first communication device, the first communication device including a plurality of antennas each having a transmission terminal configured to be capable of feeding a transmission signal and a reception terminal configured to be capable of supplying a reception signal, a control unit configured to control wireless communication with a plurality of external communication devices, and a connection unit configured to be able to connect any of the transmission terminals of the plurality of antennas to the control unit and to be able to connect any of the reception terminals of the plurality of antennas to the control unit, the transmission terminal of one of the plurality of antennas being arranged so as to ensure isolation between the reception terminals of the other of the plurality of antennas.

The control method according to one aspect is a method for controlling a communication device, comprising: a plurality of antennas, each having a transmitting terminal configured to be capable of feeding a transmitting signal and a receiving terminal configured to be capable of feeding a receiving signal; a control unit configured to control wireless communication with a plurality of external communication devices; and a connection unit configured to be capable of connecting any of the transmitting terminals of the plurality of antennas to the control unit and any of the receiving terminals of the plurality of antennas to the control unit, wherein the transmitting terminal of one of the plurality of antennas is arranged so as to ensure isolation from the receiving terminals of the other of the plurality of antennas, and the control unit attempts transmission and reception by changing at least one of the transmitting terminal and the receiving terminal connected via the connection unit.

FIG. 1 is a diagram illustrating an example of a communication system according to an embodiment. FIG. 2 is a diagram illustrating an example of a communication system according to the embodiment. FIG. 3 is a perspective view illustrating an example of an antenna according to the embodiment. FIG. 4 is a cross-sectional view of the antenna taken along line L1-L1 shown in FIG. FIG. 5 is a partially exploded perspective view of the antenna shown in FIG. FIG. 6 is a block diagram of the antenna shown in FIG. FIG. 7 is a plan view illustrating the configuration of the radiation conductor shown in FIG. FIG. 8 is a flowchart illustrating an example of a processing procedure of the first communication device according to the embodiment. FIG. 9 is a diagram for explaining an example of the operation of the first communication device according to the embodiment. FIG. 10 is a schematic diagram showing an example of the arrangement of a plurality of antennas of the first communication device according to the embodiment. FIG. 11 is a schematic diagram showing a modified example of the arrangement of a plurality of antennas according to the embodiment. FIG. 12 is a schematic diagram showing a modified example of the configuration and arrangement of a plurality of antennas according to the embodiment. FIG. 13 is a schematic diagram showing a modified example of the configuration and arrangement of a plurality of antennas according to the embodiment. FIG. 14 is a schematic diagram showing a modified example of the configuration and arrangement of a plurality of antennas according to the embodiment.

Several embodiments for implementing the communication system according to the present application will be described in detail with reference to the drawings. In the following description, similar components may be given the same reference numerals. Furthermore, duplicate descriptions may be omitted.

[An example of a communication system]
1 and 2 are diagrams for explaining an example of a communication system according to an embodiment. As shown in FIG. 1 and FIG. 2, the communication system 1000 has a first communication device 1 and a plurality of second communication devices 500-1, 500-2, and 500-3. The first communication device 1 is, for example, a parent device. The second communication devices 500-1, 500-2, and 500-3 are, for example, child devices located in different positions. The first communication device 1 is configured to be capable of wireless communication with the plurality of second communication devices 500-1, 500-2, and 500-3. The first communication device 1 has a function of collecting information from the plurality of second communication devices 500-1, 500-2, and 500-3.

In the example shown in FIG. 1, the communication system 1000 is configured such that the first communication device 1 emits electromagnetic waves including a transmission signal from the antenna 10-1, and receives electromagnetic waves including reception signals from the multiple second communication devices 500 at the antenna 10-1. When the multiple second communication devices 500 receive electromagnetic waves including a transmission signal from the antenna 10-1, the electromagnetic waves are modulated according to the electric circuit in the second communication device 500 and backscattered. The backscattered electromagnetic waves include a reception signal. The reception signal includes sensor information. In the example shown in FIG. 2, the communication system 1000 is configured such that the first communication device 1 emits electromagnetic waves including a transmission signal from the antenna 10-2, and receives electromagnetic waves including reception signals from the multiple second communication devices 500 at the antenna 10-1. In this way, the communication system 1000 can improve wireless communication between the multiple second communication devices 500 in different positions by switching between the antennas 10-1 and 10-2.

In the following, when there is no particular distinction between antennas 10-1 and 10-2, antennas 10-1 and 10-2 will be referred to as "antenna 10." In this embodiment, a case will be described in which the communication system 1000 has two antennas, 10-1 and 10-2, but this is not limited to this. The communication system 1000 may have three or more antennas 10.

In the following, when there is no particular distinction between the second communication devices 500-1, 500-2, and 500-3, the second communication devices 500-1, 500-2, and 500-3 will be described as "second communication devices 500." In this embodiment, a case will be described in which the communication system 1000 has three second communication devices 500-1, 500-2, and 500-3, but this is not limited to this. The communication system 1000 may have a number of second communication devices 500 other than three.

[An example of a second communication device]
1 and 2, the second communication device 500 has, for example, a sensor 510, a communication unit 520, and a control unit 530. The control unit 530 is electrically connected to the sensor 510 and the communication unit 520. The second communication device 500 includes, for example, a communication device capable of providing various information to the first communication device 1. The second communication device 500 may be, for example, an RF (Radio Frequency) tag or the like.

The sensor 510 may include, for example, a speed sensor, a vibration sensor, an acceleration sensor, a rotation angle sensor, an angular velocity (gyro) sensor, a geomagnetic sensor, a magnet sensor, a temperature sensor, a humidity sensor, an air pressure sensor, a light sensor, an illuminance sensor, a UV sensor, a gas sensor, a gas concentration sensor, an atmosphere sensor, a level sensor, an odor sensor, a pressure sensor, an air pressure sensor, a contact sensor, a wind sensor, an infrared sensor, a human presence sensor, a displacement sensor, an image sensor, a weight sensor, a smoke sensor, a leakage sensor, a vital sensor, a battery level sensor, an ultrasonic sensor, or a receiving device for a GPS (Global Positioning System) signal. The sensor 510 can supply sensor information indicating the sensing result to the control unit 530.

The communication unit 520 has an antenna 521. The communication unit 520 can receive radio waves via the antenna 521 and supply the received data to the control unit 530. The communication unit 520 can transmit radio waves from the antenna 521 under the control of the control unit 530.

The control unit 530 is an arithmetic processing device. The arithmetic processing device includes, but is not limited to, a central processing unit (CPU), a system-on-a-chip (SoC), a micro control unit (MCU), a field-programmable gate array (FPGA), and a coprocessor. The control unit 530 is configured to execute a program stored in a storage device inside the second communication device 500, for example, to comprehensively control the operation of the second communication device 500 and realize various functions. When the control unit 530 receives a transmission command from the first communication device 1, it can control the communication unit 520 to emit radio waves indicating a response signal including information on the command target. The response signal can include information that can identify the second communication device 500. When the control unit 530 receives a stop command from the first communication device 1, it executes a process to stop the transmission of radio waves from the antenna 521.

A configuration example of the second communication device 500 according to this embodiment has been described above. Note that the above configuration described using Figures 1 and 2 is merely an example, and the configuration of the second communication device 500 according to this embodiment is not limited to this example. The configuration of the second communication device 500 according to this embodiment can be flexibly modified according to the specifications and operation.

[Configuration Example of First Communication Device]
1 and 2, the first communication device 1 includes, for example, a communication device configured to collect various information from a plurality of second communication devices 500. The first communication device 1 has a plurality of antennas 10-1, 10-2, a connection unit 11, a storage unit 12, a control unit 13, a transmission unit 14, a reception unit 15, and a cancellation unit 16. The control unit 13 is electrically connected to the connection unit 11, the storage unit 12, the transmission unit 14, the reception unit 15, and the cancellation unit 16.

In this embodiment, the first communication device 1 has two antennas 10-1 and 10-2, but is not limited to this. The number of antennas 10 of the first communication device 1 may be one, or may be three or more.

[Antenna configuration example]
Fig. 3 is a perspective view showing an example of an antenna 10 according to an embodiment. Fig. 4 is a cross-sectional view of the antenna 10 taken along line L1-L1 shown in Fig. 3. Fig. 5 is a perspective view in which a part of the antenna 10 shown in Fig. 3 is exploded. Fig. 6 is a block diagram of the antenna 10 shown in Fig. 3. Fig. 7 is a plan view for explaining the configuration of the radiation conductor shown in Fig. 3.

3 and 4, the antenna 10 includes a base 120, a radiation conductor 130, a ground conductor 140, a first connecting conductor 155, a second connecting conductor 156, a third connecting conductor 157, and a fourth connecting conductor 158. The antenna 10 includes a feeder 150 and a circuit board 160. The radiation conductor 130, the ground conductor 140, and the feeder 150 function as an antenna element 111. The feeder 150 includes a first feeder 151, a second feeder 152, a third feeder 153, and a fourth feeder 154. The number of each of the first connecting conductors 155 to the fourth connecting conductors 158 included in the antenna 10 shown in FIG. 3 is two. However, the number of each of the first connecting conductors 155 to the fourth connecting conductors 158 included in the antenna 10 may be one, or may be three or more.

The antenna element 111 is configured to be capable of oscillating at a predetermined resonant frequency. The antenna 10 is configured to radiate electromagnetic waves by the antenna element 111 oscillating at the predetermined resonant frequency. The antenna 10 may have at least one of the at least one resonant frequency band of the antenna element 111 as an operating frequency. The antenna 10 may radiate electromagnetic waves at the operating frequency. The wavelength of the operating frequency may be an operating wavelength, which is the wavelength of the electromagnetic waves at the operating frequency of the antenna 10.

The antenna element 111 is configured to exhibit artificial magnetic conductor characteristics, as described below, for electromagnetic waves of a predetermined frequency incident on a surface approximately parallel to the xy plane of the antenna element 111 from the positive direction of the z axis. In this disclosure, "artificial magnetic conductor characteristics" refers to the characteristics of a surface where the phase difference between the incident wave and the reflected wave at the operating frequency is 0 degrees. On a surface that has artificial magnetic wall characteristics, the phase difference between the incident wave and the reflected wave is -90 degrees to +90 degrees in the operating frequency band. The operating frequency band includes the resonant frequency that exhibits the artificial magnetic wall characteristics and the operating frequency.

Since the antenna element 111 exhibits the above-mentioned artificial magnetic wall characteristics, the radiation efficiency of the antenna 10 can be maintained even if the ground conductor 165 (described below) of the circuit board 160 is positioned on the negative side of the z-axis of the antenna 10, as shown in FIG. 5.

The substrate 120 may contain, for example, a ceramic material or a resin material as its composition. The ceramic material includes an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, a crystallized glass in which crystal components are precipitated in a glass matrix, and a microcrystalline sintered body such as mica or aluminum titanate. The resin material includes cured uncured materials such as epoxy resin, polyester resin, polyimide resin, polyamideimide resin, polyetherimide resin, and liquid crystal polymer.

The base 120 is in contact with the radiation conductor 130, the ground conductor 140, and the feed line 150. The base 120 may have a shape corresponding to the shape of the radiation conductor 130. The base 120 may be a substantially regular square prism. The base 120 includes an upper surface 121 and a lower surface 122. Each of the upper surface 121 and the lower surface 122 may be the upper surface and the bottom surface of the base 120, which is a substantially regular square prism. The upper surface 121 and the lower surface 122 may be substantially parallel to the xy plane. Each of the upper surface 121 and the lower surface 122 may be substantially square. One of the two diagonals of the substantially square upper surface 121 and the lower surface 122 is along the x direction. The other of the two diagonals is along the y direction. The upper surface 121 is located on the positive side of the z axis than the lower surface 122.

The radiating conductor 130 functions as a resonator. The radiating conductor 130 may contain, for example, any of a metal material, an alloy of a metal material, a hardened metal paste, and a conductive polymer as a composition. The metal material includes copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cadmium-lead, selenium, manganese, tin, vanadium, lithium, cobalt, and titanium. The alloy includes a plurality of metal materials. The metal paste agent includes a mixture of powder of a metal material with an organic solvent and a binder. The binder includes an epoxy resin, a polyester resin, a polyimide resin, a polyamide-imide resin, and a polyetherimide resin. The conductive polymer includes a polythiophene-based polymer, a polyacetylene-based polymer, a polyaniline-based polymer, a polypyrrole-based polymer, and the like.

As shown in FIG. 3, the radiating conductor 130 may be located on the upper surface 121 of the base 120. The radiating conductor 130 extends along the xy plane. The radiating conductor 130 is configured to capacitively connect the first connecting conductor 155 to the fourth connecting conductor 158. The radiating conductor 130 is surrounded by the first connecting conductor 155 to the fourth connecting conductor 158 in the xy plane.

The radiation conductor 130 can resonate in the y direction, for example, when the first feeder 151 and the third feeder 153 are supplied with electrical signals of opposite phases. When the radiation conductor 130 resonates in the y direction, the first connection conductor 155 appears as an electric wall located on the negative side of the y axis, and the third connection conductor 157 appears as an electric wall located on the positive side of the y axis. When the radiation conductor 130 resonates in the y direction, the positive side of the x axis appears as a magnetic wall, and the negative side of the x axis appears as a magnetic wall. When the radiation conductor 130 resonates in the y direction, the radiation conductor 130 is surrounded by these two electric walls and two magnetic walls, and the antenna 10 exhibits artificial magnetic wall characteristics with respect to electromagnetic waves of a predetermined frequency that are incident on the xy plane included in the antenna 10 from the positive side of the z axis.

The radiation conductor 130 can be configured to resonate in the x direction, for example, by supplying electrical signals of opposite phases from the second feeder 152 and the fourth feeder 154. When the radiation conductor 130 resonates in the x direction, the second connection conductor 156 appears as an electric wall located on the positive side of the x axis, and the fourth connection conductor 158 appears as an electric wall located on the negative side of the x axis. When the radiation conductor 130 resonates in the x direction, the positive side of the y axis appears as a magnetic wall, and the negative side of the y axis appears as a magnetic wall. When the radiation conductor 130 resonates in the x direction, the radiation conductor 130 is surrounded by these two electric walls and two magnetic walls, and the antenna 10 exhibits artificial magnetic wall characteristics with respect to electromagnetic waves of a predetermined frequency that are incident on the xy plane included in the antenna 10 from the positive side of the z axis.

As shown in FIG. 6, the radiation conductor 130 includes a center O1. The center O1 is the center of the radiation conductor 130 in both the x-direction and the y-direction. The radiation conductor 130 may include a first axis of symmetry T1 extending along the xy plane. The first axis of symmetry T1 passes through the center O1 and extends in a direction intersecting the x-direction and the y-direction. The first axis of symmetry T1 may extend along a direction inclined 45 degrees from the positive direction of the y-axis toward the negative direction of the x-axis. The radiation conductor 130 may include a second axis of symmetry T2 extending along the xy plane. The second axis of symmetry T2 passes through the center O1 and extends in a direction intersecting the first axis of symmetry T1. The second axis of symmetry T2 may extend along a direction inclined 45 degrees from the positive direction of the y-axis toward the positive direction of the x-axis. The radiation conductor 130 may have a size of half the operating wavelength. For example, the length of the radiating conductor 130 in the x-direction and the length of the radiating conductor 130 in the y-direction may be one-half of the operating wavelength.

As shown in FIG. 5, the radiating conductor 130 includes a first conductor 131, a second conductor 132, a third conductor 133, and a fourth conductor 134. The first conductor 131 to the fourth conductor 134, the ground conductor 140, the first power feed line 151 to the fourth power feed line 154, and the first connecting conductor 155 to the fourth connecting conductor 158 may all include the same material or may include different materials. Any combination of the first conductor 131 to the fourth conductor 134, the ground conductor 140, the first power feed line 151 to the fourth power feed line 154, and the first connecting conductor 155 to the fourth connecting conductor 158 may include the same material.

Each of the first conductor 131 to the fourth conductor 134 may be, for example, of the same shape and approximately square. The two diagonals of the approximately square first conductor 131 and the two diagonals of the approximately square third conductor 133 are aligned along the x and y directions. The length of the diagonal of the first conductor 131 along the y direction and the length of the diagonal of the third conductor 133 along the y direction may be approximately one-quarter of the operating wavelength. The two diagonals of the approximately square second conductor 132 and the two diagonals of the approximately square fourth conductor 134 are aligned along the x and y directions. The length of the diagonal of the second conductor 132 along the x direction and the length of the diagonal of the fourth conductor 134 along the x direction may be approximately one-quarter of the operating wavelength.

At least a portion of each of the first conductor 131 to the fourth conductor 134 may be exposed to the outside of the base 120. A portion of each of the first conductor 131 to the fourth conductor 134 may be located within the base 120. The entirety of each of the first conductor 131 to the fourth conductor 134 may be located within the base 120.

The first conductor 131 to the fourth conductor 134 extend along the upper surface 121 of the base 120. As an example, the first conductor 131 to the fourth conductor 134 may be arranged in a square lattice on the upper surface 121. In this case, the first conductor 131 and the fourth conductor 134, and the second conductor 132 and the third conductor 133 may be arranged along the first symmetry axis T1. The first conductor 131 and the second conductor 132, and the fourth conductor 134 and the third conductor 133 may be arranged along the second symmetry axis T2. The two diagonal directions of the square lattice in which the first conductor 131 to the fourth conductor 134 are arranged are along the x direction and the y direction. Of the two diagonal directions, the diagonal direction along the y direction is referred to as the first diagonal direction. Of the two diagonal directions, the diagonal direction along the x direction is referred to as the second diagonal direction. The first and second diagonal directions can intersect at the center O1.

The first conductor 131 to the fourth conductor 134 are positioned at a predetermined interval from each other. For example, as shown in FIG. 3, the first conductor 131 and the second conductor 132 are positioned at a distance t1 from each other. The third conductor 133 and the fourth conductor 134 are positioned at a distance t1 from each other. The first conductor 131 and the fourth conductor 134 are positioned at a distance t2 from each other. The second conductor 132 and the third conductor 133 are positioned at a distance t2 from each other. The first conductor 131 to the fourth conductor 134 are configured to be capacitively connected to each other by being positioned at a predetermined interval from each other.

As shown in FIG. 3, the antenna element 111 may have capacitance elements C1 and C2 in the gap Sx. The antenna element 111 may have capacitance elements C3 and C4 in the gap Sy. The capacitance elements C1 to C4 may be chip capacitors or the like. The capacitance element C1 located in the gap Sx is configured to capacitively connect the first conductor 131 and the second conductor 132. The capacitance element C2 located in the gap Sx is configured to capacitively connect the third conductor 133 and the fourth conductor 134. The capacitance element C3 located in the gap Sy is configured to capacitively connect the first conductor 131 and the fourth conductor 134. The capacitance element C4 located in the gap Sy is configured to capacitively connect the second conductor 132 and the third conductor 133. The positions of the capacitance elements C1 and C2 in the gap Sx and the positions of the capacitance elements C3 and C4 in the gap Sy may be appropriately adjusted according to the desired resonant frequency of the antenna 10. The capacitance values of the capacitance elements C1 to C4 may be adjusted as appropriate according to the desired resonant frequency of the antenna 10. Increasing the capacitance values of the capacitance elements C1 to C4 can lower the resonant frequency of the antenna 10. Reducing the capacitance values of the capacitance elements C1 to C4 can raise the resonant frequency of the antenna 10.

The ground conductor 140 may contain any of the following compositions: a metal material, an alloy of a metal material, a hardened metal paste, and a conductive polymer. The ground conductor 140 may function as a ground for the antenna element 111. As shown in FIG. 4, the ground conductor 140 may be connected to a ground conductor 165 (described below) of the circuit board 160. In this case, the ground conductor 140 may be integrated with the ground conductor 165 of the circuit board 160. The ground conductor 140 may be a flat conductor. The ground conductor 140 is located on the lower surface 122 of the base 120.

5, the ground conductor 140 extends along the xy plane. The ground conductor 140 faces the radiating conductor 130 in the z direction. The base 120 is interposed between the ground conductor 140 and the radiating conductor 130. The ground conductor 140 may have a shape corresponding to the shape of the radiating conductor 130. In this embodiment, the ground conductor 140 is substantially square in shape corresponding to the radiating conductor 130, which is substantially square in shape. However, the ground conductor 140 may have any shape corresponding to the radiating conductor 130. The ground conductor 140 includes openings 141, 142, 143, and 144. The positions of the openings 141 to 144 in the xy plane may be appropriately adjusted according to the positions of the first feed line 151 to the fourth feed line 154 in the xy plane.

The power feed line 150 can be configured to supply an electrical signal from the outside to the antenna element 111. The power feed line 150 can be configured to supply an electrical signal from the antenna element 111 to the outside. The power feed line 150 may be a through-hole conductor or a via conductor, etc. The power feed line 150 is configured to be able to supply an electrical signal from the antenna element 111 to an external circuit board 160, etc. Each of the first power feed line 151 to the fourth power feed line 154 contacts a different position of the radiation conductor 130. For example, as shown in FIG. 3 and FIG. 6, the first power feed line 151 is electrically connected to the first conductor 131. The second power feed line 152 is electrically connected to the second conductor 132. The third power feed line 153 is electrically connected to the third conductor 133. The fourth power feed line 154 is electrically connected to the fourth conductor 134. However, each of the first to fourth power feed lines 151 to 154 may be configured to be magnetically connected to each of the first to fourth conductors 131 to 134. The points where each of the first to fourth power feed lines 151 to 154 are connected to each of the first to fourth conductors 131 to 134 are also referred to as power feed point 151A, power feed point 152A, power feed point 153A, and power feed point 154A. As shown in FIG. 5, each of the first to fourth power feed lines 151 to 154 leads to the outside through each of the openings 141 to 144 of the ground conductor 140. Each of the first to fourth power feed lines 151 to 154 may extend along the z direction.

The first feed line 151 and the third feed line 153 are configured to at least contribute to the external supply of an electrical signal when the radiation conductor 130 resonates in the y direction. The second feed line 152 and the fourth feed line 154 are configured to at least contribute to the external supply of an electrical signal when the radiation conductor 130 resonates in the x direction.

The first feed line 151 and the third feed line 153, and the second feed line 152 and the fourth feed line 154 are configured to excite the radiation conductor 130 in different directions. For example, the first feed line 151 and the third feed line 153 are configured to excite the radiation conductor 130 in the y direction. The second feed line 152 and the fourth feed line 154 are configured to excite the radiation conductor 130 in the x direction. By having such feed lines 150, the antenna 10 can reduce the excitation of the radiation conductor 130 in one direction when exciting the radiation conductor 130 in the other direction.

The first feeder 151 and the third feeder 153 are configured to excite the radiating conductor 130 with a differential voltage. The second feeder 152 and the fourth feeder 154 are configured to excite the radiating conductor 130 with a differential voltage. By exciting the radiating conductor 130 with a differential voltage, the antenna 10 can reduce the fluctuation of the potential center from the center O1 of the radiating conductor 130 when the radiating conductor 130 is excited.

As shown in FIG. 6, in the y direction, the center O1 of the radiation conductor 130 is located between the first power supply line 151 and the third power supply line 153. The first distance D1 between the first power supply line 151 and the center O1 and the third distance D3 between the third power supply line 153 and the center O1 are approximately equal.

As shown in FIG. 6, in the x direction, the center O1 of the radiation conductor 130 is located between the second power supply line 152 and the fourth power supply line 154. The second distance D2 between the second power supply line 152 and the center O1 and the fourth distance D4 between the fourth power supply line 154 and the center O1 are approximately equal. In this embodiment, the second distance D2 is approximately equal to the first distance D1. However, the second distance D2 may be different from the first distance D1.

The first feed line 151 and the second feed line 152 may be symmetrical with respect to the first axis of symmetry T1. The third feed line 153 and the fourth feed line 154 may be symmetrical with respect to the first axis of symmetry T1. For example, the feed point 151A and the feed point 152A, and the feed point 153A and the feed point 154A may be symmetrical with respect to the first axis of symmetry T1.

The first feed line 151 and the fourth feed line 154 may be symmetrical with respect to the second axis of symmetry T2. The second feed line 152 and the third feed line 153 may be symmetrical with respect to the second axis of symmetry T2. For example, the feed point 151A and the feed point 154A, and the feed point 152A and the feed point 153A may be linearly symmetrical with respect to the second axis of symmetry T2.

The direction connecting the first power feed line 151 and the third power feed line 153 is along the y direction. The direction connecting the first power feed line 151 and the third power feed line 153 is along the first diagonal direction. The direction connecting the second power feed line 152 and the fourth power feed line 154 is along the x direction. The direction connecting the second power feed line 152 and the fourth power feed line 154 is along the second diagonal direction. However, the direction connecting the first power feed line 151 and the third power feed line 153 may be inclined with respect to the first diagonal direction. The direction connecting the second power feed line 152 and the fourth power feed line 154 may be inclined with respect to the second diagonal direction.

As shown in FIG. 7, the circuit board 160 includes a first power supply circuit 61 and a second power supply circuit 62. The first power supply circuit 61 is electrically connected to the transmission terminal Tx. The second power supply circuit 62 is electrically connected to the reception terminal Rx. That is, each of the antennas 10-1 and 10-2 has a transmission terminal Tx and a reception terminal Rx. When distinguishing between the transmission terminal Tx and the reception terminal Rx, the antenna 10-1 will be described as the transmission terminal Tx1 and the reception terminal Rx1, and the antenna 10-2 will be described as the transmission terminal Tx2 and the reception terminal Rx2.

The first power supply circuit 61 is electrically connected to the first power supply line 151 and the third power supply line 153. The first power supply circuit 61 is configured to supply the first power supply line 151 and the third power supply line 153 with opposite phase signals whose phases are approximately opposite to each other. In other words, the first power supply signal supplied to the first power supply line 151 is approximately opposite in phase to the third power supply signal supplied to the third power supply line 153.

The first inversion circuit 63 may be a circuit that inverts the phase of one input electrical signal in a resonant frequency band. The first inversion circuit 63 may be a circuit that outputs an inverted phase signal, the phases of which are approximately inverse to each other, from the input electrical signal. The first inversion circuit 63 may be a balun, or any of a power distribution circuit and a delay line. The first inversion circuit 63 may include an inductance element connected to one of the first feed line 151 and the third feed line 153, and a capacitance element connected to the other. The first feed circuit 61 is configured to supply inverted phase signals, the phases of which are approximately inverse to each other, to the first feed line 151 and the third feed line 153. In the antenna 10, electrical signals of inverted phase are supplied to the first feed line 151 and the third feed line 153. In this case, the antenna 10 has the radiation conductor 130 resonating along the y direction.

The second power feed circuit 62 is electrically connected to the second power feed line 152 and the fourth power feed line 154. The second power feed circuit 62 is configured to supply, to the second power feed line 152 and the fourth power feed line 154, out-of-phase signals whose phases are approximately opposite to each other. In other words, the second power feed signal supplied to the second power feed line 152 is approximately out-of-phase with the fourth power feed signal supplied to the fourth power feed line 154.

The second feed circuit 62 is electrically connected to the second feed line 152 and the fourth feed line 154. The second feed circuit 62 includes a second inversion circuit 64, a second wiring 162, and a fourth wiring 164. In this embodiment, the second inversion circuit 64 may include an inductance element connected to one of the second feed line 152 and the fourth feed line 154, and a capacitance element connected to the other. The second feed circuit 62 is configured to supply the second feed line 152 and the fourth feed line 154 with opposite phase signals whose phases are approximately opposite to each other. In the antenna 10, opposite phase electrical signals are supplied to the second feed line 152 and the fourth feed line 154. In this case, the antenna 10 has the radiation conductor 130 resonate along the x direction.

The first wiring 161 to the fourth wiring 164 include any conductive material. The first wiring 161 to the fourth wiring 164 may be formed on the circuit board 160 as a wiring pattern.

The first wiring 161 electrically connects the first inversion circuit 63 and the first power supply line 151. The second wiring 162 electrically connects the second inversion circuit 64 and the second power supply line 152. The third wiring 163 electrically connects the first inversion circuit 63 and the third power supply line 153. The fourth wiring 164 electrically connects the second inversion circuit 64 and the fourth power supply line 154.

The wiring length and width of the first wiring 161 and the wiring length and width of the third wiring 163 may be approximately equal. By making the wiring length and width of the first wiring 161 and the wiring length and width of the third wiring 163 approximately equal, the impedance of the first wiring 161 and the impedance of the third wiring 163 can be approximately equal.

The length and width of the second wiring 162 and the length and width of the fourth wiring 164 may be approximately equal. By making the length and width of the second wiring 162 and the length and width of the fourth wiring 164 approximately equal, the impedance of the second wiring 162 and the impedance of the fourth wiring 164 can be approximately equal.

As shown in FIG. 4, the circuit board 160 includes a ground conductor 165. The ground conductor 165 includes any conductive material. The ground conductor 165 may be a conductive layer. The ground conductor 165 is located on the surface located on the positive side of the z-axis out of two surfaces that are substantially parallel to the xy plane included in the circuit board 160.

The antenna 10 includes a radiating conductor 130, a ground conductor 140, a first feeder 151 configured to be electromagnetically connected to the radiating conductor 130, a second feeder 152 configured to be electromagnetically connected to the radiating conductor 130, a third feeder 153 configured to be electromagnetically connected to the radiating conductor 130, a fourth feeder 154 configured to be electromagnetically connected to the radiating conductor 130, a first feed circuit 61 configured to feed inverse-phase signals that are in opposite phases to the first feeder 151 and the third feeder 153, and a second feed circuit 62 configured to feed inverse-phase signals that are in opposite phases to the second feeder 152 and the fourth feeder 154. The radiation conductor 130 is configured to be excited in a first direction by power supply from the first feed line 151 and the third feed line 153, and is configured to be excited in a second direction by power supply from the second feed line 152 and the fourth feed line 154, the third feed line 153 being located on the opposite side to the first feed line 151 in the first direction when viewed from the center of the radiation conductor 130, and the fourth feed line 154 being located on the opposite side to the second feed line 152 in the second direction when viewed from the center of the radiation conductor 130. In the antenna 10, the direction connecting the first feed line 151 and the third feed line 153 is inclined with respect to the first direction, and the direction connecting the second feed line 152 and the fourth feed line 154 is inclined with respect to the second direction.

As shown in Figures 1 and 2, the antenna 10 of the first communication device 1 has a symmetrical structure in which a first direction excited by power supply from the first feeder 151 and the third feeder 153 is perpendicular to a second direction excited by power supply from the second feeder 152 and the fourth feeder 154. Therefore, each of the antennas 10-1 and 10-2 is ensured to be isolated. Ensuring isolation includes, for example, being separated or isolated from each other. The first communication device 1 is arranged so that the first diagonal direction and the second diagonal direction of the antennas 10-1 and 10-2 are parallel, so that isolation between the antennas 10-1 and 10-2 is ensured.

The transmitting terminal Tx1 of the antenna 10-1 is arranged so as to ensure isolation between the receiving terminals Rx of the antennas 10-1 and 10-2. In other words, the transmitting terminal Tx1 of the antenna 10-1 is arranged so as to be spaced apart or separated from the receiving terminals Rx1 of the antenna 10-1 and the receiving terminals Rx2 of the antenna 10-2. Similarly, the transmitting terminal Tx2 of the antenna 10-2 is arranged so as to ensure isolation between the receiving terminals Rx1 of the antenna 10-1 and the receiving terminals Rx2 of the antenna 10-2. The transmitting terminal Tx and the receiving terminals Rx may be arranged inside the antenna 10.

As shown in Figures 1 and 2, the connection unit 11 is configured to be connectable to any one of the transmission terminals Tx and reception terminals Rx of the multiple antennas 10. The connection unit 11 is configured to be connectable to one of the transmission terminals Tx of the multiple antennas 10. The connection unit 11 is configured to be connectable to one of the reception terminals Rx of the multiple antennas 10.

In this embodiment, the connection unit 11 has, for example, contacts 11A and 11B. The contact 11A is electrically connected to the control unit 13 via the transmission unit 14. The contact 11A is configured to be able to switch the connection between the transmission terminal Tx1 of the antenna 10-1 and the transmission terminal Tx2 of the antenna 10-2 in response to a switching instruction from the control unit 13. The contact 11B is electrically connected to the control unit 13 via the reception unit 15. The contact 11B is configured to be able to switch the connection between the reception terminal Rx1 of the antenna 10-1 and the reception terminal Rx2 of the antenna 10-2 in response to a switching instruction from the control unit 13.

The memory unit 12 is controlled to store programs and data. The memory unit 12 is also used as a working area for temporarily storing the processing results of the control unit 13. The memory unit 12 may include any non-transitory storage medium, such as a semiconductor storage medium and a magnetic storage medium. The memory unit 12 may include multiple types of storage media. The memory unit 12 may include a combination of a portable storage medium, such as a memory card, an optical disk, or a magneto-optical disk, and a storage medium reader. The memory unit 12 may include a storage device used as a temporary storage area, such as a RAM (Random Access Memory).

The storage unit 12 is controlled to store, for example, a control program 12A, setting data 12B, etc. The storage unit 12 is controlled to output, for example, the control program 12A, setting data 12B, etc. The control program 12A can provide various control functions for operating the first communication device 1. The control program 12A can provide, for example, a function for switching either the transmission terminal Tx or the reception terminal Rx to another terminal depending on the reception status of a response from the second communication device 500. The control program 12A can provide, for example, a function for switching at least one of the transmission terminal and the reception terminal connected to the connection unit 11 to another terminal when a reception signal corresponding to a transmission signal cannot be received from the second communication device 500. The control program 12A can provide a function for changing at least one of the transmission terminal Tx and the reception terminal Rx connected via the connection unit 11 to attempt transmission and reception. The setting data 12B includes, for example, information indicating a condition for switching the transmission terminal Tx and the reception terminal Rx of the antenna 10 to another terminal. The setting data 12B includes, for example, information that can identify the second communication device 500 with which communication is to be performed.

The control unit 13 is a calculation processing device. Examples of the calculation processing device include, but are not limited to, a CPU, an FPGA, an MCU, and a coprocessor. The control unit 13 comprehensively controls the operation of the first communication device 1 to realize various functions.

Specifically, the control unit 13 executes instructions included in the program stored in the storage unit 12 while referring to the data stored in the storage unit 12 as necessary. The control unit 13 then controls the functional units according to the data and instructions, thereby achieving various functions. The functional units include, for example, but are not limited to, the connection unit 11, the transmission unit 14, the reception unit 15, and the cancellation unit 16.

By executing control program 12A, control unit 13 attempts transmission and reception by changing at least one of the transmission terminal Tx and the reception terminal Rx connected via connection unit 11. By executing control program 12A, control unit 13 realizes the function of changing at least one of the transmission terminal Tx and the reception terminal connected to connection unit 11 when a reception signal corresponding to a transmission signal transmitted via transmission terminal Tx cannot be received via reception terminal Rx.

The transmitter 14 is electrically connected to the connection unit 11, the control unit 13, and the cancellation unit 16. The transmitter 14 outputs a signal including various types of transmission information to be transmitted outside the first communication device 1 to the antenna 10 via the connection unit 11. As a result, the antenna 10 converts the signal including the various types of transmission information input from the transmitter 14 into an electromagnetic wave. The antenna 10 radiates the electromagnetic wave converted from the signal including the transmission information into space.

The receiving unit 15 is electrically connected to the connection unit 11, the control unit 13, and the cancellation unit 16. The receiving unit 15 receives various signals output from the antenna 10 via the connection unit 11. The receiving unit 15 supplies the reception information contained in the received signals to the control unit 13.

The cancellation unit 16 is electrically connected to the control unit 13, the transmission unit 14, and the reception unit 15. The cancellation unit 16 includes a cancellation circuit configured to cancel a signal that leaks directly from the transmission unit 14 to the reception unit 15.

A configuration example of the first communication device 1 according to this embodiment has been described above. Note that the above configuration described using Figures 1 and 2 is merely an example, and the configuration of the first communication device 1 according to this embodiment is not limited to this example. The configuration of the first communication device 1 according to this embodiment can be flexibly modified according to the specifications and operation.

[Example of control of first communication device]
Fig. 8 is a flowchart showing an example of a processing procedure of the first communication device 1 according to the embodiment. The processing procedure shown in Fig. 8 is realized by the control unit 13 of the first communication device 1 executing the control program 12A. The processing procedure shown in Fig. 8 is executed by the control unit 13 at a predetermined timing. The predetermined timing includes, for example, the timing when a start instruction is received, a preset timing, etc.

As shown in FIG. 8, the control unit 13 of the first communication device 1 sends a transmission command signal (step S101). For example, the control unit 13 controls the transmission unit 14 to output a signal including communication information indicating the transmission command to the antenna 10. The transmission command is, for example, a command to the second communication device 500 to transmit a response signal. As a result, the control unit 13 causes the antenna 10, including the transmission terminal Tx to which the connection unit 11 is connected, to radiate electromagnetic waves including the transmission command to the outside of the first communication device 1. When the process of step S101 is completed, the control unit 13 advances the process to step S102.

The control unit 13 detects the received signal (step S102). For example, the control unit 13 detects the presence or absence of a received signal from the second communication device 500 based on the reception information provided by the receiving unit 15. When the control unit 13 stores information indicating the detection result in the memory unit 12, the process proceeds to step S103.

The control unit 13 judges whether or not a reception signal has been received or the designated number of times has been exceeded (step S103). For example, the control unit 13 judges that a reception signal has been received when the detection result of the memory unit 12 indicates that a reception signal has been received. For example, the control unit 13 judges that the designated number of times has been exceeded when the number of times that a reception signal has been received or the number of times that a transmission command signal has been sent, etc., indicated by the detection result of the memory unit 12, exceeds the designated number of times. The designated number of times includes, for example, a number of times that has been specified in advance. When the control unit 13 judges that a reception signal has not been received or that the designated number of times has not been exceeded (No in step S103), the process returns to step S101 already described, and the process from step S101 onwards is executed. When the control unit 13 judges that a reception signal has been received or that the designated number of times has been exceeded (Yes in step S103), the process proceeds to step S104.

The control unit 13 determines whether the switching condition is satisfied (step S104). For example, the control unit 13 determines whether the reception result from the second communication device 500 satisfies the switching condition set in the setting data 12B.

For example, if an object, obstacle, or the like is placed between the first communication device 1 and the second communication device 500 after the second communication device 500 is installed, the first communication device 1 may have difficulty communicating with the second communication device 500. For this reason, the switching condition may be set to be less than a threshold value such as the number of installed second communication devices 500, the number of receptions of received signals, etc. This allows the control unit 13 to quickly switch the transmission terminals Tx and reception terminals Rx of the multiple antennas 10 based on the reception signal received from the second communication device 500. In other words, the switching condition is configured to include a condition that allows switching between the combination of the transmission antennas and the reception antennas in the multiple antennas 10. Note that the switching condition may be, for example, a condition based on the time since the transmission command was transmitted.

For example, if the switching condition is smaller than a threshold value for the number of installed second communication devices 500, the number of receptions of received signals, etc., the control unit 13 determines that the switching condition is met since signals have not been received from all second communication devices 500. If the control unit 13 determines that the switching condition is not met (No in step S104), the received signals from the second communication devices 500 have reached the number of installed devices, the number of receptions, etc., and therefore ends the processing procedure shown in FIG. 8. Also, if the control unit 13 determines that the switching condition is met (Yes in step S104), the processing proceeds to step S105.

The control unit 13 controls the switching of the antenna 10 (step S105). For example, the control unit 13 instructs the connection unit 11 to switch the contacts 11A and 11B so as to connect the transmission terminal Tx and the reception terminal Rx of the antenna 10 indicated by the switching information. The switching information is included in, for example, the control program 12A, the setting data 12B, etc., and includes, for example, a pattern indicating which antenna 10's transmission terminal Tx and reception terminal Rx are to be switched to, a combination pattern of the transmission terminal Tx and the reception terminal Rx, and an order in which the transmission terminal Tx and the reception terminal Rx are to be switched. When the control unit 13 ends the processing of step S105, it returns the processing to step S101 already described, and executes the processing from step S101 onwards. As a result, the control unit 13 causes the transmission terminal Tx of the switched antenna 10 to emit radio waves indicating a transmission command, and checks whether or not there is a received signal from the second communication device 500.

In the processing procedure shown in FIG. 8, the control unit 13 returns the process to step S101 when it controls the switching of the antenna 10 in step S105, but this is not limited to the above. The processing procedure shown in FIG. 8 may be a processing procedure in which, if the transmission terminal Tx of the antenna 10 is switched in step S105, the process is returned to step S101, and, if the transmission terminal Tx is not switched, the process is returned to step S102.

[Operation Example of First Communication Device]
Fig. 9 is a diagram for explaining an example of the operation of the first communication device 1 according to the embodiment. In Fig. 9, the storage unit 12 of the first communication device 1 is omitted.

As shown in FIG. 9, in pattern P1, the first communication device 1 connects contact 11A of connection part 11 to transmission terminal Tx1 of antenna 10-1, and contact 11B to reception terminal Rx1 of antenna 10-1. The first communication device 1 radiates electromagnetic waves including a transmission command from antenna 10-1 to the outside of the first communication device 1. In this case, when the second communication device 500 receives electromagnetic waves including a transmission command, it radiates electromagnetic waves including a response signal from antenna 521. When the first communication device 1 receives a response signal from the second communication device 500 via antenna 10-1, it radiates electromagnetic waves including a stop command from antenna 10-1 to the outside of the first communication device 1. In pattern P1, antenna 10-1 functions as a transmission antenna and a reception antenna for the first communication device 1.

In pattern P2, the first communication device 1 connects contact 11A of connection part 11 to transmission terminal Tx1 of antenna 10-1, and contact 11B to reception terminal Rx2 of antenna 10-2. The first communication device 1 radiates electromagnetic waves including a transmission command from antenna 10-1 to the outside of the first communication device 1. In this case, when the second communication device 500 receives electromagnetic waves including a transmission command, it radiates electromagnetic waves including a response signal from antenna 521. When the first communication device 1 receives a response signal from the second communication device 500 via antenna 10-2, it radiates electromagnetic waves including a stop command from antenna 10-1 to the outside of the first communication device 1. In pattern P2, antenna 10-1 functions as a transmission antenna for the first communication device 1. Antenna 10-2 functions as a reception antenna.

In pattern P3, the first communication device 1 connects contact 11A of connection part 11 to transmission terminal Tx2 of antenna 10-2, and contact 11B to reception terminal Rx1 of antenna 10-1. The first communication device 1 radiates electromagnetic waves including a transmission command from antenna 10-2 to the outside of the first communication device 1. In this case, when the second communication device 500 receives electromagnetic waves including a transmission command, it radiates electromagnetic waves including a response signal from antenna 521. When the first communication device 1 receives a response signal from the second communication device 500 via antenna 10-1, it radiates electromagnetic waves including a stop command from antenna 10-2 to the outside of the first communication device 1. In pattern P3, antenna 10-2 functions as a transmission antenna for the first communication device 1. Antenna 10-1 functions as a reception antenna.

In pattern P4, the first communication device 1 connects contact 11A of connection part 11 to transmission terminal Tx2 of antenna 10-2, and contact 11B to reception terminal Rx2 of antenna 10-2. The first communication device 1 radiates electromagnetic waves including a transmission command from antenna 10-2 to the outside of the first communication device 1. In this case, when the second communication device 500 receives electromagnetic waves including a transmission command, it radiates electromagnetic waves including a response signal from antenna 521. When the first communication device 1 receives a response signal from the second communication device 500 via antenna 10-2, it radiates electromagnetic waves including a stop command from antenna 10-2 to the outside of the first communication device 1. In pattern P4, antenna 10-2 functions as a transmission antenna and a reception antenna for the first communication device 1.

The first communication device 1 can improve wireless communication between multiple second communication devices 500 located at different positions by switching between transmitting and receiving antennas in multiple antennas 10. Even if an obstacle exists between the first communication device 1 and the second communication device 500, the communication system 1000 can improve the possibility of avoiding a situation in which wireless communication is impossible by the first communication device 1 switching between the multiple antennas 10.

When the first communication device 1 cannot receive a reception signal corresponding to a transmission signal from the second communication device 500, the first communication device 1 can switch at least one of the transmission terminal Tx and the reception terminal Rx to which the connection unit 11 is connected. This allows the first communication device 1 to switch between the multiple antennas 10 according to the status of the reception signals from the multiple second communication devices 500.

Figure 10 is a schematic diagram showing an example of the arrangement of multiple antennas 10 of a first communication device 1 according to an embodiment. As shown in Figure 10, the first communication device 1 may include six antennas 10 arranged in an array. The six antennas 10 have the same structure and orientation. The six antennas 10 are arranged so that adjacent antennas 10 are isolated from each other. That is, the six antennas 10 are arranged so that a first direction connecting the first feed line 151 and the third feed line 153 and a second direction connecting the second feed line 152 and the fourth feed line 154 are parallel to each other. The transmission terminals Tx and reception terminals Rx of the six antennas 10 are electrically connected to the connection portion 11.

Fig. 11 is a schematic diagram showing a modified arrangement of multiple antennas 10 according to the embodiment. As shown in Fig. 11, the multiple antennas 10 may be arranged such that the first directions connecting the first feed line 151 and the third feed line 153 overlap each other and the second directions connecting the second feed line 152 and the fourth feed line 154 are parallel to each other.

Figure 12 is a schematic diagram showing a modified configuration and arrangement of multiple antennas 10 according to the embodiment. As shown in Figure 12, the multiple antennas 10 are configured so that a first direction connecting the first feed line 151 and the third feed line 153 intersects with two sides of the base 120, and a second direction connecting the second feed line 152 and the fourth feed line 154 intersects with the other two sides of the base 120. In this case, the first communication device 1 can be arranged so that the corners of the base 120 of adjacent antennas 10 face each other, and the first and second directions of the antennas 10 are parallel to each other.

Figure 13 is a schematic diagram showing a modified example of the configuration and arrangement of multiple antennas 10 according to the embodiment. As shown in Figure 13, the multiple antennas 10 are configured to be arranged in the antenna element 111 so that the first feed line 151 to the fourth feed line 154 are in the vicinity of the center of the side of the base 120. In this case, the first communication device 1 can be arranged so that the first directions connecting the first feed lines 151 and the third feed line 153 of the multiple antennas 10 overlap with each other, and the second directions connecting the second feed lines 152 and the fourth feed lines 154 are parallel to each other.

14 is a schematic diagram showing a modified example of the configuration and arrangement of the multiple antennas 10 according to the embodiment. As shown in FIG. 14, the multiple antennas 10 are configured to be arranged in the antenna element 111 so that the first feeder 151 to the fourth feeder 154 are in the vicinity of the center of the side of the base 120. The multiple antennas 10 are arranged in such a manner that the antenna element 111 is arranged on the base 120 so that the first direction connecting the first feeder 151 and the third feeder 153 passes through a pair of corners of the base 120, and the second direction connecting the second feeder 152 and the fourth feeder 154 passes through another matching corner of the base 120. In this case, the first communication device 1 can be arranged so that the first directions of the multiple antennas 10 overlap each other and the second directions are parallel to each other.

The first communication device 1 is arranged so that at least one of the first direction connecting the first feed line 151 and the third feed line 153 and the second direction connecting the second feed line 152 and the fourth feed line 154 is parallel or overlapping. This allows the first communication device 1 to ensure isolation between the multiple antennas 10, thereby further improving wireless communication between multiple second communication devices 500 located in different positions.

In this embodiment, the first communication device 1 has been described as having multiple antennas 10 arranged on the same plane, but this is not limited to the above. For example, the first communication device 1 may be configured to have multiple antennas 10 arranged in a direction substantially perpendicular to the antenna element 111.

The appended claims have been described with respect to specific embodiments in order to fully and clearly disclose the technology to which they relate. However, the appended claims should not be limited to the above-described embodiments, but should be construed to embody all modifications and alternative configurations that may be conceived by those skilled in the art within the scope of the basic matters set forth in this specification.

In this disclosure, the descriptions such as "first", "second", and "third" are examples of identifiers for distinguishing the configuration. In the configurations distinguished by descriptions such as "first" and "second" in this disclosure, the numbers in the configurations can be exchanged. For example, the first power supply line can exchange the identifiers "first" and "second" with the second power supply line. The identifiers are exchanged simultaneously. The configurations are still distinguished after the identifiers are exchanged. The identifiers may be deleted. The configurations from which the identifiers have been deleted are distinguished by the symbols. For example, the first power supply line 151 can be the power supply line 151. The descriptions of identifiers such as "first" and "second" in this disclosure should not be used solely to interpret the order of the configurations, to justify the existence of identifiers with smaller numbers, or to justify the existence of identifiers with larger numbers. This disclosure includes a configuration in which the circuit board 160 includes the second power supply circuit 62 but does not include the first power supply circuit 61.

REFERENCE SIGNS LIST 1 First communication device 10 Antenna 11 Connection section 12 Memory section 13 Control section 14 Transmitter section 15 Receiver section 16 Cancellation section 61 First power feed circuit 62 Second power feed circuit 63 First inversion circuit 64 Second inversion circuit 111 Antenna element 120 Base 130 Radiation conductor 140 Ground conductor 150 Power feed line 151 First power feed line 152 Second power feed line 153 Third power feed line 154 Fourth power feed line 160 Circuit board Tx, Tx1, Tx2 Transmitting terminal Rx, Rx1, Rx2 Receiving terminal

Claims (5)

A plurality of antennas, each having a transmitting terminal configured to be capable of feeding a transmitting signal and a receiving terminal configured to be capable of supplying a receiving signal;
A control unit configured to control wireless communication with a plurality of external communication devices;
a connection unit configured to connect any one of the transmission terminals of the plurality of antennas to the control unit, and to connect any one of the reception terminals of the plurality of antennas to the control unit,
the transmission terminal of one of the plurality of antennas is arranged so as to ensure isolation between the reception terminal of another of the plurality of antennas,
the control unit is configured to change at least one of the transmitting terminal and the receiving terminal connected to the connection unit to at least one of the transmitting terminal and the receiving terminal of another antenna when the control unit is connected to the transmitting terminal and the receiving terminal of one of the antennas via the connection unit and cannot receive, via the receiving terminal, the receiving signal corresponding to the transmitting signal transmitted via the transmitting terminal ;
Each of the plurality of antennas comprises:
A radiating conductor;
A ground conductor;
A first feed line configured to be electromagnetically connected to the radiation conductor;
A second feed line configured to be electromagnetically connected to the radiation conductor;
a third feed line configured to be electromagnetically connected to the radiation conductor;
a fourth feed line configured to be electromagnetically connected to the radiation conductor;
A first feed circuit configured to feed opposite-phase signals to the first feed line and the third feed line;
a second feed circuit configured to feed opposite-phase signals to the second feed line and the fourth feed line;
The radiation conductor is
configured to be excited in a first direction by power supply from the first power supply line and the third power supply line;
configured to be excited in a second direction by power supply from the second power supply line and the fourth power supply line;
the third feed line is located on an opposite side to the first feed line in the first direction as viewed from the center of the radiation conductor,
the fourth feed line is located on an opposite side to the second feed line in the second direction as viewed from the center of the radiation conductor,
The antenna has an artificial magnetic wall characteristic with respect to an electromagnetic wave of a predetermined frequency when the first feeder line and the third feeder line are fed with opposite-phase signals having opposite phases to each other, or when the second feeder line and the fourth feeder line are fed with opposite-phase signals having opposite phases to each other.
Communication equipment. 2. The communication device according to claim 1,
A communication device, wherein the control unit is configured to attempt transmission and reception by changing at least one of the transmission terminal and the reception terminal connected via the connection unit. 3. A communication device according to claim 1,
The plurality of antennas are arranged so that adjacent antennas have isolation from each other.
Communication equipment. A first communication device;
A plurality of second communication devices configured to be capable of wireless communication with the first communication device;
having
The first communication device is
A plurality of antennas, each having a transmitting terminal configured to be capable of feeding a transmitting signal and a receiving terminal configured to be capable of supplying a receiving signal;
A control unit configured to control wireless communication with a plurality of external communication devices;
a connection unit configured to connect any one of the transmission terminals of the plurality of antennas to the control unit, and to connect any one of the reception terminals of the plurality of antennas to the control unit,
the transmission terminal of one of the plurality of antennas is arranged so as to ensure isolation between the reception terminal of another of the plurality of antennas,
the control unit is configured to change at least one of the transmitting terminal and the receiving terminal to which the connection unit is connected to at least one of the transmitting terminal and the receiving terminal of one of the antennas when the control unit is connected to the transmitting terminal and the receiving terminal of one of the antennas via the connection unit and cannot receive, via the receiving terminal, the receiving signal corresponding to the transmitting signal transmitted via the transmitting terminal ;
Each of the plurality of antennas comprises:
A radiating conductor;
A ground conductor;
A first feed line configured to be electromagnetically connected to the radiation conductor;
A second feed line configured to be electromagnetically connected to the radiation conductor;
a third feed line configured to be electromagnetically connected to the radiation conductor;
a fourth feed line configured to be electromagnetically connected to the radiation conductor;
A first feed circuit configured to feed opposite-phase signals to the first feed line and the third feed line;
a second feed circuit configured to feed opposite-phase signals to the second feed line and the fourth feed line;
The radiation conductor is
configured to be excited in a first direction by power supply from the first power supply line and the third power supply line;
configured to be excited in a second direction by power supply from the second power supply line and the fourth power supply line;
the third feed line is located on an opposite side to the first feed line in the first direction as viewed from the center of the radiation conductor,
the fourth feed line is located on an opposite side to the second feed line in the second direction as viewed from the center of the radiation conductor,
The antenna has an artificial magnetic wall characteristic with respect to an electromagnetic wave of a predetermined frequency when the first feeder line and the third feeder line are fed with opposite-phase signals having opposite phases to each other, or when the second feeder line and the fourth feeder line are fed with opposite-phase signals having opposite phases to each other.
Communications system. A method for controlling a communication device, comprising: a plurality of antennas, each having a transmitting terminal configured to be capable of feeding a transmitting signal and a receiving terminal configured to be capable of supplying a receiving signal; a control unit configured to control wireless communication with a plurality of external communication devices; and a connection unit configured to be able to connect any of the transmitting terminals of the plurality of antennas to the control unit, and configured to be able to connect any of the receiving terminals of the plurality of antennas to the control unit, wherein the transmitting terminal of one of the plurality of antennas is arranged so as to ensure isolation from the receiving terminals of other of the plurality of antennas,
when the control unit is connected to the transmission terminal and the reception terminal of one of the antennas via the connection unit and is unable to receive, via the reception terminal, the reception signal corresponding to the transmission signal transmitted via the transmission terminal, the control unit changes at least one of the transmission terminal and the reception terminal to which the connection unit is connected to at least one of the transmission terminal and the reception terminal of the other antenna, and attempts transmission and reception ;
Each of the plurality of antennas comprises:
A radiating conductor;
A ground conductor;
A first feed line configured to be electromagnetically connected to the radiation conductor;
A second feed line configured to be electromagnetically connected to the radiation conductor;
a third feed line configured to be electromagnetically connected to the radiation conductor;
a fourth feed line configured to be electromagnetically connected to the radiation conductor;
A first feed circuit configured to feed opposite-phase signals to the first feed line and the third feed line;
a second feed circuit configured to feed opposite-phase signals to the second feed line and the fourth feed line;
The radiation conductor is
configured to be excited in a first direction by power supply from the first power supply line and the third power supply line;
configured to be excited in a second direction by power supply from the second power supply line and the fourth power supply line;
the third feed line is located on an opposite side to the first feed line in the first direction as viewed from the center of the radiation conductor,
the fourth feed line is located on an opposite side to the second feed line in the second direction as viewed from the center of the radiation conductor,
The antenna has an artificial magnetic wall characteristic with respect to an electromagnetic wave of a predetermined frequency when the first feeder line and the third feeder line are fed with opposite-phase signals having opposite phases to each other, or when the second feeder line and the fourth feeder line are fed with opposite-phase signals having opposite phases to each other.
Control methods.

Images